City Council Meeting - Wednesday, 24th January, 2018 5.05 p.m.
Summary: During the Liverpool City Council Meeting on 24 January 2018, Deputy Mayor Councillor Ann O’Byrne put an Amended Motion to Council under the heading of ‘Protect Our Parks and Green Spaces’, which included the following – ‘Council welcomes the protection given to green spaces across the city in the final draft Local Plan, in particular the recognition that there ‘is no need to allocate open space to meet the City’s housing requirement’. Council welcomes the protection given to green and open spaces in the Local Plan by their classification on the Policies Map as covered by Policies GI 1, GI 2 and GI 3. Council believes that the draft Local Plan provides the basis for a new consensus in the city that can protect Green and Open Spaces and support the provision of new housing. Council calls on councillors to act responsibly and support plans to build houses on brownfield sites. Council welcomes the proposals in the Green and Open Space Review and is working to implement it. Council asks the Mayor to reconvene the Review in the run up to the 2020-2023 budget round to report on progress in protecting green and open spaces, implementing their recommendations and securing sustainable funding for parks and green spaces.’ The Substantive Motion was approved by 54 votes to 7 by Council.
Councillors and committees Agenda item 254 Protect Our Parks and Green Spaces by Councillors Lawrence Brown, Tom Crone, Sarah Jennings, and Anna Key
• Meeting of City Council Meeting, Wednesday, 24th January, 2018 5.05 p.m. (Item 254.)
Minutes:
Motion by Councillor Lawrence Brown and seconded by Councillor Tom Crone that –
“Liverpool's parks and green spaces are key to the future health and prosperity of the city. We are fortunate to enjoy the tremendous range of green and open spaces that exist today, many of them donated to the city by our predecessors. It is right and proper that these vital assets should be protected for current and future generations to enjoy and benefit from long into the future.
The combination of central Government cuts to the Council's revenue funding base and the fact that the provision of parks and green spaces is not a statutory service means that threats to green spaces have increased, including: · Housebuilding; the national requirement to build more homes has put pressure on green spaces across the city. · Plans to install 3G sports pitches at four hubs will see green space disappear at those sites. · Enlivening' of parks by putting on more events e.g. parts of Sefton Park are now severely damaged. · Other ad hoc developments including car parks, office buildings etc which are gradually eating into the green fabric of the city.
Council considers that the time has come for important green spaces across the city to be protected from development. The publication of the Green and Open Spaces Review in October 2016 provided an opportunity for the Council to formally adopt policies to provide greater security to our parks and green spaces but this has not been the case to date.
Council requests the Mayor and Cabinet to:
· Formally adopt the recommendations of the Green and Open Spaces Review as Council policy. · Consult with Historic England with a view to adding key parks including Calderstones Park, Walton Hall Park and Greenbank Park to the Register of Parks and Gardens. · Work with councillors, residents' groups and partners to identify green spaces which should be protected from development.
Council further requests that a progress report is brought to a full meeting of the City Council prior to September 2018.”
_____
Amendment by Councillor Ann O’Byrne and seconded by Councillor Nick Small that all text after the first paragraph be deleted and the following replacement text be inserted –
“Council welcomes the fact that despite the cuts to Council funds by the previous coalition Government and now the Conservative government, the Mayor and Cabinet have continued to invest in our green and open spaces and bring forward measures to improve facilities and their use. These include
• Plans for 20 new natural play areas;
• Creating hundreds of new community gardens and the first new allotments for over 50 years;
• Investing in essential work in Calderstones Park and Princes Park lake;
• Creating a new vitality trail and improving waterways in Sefton Park;
• Commitment to fund protection of the Allerton Oak, a thousand year old tree in Calderstones Park;
• Support for the Mandela 8 project on the island in Princes Park lake;
• Securing additional Section 106 funds to invest in green and open spaces;
• The Horizon 2020 project to create new green corridors and improvements to waterways, building on ideas in the Green and Open Space Review; • Proposals for a new charging policy for events in the city’s parks and open spaces, which will increase income to support our parks and green spaces and encourage a shift in use;
• Creation of new parks, such as Alt Valley Park.
Council welcomes the protection given to green spaces across the city in the final draft Local Plan, in particular the recognition that there ‘is no need to allocate open space to meet the City’s housing requirement’. Council welcomes the protection given to green and open spaces in the Local Plan by their classification on the Policies Map as covered by Policies GI 1, GI 2 and GI 3. Council believes that the draft Local Plan provides the basis for a new consensus in the city that can protect Green and Open Spaces and support the provision of new housing. Council calls on councillors to act responsibly and support plans to build houses on brownfield sites.
Council welcomes the proposals in the Green and Open Space Review and is working to implement it. Council asks the Mayor to reconvene the Review in the run up to the 2020-2023 budget round to report on progress in protecting green and open spaces, implementing their recommendations and securing sustainable funding for parks and green spaces.
_____
A Vote was taken on the Amendment when there appeared –
For the Amendment – 52 Against the Amendment – 4 Abstentions – 3
The Amendment was carried and became the Substantive Motion.
_____
A Vote was taken on the Substantive Motion when there appeared –
For the Motion – 54 Against the Motion – 7 Abstentions – 0
The Substantive Motion was carried unanimously and it was resolved accordingly.
Health Benefits: Mitigating Air Pollution and Improving Urban Microclimate
Dr Konar Mutafoglu Senior Policy Analyst, Green Economy Programme, IEEP Workshop The Health and Social Benefits of Nature and Biodiversity Protection 27 January 2016, Brussels
#naturehealth #naturefit4all
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Session Questions
• What are the health and social benefits from protected areas and wider green infrastructure in terms of air pollution and heat stress? • Are there any good examples of these benefits (and their values) across Europe? • Who has driven this practice? What tools and measures have enabled progress? • To what extent are the experiences replicable and transferable across issues and across Europe?
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Analysing Nature Based Solutions
1. What is the problem? Key drivers and variables
2. Health burden? Including social and economic impacts
3. What contribution can nature make? What does the science say? 4. Natura 2000? Do protected areas play a role?
5. Green Infrastructure? Any green innovations?
6. Governance? How can we capitalise on benefits?
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 1. What is the Problem?
Air Pollution Heat Stress • Urban air quality • Temperatures already persistantly poor across higher in urban spaces due Europe – mostly linked to to UHI (up to +12oC) transport • Climate projections: ~75% • 2011-2013: 75% of urban of EU urban populations populations in EU-28 exposed to increased heat exposed to harmful levels stress (EEA 2012) of PM, O3, BaP (WHO 2015)
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 2. Health Burden
Air Pollution Heat Stress • Risks linked to cardiovascular • Forecasts: increased heat and respiratory disease related mortality across EU (EEA 2012) • Poor air quality linked to • 2003 heatwave: 70,000 400,000 deaths in EU-28 in deaths 2012 (EEA 2015) • Heat induced output losses up • Largest environmental health to 0.5% of GDP by 2100 risk in Europe (Hubler 2007, Lancet Commission 2015) • Annual economic burden >EUR 1 billion (WHO Europe)
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 3. What contribution can nature make? – Air quality A number of nature based solutions to air quality. Many of them are overlooked in existing debates, which focus on 1. 1. Providing barriers or sinks for pollutants: most research has been done on this pathway, mixed evidence, complex variables (e.g. street canyons), uncertainty. Could be valuable in highly polluted streets, increasingly applied in cities 2. Providing clean air oases: (large) green spaces lack pollutant sources and have markedly cleaner air than other urban spaces
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 3. What contribution can nature make? – Air quality
3. Interaction with climate: cooling effect of vegetation and water promotes clear air exchange through urban spaces 4. Facilitating behavioural change: green infrastructure can reduce pollutants at source by facilitating lifestyle change – e.g. promoting cycling
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 3. What contribution can nature make? - Heat
Green and blue spaces contribute to cooling by providing shade and through evapotranspiration. Offer an invalubale tool in climate change mitigation. Multiple variables determine benefits: 1. Configuration: tree-lined streets, green walls, green roofs, and protected areas all offer different forms of cooling 2. Type: certain species provide more shade than others, key differences between grassland and forests 3. Size and density: large trees offer more shade than small ones, but take a longer time to mature
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 3. What contribution can nature make? - Heat
4. Health of vegetation: maintenance of green infrastructure ensures continuous contributions to cooling 5. Temporal & seasonable variations: differences between deciduous or coniferous vegetation 6. Air exchange: green corridors can encourage air exchange through built up areas
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 4. Protected Areas
Large protected areas are oases of clean and cool air, offering essential relief to millions of urban dwellers on a daily basis
Example: Vitoria-Gasteiz and Salburua Wetlands (Spain): 5 degree UHI and high vulnerability to heat waves; 250,000 citizens never more than 300 meters from green and blue infrastructure, including protected green belt of Natura 2000 and Ramsar sites
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Natura 2000
Peri-urban GI
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 5. Green Infrastructure
Carefully designed and strategically placed green infrastructure can maximise street level benefits, providing valubale relief in high risk areas.
Example: Mayor of London (GLA) & Transport for London (TfL) clean air initiatives. London 10,000 deaths annually from air pollution (KCL 2015). TfL and GLA invest >EUR 15 million, including in green walls at sites with high PM.
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions 6. Capitalising on benefits
Actor Tools Example City authorities Air quality and green infrastructure Lyon, France: Berges du Rhône strategies, tree planting campaigns, (2007) green roof policies/finance Transport bodies Funding for green infrastructure London, UK: TfL Clean Air Fund and research (2012) Citizens Citizen science, mobile applications, Berlin, Germany: Initiative guerrilla gardening, advocacy % Tempelhofer Feld and referendum (2014) Science Research, dedicated mapping and Stuttgart, Germany: StadtKlima climatology teams
Designers Innovative projects Milan, Italy: Bosco Verticale (2014)
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Next in Session…
• Barcelona s Green Infrastructure and Biodiversity Plan, Laura Zapata Gonzales, Municipality of Barcelona, Spain • StadtKlima and Nature Conservation for Clean Air, Ulrich Reuter, City of Stuttgart, Germany • With a floor contribution from Tajana Ban Ćurić, Medvednica Natural Park, Croatia
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions #naturehealth
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Barcelona, a city committed to Nature and Biodiversity
Laura Zapata González #naturehealth Energy and Environmental Quality #naturefit4all Barcelona City Council
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Location: 41º23’ N / 02º12’ E Precipitation: 598 mm Average Temperature: 16,5ºC Solar radiation: 1.502 kWh/sq m Hours of sun: 2.583h/year
Barcelona, a Mediterranean city
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Barcelona, a dense and compact city
Population: 1.619.337 hab. Surface: 104 km2 Density: 15.570 hab./km2 Metropolitan Area: 4.720.951 hab.
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions CHALLENGES 1.Climate change
Nearly 70% of the expected impacts of climate change are already being observed in Catalunya.
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions CHALLENGES 2.Air quality
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions CHALLENGES 3.Urban Heat Island
Average ºC at night
Llobregat Urban Heat Besòs Urban Heat River Island River Island Barcelona Badalona
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS Green Infrastructure and biodiversity plan
+ green surface + biomass + quality
1. STUDIES ON ENVIRONMENTAL SERVICES 2. GREEN CORRIDORS AREAS OF OPPORTUNITY 3.TREES MASTER PLAN 4. BIODIVERSITY GARDENS
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 1. STUDIES ON ENVIRONMENTAL SERVICES
Due to the density of Barcelona, the environmental services of the urban green have a modest contribution and especially to local level. The social services, no included in this study, are very important because of the need of the people (*biophilia) to enjoy the presence of the green.
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 1. STUDIES ON AIR QUALITY SERVICES
AirDue Quality to the Plans density do notof Barcelona, consider green the environmental infrastructure services to meet of policy the urbantargets, it focusesgreen havemainly a modest on technical contribution measures and (reduction especially of to traffic local ,level. promotion of less pollutingThe social fuels) services, no included in this study, are very important because of the need of the people (*biophilia) to enjoy the presence of the green. Contribution of Barcelona urban forests to air quality (Baró F. et al, 2014):
- Contribution to NO2 removal is low (0,52% to total emissions) - Contribution to PM10 removal should not be neglected (22,31%) but considering background pollution levels removal drops to 2,66% of total.
Contribution of urban forests in Barcelona (most in Collserola, Natura 2000) to abate pollution is substantial in absolute terms, yet modest when compared to overall city levels. To be effective, green infrastructure efforts have to be coordinated at broader spatial scales, at metropolitan level.
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 2. GREEN CORRIDORS
BEFORE INTERVENTION
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 2. GREEN CORRIDORS
AFTER INTERVENTION
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 3. AREAS OF OPPORTUNITY
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 4. TREE MASTER PLAN Giving conditions to increase its environmental services STRATEGIC VISION OF STREET- TREES Sp selection • No one species to exceed 15% of the total of street-trees to avoid pests and disease Biologically diverse mature, • Resilient to environmental conditions, water and native, healthy, sustainable heat stress Best growing conditions • Preferably native available. Space Adapted to urban ecosystem • Aerial space providing high quality of life. • Transforming individual tree pits into continuous pits • Improve soil conditions (permeability, volume) Water 200.000 • Use of alternative water urban trees • Appropriate irrigation according each sp. (2014) • Automatic irrigation systems and leak control
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STRATEGIES & ACTIONS 5. TOWARDS ECO-MANAGEMENT
• Management and maintenance incorporates good practices considering biodiversity Including shrubs and dry herbaceous layers Less pruning, more biomass in street-trees Achieve a more abundant, mature and stratified vegetation Improve habitats in parks and gardens introducing species to attract native fauna (pollinators, birds)
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions STAKEHOLDERS Understanding and taking into account the priorities and concerns of different stakeholders to plan innovative solutions and set communication strategies.
Experts, Universities, Research centres Participation processes: Barcelona’s Commitment to the climate Provincial, Green Infrastructure and Metropolitan BCN City Citizens and Regional Council Biodiversity Plan Government Citizen Commitment to Sustainability Air quality municipal Social and board environmental institutions
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions COMMITMENT Green Infrastructure and Biodiversity Plan • The Plan has a 2020 horizon, taking as benchmarks the EU Biodiversity Strategy to 2020, and the United Nations’ Convention on Biological Diversity (CBD), as expressed in the Strategic Plan for Biodiversity 2011–2020 and the Aichi Biodiversity Targets. • A Green Spaces and Biodiversity Program was created to carry out the Plan • It was introduced by consensus by the municipal government in 2013 to ensure political commitment and long-term success • Fundings come from all municipal skateholders (only partially controlled) Barcelona’s Commitment to the climate 2014 Through collective action,the aim is that by 2030 Barcelona:
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions NEEDS
ACHIEVE ECO-MANAGEMENT OF GREEN INFRASTRUCTURE AND INCREASE URBAN GREEN SURFACE
STRENGTHEN POLICIES AT MUNICIPAL AND REGIONAL LEVELS. HOW TO COORDINATE MULTIPLE FINANCIAL SOURCES
ECONOMIC ASSESSMENT OF BENEFITS ARE NEEDED IN GREEN INFRASTRUCTURE (COST-EFFECTIVE STRATEGIES)
MORE INFORMATION ABOUT SOCIAL AND HEALTH SERVICES IS NEEDED
IMPROVE MONITORING SYSTEMS AND INDICATORS OF GREEN AND BIODIVERSITY
CHANGE CULTURE, ACTIVE POLICIES OF COMMUNICATION AND NATURE AWARENESS
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions “Nature is not a place to visit. It is home.” Gary Snyder
[email protected]#naturehealth
A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions StadtKlima and Nature Conservation for optimized Microclimate and Clean Air
Dr. Ulrich Reuter City of Stuttgart, Office for Enviromental Protection, Germany
#naturehealth #naturefit4all
1 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Contents
• The problem
• The strategy to use nature
• The Activities
• Benefits
• Stakeholders
• Recommendations/ Challenges
2 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions The Problem lowest point 207 m highest point 549 m total area 207 km² population 590 000 population of the region 2 600 000 many days with heat stress high level of air pollution along main roads
y
3 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Contents
• The problem
• The strategy to use nature
• The Activities
• Benefits
• Stakeholders
• Recommendations/ Challenges
4 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Section of Urban Climatology
The activity of the urban climatology in Stuttgart has a long tradition. In the year 1938 the municipal council decided to employ a meteorologist, to investigate the special urban climate of Stuttgart and the connection to town planning.
Since that time urban climate is a very important factor for town planning in Stuttgart, especially concerning ventilation and thermal effects.
5 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Federal building code Baugesetzbuch - BauGB
• The requirements of environmental protection
• Ecological balance in nature, and of water, the air, and the climate
• Contribute to an environment which is good for human being, protect the natural basis of life, promote climate protection and climate adaptation.
6 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Spatial distribution Measurement of emissions IR Thermography Digital Elevation Model
Wind Field; Cold Air Simulation Climate Atlas
Climate Atlas Region Stuttgart
Land Use Data
7 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Map with hints for the planning
8 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Contents
• The problem
• The strategy to use nature
• The Activities
• Benefits
• Stakeholders
• Recommendations/ Challenges
9 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Green in the city
Green roofs
Green rails Green parks
Green parking lots Green streets
10 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Forest (25%), Protected Landscape (40%)
11 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Funding program
„More trees and plants in the city“
Budget: 1.800.000 Euro
12 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Planting for local climate and to reduce air pollution
13 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Moss wall planned; about 500.000 Euro
14 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Quarter „Das Rosenberg“
15 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Slopes
Strategy plan for the slopes
16 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Contents
• The problem
• The strategy to use nature
• The Activities
• Benefits
• Stakeholders
• Recommendations/ Challenges
17 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Costs/ Benefits
• Nature in urban planning means no additional costs, if you have municipal experts.
• Personal costs and investigation costs.
• The municipality sometimes works together with universities.
• Funding from the national and EU level.
• The role of nature for climate and air pollution: costs of prevention are much less than the costs of repairing the consequences.
18 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Benefits • Less than 300 m distance from a green space
• Green infrastructure • Ventilation corridors lead to reduced air pollution • Traffic measures
19 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Contents
• The problem
• The strategy to use nature
• The Activities
• Benefits
• Stakeholders
• Recommendations/ Challenges
20 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Involved stakeholders
Climatologist, City planner & Municipal politician
- health and social department for heat warming strategies
21 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Recommendations/ Challenges
Green infrastructure and ventilation corridors reduce heat stress and air pollution. The strategy of the city of Stuttgart shows: That works. Interdisciplinary working of the different stakeholders and engaged employes are necessary and the key for success. The impacts of global climate change and the need to adapt make this more and more important.
22 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions Thank you for your attention!
email: [email protected] www.stadtklima-stuttgart.de www.staedtebauliche-klimafibel.de #naturehealth
23 A project funded by the European Commission (ENV.B.3/ETU/2014/0039) and workshop hosted by the Committee of the Regions
USING GREEN INFRASTRUCTURE TO PROTECT PEOPLE FROM AIR POLLUTION April 2019
USING GREEN INFRASTRUCTURE TO PROTECT PEOPLE FROM AIR POLLUTION
COPYRIGHT
Greater London Authority April 2019
Published by Greater London Authority City Hall The Queen’s Walk More London London SE1 2AA www.london.gov.uk enquiries 020 7983 4000 minicom 020 7983 4458 ISBN Photographs © Copies of this report are available from www.london.gov.uk
USING GREEN INFRASTRUCTURE TO PROTECT PEOPLE FROM AIR POLLUTION 3
EXECUTIVE SUMMARY
This guide summarises the current best practice for how green infrastructure can reduce public exposure to air pollution in the urban environment. It has been produced in consultation with the Birmingham Institute of Forest Research (University of Birmingham), the Global Centre for Clean Air Research (University of Surrey) and Transport for London.
London’s green infrastructure includes a network of parks, green spaces, gardens, woodlands, rivers and wetlands. It also includes street trees, hedges, green walls and green roofs. This guidance relates to the elements of green infrastructure found within a city’s streets (e.g. street trees and hedges) and close by areas (e.g. parks and green spaces).
Green infrastructure offers many benefits for the health of both people and the environment. This guide focuses specifically on the benefit to public health from reducing exposure to the air pollution produced by vehicles (i.e. exposure to lower levels of nitrogen dioxide and particulate matter and/or exposure for shorter periods of time).
At regional and national scales, vegetation plays an important part in removing air pollutants by the process of deposition to leaf surfaces (see Evidence Base for definition). However, at the street scale deposition is of limited benefit. The main value of green infrastructure for urban air quality is not its ability to remove pollutants, but its ability to control their flow/ distribution.
Vegetation at smaller scales – street scale – can be used to control the flow/ distribution of pollutants by controlling their dispersion: the transport of pollutants by the wind away from the source and dilution with cleaner surrounding air. There is no ‘one size fits all’ intervention (and the effects are highly localised) but the right green infrastructure in the right place can reliably reduce exposure to air pollution. A vegetation barrier can as much as halve the levels of pollutants just behind the barrier.
To identify the right type of green infrastructure, and the right place to put it to reduce exposure, the first step is to identify the type of urban road in question:
• Street canyon – a street with buildings on both sides
• Open road – a road with buildings only on one side or detached, single-storey buildings that are widely spaced and/or set back a long way from the road
As summarised in Table 1 below, the appropriate intervention in a street canyon depends on: how the air quality at street level compares with that above the surrounding buildings; and the height/width ratio of the street canyon (i.e., height of surrounding buildings divided
USING GREEN INFRASTRUCTURE TO PROTECT PEOPLE FROM AIR POLLUTION 4
by width of street between). On an open road, the critical question is whether the priority is to protect people close to the roadside (e.g. pedestrians and cyclists) or people further away (e.g. children in a school playground bordering the street).
Table 1. Right green infrastructure, right place
Street Canyons Open Roads Where air quality Where air quality at street level Where priority Where priority is at street level is is worse than above is to protect to protect people better than surrounding buildings: street people further away above canyons with moderate or immediately at (e.g. children in surrounding heavy traffic the roadside a school buildings: street (e.g. playground All street Canyons of canyons with pedestrians and bordering the canyons with this sort with little or no cyclists) street) moderate or height/width traffic heavy traffic ratio < 2 A dense Addition of A hedge or A hedge or A combination avenue of trees green open green wall green wall of hedge and can provide space to one between between dense line of effective side (opening vehicles and vehicles and trees can protection from up the street people can people can as provide a taller polluted air canyon) is reduce much as halve vegetation above and always exposure in exposure in barrier, offering create a clean beneficial their their immediate protection over a ‘green corridor’ immediate wake greater distance for active travel wake downwind
Having identified the right green infrastructure and the right place to put it, the details of its implementation are critical to its success. Used as vegetation barriers, hedges and green walls should: extend from ground level to a height of at least 2m; and be as thick and dense as possible to ensure effective blocking of air flow from vehicles to people. Green walls must also be suitably maintained to remain effective at blocking the flow of air.
If a hedge and dense line of trees are combined to provide a taller vegetation barrier – to protect a greater distance downwind – the trees should: be located as close as possible to the hedge; and located as close to each other as possible to provide a continuous barrier. Evergreen trees are preferred as they will provide year-round protection (deciduous trees offer protection only when in leaf) but borough tree officers should be consulted for species selection, not least to ensure successful long term growth.
USING GREEN INFRASTRUCTURE TO PROTECT PEOPLE FROM AIR POLLUTION 5
INTRODUCTION
In the London Environment Strategy, the Mayor committed to support and empower London and its communities, particularly the most disadvantaged, to reduce their exposure to poor air quality. As well as reducing exposure, the Mayor has pledged to take action to achieve legal compliance with the UK and EU pollution limits as soon as possible. The Mayor has also committed to help make London the world’s first National Park City, where more than half its area is green, the natural environment is protected, and the network of green infrastructure is managed to benefit all Londoners.
London’s “green infrastructure” is the network of parks, green spaces, gardens, woodlands, rivers and wetlands (as well as features such as street trees and green roofs) that is planned, designed and managed to:
• promote healthier living o encouraging walking, cycling and outdoor recreation o creating public spaces to improve mental and physical wellbeing
• lessen the impacts of climate change o removing carbon dioxide from the air o reducing the risk of severe weather events o providing sustainable urban drainage
• improve air quality and water quality o reducing exposure to air pollution o providing a safe and sustainable source of water
• improve biodiversity and ecological resilience o protecting and linking habitats
The use of green infrastructure to reduce exposure to air pollutants is a relatively new and fast-evolving area of research. Some interventions have already been identified that can deliver significant reductions in exposure and, therefore, improvements in public health. This guidance will ensure new green infrastructure projects follow current, evidence-based best practice.
The best way to improve urban air quality is to reduce the emissions of pollutants, such as nitrogen dioxide (NO2) and particulate matter (PM), at the source. Reductions in emissions improve air quality both locally and regionally. In London, road transport is the
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main source of local air pollution, and the Mayor is taking bold action to reduce these emissions. Reducing the use of vehicles is key and green infrastructure has a role to play in incentivising ‘active travel’ (e.g. walking and cycling) through the creation of attractive ‘green corridors’ and networks of green space. However, the health impacts of road transport pollution can be further reduced by decreasing the public’s exposure to what is emitted. ‘Green corridors’ often have better than average air quality, and the attraction of people away from busy roads into cleaner areas will reduce their exposure to road transport pollution. The remainder of this guide, however, focuses on the use of green infrastructure close to busy roads to reduce public exposure to pollution, principally at the kerbside.
Green infrastructure will play an important role in reducing exposure for many years to come as our transport system evolves. Whilst pollution from road transport is forecast to decrease significantly, an important source of ultrafine PM (the smallest particles) from road transport is the non-exhaust emissions associated with brake, tyre and road wear. In the long term, a reduction in traffic volume will be required to address these non-exhaust emissions. This is why the Mayor’s Transport Strategy includes the ambitious target that 80 per cent of trips in London are made on foot, by cycle or using public transport by 2041. Meanwhile, green infrastructure can help reliably reduce exposure to ultrafine PM emissions, and their impacts on public health.
There are two key processes that explain how green infrastructure can protect people from pollution, dispersion and deposition.
Dispersion: Urban vegetation can greatly reduce the amount of emissions people are exposed to. It does this by changing the speed and distance pollutants travel before they reach people. The further the distance the more the pollution is diluted with cleaner air – this process is known as dispersion.
Deposition: Urban vegetation typically removes a few per cent of emissions by a process called deposition. This refers to when pollution lands on the surface of the leaf and is removed from the air. This process is less important for reducing exposure to air pollutants in the urban environment than dispersion.
The next section of this guidance summarises the scientific evidence so far. Supporting information on general planting considerations, and links to practical guidance on implementation are also included. The guidance is divided into two parts:
• Street canyons – streets with buildings on both sides
• Open roads – roads with buildings only on one side, or flanked by detached, single- storey buildings that are widely spaced and/or set back by a considerable distance
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EVIDENCE BASE
This guidance summarises the current best practice, informed by scientific evidence, for using green infrastructure to reduce public exposure to road transport pollution. In 2015, the Forestry Commission established, via its London iTree Eco Project, that trees have a role to play in tackling urban air quality. Last year, the Trees and Design Action Group published practical guidance in partnership with the University of Birmingham and Lancaster University (First Steps in Urban Air Quality for Built Environment Practitioners) and the University of Surrey led a review of the scientific literature then available1.
In July 2018 the Air Quality Expert Group (AQEG) produced a report, Impacts of Vegetation on Urban Air Pollution. The report was a comprehensive and critical review of the scientific evidence available. They found the main value of green infrastructure for urban air quality does not lie in its ability to remove pollutants, but in its ability to control their distribution. The distribution of road transport pollution is affected by the location of the source, the movement of emissions away from that source (e.g. by the wind) and the mixing of emissions with cleaner surrounding air. Urban vegetation typically removes only a low percentage of emissions by a process called deposition, which is when pollution sticks to the surface of a leaf and is removed from the air. However, urban vegetation can greatly reduce the amount of emissions people are exposed to. It does this by changing the distance they must travel from the source to reach people, and the extent to which they are diluted with cleaner air along the way– this process is known as dispersion.
The main messages from the AQEG report, which provides much of the evidence base for this guidance, are summarised below.
• Large scale vegetation, for example in rural environments, can influence air quality in three ways:
a. air pollutants are deposited to leaf surfaces, leading to improved air quality in a process known as deposition;
b. Volatile Organic Compounds (VOCs) are emitted from vegetation that, in the presence of pollution, can contribute to the formation of further pollutants, such as PM and ozone; and,
1 Air pollution abatement performances of green infrastructure in open road and built-up street canyon environments – A review, Abhijith et al, (2017)
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• vegetation can affect the dispersion of pollutants, neither removing nor adding to emissions, but changing the way they mix with the cleaner air around them. Smaller scale vegetation, the kind found in towns and cities, generally makes only a small contribution to the improvement of air quality via deposition; large parks can offer a greater benefit in this respect. However, at the smaller scale of street planting schemes, dispersion has a significant influence on the levels of pollutants. The influence of green infrastructure via dispersion is highly localised: regional air quality will be unaffected but, on a specific stretch of a street, green infrastructure can reduce exposure to pollution.
• A vegetation barrier can as much as halve the levels of pollutants just behind the barrier. The benefit largely comes from forcing the main flow of air over and around the barrier. This creates a sheltered area of air just behind the barrier (i.e., within the first few metres). Most of the polluted air then bypasses this space so the people within it are protected. The benefit of a vegetation barrier (e.g. a hedge) is mainly attributable to its effect on dispersion. However, vegetation barriers are not solid and even the thickest hedges will allow some air to flow through them. The deposition of pollutants in the air that passes through the hedge onto the leaf surfaces will have a small but beneficial effect. The levels of pollutants here may be as much as halved, but the benefit tails off with increasing distance from the hedge. This was demonstrated by one study by King’s College London that found levels of NO2 reduced by 23 per cent when a green wall was placed between a busy road and a school playground. 2
• The deposition of pollutants onto green infrastructure is helpful because it improves air quality both locally and regionally (downwind), but the benefit is small. Some plant species are better than others at removing pollutants by deposition3. Overall, the AQEG report concluded that deposition typically removes just a few percent of PM and a similarly small fraction of NO2. Furthermore, the NO2 that is deposited onto leaves is partly cancelled out by soil emissions of nitrogen monoxide (NO). In the presence of sunlight, chemical reactions rapidly convert NO2 into NO and vice versa, and the soil emissions of NO therefore reduce the already small benefits of NO2 deposition.
The emission of VOCs from green infrastructure, at the scale of urban street planting schemes, is also minor. Green Infrastructure is responsible for a small fraction of total urban VOCs, particularly when assessed over all four seasons, and their small influence on air quality is mainly felt at a distance downwind.
2 For more information see: The impact of a green screen on concentrations of nitrogen dioxide at Bowes Primary School, Enfield, A Tremper, (2018) 3 For more information see: Variation in Tree Species Ability to Capture and Retain Airborne Fine Particulate Matter (PM2.5), Chen et al, (2017)
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GUIDANCE FOR STREET CANYONS
Street canyons are streets with buildings on both sides. They come in many shapes and sizes but one important consideration is the ratio of their height to their width (this will be explained in more detail later in this guidance).
When deciding what green infrastructure will be best for air quality in a street canyon, the first consideration is the difference between the air quality at street level and the air quality above the surrounding buildings. Is the air at street level more or less polluted than the air above?
(i) Street canyons: Air at street level is more polluted than the air above the buildings
Prevailing wind
On very busy roads, the air pollution at street level is usually worse than the air above the buildings. In these canyons reducing the flow of air upwards and downwards should be avoided. A dense avenue of trees could trap the pollution emitted from vehicles at street level and prevent it from mixing with cleaner air above. However, a ‘dense avenue of trees’ refers to trees packed so closely together that they form an almost unbroken canopy. Trees spaced more widely will have little effect on air quality but will deliver the many other environmental and health benefits presented in the Introduction.
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Prevailing wind
On very busy roads, where the air pollution at street level is worse than the air above, a vegetation barrier (i.e., a hedge) between the road and pedestrians may offer some protection. A vegetation barrier between vehicles and cyclists (i.e., in a separate cycle lane) can likewise reduce cyclists’ exposure. As mentioned in the Evidence Base, studies have shown that in an open road environment (which will be discussed the next section), a vegetation barrier can as much as halve the levels of pollutants just behind it. The effect of a vegetation barrier in a street canyon is less certain and depends on local conditions, including wind speed and direction, the height of the buildings, and the width of the road. These factors interact to determine the flow of air within the canyon.
In general, any intervention that increases the distance pollution must travel from vehicles to pedestrians or cyclists will reduce the amount of pollution they are exposed to. However, in street canyons with narrow roads and very tall buildings it is not yet clear if installing a hedge will reduce or increase exposure, and we do not currently recommend it. As a guide, we do not currently recommend adding vegetation barriers in canyons where the height of the buildings either side is more than twice the width of the street between them (i.e., a height to width ratio > 2).
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(ii) Street Canyons: Air above the buildings is more polluted than the air at street level
Prevailing wind
It is also possible to reduce public exposure to pollution using green infrastructure on very quiet roads. In a city like London, there are some roads with little or no traffic, where the air quality at street level is better than that above the surrounding buildings. We can reduce the public’s exposure to the polluted air above by creating a pocket of clean air where people are. A dense avenue of trees, forming an almost unbroken canopy, provides a barrier to downward dispersion, reducing the flow of polluted air down to street level where people would be exposed to it.
As mentioned in the Introduction, there are many ways in which green corridors reduce exposure to air pollution. They incentivise walking and cycling, thereby helping to reduce road transport emissions; they reduce the overall public exposure to pollution by attracting people away from busier routes onto cleaner ones. This is in addition to the many other benefits of green infrastructure not related to air quality.
(iii) Street Canyons: Green roofs, green walls and green open space
The benefits of green roofs include sustainable urban drainage, mitigation of the urban heat island effect (cooling buildings and reducing energy used for air conditioning) and increased biodiversity. However, their potential for reducing exposure to road transport pollution is limited for two reasons: they have little effect on the dispersion of this pollution; and their relatively minor effect via the deposition of pollutants is focussed on the air above the buildings, not at street level.
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Green walls (if they are dense enough and well maintained) can be used instead of hedges as effective vegetation barriers between pedestrians and busy roads. When they are mounted on building facades, green walls have some potential to reduce public exposure to road transport pollution, but further research is needed. Here, they might be expected to improve air quality within a street canyon solely via deposition of pollutants to their leaf surfaces. A computer-modelling study, however, found that the potential for deposition strongly depended on the average time air spends circulating within the street canyon, and that this changed when a green facade was added on both sides of the 4 street . The modelling found significant reductions in PM10 (and some reduction in NO2) but the results varied a lot depending on the height and width of the street canyon. Further research is needed into the effect on air quality of green walls in street canyons.
If there was an opportunity to open up one side of a street canyon onto an open space, particularly a green open space, this would greatly improve the air quality in that street; open space allows the efficient dispersion of road transport pollution. In effect, the street canyon would be turned into an ‘open road’ environment – the subject of the next section.
4 For more information see: Pugh, T.A.M., A.R. MacKenzie, J.D. Whyatt, and C.N. Hewitt, Effectiveness of Green Infrastructure for Improvement of Air Quality in Urban Street Canyons, Environ. Sci. Technol., 2012, 46 (14), pp 7692–7699
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GUIDANCE FOR OPEN ROADS
The term ‘Open roads’ includes roads with buildings on one side only. It also includes roads where houses are detached, single-storey buildings with big gaps between them and/or set back a long way from the road. These are common features of the urban environment, mainly found in suburban areas, at the edges of parks and other residential areas.
(i) Open roads: the value of open space, particularly green open space
Prevailing wind
Open space next to a road, particularly green open space such as a park, plays a vital role in reducing public exposure to road transport pollution. Open space allows pollutants to disperse, meaning they quickly decrease to background levels. Within parks, trees are very beneficial to the dispersion of pollution: they disturb the flow of air around them and increase the mixing of the more polluted air at street level with cleaner air above. Green open spaces also take the place of space that would otherwise include further sources of pollution.
Similar to green corridors, there are many benefits associated with the provision of green open space: it can form part of a network of green infrastructure that incentivises walking and cycling, and thereby help to reduce road transport emissions; and it can reduce public exposure to these emissions by attracting people away from more polluted areas into cleaner ones, and encouraging them to stop and spend time here for recreational
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purposes. A recent study found that children with asthma who live close to a green space present fewer asthma symptoms in later life than those who live further away.5
(ii) Open roads: Protecting people at the side of an open road
Prevailing wind
Hedges can provide effective barriers between cars and pedestrians to protect people close to the side of open roads. As noted in the previous section (Guidance for Street Canyons), vegetation barriers between vehicles and cyclists (i.e. in separate cycle lanes) can likewise reduce cyclists’ exposure to vehicular pollution. (Cyclists sharing the road with vehicles, though not protected by a vegetation barrier will benefit from systematic interventions suchas the introduction of the Ultra Low Emission Zone in April 2019, and cleaning up the bus fleet).
As with a street canyon, the effect of a hedge located close to neighbouring buildings (such as the hedge on the left in the diagram above) is less certain than one bordering open space (such as the hedge on the right in the picture above). The benefit of a hedge located close to buildings is that it increases the distance pollutants must travel between vehicles and, in this case, pedestrians. A hedge or green wall bordering open space, however, has the additional potential to create a sheltered region of air immediately behind it. By forcing the main flow of polluted air over and around this space, the people within it, close to the hedge, are protected. The levels of pollutants here may be as much as halved, but the benefit tails off with increasing distance from the hedge.
The cyclists (pictured to the far right, in the above diagram) are likely to be exposed to similar levels of pollutants as if there were no hedge, though much of the pollution from the vehicles will have dispersed before it reaches them, meaning pollution levels will already
5 For more information see: Green space near home during childhood linked to fewer respiratory problems in adulthood, European Lung Foundation, (2018)
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be much lower than at the roadside. The taller the barrier, the larger the area protected, but further research is needed to quantify the relationship between the two.
(iii) Open roads: Protecting people further from an open road
Prevailing wind
An additional, taller barrier is needed when the aim is to protect people occupying a larger area, further from the road, such as children in a school playground. A dense line of trees, with a hedge or green wall beneath, can provide an effective barrier. The benefit of a hedge or green wall on its own will critically depend on its height: a barrier to a height of 2m will protect children in the first few metres of the playground, but a taller barrier is needed to offer effective protection to children further away.
As a rule of thumb, a barrier of height, H metres can protect a distance of up to (3H) - 3 metres downwind under the right wind conditions. For example, a 2m high barrier can protect up to (3 x 2) – 3 = 3m downwind, whilst a 10m high barrier can protect up to (3 x 10) – 3 = 27m downwind. (This rule of thumb assumes that a sufficiently thick and dense vegetation barrier creates a sheltered region behind it similar to the ‘recirculation region’ downwind of a building).6
There is a risk that this taller barrier may reduce the dispersion of pollutants between it and the road, increasing the exposure to pollution on the road side.
When the net public health impact is considered, reduced exposure in the playground may justify a small increase in pollutant levels between the playground and the road. Considerations include; the number of people exposed either side (more children may be exposed in the playground than passersby on the road); the average length of time for which they are exposed (children may spend longer in the playground, at lunchtime and during breaks, than passersby spend walking past the school); and the vulnerability of those exposed (children are more vulnerable to the impacts of air pollution than the majority of adult passersby). Note, the elderly also tend to be more vulnerable to the impacts of air pollution, as do people with certain pre-existing medical conditions.
6 For more information see: Scalar Fluxes from Urban Street Canyons. Part II: Model, Harman et al. (2004).
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Alternatively, it may be possible to position the tall barrier (dense line of trees and a hedge) at the kerbside. This would still protect the children in the playground, albeit to a slightly lesser extent, whilst also protecting the people between the playground and the road.
(iv) Open roads: Green roofs and green walls
As outlined in the previous section, green roofs provide many benefits including their significant contributions to sustainable urban drainage, mitigation of the urban heat island effect (cooling buildings and reducing energy used for air conditioning) and increased biodiversity. However, at street level, they have limited potential for reducing exposure to road transport pollution.
On open roads, green walls can be used in place of hedges and trees as effective vegetation barriers between vehicles and pedestrians (if equally tall and dense, and well maintained). This is particularly the case where hedges and trees cannot be planted due to, e.g. sub-surface infrastructure constraints. However, when mounted on building facades, they are not effective at reducing exposure to road transport pollution. With no buildings on one side of the road, the average time air spends circulating close to the green facades will be short, and the benefit of deposition very small.
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PRACTICAL CONSIDERATIONS
Supporting information regarding general planting considerations is provided in Table 2, followed by links to further guidance on practical implementation.
Table 2. General planting considerations
Vegetation characteristics associated with species selection
For an effective, year-round barrier to pollutants, evergreen plants are recommended; deciduous trees and shrubs will be less effective in winter months due to
Seasonal effects their lack of foliage. However, species selection must account for many other factors, including the likelihood of successful long-term growth, and borough tree officers should be consulted.
The vegetation should be resistant to the effects of air pollution. Depending on local conditions, it should also be resistant to other relevant stresses, such as salt (used during winter road conditioning), drought and high wind turbulence often associated with busy roads. Stress resistance, invasiveness Invasive species should be avoided, as should and allergens poisonous species, and species responsible for the production of common allergens. For example, the planting of birches in and around schools should be avoided. For all of these considerations, London tree officers should be consulted.
Although a relatively minor influence compared to the redistribution of pollution by enhanced/reduced dispersion, the removal of pollutants by deposition is greater to some leaf surfaces than others: leaves with large surface areas, and complex waxy (e.g., Hedera Leaf surfaces for deposition helix, Juniperus chinensis) and/or hairy surfaces (e.g., Sorbus aria, Stachys byzantine), are particularly good. However, species selection must account for many other factors, including the likelihood of successful long-term growth, and tree officers should be consulted.
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Green infrastructure is a relatively minor source of VOCs in the urban environment. Some VOCs, however, are more chemically reactive than others – isoprene is a particularly reactive one – and VOC emissions from vegetation will likely increase somewhat as the climate continues to warm. It may therefore be prudent to plant somewhat fewer trees of species
Volatile Organic Compound known to be particularly strong sources of isoprene (VOC) emissions (e.g. oaks) and somewhat more trees known to emit little isoprene (e.g. larch), but simply planting a mixture of species will mitigate the (relatively minor) concerns regarding their emissions; guides are available such as Donovan et al.’s (2005) ‘Urban Tree Air Quality Score’. Species selection must take account of many other factors, not least those governing successful long-term growth, and tree officers should be consulted.
Physical characteristics of vegetation barriers between vehicle emissions and people
To protect people in the surrounding area, hedges/ green walls should provide as complete a barrier as possible from ground level to a minimum height of 2m. Above 2m, further increasing the height of the vegetation barrier, be it a hedge, green wall, or a combination of a line of trees with a hedge at its base, Height will protect a greater distance downwind. As a rule of thumb, a barrier of height, H metres can protect a distance of up to (3H) - 3 metres downwind under the right wind conditions. For example, a 2m high barrier can protect up to (3 x 2) – 3 = 3m downwind, whilst a 10m high barrier can protect up to (3 x 10) – 3 = 27m downwind.
Vegetation barriers – where recommended to reduce exposure to road transport emissions (see previous sections) should be as thick as possible: the thicker the Thickness vegetation barrier, the more effective it will be at blocking road transport emissions through it and, thereby, forcing air over it; see Evidence Base for further information.
Likewise, vegetation barriers – where recommended to reduce exposure to road transport emissions (see Density previous sections) – should be as dense as possible: the denser the vegetation barrier, the more effective it will be at blocking transport through it and, thereby,
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forcing air over it; see Evidence Base for further information.
Gaps between stretches of a vegetation barrier, be it a hedge, green wall, or a combination of a line of trees with a hedge at its base, will reduce its effectiveness at blocking horizontal transport. However, appropriate guidance must be sought to ensure all sight lines, Continuity and safety vision splays, and any other safety provisions for drivers, cyclists and pedestrians, are maintained.
Green Infrastructure should be designed to support streets where people feel safe from crime in line with the Healthy Streets approach.
Vegetation barriers must be properly installed for long term success, and appropriately maintained to remain effective at blocking the transport of pollution. Some
Installation and maintenance types of barrier will be more expensive to install and maintain than others, and tree officers should be consulted at all stages (i.e., from early planning activities to installation and maintenance).
Links to further guidance on practical implementation
The planting of street trees and hedges can be challenging. Considerable space is needed to accommodate good cellular root systems, and space may be limited due to the routing of existing utilities underground (and services overhead) and the preservation of safety-critical sight lines, vision splays and so forth (e.g. at road junctions and pedestrian crossings. The Tree and Design Action Group’s Trees in Hard Landscapes guide and the Forestry Commission’s Urban Tree Manual offer technical guidance on integrating trees into the urban landscape. The Tree Species Selection for Green Infrastructure: A Guide for Specifiers is a guide and searchable database.
Where green walls are sought as part of an urban design, our 2008 Living Roofs and Walls Technical Guide provides further advice on their benefits and constraints, an updated version of which will be published in April 2019. Further advice and best practice on delivering high quality urban greening can be found on our website.
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SUMMARY
Below is a summary of the guidance contained within this report. For further details, please refer to the preceding sections. The flowchart below is a reminder of general recommendations but local factors should always be taken into account.
What type of urban road is it?
Street canyon Open road
Is the air quality at street level better or worse Open space beside a road, particularly than above the surrounding buildings? green open space, is always beneficial.
Better Worse Is the priority to protect people at the roadside, or people distributed further from the road e.g. schools, hospitals A dense avenue What is the street of trees can canyon’s height/ protect a very width ratio? Roadside quiet road from Further away the polluted air above and create a clean ‘green Hedges/green The combination corridor’ for active H/W < 2 H/W ≥ 2 walls between of a dense line of travel. vehicles and trees and a pedestrians can hedge/green wall protect people can provide a taller vegetation Hedges/green walls The addition of close to the road. barrier, offering between vehicles and hedges/ green walls The level of protection over a pedestrians can is not currently protection will greater distance; protect people nearby; recommended depend on local this may come at the level of protection though adding or wind conditions, the risk of depends on local wind maintaining existing height of increased conditions, height of green infrastructure buildings and pollutant levels buildings and width of for the many other width of road. between the road road. benefits it brings. With open space beyond, the and the tall pollutant levels barrier. may be as much Note: Opening up a street canyon with additional green open space is always beneficial. as halved.
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Acknowledgements
This guide has been produced in consultation with the Birmingham Institute of Forest Research (University of Birmingham), the Global Centre for Clean Air Research (University of Surrey) and Transport for London.
Disclaimer
The guidance provided herein is intended to describe best practice subject to the scientific evidence available at the time of writing. Uncertainties remain, and revised guidance will be issued as these are addressed through further research.
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Other formats and languages For a large print, Braille, disc, sign language video or audio-tape version of this document, please contact us at the address below:
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AIR QUALITY EXPERT GROUP Impacts of Vegetation on Urban Air Pollution
Prepared for: Department for Environment, Food and Rural Affairs; Scottish Government; Welsh Government; and Department of the Environment in Northern Ireland
AIR QUALITY EXPERT GROUP Effects of Vegetation on Urban Air Pollution
Prepared for:
Department for Environment, Food and Rural Affairs; Scottish Government; Welsh Government; and Department of the Environment in Northern Ireland
This is a report from the Air Quality Expert Group to the Department for Environment, Food and Rural Affairs; Scottish Government; Welsh Government; and Department of the Environment in Northern Ireland, on the impacts of vegetation on urban air pollution. The information contained within this report represents a review of the understanding and evidence available at the time of writing.
© Crown copyright 2018
Front cover image credit: Getty Images.
United Kingdom air quality information received from the automatic monitoring sites and forecasts may be accessed via the following media:
Freephone Air Pollution Information Service 0800556677
Internet http://uk-air.defra.gov.uk
PB14503
Terms of reference
The Air Quality Expert Group (AQEG) is an expert committee of the Department for Environment, Food and Rural Affairs (Defra) and considers current knowledge on air pollution and provides advice on such things as the levels, sources and characteristics of air pollutants in the UK. AQEG reports to Defra’s Chief Scientific Adviser, Defra Ministers, Scottish Ministers, the Welsh Government and the Department of the Environment in Northern Ireland (the Government and devolved administrations). Members of the Group are drawn from those with a proven track record in the fields of air pollution research and practice.
AQEG’s functions are to:
Provide advice to, and work collaboratively with, officials and key office holders in Defra and the devolved administrations, other delivery partners and public bodies, and EU and international technical expert groups;
Report to Defra’s Chief Scientific Adviser (CSA): Chairs of expert committees will meet annually with the CSA, and will provide an annual summary of the work of the Committee to the Science Advisory Council (SAC) for Defra’s Annual Report. In exception, matters can be escalated to Ministers;
Support the CSA as appropriate during emergencies;
Contribute to developing the air quality evidence base by analysing, interpreting and synthesising evidence;
Provide judgements on the quality and relevance of the evidence base;
Suggest priority areas for future work, and advise on Defra’s implementation of the air quality evidence plan (or equivalent);
Give advice on current and future levels, trends, sources and characteristics of air pollutants in the UK;
Provide independent advice and operate in line with the Government’s Principles for Scientific Advice and the Code of Practice for Scientific Advisory Committees (CoPSAC).
Expert Committee Members are independent appointments made through open competition, in line with the Office of the Commissioner for Public Appointments (OCPA) guidelines on best practice for making public appointments. Members are expected to act in accord with the principles of public life.
Further information on AQEG can be found on the Group’s website at: https://www.gov.uk/government/policy-advisory-groups/air-quality-expert-group
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Membership
Chair Professor Paul Monks University of Leicester
Members Dr James Allan National Centre for Atmospheric Science, University of Manchester
Dr David Carruthers Cambridge Environmental Research Consultants
Dr David Carslaw Ricardo Energy and Environment and University of York
Dr Chris Dore Aether Ltd
Dr Gary Fuller King's College London
Professor Roy Harrison OBE University of Birmingham
Dr Mat Heal University of Edinburgh
Professor Alastair Lewis National Centre for Atmospheric Science, University of York
Professor Alison Tomlin University of Leeds
Professor Martin Williams King's College London
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Ad hoc members Professor David Fowler CBE Formerly Centre for Ecology and Hydrology
Dr Ben Marner Air Quality Consultants
Ex officio members Central Management and Control Unit of the automatic urban and rural networks: Dr Richard Maggs, Bureau Veritas
National Atmospheric Emissions Inventory: Dr Tim Murrells, Ricardo Energy and Environment
Non-automatic hydrocarbon monitoring networks and metals monitoring network: Dr Paul Quincey, National Physical Laboratory
Quality Assurance and Quality Control of the automatic urban network and the non- automatic monitoring networks: Dr Paul Willis, Ricardo Energy and Environment
Assessors and observers Simon Baldwin Welsh Government
Barry McCauley Department of the Environment in Northern Ireland
Andrew Taylor Scottish Government
Alison Gowers Public Health England
Secretariat Dr Sarah Moller National Centre for Atmospheric Science, University of York and Department for Environment, Food and Rural Affairs
Dr Ailsa Stroud Department for Environment, Food and Rural Affairs
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Acknowledgements The Air Quality Expert Group would like to acknowledge the following individuals and organisations for their help in the preparation of this report:
Dr Eiko Nemitz Centre for Ecology and Hydrology
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Contents
1 Introduction ...... 6 2 Policy implications ...... 7 3 Effects of vegetation on atmospheric dispersion ...... 9 3.1 Introduction...... 9 3.2 Effects of trees on airflow and turbulence...... 9 3.3 Effects of Trees on Dispersion ...... 9 3.4 Tree Barriers ...... 10 3.5 Trees within street canyons...... 10 4 Effects of vegetation on dry deposition in urban areas ...... 15 4.1 Introduction ...... 15 4.1.1 The deposition process ...... 15 4.2 Measurements of trace gas and particulate matter deposition in urban areas ...... 17 4.3 Modelling effects of trees in urban areas ...... 19 5 Biogenic volatile organic compound emission from urban tree planting ...... 24 5.1 Introduction ...... 24 5.2 Considerations for urban tree planting ...... 24 6 Summary ...... 28 7 Valuing the benefits of vegetation as a sink for air pollutants ...... 29 8 References ...... 31
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1 Introduction This report addresses the research and policy aspects of the interactions between vegetation and air pollutants in urban areas. The focus is on the ways in which existing vegetation and potential plantings influence atmospheric composition through emission of trace gases and by dispersion and deposition of air pollutants, and as a consequence, the concentrations of pollutants to which people in urban areas are exposed. The main criteria for selection of the reviewed literature for inclusion was quantification of the effects on fluxes, concentrations or mass budgets. Additional reference material to provide context and links to the wider literature on this subject have been included. Overall, vegetation and trees in particular are regarded as beneficial for air quality, but they are not a solution to the air quality problems at a city scale.
Compared with emissions control at source, removing pollutants once diluted into the atmosphere is challenging because of the large volume of air into which the pollutants have been dispersed compared to the surface area to which any potential abatement technology may be applied. The report comprises two main sections, on the effect of vegetation on dispersion, and on the capture of pollutants by vegetation. The report begins with a summary of the policy implications.
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2 Policy implications The report aims to answer the following questions.
Is there definitive observational evidence of the effectiveness of urban vegetation in mitigating air pollution?
The effects of realistic planting schemes to alleviate air quality problems by enhancing deposition to the surface with vegetation in cities are small. Reductions in concentrations of
PM10 for realistic planting schemes would be expected to be at the scale of a few percent. The work to date both from measurement and modelling shows that it is unlikely that large reductions in concentration (>20%) could be achieved using vegetation to enhance deposition over a substantial area.
For nitrogen dioxide (NO2), vegetation is, generally speaking, of little benefit; it is not a very efficient sink. The deposition occurs in daytime, and primarily in the warmer months, when
NO2 is less of a problem. Vegetation is a very poor sink for nitric oxide (NO) and soil is a source of NO, at least partially offsetting any potential benefit of uptake by vegetation.
Locally (tens to hundreds of square metres) tree planting may enhance or reduce dispersion; this redistributes pollution but does not remove it. Where vegetation acts as a barrier close to a source, concentrations immediately behind the barrier owing to that source are reduced typically by a factor of about 2 relative to those which would occur without the barrier, whereas on the source side of the barrier concentrations are increased. Tree planting may also exacerbate the build-up of pollution within street canyons by reducing air-flow.
The use of trees to improve air quality is not without negative impacts as some tree species are important sources of biogenic volatile organic compounds (BVOCs), notably isoprene. BVOCs can enhance the formation of pollutants including PM and ozone. However, BVOC emissions could be avoided by selecting low emitting species. Similarly, the choice of plant species which are known sources of aeroallergens should be avoided.
It is important in communicating the potential benefits of vegetation in mitigating urban air pollution problems to provide quantitative estimates, supported by measurement and modelling and their uncertainties, and avoid the campaigning zeal, which is commonly associated with popular publications on the subject.
What role does vegetation and its effects on air pollution play in integrated urban planning and policy?
Recognising that the potential for improving Air Quality using vegetation is modest, an important limitation to mitigation of current Air Quality problems with vegetation is that the most polluted areas of cities are those with very limited space for planting, greatly reducing the potential for mitigation using these methods. An integrated policy which separates people spatially from major pollution sources (especially traffic) as far as possible and in which vegetation is used between the sources and the urban population maximises its beneficial effects.
Are the data and models to quantify effects of urban planting schemes on air quality in the major cities of the UK generally available?
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A range of models have been applied to address the problem, all of which are available. However, the complexity of the physical and chemical environment in urban areas and knowledge of the interactions between the flow regimes and urban structures with emission sources have all been greatly simplified in the modelling to date. Thus, while the scale of the effects of vegetation on concentrations of particulate matter in urban areas is probably correct within a factor of 2, there is a great deal more to be learned from further very detailed measurement and modelling.
In the following sections, evidence has been selected from the literature where the papers directly address the quantification of effects of vegetation on dispersion and deposition of pollutants and their effects on ambient concentrations. In addition a range of recent reviews of the wider subject area are included for context.
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3 Effects of vegetation on atmospheric dispersion
3.1 Introduction. This section considers the impact of vegetation, in particular trees, on pollutant concentrations due to their effect on the dispersion of pollutants. The impacts on deposition are considered in Section B below. Janhall (2015), for example, includes a review of the impact of both processes.
It is the impact of trees on airflow and turbulence which determines any resulting impact on dispersion. This effect is first outlined for different examples, including different numbers, configuration and density of trees. This information is then extended to consider the dispersion of pollutants from a source upwind of, within and downwind of trees.
3.2 Effects of trees on airflow and turbulence. Figure 1 illustrates the impact on the airflow and turbulence of a single tree and groups of trees of different density and layout. Considering first a single tree (Figure 1(a)) there is some deceleration of the flow upwind and around the tree due to blocking of the flow. Close to the tree there is further deceleration of the flow and also generation of turbulence as the air flows around and through the branches of the tree. Downstream in the near wake, the flow may be highly perturbed with substantial turbulence generation; in the far wake the flow slowly recovers to its upstream form with acceleration and decay of the wake turbulence. As trees change shape to some extent with wind speed, the magnitude of these effects is also dependent on wind speed. Detailed studies of the impact of a single tree on airflow are given in Gross (1987) and Green (1990).
Understanding how groups of trees affect the airflow and turbulence can be deduced from consideration of the effects of single trees in combination (Belcher et al. 2003, Britter and Hanna 2003, Belcher et al. 2012). For a sparse array of trees more than about 8 tree diameters apart (Figure 1(b)) the perturbation to the flow can broadly be considered as the sum of perturbations from individual trees – the direction of the flow is little affected by the trees but the mean flow speed is reduced and there is an increase in turbulence. As the density of the tree array increases, the flow through and around the trees is reduced and there is increased airflow over the trees, which descends again on the downwind edge of trees (see Figure 2). In this case the largest shear stresses are at the top of the canopy, so turbulence levels are increased here but reduced within the tree canopy. As the tree array density increases still further so that trees are less than 2 tree diameters apart (Figures 1(c,d)), the flow becomes increasingly blocked and for the highest array densities it is almost completely blocked, diverging over and around the group of trees much as it does around a building and providing a barrier to noise.
3.3 Effects of Trees on Dispersion Once the effects of the trees on airflow and turbulence have been determined, it is straightforward in principle to determine their impact on dispersion and hence on pollutant concentrations. The mean airflow determines the plume trajectory and also impacts on the near field concentration which is inversely proportional to wind speed. The turbulence
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determines the rate of mixing with ambient air and hence the rate of dilution and spread of the plume. So, in general, an increase in wind speed or turbulence increases dispersion. Neglecting cases where the plume has high momentum or buoyancy, for ground level sources an increase in dispersion reduces ground level concentrations and vice versa. For elevated sources no such simple rule applies, but downward flows (e.g. behind obstacles) or an increase in the vertical component of turbulence brings pollutant down towards the ground tending to increase maximum surface concentrations. In these cases the sensitivity of concentration to wind speed is similar to ground level sources.
We have used these considerations in Table 1 to describe the impact on sources of pollution located upwind of trees, within the trees and downwind of trees, dependent on the proximity of trees to each other. Drawing the most general conclusions from this table, we can surmise that there is negligible impact upstream of well-spaced trees. However, there is an increasing adverse impact as tree density increases, and a slight positive impact within widely spaced trees changing to strongly adverse impact within closely packed trees. Impacts downstream are complex and depend on the location of the source and the density of the tree array.
In view of specific interest of the effect on pollutant concentrations of tree barriers and trees within street canyons we now consider these two cases separately and provide some limited quantitative estimates of their impact on pollutant concentrations.
3.4 Tree Barriers The impact of tree barriers (or lines of closely packed trees Figure 1(D)) and also of noise barriers, particularly those adjacent to roads, have been studied in some detail in the field, in wind tunnels and with CFD models (e.g. Baldauf et al. 2008, Baldauf et al. 2013, Al-Dabbous and Kumar 2014). Consistent with the broad descriptions above, when the wind blows from the road to the barrier there are reductions in concentrations on the downwind side of the barrier. These reductions decrease with distance away from the barrier and depend on the height and density of the barrier as well as other factors such as atmospheric stability and building morphology in the neighbourhood of the barrier. The measurements show a broad range in the maximum reduction in concentrations up to a factor of 5 (Baldauf et al. 2013), but reductions within a factor of 2 are more typical; see for example noise barrier studies of Heist et al. 2014 and Baldauf et al. 2008 and tree barrier studies of Hagler et al. 2012, Al- Dabbous and Kumar 2014 and Brantley et al. 2014. It is noted that for the studies conducted in the field, some of the concentration reduction may be attributable to deposition rather than dispersion effects. In very light winds reductions in concentration are less apparent and in some cases increases are observed. Roadside of the barrier, concentrations may show some increase close to the barrier, as in a single sided street canyon, both when the wind blows from the road to the barrier and from the barrier to the road.
3.5 Trees within street canyons. There have been fewer studies of this case, which presents a greater challenge for experimental design. Most studies have considered impacts on deposition (Pugh et al. 2012), however Gromke and Ruck (2008) and Gromke et al. (2008) have conducted wind tunnel studies and CFD modelling of the impacts of avenues of trees within canyons. As
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discussed, single trees may increase turbulence levels with relatively little impact on the mean flow, however this is likely to be of little consequence in an urban street canyon where turbulence levels are already typically high. More important is the blocking effect which is enhanced in the confined space of a street canyon, leading to decreased dispersion and higher concentrations due to road sources (Woodland Trust 2012). This effect increases with the number of trees or their foliage density (Gromke et al. 2008) and may increase concentrations by as much as a factor of 2 when there are a sufficient density of trees to substantially reduce the air flow within the canyon.
Finally, we note that the magnitude of the impacts on concentrations discussed above are for primary pollutants. Impacts on secondary pollutants, in particular NO2, are reduced.
A. Single tree Turbulence generation
Some Near wake blocking Far wake
B. Well-spaced tree array
Increased turbulence and mixing
Far wake
Reduced mean flow
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C. Moderate density tree array
Increased flow around trees Increased turbulence over trees and in wake
Blocking Reduced flow and reduced turbulence within trees
D. Densely packed tree array
Increased turbulence over trees and in wake
Far wake Almost completely blocked flow Near wake recirculation possible
Figure 1. Schematic depiction of the impact of trees of different packing density on airflow and turbulence
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Figure 2 (From Belcher et al. 2012). Contour plots of the evolution of (a) the mean streamwise velocity, (b) mean vertical velocity, and (c) turbulent kinetic energy across a forest edge replotted from the original LES data of Dupont and Brunet (2008). The domain is periodic in the x direction. The black dashed lines mark the location of the canopy. Overlain are white dashed lines indicating a schematic of the adjustment of the flow (adapted from Belcher et al. 2003). Adjustment of the mean flow is indicated in panels a and b, and adjustment of the turbulence is indicated in panel c. Abbreviations: A, adjustment region; C, canopy flow region; E, exit region; I, impact region; M, mixing-layer region; R, roughness change region; T, turbulence impact region;W, wake region.
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Source location
Source upwind Source within Source downwind of trees/in of trees trees the wake
Negligible effect upwind of trees; Increased Well within trees or dispersion due to Increased dispersion due to spaced downwind may increased increased turbulence trees increase turbulence dispersion
For source near trees effects are complex: an increase in turbulence increases dispersion, Some blocking Decreased a reduction in the mean flow close to trees Moderate dispersion due to reduces it; there may be down- reducing density decreased flow flow behind the trees increasing dispersion and turbulence ground-level impact of elevated upwind of trees sources. For sources further downwind an increase in turbulence increases dispersion
For source near trees effects
Density of group of trees of group of Density are complex: an increase in turbulence increases dispersion, Close to trees a reduction in the mean flow and blocking reduces Densely recirculating flow (near wake) dispersion; main Much decreased packed reduces it; down flow behind the trajectory of dispersion trees increasing ground-level trees plume over or impact of elevated sources. For around trees sources further downwind an increase in turbulence increases dispersion
Table 1. Impacts of trees on dispersion. Increased/decreased dispersion results in reduced/increased pollutant concentrations for ground-level sources. For elevated sources increased/reduced dispersion may increase/decrease maximum ground level concentrations as the pollutants can be mixed more rapidly to the surface.
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4 Effects of vegetation on dry deposition in urban areas
4.1 Introduction Terrestrial surfaces are an important sink for pollutants in the boundary layer by direct deposition to the surface (dry deposition), and enhancing the deposition flux to the surface has the benefit of reducing concentrations near the ground and thus exposure of people in urban areas. As with so many aspects of urban air quality, the matter is not straightforward: the rates of deposition of gaseous and particulate pollutants on vegetation vary greatly between individual gases and for particulate matter mainly with particle size. Quite a lot is known about deposition rates in the countryside where most measurements have been made. The (micrometeorological) techniques most widely used to measure deposition of pollutants require extensive uniform areas of vegetation to quantify the vertical flux to the surface. In urban areas, vegetation is usually present in areas which are too small for micrometeorological methods of flux measurement. Urban vegetation typically in parkland or within gardens or as amenity planting along roads requires more specialised techniques for measurement, which few have attempted.
Vegetation also changes the dispersion rates of pollutants as discussed in section 3 above. This section provides a guide to current knowledge of deposition from physical and chemical principles and research to date. Where possible the focus has been to quantify the scale of reductions in concentrations in urban areas in response to planting schemes rather than provide a comprehensive review of the literature. The discussion is based on published research, and where possible for UK conurbations.
The literature on the subject of pollutant deposition is reasonably large and includes both direct measurements of rates of deposition to canopies of vegetation for a range of gaseous and particulate pollutants, many of which are described in a recent review (Fowler et al 2009). The literature also includes laboratory studies of the exchange of pollutants with plant surfaces (Freer-Smith et al 2004) and models which simulate deposition fluxes over large areas or time scales, to provide e.g. annual deposition fluxes to the UK (Smith et.al 2000).
There is a much wider literature on the benefits of vegetation for improving air quality in urban areas and many recent reviews (e.g. Janhall 2015, Salmond et al 2016, Abhijit et al 2017, Gallagher et al 2015, Berardi et al 2014). These reviews provide a useful guide to the extensive recent literature, but they are not focussed on the scale of reductions in concentrations of the major pollutants that can be achieved by policies to increase vegetation in urban areas. Furthermore, there is a general lack of the quantitative analysis required to quantify the benefits of urban vegetation for air quality, (e.g. Willis and Petrokosky 2017). It has therefore become difficult to separate the campaigning zeal for vegetation for all its acknowledged benefits from an analytical assessment of the value of vegetation to augment the dry deposition sink.
4.1.1 The deposition process Pollutant gases and sub-micron particulate matter are transported from the atmosphere to absorbing surfaces by turbulent transfer (Figure 3), sedimentation only becomes important for particles appreciably larger than a micron in diameter. Close to surfaces, turbulence is supressed and transport of gases relies on molecular diffusion across a layer of laminar air
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flow to reach sites of reaction or sorption at the surface. Most of the particulate matter (by mass) is too large to diffuse efficiently through the laminar sub-layer and relies on impaction, interception and phoretic processes for transport to the surface (Garland 2001). The large flat structures of buildings are associated with substantial laminar boundary layers, so that capture of particulate matter is most efficient on those parts of the structure with the shallowest boundary layers, as is distinct on some buildings from the pattern of soiling.
One of the potential benefits of vegetation is that the finely divided structure of many leaves, especially of conifers provides both larger collecting surface per unit ground area and shallow laminar boundary layers over the leaves, especially at the edges to collect particles and reactive gases. A consideration of the leaf area available for capture of pollutants raises the question of which species are best suited to the role of pollutant deposition and whether evergreen or deciduous species are preferred. These aspects have been discussed by Grote et al (2016) and by Hewitt (2002) and includes a consideration of the emission of BVOCs, considered later in this report.
Figure 3. The deposition process for pollutant gases and particulate matter. The atmospheric transport to the surface is largely by turbulent diffusion for both gases and sub-micron particulate matter except very close to the surface where molecular diffusion transports gases to the absorbing surfaces while particulate matter relies on a combination of impaction, interception, diffusion, gravitational settling, diffusion and phoretic process, which vary greatly with particle size.
In principle, adding vegetation to an urban landscape introduces both extra surfaces for uptake and larger deposition velocities per unit area than most building surfaces. Vegetation may be added to urban areas by planting in green spaces or by covering buildings with vegetation (green walls).
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4.2 Measurements of trace gas and particulate matter deposition in urban areas The majority of published measurements of pollutant deposition to vegetation are in rural areas, where fluxes have been measured over extensive areas of uniform vegetation. A requirement of the widely applied micrometeorological methods is a uniform surface within the flux footprint (e.g. Vesala et al 2008) in which the deposition to the surface is deduced from the vertical flux measured at a height above the surface. The vertical flux needs to be constant with height and this in turn requires stationarity of the mixing ratios with time and in space along the footprint within the measurement period to avoid the effects of storage and advection contaminating the measured flux. Such conditions are hard to satisfy in urban areas, close to spatially and temporally variable sources of pollutants. In addition, in urban areas it is difficult to identify a particle metric that only undergoes deposition, these are areas in which the sources are much larger than the sinks, and most reported vertical flux measurements within urban areas to date are dominated by emissions (e.g. Dorsey et al 2002).
Large areas of uniform vegetation make it possible to deduce the effects of specific processes on the exchange processes, such as the response of changes in stomatal conductance on vertical exchange fluxes. The practical and theoretical difficulties of making and interpreting flux measurements of pollutant gases or particulate matter in urban areas prevented significant measurements in urban areas until quite recently (Nemitz et al 2008).
For the gaseous pollutants, the only measurements of urban fluxes have reported net emissions rather than deposition (Velasco et al 2009, Vaughan et al 2016). There are few mechanisms by which dry deposition rates of the major pollutant gases to vegetation would be expected to differ substantially between urban and rural areas because the main restriction to transfer is at the surface, characterised by surface resistance. The added complexity of flow regimes in urban areas will probably lead to small underestimates of deposition fluxes, especially for the very reactive gases (notably HNO3) but for those gases relying on stomatal deposition pathways for uptake (NO2) and for those which exhibit a cuticular resistance which is at least an order of magnitude larger than the aerodynamic resistance (e.g. for O3) deposition velocities from the wider literature appear appropriate. In the case of HNO3 this very reactive species appears to deposit as quickly as the diffusional processes are able to deliver molecules to the surface, and adding substantial areas of absorbing surfaces per unit land area are likely to appreciably enhance removal rates.
However, HNO3 is an exception and is a minor component of urban NOy (NOy = the sum of all oxidized nitrogen compounds, NO, NO2, HONO, HNO3 PAN…). For NO2, deposition rates on vegetation are quite small relative to other gaseous pollutants (SO2, O3, NH3), and the process is restricted to stomatal uptake, thus are smallest in winter and night periods when vegetation removes negligible amounts of NO2 and when urban NO2 concentrations are largest (Fowler et al 2009). Vegetation is therefore generally considered an inefficient sink for urban NO2. This said, some studies have found that plant species differ greatly in their capacity to assimilate nitrogen from gaseous NO2 (e.g. Morikawa et al 1998), but the study was not set up to quantify the NO2 removal rate from the atmosphere and it cannot currently be concluded that “NO2-phyllic” plant species provide an efficient sink, especially during the conditions of high NO2 pollution. It nevertheless suggests that through careful selection of plant species, the benefit may be maximised. Vegetation is also a very poor sink for nitric
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oxide (NO), with deposition velocities substantially smaller than 1 mm s-1, and soils, in particular forest soils, act as sources of NO, emission from soils at least partially offsetting any benefits of uptake by vegetation of NO2 from the air.
Lichens and moss have been used as passive collectors of pollutants, especially for metals and to a lesser extent nitrogen compounds (Barqaqli et al 2002) and have proved useful to map the spatial pattern of metal deposition to moss and to detect hot spots. However, the method does not quantify the overall deposition to other surfaces (taller vegetation, soil, etc.), because moss accumulates pollutants at a different rate than the vegetation canopy as a whole, and it requires calibration with other methods to provide deposition estimates to the landscape.
Measurements of aerosol fluxes over urban areas by eddy covariance methods have been used to quantify aerosol fluxes (Dorsey et al 2002, Nemitz et al 2008, Zalakeviciute et al 2012, Deventer et al 2015). These studies show that urban areas are primarily a net source, rather than a sink for particulate matter.
Measurements above closed urban forest canopies are rare. Particle deposition on a ‘peri- urban’ forest has been measured by eddy covariance by Fares et al (2016) who showed deposition velocities up to 10 cm s-1 in the 3 hours centred on mid-day, but much smaller values at other times of day. The measurements were made at a site 25 km from Rome with the flux footprint being entirely within an area of vegetation dominated by holm oak. Thus these measurements are not really in an urban area, and so do not reveal the effects of vegetation within an urban environment on city scale deposition rates.
Measurements of particle deposition have also been made using radioactive tracer methods by Graunstein and Turekian (1989) in which the inventory of 210Pb (half-life 22.3 years) in surface soil horizons of organic matter is used to deduce the long-term average flux to the surface. The 210Pb in the atmosphere arises from the radioactive decay of Radon (222Rn) emitted from soil as a gas. In the atmosphere, the 222Rn decays through a series of very short lived daughters to 210Pb and is transformed from a gas to a particle, which in turn attaches within a minute or so to existing particulate matter (Chamberlain, 1991). Thus the 210Pb effectively tags particulate matter in the atmosphere and also in the soil. The inventory of 210Pb in soil when in equilibrium with atmospheric input provides a measure of the long- term average flux. As the half-life is 22.3 years, the soil needs to be undisturbed and land use constant for 50 years or more to bring the system to equilibrium. However, the benefit of the method is that it integrates the deposition events over many decades, and provides a long-term average deposition rate for the site.
The method was applied by Fowler et al (2004) at a range of sites in the West Midlands conurbation, measuring rates of particle deposition onto grassland and small pockets of mixed woodland close to urban development in Moseley, Edgbaston and Sutton Park.
The sites were chosen to span a wide range of locations in the West Midlands urban area, but the requirement for sites with undisturbed soils for 50 years or more is quite restricting in an urban area. The results, shown in Table 2, show the enhancement in deposition of particulate matter in woodland, relative to grassland. Clearly, the large height and aerodynamically rough surfaces of woodland capture particulate matter by dry deposition at approximately three times the rate of shorter grass surfaces. Further, these measurements
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provide deposition velocities that can be used in models to simulate effects of additional woodland within an urban area on deposition.
Site Sutton Park Edgbaston Moseley Average ……………………………………………………………………......
Grass
Dry Deposition 24 21 17 (Bqm-2a-1)
Deposition velocity 3.8 3.3 2.8 3.3 mm s-1
Woodland
Dry Deposition 45 60 67 (Bqm-2a-1)
Deposition velocity 7 9.4 10.7 9 mm s-1
Table 2. Dry deposition of deposition velocities of 210Pb aerosols on grassland and woodland in the West Midlands conurbation (from Fowler et al 2004)
4.3 Modelling effects of trees in urban areas The evidence so far suggests that planting more trees in an urban area will increase deposition rates of particulate matter. The next step is to quantify the scale of the reduction in ambient concentrations for a specified increase in tree cover in UK conurbations. Such exercises have been explored using dispersion models over UK cities by McDonald et al (2007), and by Bealey et al (2006) and for a more complex treatment of vegetation covering building surfaces (green walls) within urban street canyons by Pugh et al (2012) and by Jeanjean et al (2017).
The approach by McDonald et al was to use a multi-layer trajectory model to simulate the emission, transport and deposition of particulate matter in two large conurbations, the West Midlands and Glasgow. For both conurbations detailed land use information was available, and in the West Midlands a separate study identified the species composition and location of the urban tree population and the locations for new planting throughout the urban area (Donovan 2003). The deposition parameters were taken from measurements over moorland and grassland (Nemitz et al 2002) and closed forest (Gallagher et al 1997) and the scenarios simulated included removing all existing trees, and planting 25%, 50% 75% and 100% of the future planting potential throughout the area.
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Modelled concentration and deposition changes due to tree planting for the West Midlands
Concentration Deposition
-3 Average µg m % change Primary PM10
Primary PM10 of Primary PM10 tonnes % change
Status Quo 2.3 n/a 575 n/a
No trees 2.4 4 536 -7
FPP25 2.1 -10 685 19
FPP50 1.9 -17 747 30
FPP75 1.8 -22 773 34
FPP100 1.7 -26 774 35
Table 3: Modelled concentration and deposition changes for the West Midlands as a consequence of tree planting in 6 scenarios, (From McDonald et al 2007). (FPP refers to the Future Planting Potential and the subscript 100 means that ALL open space not already covered by hard surfaces is planted)
The results (Table 3) for the West Midlands show that current tree cover is responsible for removal of 7% of the primary particulate deposition and reduces the concentration by 4%. By planting 100% of the potential maximum, the concentrations of primary PM10 are reduced by 26%. It must be appreciated that planting all available space in a city is not practical or desirable, and even the least ambitious planting scheme (FPP25 meaning 25% of the area available for planting is used), would include planting important amenity areas (gardens, parkland), and would reduce concentrations of primary PM10 by 10%. The exercise does however quantify the scale of the effect of vegetation on concentration and deposition of the primary emissions within the conurbation.
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Modelled concentration and deposition changes due to tree planting for Glasgow
Concentration Deposition
-3 Average µg m % change Primary PM10
Primary PM10 of Primary PM10 tonnes % change
Status Quo 1.26 n/a 72 n/a
No trees 1.30 3 67 -7
FPP25 1.23 -2 76 6
FPP50 1.21 -4 80 11
FPP75 1.19 -6 83 14
FPP100 1.17 -7 85 18
Table 4: Modelled concentration and deposition changes for Glasgow (From McDonald et al 2007)
For Glasgow, the model shows that current tree cover removes 3% of the primary PM10 and that by planting all available areas of the city the average primary PM10 concentration would be reduced by 7%. (Table 4). Again taking a more realistic planting scenario (25% of the maximum) reductions in the primary PM10 would be 2%.
Because deposition rates were taken from woodlands, the results reflect the effect of introducing closed urban woodlands into the urban matrix, rather than small groups of trees or individual trees. More detailed modelling of the interactions within the street canyons would be required to quantify the effect of the latter, which is computationally expensive and has been applied to relatively small areas to date. Using a street canyon focussed study with or without green-walls Pugh et al (2012) showed that the vegetation could appreciably reduce local concentrations.
These modelling studies quantify the effect of tree planting on primary PM10, but the nature of the modelling did not allow the larger scale sources of PM10 outside the city to be fully quantified. Furthermore, the sources of PM10 from outside the urban area, and including long range transported material from continental sources frequently contribute a large fraction of the PM10 in urban areas (e.g. Keuken et al 2013). The deposition processes operate in exactly the same way, but the atmospheric boundary layer, which in daytime conditions is often 1000m or more deep is not as efficiently scavenged by deposition to the surface as the primary urban emissions. Thus the values presented for the efficiency of vegetation in removing PM10 are overestimates. Further, more detailed modelling is required to provide the extent of the overestimation. A modelling study of the effectiveness of urban vegetation in reducing PM2.5 concentrations by Jeanjean et al (2017), using CFD approaches over a
2km x 2km area of central Leicester showed that the dispersive effect of trees reduced PM2.5
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concentrations by 9% while dry deposition to the trees reduced concentrations by 2.8%. Thus modelling and measurement approaches provide broadly consistent reductions in concentrations of particulate matter. Consideration of local ‘micro-scale’ interventions, using planters or living walls on local exposure have not been studied in detail but the same principles apply and are unlikely to offer significant benefit except very close to the absorbing surface in calm conditions. Given the scale at which planting is practical, the scale of mitigation of exposure to PM10 (or PM2.5) in urban areas is unlikely to exceed a few percent.
While the use of the naturally occurring radioactive tracer is valuable in quantifying the additional dry deposition of particulate matter by tree canopies, there is additional evidence of the effect of the trees in capturing particulate matter from additional measurements at the West Midlands sampling locations noted above. Atmospheric lead in particulate matter from vehicle emissions in the pre lead-free petrol days and a range of other metal processing industries has accumulated in organic matter in soils of most cities, and the additional filtering by trees leads to the accumulation of large concentrations in the surface soils in these areas. The particle deposition studies in the West Midlands reported above revealed concentrations of Pb in surface soil in the range 100ppm to 400 ppm (Table 5). The proximity of the largest Pb values to major roads strongly suggests traffic as the main source. The concentrations of other heavy metals were also enhanced in soils beneath woodland at the measurement sites (Table 5).
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Table 5: Heavy metal concentrations in soils of the West Midlands (From Fowler et al 2004)
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5 Biogenic volatile organic compound emission from urban tree planting
5.1 Introduction Natural or biogenic emissions of volatile organic compounds (BVOCs) from vegetation are the dominant global source of reactive carbon in the atmosphere (Goldstein and Galbally, 2007). The most abundant BVOC is isoprene, but many hundreds of other VOCs are also emitted by vegetation (Guenther et al. 1995). Other classes of BVOCs include monoterpenes, (C10 hydrocarbons, those with 10 carbon atoms in a molecule), sesquiterpenes (C15) and di-terpenes (C20), green leaf volatiles such as hexanol and hexenel, and small oxygenated compounds including acetone and methanol. In general terms the atmospheric reactivity of biogenic hydrocarbons is higher than hydrocarbons emitted from fossil fuel combustion processes (Carter, 1994).
The atmospheric oxidation of BVOCs, when in the presence of nitrogen oxides, leads to the formation of ozone. The secondary organic oxidation products formed on oxidation can also form new particles or condense to existing PM. The potential urban air quality impacts of BVOCs have been known for many years, see for example estimates of the BVOC contribution to ozone in US cities by Rasmussen (1972), Chameides et al. (1988) and Geron et al. (1995).
5.2 Considerations for urban tree planting Any practical policy interventions that substantially increase the vegetative cover in an urban environment should pay due attention to the potential effects that may arise from changes in emission of BVOCs and the consequential impacts on ozone and PM arising. BVOCs participate in the same atmospheric chemical degradation processes as anthropogenic
VOCs, reacting primarily with OH but also O3, and with NO3 during the night. Their rates of reaction with these oxidants are often faster than comparable carbon number fossil fuel aliphatic hydrocarbons, a consequence of weak and accessible hydrogen double bonds in BVOCs. In turn their atmosphere lifetimes are often therefore shorter than anthropogenic hydrocarbons. In the case of some sesiquiterpenes and diterpenes (C15 and C20 structures) reaction with O3 is so fast that their lifetimes in the atmosphere can be as short as a few minutes or less. The most abundance biogenic VOC isoprene has a daylight lifetime in summer of around 20-30 minutes. When considering impacts of tree planting and changes to VOCs it is important therefore to consider not only any changes to the total mass of VOC that the additional trees may release but the atmospheric reactivity of those VOCs. In general terms higher reactivity VOCs have the potential to generate higher concentrations of secondary pollutants closer to the point of emission.
Even given the reactivity of many BVOCs the formation of ozone or generation of secondary aerosols is not instantaneous, and the majority of effects from additional BVOC emissions would occur some distance downwind, with regional increases in air pollution rather than substantial BVOC-induced changes in urban centres themselves (see for example Mackenzie et al. 1991). These spatial effects of urban emissions of BVOCs are illustrated by Nowak et al. (2000), who modelled that changing tree coverage in cities (from 20 to 40%) led
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to modest decreases in urban ozone (~1 ppb) and increases (0.26 ppb) in the wider regional domain.
The emission rate of BVOCs from trees and plants increases with ambient temperature, or both temperature and photosynthetically active radiation (PAR) (Geron et al. 1994), with highest BVOC emission rates generally associated with trees in warm climates. Emission rates, and the response to temperature and PAR vary greatly, even between trees of very similar species. “Wounding events”, such as grass cutting and crop harvesting, also give rise to BVOC emissions (including aldehydes, ketones and alcohols). Such sources can be relevant for rural ozone formation, but are unlikely to be large enough to make a significant contribution to a city centre environment. In general terms BVOC emissions from most plant species are low below 20 °C, with peak emission rates at around 35 °C before plateauing and then declining above 40 °C. Previous literature has focused in particular on BVOC - air quality interactions in US cities such as Houston, Los Angeles and Atlanta and also in the Mediterranean, locations with high mean summertime air temperatures and substantial regional vegetation.
The temperate nature of the UK climate has meant that historically BVOCs have not been considered a substantial contributor to overall VOC emissions or consequential ozone production. Owen et al. (2003), made an estimate of BVOC emissions for various landscape types in the West Midlands, apportioning land-cover to trees and other vegetation and then assigning emissions based on known species type. The conclusion was that under conditions of the study period and region, BVOCs were a very minor contributor (< 1%) to overall UK VOC emissions, when considered on an annual basis. It is worth noting that since that study anthropogenic VOCs have declined further and the fractional contribution from BVOC is likely to have increased.
Stewart et al. (2003) generated the first UK BVOC emissions inventory. This required the assignment of BVOC emission rates and response curves to more than 1,000 plant species, combined with highly detailed and spatially resolved vegetation cover data for the UK. Results from this study concluded that Sitka spruce species were the dominant source of BVOCs in the UK as a whole, with emissions arising predominately from coniferous areas in Northern England and Scotland. Stewart et al. also identified poplar (Populus spp.) as a notable isoprene source in eastern England. The peak in both isoprene and monoterpene emissions was estimated to be in the summer months in this inventory based on established temperature and PAR relationships.
The current influence of BVOCs on the UK atmosphere is not straightforward to discern directly since there are very few observations that allow for a quantification of BVOC abundances or emissions. The Defra Automatic non-methane hydrocarbon network has collected a long time-series of VOCs that includes isoprene, but the more extensive diffusion tube network does not include any BVOC measurements. In many urban locations the majority of urban isoprene can be attributed to fuel and combustion sources, evident through the close correlations with other combustion tracers such as 1,3-butadiene. However in the summer months a second uncorrelated temperature dependent source of isoprene has been detectable in the UK, becoming most obvious on the warmest days. This has been strongly indicative of an existing vegetative isoprene source in most UK cities (von Schneidemesser et al. 2011). Fluxes, as well as concentrations, of isoprene were measured in central London by Valach et al. (2015) between August and December 2012. In August and September,
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measured isoprene fluxes correlated strongly with temperature and PAR, and the magnitude of the fluxes agreed well with model predictions of the urban biogenic emissions.
The scale of possible impacts of BVOCs on UK ozone were studied in some detail following the warm summer of 2003, a year which is often taken as a proxy for potential summertime conditions in future climate scenarios with increased anticyclonic blocking. 2003 had extended multi-day periods where the UK urban environment was more similar in climate to BVOC-air quality conditions from North America, with daytime ozone reaching mixing ratio of 100 ppb and air temperature >30 °C. Lee et al. (2006) reported isoprene concentrations of > 2 µg m-3 in South East England during the hottest days of August 2003, more than 10 times the typical mean UK summertime values. Vieno et al. (2010) reported a modeling study of the same event which showed that model performance simulating UK BVOCs was in general good, but with increasing underestimates of BVOC emissions at higher temperatures, and up to a factor of 5 too low on the hottest day studied.
There are very few atmospheric observations of monoterpenes in a UK urban context. Dunmore et al. (2015) observed a constant background of around 20 ppt α-pinene in central London during UK winter, but a temperature-dependent diurnal profile during summertime, with peak daytime values of around 150 ppt. During the wintertime BVOCs contributed around 1% of the total primary OH reactivity to organic compounds (around 0.025 s-1); this value increased to around 10% of organic-OH reactivity during the summertime (~ 0.5 s-1, out of a total ~5 s-1) in central London at the North Kensington AURN site.
There is evidence therefore to show that BVOCs from trees are already present in the UK urban environment, and most abundant on the warmest days in summer. Their contribution to the urban OH reactivity is however currently very small compared to the effects from anthropogenic VOCs. Vieno et al. (2010) varied ambient temperature by up to 5°C as a means to drive changes in BVOC across the UK in the EMEP air quality model. This found incremental regional ozone changes no greater than 10 ppb, and with the majority of ozone deriving from trans-boundary sources (although that trans-boundary ozone had a continental BVOC contribution). Donovan et al. (2005) reported regional-scale simulations of air quality changes under a range of different vegetation and climatic scenarios in the UK. Under the most extreme scenarios where there were substantial urban and regional increases in the number of high BVOC emitting trees in the UK, coupled with an average 2°C temperature increase, incremental increases in regional ozone of 6% were simulated. Where low BVOC- emitting trees were planted instead, the simulation showed reductions of the order 1-2% in ozone, even under +2 °C temperature scenarios.
Whilst the potential impacts on regional ozone from an increase in the density and number of trees in cities appears in principle small, the size and sign of the effect is clearly dependent on the type of vegetation planted. The emissions of BVOCs from different species vary over several orders of magnitude, and indeed many plant types have no measureable BVOC emissions at all. For example, perennial rye grass is the most abundant vegetation type by peak biomass in the UK and it has no measureable BVOC emissions (Hewitt and Street 1992). There is huge reported variation in emissions from different tree types. For example oak is estimated to have approximately ten times the isoprene emission potential of Sitka spruce, when expressed as kg BVOC emissions per kg dry weight of biomass per unit time.
If all other environmental factors are unchanged (e.g. temperature, rainfall, CO2 etc.) then
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BVOC emissions can to some degree be controlled by manipulation of land-cover and vegetation type through the selection of low emitting species.
Benjamin and Winer (1998) made a comprehensive assessment of the ozone impacts arising from different tree species in California, covering more than 300 different varieties. Whilst many of these species are unlikely to be relevant for tree planting in a UK context, it is illustrative of the potential range of impacts that different tree selections might have. Using local atmospheric conditions and literature BVOC emission values Benjamin and Winer estimated a mass formation of ozone per tree per day. The highest potential was from oil -1 -1 palm (Elaeis guineesis) at more than 400 gozone tree day , followed by weeping willow (134 g tree-1 day-1 and coast live oak (114 g tree-1 day-1). In broad terms palms, willows, eucalypts, gums and oaks all had high ozone forming potential from their BVOC emissions. In contrast almost 100 tree species were estimated to have no ozone forming potential since they had no measurable BVOC emissions (for example species such as juniper, myrtle, hickory and walnut). The potential ozone changes induced by these low-emitting species would likely then be net negative through ozone deposition and removal, although this wasn’t quantified in the study. The study does highlight that there are far more variety of tree that are low BVOC-emitting than high.
Donovan et al. (2005) made an assessment of the impacts on air quality arising from changing the tree coverage in the West Midlands and in different temperature scenarios. Although not explicitly quantifying the relative BVOC emissions potential from each species, it can be inferred from the resultant ozone changes calculated for a particular tree type scenario. From a BVOC emissions perspective English oak, white willow, aspen, sessile oak, red oak and goat willow were modelled as having the highest emissions, with an increase in ozone detectable in the regional domain (range +0.8 to + 2.9%), whilst planting species such as Austrian pine, larch, silver birch and maple led to small (0.3 – 0.8%) reductions in regional ozone, since BVOC emissions were insignificant and the trees act as a surface for enhanced deposition.
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6 Summary In summarising the effects of urban vegetation on ambient concentrations of particulate matter and gaseous pollutants, there are potential benefits of vegetation in changing dispersion and deposition processes and also potential problems. For dispersion, locally (tens to hundreds of square metres) the planting of trees may enhance or reduce dispersion; this redistributes pollution but does not remove it. Where vegetation acts as a barrier close to a source, concentrations immediately behind the barrier owing to that source are reduced typically by a factor of about 2 relative to those which would occur without the barrier, whereas on the source side of the barrier concentrations are increased.
Effects of vegetation removing pollutants from urban air by deposition, and thereby reducing concentrations and population exposure to particulate matter have been demonstrated in field measurements and using models. However, the magnitude of the reduction in concentration by realistic planting schemes, using trees, is small and in the range 2% to 10% for primary PM10 and ambitious plantings. For practical planting schemes and PM from all sources, the scale of reductions is expected to be no more than a few percent. For NO2, vegetation is not a very efficient sink, and as the deposition occurs in daytime, and primarily in the warmer months, there is little benefit for air quality for most of the time that NO2 is a problem.
BVOC are already present in small amounts in UK cities from existing vegetation emissions, and are highest during warm summer weather. At present regional BVOC emissions from the UK make only very minor contributions to ambient ozone, and the specific contribution from city centre vegetation is too small to be isolated in modelling studies. Increasing tree cover in cities has the potential to increase BVOC emissions, with impacts felt through small increases in ozone and possibly aerosols downwind. The reactivity of BVOC emissions can be higher than similar carbon number fossil fuel derived VOCs and this reactivity should be considered (and minimised) along with any potential change in total mass of VOC emissions. Of potential relevance to UK planting, oak, aspen and willow species should be avoided since these are estimated to being highest BVOC emitting species. The potential ozone increase from additional urban tree planting appears entirely avoidable however through selection of low BVOC emitting species, of which many varieties are reported in literature.
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7 Valuing the benefits of vegetation as a sink for air pollutants The UK office of National Statistics has in recent years estimated the value of natural capital as a way of measuring economic progress. Within this exercise the asset value of UK woodlands for the filtration of atmospheric particulate matter (PM10) and SO2 was for the first time included in ONS-Defra statistics and valued at £4.5 billion in 2012, creating a total asset value of £114 billion (AECOM, 2015). The exercise was useful in recognising an important property of vegetation. However, the very simplistic approach used to value this ecosystem service was subject to considerable uncertainty.
A follow-up study (Jones et al., 2017) developed a more sophisticated approach for valuing the service, based on a Chemistry and Transport Model (CTM), now comparing the effect of deposition to vegetation to that of bare soil. This approach takes account of chemical interactions, the interaction with wet deposition, and enables a more direct impact valuation based on human exposure rather than on the amount removed. It also extended the approach to additional pollutants (PM2.5, NH3, NO2, O3, PM2.5). Assessments were carried out for 2007, 2011, 2015 and, based on emission projections, with 2015 meteorology, for 2030.
It should be noted that overall, vegetation was estimated to have a detrimental net effect on
NO2 concentrations. The prime reason is likely that vegetated soils present a larger source of soil nitrogen oxides (as NO) than bare (desert) soil. There might have been other effects which were not quantified in isolation, such as interactions with changes in biogenic volatile organic compounds and O3.
Overall, UK vegetation is estimated to remove 1,354 ktonnes of PM2.5, SO2, NO2 and O3, with an annual value of £1.00 billion (2015, at 2012 prices), presenting an asset value of £34.5 billion (2015, incl. income uplift). The study also developed initial, more detailed accounts, for urban areas.
The study suggested that for 2015, the total existing UK vegetation reduces the average annual surface concentration by about 10% for PM2.5, 6% for PM10, 13% for O3, 24% for NH3 and 30% for SO2, but did not markedly change NO2 concentrations. Woodland dominated the removal of PM, whilst agricultural land (accounting for 4.3 times as much land area), dominated the removal of gaseous pollutants.
Whilst the overall amount of pollutant removed was broadly consistent with an alternative approach, i-tree Eco London study (Rogers et al., 2015) that assessed the value of trees in London only, but the split across pollutants differed significantly. This is partly due to difficulties in comparing a national with a much more regional estimate, which is dominated by a different land cover. It also reflects differences in how deposition is calculated in the two studies, each approach with some advantages and disadvantages. The i-tree study used a more detailed tree cover database which is not available for the whole of the UK and includes parameterisations to deal with smaller woodland features and single trees. By contrast, it fails to reproduce the feedback of pollutant removals on concentrations downwind in a way a CTM can. There are also important uncertainties in the parameterisations of deposition between CTMs. For example, in a European study Flechard et al. (2011)
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demonstrated that deposition estimates of nitrogen compounds can vary by a factor of 3 for
NH3, 7 for NO2 and 10 for aerosol, depending on the approach used.
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Stewart, H.E., Hewitt, C.N., Bunce, R.G.H., Steinbrecher, R., Smiatek, G., and Schonemeyer, T. (2003). A highly spatially and temporally resolved inventory for biogenic isoprene and monoterpene emissins: Model description and application to Great Britain. Journal of Geophysical Research (Atmospheres), 108, D20, 4644.
UK-GOV, Air quality benefits of vegetation. Available at: https://www.ons.gov.uk/economy/environmentalaccounts/bulletins/ukenvironmentalaccounts/ 2016/previous/v1#air-pollution-absorption-estimates and Annex: https://www.ons.gov.uk/economy/environmentalaccounts/methodologies/annex1background andmethodsforexperimentalpollutionremovalestimates
Valach, A. C., Langford, B., Nemitz, E., MacKenzie, A. R. and Hewitt, C. N. (2015). Seasonal and diurnal trends in concentrations and fluxes of volatile organic compounds in central London, Atmospheric Chemistry & Physics, 15, 7777-7796.
Velasco. E. Pressley. S. Grivicke R. Allwine E. Coons T.. Foster W. Jobson B.T. Westberg.H.. Ramos R., Hern´andez H, Molina. L, and Lamb. B. Eddy covariance flux measurements of pollutant gases in urban Mexico city 2009 Atmos. Chem. Phys., 9, 7325– 7342, 2009
Vesala.T, Kljun N, Rannik U, J. Rinne A. Sogachev a, T. Markkanen a,c,K. Sabelfeld d,e, Th. Foken c, M.Y. Leclerc 2008 Flux and concentration footprint modelling: State of the art Environmental Pollution 152 (2008) 653e666
Woodland Trust (2012). Urban air quality. Retrieved from https://www.woodlandtrust.org.uk/mediafile/100083924/Urban-air-quality-report-v4-single- pages.pdf
Vieno, M., Dore, A.J., Stevenson, D.S., Doherty, R., Heal, M.R., Reis, S., Hallsworth, S., Tarrason, L., Wind, P., Fowler, D., Simpson, D., and Sutton, M.A. (2010). Modelling surface ozone during the 2003 heat-wave in the UK. Atmospheric Chemistry & Physics, 10, 7963- 7978. von Schneidemesser, E., Monks, P. S., Gros, V., Gauduin, J. and Sanchez, O. (2011) How important is biogenic isoprene in an urban environment? A study in London and Paris. Geophysical Research Letters 38, L19804, DOI:10.1029/2011GL048647.
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Zalakeviciute. R,. Alexander. M.L., Allwine. E., Jimenez. J.L., Jobson. B.T., Molina. L.T., Nemitz. E.,. Pressley. S.N., VanReken. T. M., Ulbrich. I.M., Velasco7, and Lamb. K. 2012 Chemically-resolved aerosol eddy covariance flux measurements in urban Mexico City during MILAGRO 2006 Atmos. Chem. Phys., 12, 7809–7823, 2012 www.atmos-chem- phys.net/12/7809/2012/ DOI:10.5194/acp-12-7809-2012
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UK plan for tackling roadside nitrogen dioxide concentrations An overview
July 2017
1
© Crown copyright 2017
You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence v.3. To view this licence visit www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ or email [email protected]
This publication is available at www.gov.uk/government/publications
Any enquiries regarding this publication should be sent to us at
Joint Air Quality Unit Area 2C Nobel House 17 Smith Square London SW1P 3JR Email: [email protected] www.gov.uk/defra
2 Contents
The government’s ambition for a better environment and cleaner air ...... 4
What the government is doing to deliver clean air ...... 4
Although air pollution has improved, it still poses an urgent health problem...... 5
The government’s solution ...... 7
Delivering cleaner air in the shortest time possible...... 9
Impact on individuals ...... 10
Making the UK a global leader in air quality ...... 11
3 The government’s ambition for a better environment and cleaner air 1. We pledge to be the first generation to leave the environment in a better state than we inherited it.
2. Clean air is one of the most basic requirements of a healthy environment for us all to live, work, and bring up families. Whilst air quality has improved significantly in recent decades, and will continue to improve thanks to the action we have already taken, there are some parts of our country where there are unacceptable levels of air pollution. This can come from a range of different sources and activities. Many everyday activities such as industrial processes, farming, transport, generating energy and heating homes can have a detrimental effect on air quality. This is a problem we need to tackle.
What the government is doing to deliver clean air 3. The government has already taken significant action to improve air quality. The UK was the first country in the world to announce in 2011 our intention that conventional car and van sales would end by 2040, and for almost every car and van on the road to be a zero emission vehicle by 2050. The UK is already a leader in Europe in terms of electric vehicle manufacture and uptake. In 2016 UK manufactured Nissan Leafs accounted for almost 20% of battery electric car sales across Europe and the UK had the highest sales of battery electric vehicles and plug-in hybrids in the EU.
4. We are already committed to investing over £2.7 billion overall in air quality and cleaner transport. This includes:
• £1 billion – ultra low emission vehicles (ULEVs). This includes investing nearly £100m in the UK’s charging infrastructure and funding the Plug In Car and Plug In Van Grant Schemes.
• £290 million – National Productivity Investment Fund. In the Autumn Statement 2016, a further £290 million was committed for reducing transport emissions which includes £60 million for new buses and £40 million for bus retrofits, £50 million for a Plug In Taxi programme and £80 million for ULEV charging infrastructure.
• £11 million – Air Quality Grant. We have awarded over £11 million under our Air Quality Grant scheme to help local authorities improve air quality. • £89 million – Green Bus Fund. The UK government has invested a total of almost £89 million via the Green Bus Fund to help bus companies and local authorities in England to put over 1,200 new low carbon buses on the roads.
• £27 million – Clean Bus Technology Fund and Clean Vehicle Technology Fund. Since 2013, government has awarded over £27 million to retrofit almost 3,000 of the oldest vehicles (mainly buses) including through the Clean Bus Technology Fund and the Clean Vehicle Technology Fund.
• £1.2 billion – Cycling and walking. In April 2017, the UK government published its Cycling and Walking Investment Strategy which identifies £1.2 billion which may be invested in cycling and walking from 2016-2021.
• £100 million – National road network. Through the Road Investment Strategy, the UK government has allocated a ring-fenced £100 million for an Air Quality Fund available through to 2021 for Highways England to help improve air quality on its network.
5. We are developing further measures and will set these out in:
a. the Clean Growth Plan which the Department for Business, Energy and Industrial Strategy will bring forward in the autumn.
b. a further strategy on the pathway to zero emission transport for all road vehicles to be published by March 2018.
c. a wider Clean Air Strategy in 2018 setting out how we will meet our international commitments to significantly reduce emissions of five damaging air pollutants by 2020, and 2030.
Although air pollution has improved, it still poses an urgent health problem 6. The shift to ultra-low and zero emission vehicles is well under way, and will continue to gather pace over the coming years as we move towards 2040, by which point the government will end the sale of all new conventional petrol and diesel cars and vans. This shift will resolve our air quality problem as combustion engines gradually disappear from the streets of our towns and cities, some as soon as the early 2020s. However, this will not happen quickly enough and the impact that air pollution continues to have on the health of this nation means we must do more, sooner.
7. We therefore have a clear ambition and policy agenda to improve air quality, backed up with significant investment. Air quality has improved significantly in recent decades. Since 1970 sulphur dioxide emissions have decreased by 95%, particulate matter by
5 73%, and nitrogen oxides by 69%. Total UK emissions of nitrogen oxides fell by a further 19% between 2010 and 2015.
8. However, poor air quality persists in certain areas of the country as a direct result of the failure of the European regulatory system to deliver expected improvements in vehicle emissions. Standards on vehicle engines (known as “Euro Standards”), which should
have led to major reductions in emissions of nitrogen dioxide (NO2) from vehicles, failed to deliver, particularly for diesel vehicles, whose “real world” emissions have proven to be many times higher than laboratory tests. Diesel vehicles on our roads are causing harmful emissions far above what was assumed and contributing to pollution levels that continue to be damaging to public health. Additionally, the Volkswagen scandal showed that deliberate cheating of the emissions tests was built into some vehicles. If those Euro standards had delivered as they were supposed to, we would by now have most of the UK within the legal air quality limits. We need to take specific further action in order to address the immediate health risks presented by poor air quality in particular parts of the country. 9. There is increasing evidence that air quality has an important effect on public health, the economy, and the environment. According to Public Health England, poor air quality is the largest environmental risk to public health in the UK1. Evidence from the World Health Organization (WHO) shows that older people, children, people with pre- existing lung and heart conditions, and people on lower incomes may be most at risk2.
10. Evidence collated by Defra, Public Health England and the Local Government Association3 shows that short-term exposure to high levels of air pollution can cause a range of adverse health effects including exacerbation of asthma, effects on lung function, increases in hospital admissions and mortality. A review by the World Health Organization concludes that long-term exposure to air pollution reduces life expectancy by increasing deaths from lung, heart and circulatory conditions. There is emerging evidence from the Royal College of Physicians (amongst others) of possible links with a range of other adverse health effects including diabetes, cognitive decline and dementia, and effects on the unborn child4 5.
11. As well as having an effect on life-expectancy, air quality also impacts other aspects of health, productivity and wellbeing. Although it is difficult to quantify the economic impact of poor air quality with precision, research commissioned by Defra estimated
1 Public Health England, ‘Estimating local mortality burdens associated with particulate air pollution’, 2014, www.gov.uk/government/publications/estimating-local-mortality-burdens-associated-with-particulate-air-pollution
2 World Health Organization, ‘Review of evidence on health aspects of air pollution – REVIHAAP Project’, 2013 http://www.euro.who.int/__data/assets/pdf_file/0004/193108/REVIHAAP-Final-technical-report-final-version.pdf?ua=1
3 www.local.gov.uk/sites/default/files/documents/6.3091_DEFRA_AirQualityGuide_9web_0.pdf
4 Ibid.
5 Royal College of Physicians ‘Every breath we take. The lifelong impact of air pollution’ (2016).
6 that in 2012, poor air quality had a total cost of up to £2.7 billion through its impact on productivity6.
12. In addition to affecting health, air quality also impacts the environment. Between 2013 and 2015, 44% of sensitive habitats across the UK were estimated to be at risk of significant harm from acidity and 63% from nitrogen deposition7. It has also been found that ozone effects ecosystems (by reducing carbon uptake and biomass in sensitive plants and trees) and on agriculture (where crop production has been found to be reduced by up to 9%)8.
13. Further research continues to improve understanding of the health, economic and environmental effects of air pollution, and although the evidence is subject to change, there is substantial evidence on the health impacts from particulate matter and there is a compelling and growing body of evidence on the effects from other pollutants particularly nitrogen dioxide.
14. We must take action now to tackle NO2 pollution. Air pollution predominantly affects those living in our major towns and cities due to the concentration of vehicles and other sources of pollution. This continues to have an unnecessary and avoidable impact on people’s health, particularly amongst the elderly, people with pre-existing lung and heart conditions, the young, and those on lower incomes.
The government’s solution
15. Unlike greenhouse gases, the risk from NO2 is focused in particular places: it is the build-up of pollution in a particular area that increases the concentration in the air and the associated risks. So intervention needs to be targeted to problem areas, fewer than 100 major roads which national modelling suggests will continue to have air pollution
problems in 2021, mostly in cities and towns. The effort to reduce NO2 also needs to be targeted on the sources that make the biggest contribution to the problem: road
vehicles contribute about 80% of NO2 pollution at the roadside and growth in the number of diesel cars has exacerbated this problem.
16. Given the local nature of the problem, local action is needed to achieve improvements in air quality. As the UK improves air quality nationally, air quality hotspots are going to become even more localised and the importance of action at a local level will increase. Local knowledge is vital to finding solutions for air quality problems that are suited to
6 Department for Environment, Food and Rural Affairs, ‘Valuing the impacts of air quality on productivity’, 2015, https://uk- air.defra.gov.uk/assets/documents/reports/cat19/1511251135_140610_Valuing_the_impacts_of_air_quality_on_productivity_Final_Rep ort_3_0.pdf
7 Based on a 2013-2015 three-year average. Department for Environment, Food and Rural Affairs, ‘Provision of Mapping and Modelling of Critical Loads and Critical Levels Exceedance 2016-19’, 2016.
8 Ozone factsheets produced by the Natural Environment Research Council, Centre for ecology and Hydrology and the Science & Technology Facilities Council are available at www.ozone-net.org.uk/factsheets
7 local areas and the communities and businesses affected. A leading role for local authorities is therefore essential.
17. But we also recognise the need for strong national leadership. We will set a clear national framework for the steps that local authorities need to take. We will provide direct financial support to enable local authorities to develop and implement their plans, and pursue national measures to reinforce their efforts. And we will require those local plans to be developed and implemented at pace so that air quality limits are achieved within the shortest time possible.
18. In developing their local plans to tackle the causes of air pollution, local authorities should consider a wide range of innovative options, exploring new technologies and seeking to support the government’s industrial strategy so that they can deliver reduced emissions in a way that best meets the needs of their communities and local businesses. Their plans could include a wide range of measures such as: changing road layouts at congestion and air pollution pinch points; encouraging public and private uptake of ULEVs; using innovative retrofitting technologies and new fuels; and, encouraging the use of public transport. If these measures are not sufficient, local plans could include access restrictions on vehicles, such as charging zones or measures to prevent certain vehicles using particular roads at particular times. However, local authorities should bear in mind such access restrictions would only be necessary for a limited period and should be lifted once legal compliance is achieved and there is no risk of legal limits being breached again.
19. We will help local authorities by:
• Setting up a £255m Implementation Fund, available to support local authorities to prepare their plans and deliver targeted action to improve air quality. This funding will support the immediate work to conduct feasibility studies and develop and deliver local plans. £40 million will be made available immediately to support local authorities to take action to improve air quality in the shortest time possible.
• Establishing a Clean Air Fund, which will allow local authorities to bid for additional money to support the implementation of measures to improve air quality. This could include interventions such as improvements to local bus fleets, support for concessionary travel and more sustainable modes of transport such as cycling, or infrastructure changes. These interventions could enable local authorities to avoid the imposition of restrictions on vehicles, such as charging zones. To ensure the Fund fits the specific needs of each local area there will be a competitive process through which local authorities bid for support. Further details will be announced later in the year.
• £100 million for retrofitting and new low emission buses. As announced in the 2016 Autumn Statement, the government will provide this funding for a national programme of support for low emission buses in England and Wales, including hundreds of new low emission buses and retrofitting of thousands of older buses.
8 The government believes that continued development, promotion and implementation of innovative retrofit technology will be an important element of
reducing emissions of NOx and will help bridge the gap in the journey towards zero emissions by 2050. At a local level, the UK government expects local authorities to consider the impact retrofitting could have on their pollution levels and meeting local air quality objectives. We will set out further plans for how local authorities can access this funding later in the summer.
20. The government is clear that we must maintain discipline on public spending. Measures to improve air quality will therefore be funded through changes to the tax treatment for new diesel vehicles, or through reprioritisation within existing departmental budgets. Further details on changes to the tax regime will be announced later in the year.
Delivering cleaner air in the shortest time possible 21. It is vital that action is taken in the shortest time possible to improve air quality in those areas where air pollution is above legal limits. The government has previously said that relevant local authorities will have up to 18 months to produce their plans. In order to inject additional urgency into this process, we will now require local authorities to set out initial plans 8 months from now, by the end of March 2018. These will be followed by final plans by the end of December 2018. To assist local authorities in meeting these timescales, we will ensure they can immediately draw on our Implementation Fund, as well as central government expertise.
22. Government will assess local plans to ensure they are effective, fair, good value, and deliver the necessary air quality compliance. Government will provide feedback on local authorities’ initial plans and will decide whether or not to approve final plans. A local plan will only be approved by government, and thus be considered for appropriate funding support, if:
a. it is likely to cause NO2 levels in the area to reach legal compliance within the shortest time possible;
b. the effects and impacts on local residents and businesses have been assessed, including on disadvantaged groups, and there are no unintended consequences; and,
c. proposals that require central government funding demonstrate value for money.
23. If the government deems a local plan not to be sufficient, we will require local authorities to implement the measures necessary in their area to deliver the necessary improvement in the shortest time possible.
9 Impact on individuals 24. This package of measures will support delivery of our obligations on air quality in the shortest time possible. We are clear, however, that this must be done in a way that does not unfairly penalise ordinary working families who bought diesel vehicles in good faith. This includes those people who purchased diesel vehicles following tax changes made by previous governments which focused on fuel economy and carbon dioxide
(CO2) emissions, rather than NO2 emissions.
25. Our evidence suggests that exceedances in NO2 are highly localised – limited, for the most part, to a few problem roads rather than an entire town or city centre. The plans put forward by local authorities should reflect this, ensuring that measures are carefully targeted to minimise their impact on local residents and businesses – and government will be scrutinising local authority plans on this basis.
26. Where there are no other viable options to reduce air pollution to legally-permissible levels in the shortest possible time, some local authorities may decide to introduce access restrictions on vehicles, such as charging zones or other measures to prevent certain vehicles using particular roads at particular times. The Mayor of London has already announced that the GLA will introduce new charges on those using diesel vehicles in central London. While local authorities may deem such action to be necessary, support should be available to the owners of affected vehicles.
27. We will not know the degree to which local plans will impact residents and individuals until local authorities come forward with their plans. In the meantime, the government will work with local authorities and others to consider how to help minimise the impact of such measures on local businesses, residents and those travelling into towns and cities to work where such action is necessary; and will issue a further consultation in autumn to aid development and assessment of options. The measures considered in that consultation will include options to support motorists: in particular private car drivers on lower incomes, or those who may have to switch to a cleaner vehicle. Options considered could include retrofitting, subsidised car club membership, exemptions and discounts from any restrictions, permit schemes for vans or concessionary bus travel.
28. A targeted scrappage scheme will also be considered in this consultation focussing on certain groups of drivers who most need support (such as those on lower incomes or those living in the immediate vicinity of a Clean Air Zone) and providing an incentive to switch to a cleaner vehicle.
29. Following the consultation on the draft Plan, it is clear that a number of issues remain with such mitigation options and in particular with scrappage schemes – analysis of previous schemes has shown poor value for the taxpayer and that they are open to a degree of fraud. We welcome views from stakeholders in the forthcoming consultation on whether it is possible to overcome these issues, alongside any wider options that should be considered. All proposals considered for government support would need to
10 demonstrate that support can be targeted to those who need it most and that any scheme could be delivered effectively with minimal risk of fraud or abuse. Proposals considered would also need to demonstrate that they offer clear value for taxpayer’s money. Finally, given all measures will be funded by relevant taxes on new diesel cars alongside existing departmental budgets, proposals put forward would need to be fair to the taxpayers who would fund any measures.
Making the UK a global leader in air quality 30. We want vehicle manufacturers to show that they can be part of the solution as well as the problem. The UK led the way in Europe in pushing for tough new type approval standards for cars and vans, including the ‘real world’ driving emissions tests that start to take effect from September this year, alongside tougher laboratory tests. We want to be absolutely sure that these new standards will deliver, and that we see a significant reduction in harmful emissions from new models of cars and vans.
31. These new standards have no effect on existing vehicles on the road, many of which – even some of the newest models – show harmful emissions levels many times greater than the test limits. We have set up a Market Surveillance Unit to increase the checks that we carry out to ensure that new and existing vehicles on UK roads meet the standards that they were approved to. We will continue to examine all steps that could be taken to ensure manufacturers rectify these failings.
32. As we leave the EU, we want the UK to be a world leader in low emission transport, and will look for opportunities to strengthen further the controls on vehicle emissions which deliver both for the environment and for drivers.
33. We will also move forward with the transition to cleaner technologies and electric vehicles. Our new Automated and Electric Vehicles Bill will enable the UK to retain its position as a global leader in the market for electric vehicles. This will allow the government to require the installation of charge points for electric vehicles at motorway service areas and large fuel retailers, and to make it even easier to use electric vehicle chargepoints across the UK. This drive towards cleaner technology and zero emission transport will be reinforced by both the Clean Growth Plan and the Industrial Strategy, including investment in science and innovation through the Industrial Strategy Challenge Fund.
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Liverpool City Region Combined Authority
Initial Air Quality Action Plan
November 2019
DRAFT FINAL – V7
FOR CONSIDERATION BY LCR CA – 1/11/19
1
CONTENTS
FOREWORD 2
1. The aim of this action plan 4
2. Recap - What do we already know?
a. Responsibilities 5
b. “Mandated” work on Clean Air Zones 6
c. Best practice 7
d. Building the evidence 8
3. The Action Plan - Short, medium and long-term:
a. Actions by the Combined Authority 12
b. Actions by the constituent local authorities and 18 partners, supported by the Combined Authority
c. Actions for the Liverpool City Region‟s residents, 20 communities and businesses
d. Actions for escalation nationally with central 21 government or its agencies
4. Next steps 23
2
DRAFT FOREWORD
Ensuring that everyone can breathe clean air is one of the most fundamental issues facing us today and an issue that we must all address, together.
Earlier this year the Liverpool City Region Combined Authority declared a climate emergency and addressing poor air quality is at the heart of responding to it.
Many of us will remember when the city region‟s finest buildings were blackened by the emissions from our coal-fired economy. But while our buildings have been restored to their original glory and our air looks clearer, the reality is that air pollution continues to do us harm, with visible sulphur and soot replaced by invisible nitrogen dioxide and particulates.
As is so often the case, it is our most deprived communities, who already have to cope with multiple health problems, who suffer most from the effects of polluted air. In the Liverpool City Region, we have areas where men have a life expectancy seven years lower than the national average.
We have had some notable successes in tackling air pollution. We are home to pioneering work to develop buses and trains that run on hydrogen and we‟re building on our strength in offshore wind with the development our potentially world-leading Mersey Tidal Power scheme. We also have big plans for encouraging much more walking and cycling across the city region.
But no one organisation or individual can address poor air quality alone.
That‟s why our Air Quality Task Force is made up of elected and other representatives from across the six local authority area of the city region. And it‟s why this plan, the first result of its work, contains actions for the Combined Authority, for our constituent Local Authorities and partners, supported by the Combined Authority, for residents, communities and businesses and actions we need from central government and its agencies.
We all need to change the way we live, work and do business if we are to improve our air quality for ourselves and for future generations.
Now is the time for action.
[Signatures]
Metro Mayor and Lead Member for Transport and Air Quality
3
1. The aim of this action plan
1.1 This document supports existing action by our local authority partners and other bodies across the city region to tackle the problem of poor air quality. It sets out a vision and series of actions to improve air quality. The Combined Authority, as a strategic body, has both direct and indirect influences and powers in this area. But the fundamental principle that only through joint commitment and co-ordinated action can we solve this longstanding problem.
1.2 There is consensus locally, nationally and internationally around the need to take urgent action to address the significant challenges presented by poor air quality, and nitrogen dioxide specifically. This is a problem affecting most major towns and cities globally as a result of traffic and transport emissions in the main. Equally, the challenges presented by particulate matter (PM), especially from domestic sources and industry pose significant dangers, if not to the same extend at a city regional level.
1.3 Public Health England reiterate that air pollution has a significant impact on our health; between 28,000 – 36,000 deaths each year are attributable to human-made air pollution in the UK and that more action is needed. More specifically, Public Health England also estimate that air pollution contributes to around 700 deaths a year in the Liverpool City Region.
1.3 In the spring of 2018 the Combined Authority‟s Overview and Scrutiny Committee convened a task and finish group to examine the issue of poor Air Quality across the Liverpool City Region. This work entailed the collation of a detailed body of evidence on the causes and effects or poor air quality locally and the range of options to tackle the problem. This work drew on presentations by, and discussions with a large number of expert witnesses. This action plan does not seek to reproduce this important context in the interests of brevity, but the hyperlinks throughout the plan link to sources of further information.
1.4 The Overview and Scrutiny Committee developed a report and a series of recommendations. These were presented the Combined Authority in June 2018 and were unanimously agreed. A summary of these recommendations is set out in the Appendix.
1.5 Of the recommendations agreed by the Combined Authority, one commitment related to the development of this action plan. This was considered vital to clearly set out the Combined Authority‟s approach to taking action on a Liverpool City Region footing. Allied to this was the importance of working collaboratively with the constituent local authorities, local partners and central government to tackle the problem.
1.6 More specifically, it was agreed that this collaborative approach would be formalised through an LCR Air Quality Task Force, convened by the
4
Authority, comprising elected members and officers from the local authorities, Combined Authority and Merseytravel, key government agencies and from business, to progress the actions needed in order to improve air quality. The establishment of this group recognised that, irrespective of legal responsibilities, no individual body holds all of the powers needed; effective actions to tackle the problem are dependent upon a co-ordinated, collaborative approach. This is also an approach that‟s better able to secure value for money and economies of scale when it comes to delivery or action.
1.7 This is an interim plan that has been developed to coincide with the Air Quality Task Force‟s initial 6-month work programme. It will be refined further ahead of the end of the financial year and updated in light of new considerations affecting the city region. A prominent consideration includes the “mandated” air quality study within Liverpool City Council that the Combined Authority is fully engaged with, but which is still underway at the time of drafting this action plan. Issues stemming from this will be reflected fully in the final version of the plan. Other emerging considerations include potential air quality legislative changes, budgetary changes locally and nationally, the growing number of “Climate Emergency” responses, and the development of the Local Industrial Strategy (LIS). These are highlighted in more detail in the sections that follow.
2. Recap - what do we already know?
2.1 Responsibilities
2.1.1 Action to monitor and manage air pollution is governed by legislation stemming from European Directives. In legal terms, the main pollutant exceeding these defined standards across the LCR is nitrogen dioxide. However, as noted, particulate matter (PM), comprising microscopically small particles from combustion, vehicle brakes, tyres and road surfaces, chemical reactions, construction or agricultural processes, for example, is also a harmful pollutant affecting the city region.
2.1.2 Most nitrogen dioxide emissions stem from transport emissions from the combustion of petrol and diesel. The Scrutiny Panel‟s report contains more detail on these emissions and where Air Quality Management Areas have been declared. As transport movements are not confined to local authority boundaries, neither do the sources of these emissions follow or respect local authority boundaries.
2.1.3 At present, the Combined Authority is not specifically covered by local air quality management legislation. However, members have
5
agreed that the Authority can and must act in response to the problem and in order to raise the profile of the issue. Importantly, as the main nitrogen dioxide emissions locally stem from transport sources, and given the Combined Authority‟s statutory responsibilities for transport policy and funding, our policies and priorities have a direct bearing on transport, on transport emissions and local air quality. Equally, the Combined Authority‟s emerging economic strategies, spatial plans and housing plans, as examples, affect atmospheric emissions and air quality. The added value of the Authority as an “enabler” across a bigger area, and in being able to engage a wide range of partners is also critically important in terms of securing co-ordination and synergy and in helping to avoid any unintended consequences locally.
2.1.4 Under the emerging Environment Bill, there is the potential for statutory responsibilities for tackling poor air quality to be amended. There is a strong possibility that the Combined Authority will be mandated with a duty to co-operate with other parties as part of this process. This would formalise the collaborative approach to tackling poor air quality to date (aligning powers, funds and delivery) in a way that is similar to land use planning legislation that places a duty for local authorities to co-operate with one another on strategic cross-boundary matters.
2.2 “Mandated” work on Clean Air Zones
2.2.1 Many cities across the UK have been mandated by Defra to undertaken detailed studies to bring air quality within the prescribed limits within the shortest possible time. These mandates include a requirement to investigate Clear Air Zone options. Liverpool City Council is subject to this mandate. A highway link in Sefton was identified as being potentially problematic, but in the authority‟s 2019 Targeted Feasibility Study, concluded that the road link was compliant and that at this time, no further mandatory action is needed from Defra‟s perceptive.
2.2.2 At the time of writing this interim report, the Clean Air Zones study in Liverpool is still in development, and implications will be addressed in a later iteration of the Action Plan. Sefton MBC are also considering options around how best to improve air quality within the borough. However, dependent upon the options that are ultimately shortlisted or mandated, these interventions are likely to be highly significant in both scale and impact.
2.2.3 The Combined Authority is actively supporting Liverpool City Council with the development of options development and potential
6
delivery as part of the process of developing an outline business case submission to Defra by the end of October 2019.
2.2.4 Other major towns and cities across the UK are also developing air quality plans in response to similar Defra mandates, notably Greater Manchester as the city region‟s nearest neighbouring city region. Discussions are underway to understand cross-boundary impacts (e.g. the displacement of „clean‟ vehicles or other unintended consequences) and to understand and minimise the negative impact of their clean air plans on Liverpool City Region.
Best practice
2.3.1 The LCR Air Quality Task Force has identified a wealth of opportunities and best practice to address our air quality challenge. Some of these are ongoing activities, others would be new. And in many instances these actions need to apply more consistently across the city region. These include, but are not limited to the following examples under four main categories:-
Examples of best practice identified across the LCR Political Most of the local authorities in the Liverpool City Region have commitment declared climate emergency, including the Combined Authority itself. These declarations stems in response to the pressing threat of climate change and the urgent need to take action of climate change, air quality and the environment. For the LCRCA, this will build on the net zero carbon target of 2040. Tackling climate change and poor air quality are considered as two sides of the same coin. Local partners are actively supporting LCR Year of the Environment 2019 and which includes the issue of air quality as one of its eight priority themes. The development of effective partnerships to take collective action in response to complex problems and challenges, including the LCR Bus Alliance, the collaborative approach to Year of the Environment 2019, a technical group of expert air quality officers led by Wirral Council, and the Air Quality Task Force itself. The Metro Mayor and Combined Authority have clear visions around a net zero carbon agenda and the role of clean growth, clean, renewable energy and clean fuels. Halton and St Helens Councils are also important sources of hydrogen as an alternative fuel source for vehicles, to support these aims. Use of Many local authorities have proactive approaches to enforcing regulatory emissions from vehicles, including buses and taxis, together with
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Examples of best practice identified across the LCR powers actions to clean and retrofit vehicle fleets through e.g. taxi licensing regimes and Sefton‟s Council‟s ECOStars goods fleet accreditation scheme. The Combined Authority is exploring the pros and cons of devolved powers available under the Bus Services Act in respect of bus service operations Strong policies Many local authorities use planning guidance to tackle or and funding mitigate against poor air quality (e.g. standards for new packages developments or assessments of proposals in air quality) Access to £172.5m over the next four year to enhance sustainable travel through the Transforming Cities Fund. LCR has extensive experience of bidding for and securing funds that tackle poor air quality, and to support the uptake of cleaner engines and fund sustainable travel options, including grant aid from sources such as the Office for low Emissions Vehicles The adoption of robust policy frameworks that promote clean growth have clean growth, modal shift and air quality and resilience at their core, including the Combined Authority‟s Transport Plan and agreement around a vision for bus to secure a sustainable network that delivers commitments to air quality and health improvements. Education and The development of educational materials for schools and awareness engagement with schools and parents (e.g. Sefton‟s Clean Air Crew initiatives through its EcoCentre and an educational pack led by St Helens Council). Engagement with, and support for businesses, to tackle the problems and highlight the benefits of greener forms of transport, clean growth and clean air The delivery of a range of campaigns, communications and events (e.g. on Clean Air Day and Car Free Day) The Better By Bus Campaign to make the bus a more attractive option and to encourage a switch form private car usage The use of innovative means of communicating complex public health messages to the public to raise the profile of the issues and target action
2.3 Building the evidence
2.3.1 As the Task Force was in the process of being established, the Combined Authority was concluding a high level study to better understand, and gauge the relative impacts of various measures available in which to tackle air quality problems. This was developed by AECOM consultancy. The final report was shared with the LCR Air Quality Ask Force at its first meeting in March 2019 and provided a valuable source of material in the identification
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of potential “quick wins” and longer-term actions, pilots or developmental work.
2.3.2 The report outlines the technical details, and potential impacts of implementing a range of interventions to improve air quality. 40 potential transport and non-transport interventions were identified and were scored and ranked by AECOM as follows as per the tale in Appendix Two.
2.3.3 This helped to identify a number of “quick wins” versus more complex, policy, delivery or funding-led approaches. These quick wins can be highlighted below, and several are behavioural or regulatory in their nature and align closely with many of the examples of best practice in section 2.3.1 and in the action plan that follows:-
Engagement & Education Bus Fleet Upgrades Mersey Tunnel Tolls Fleet Management Travel Cards Web Resources Domestic Solid Fuel Burning Tackling the effect of diesel generators
2.3.4 A number of other high-scoring measures are more complex in their scope, but will have the potential to make significant improvements to local air quality. Measures like better urban traffic control traffic control systems, enhanced bus corridors and enhanced cycling infrastructure or piloting hydrogen fuelled buses are now being progressed via current funding opportunities (e.g. Transforming Cities Funding. There are also aspects identified that may form future asks of government as part of the development of the Local Industrial Strategy or as part of the Spending Review process. These are referenced in the action plan that follows.
2.3.5 Importantly, the study highlighted the importance of securing better data and evidence as a first step, together with enhanced air quality modelling capability for both the Combined Authority and the local authorities.
2.3.6 Allied to the mandated work” that is ongoing now (as set out in para 2.2), the AECOM study recognised the role of Clean Air Zones, and which a number of local authorities (including Liverpool) are considering as a measure to bring forward compliance with legal limits for nitrogen dioxide in the shortest possible time, and which entail a form of charging mechanism for non-compliant (“dirty”) vehicles.
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2.3.7 From the high level study, CAZs were afforded a lower initial priority score by AECOM, preliminary areas that may be suitable for the implementation of a CAZ focused around Liverpool and Sefton, the greatest potential benefits may be achieved in terms of improved air quality and health. Critically, the need for a better level of data on vehicle classes and engine types was highlighted, to understand better how the application of the CAZ scenario may affect local and regional emissions. This is now reflected in the detailed business case being developed by Liverpool City Council and the options being explored by Sefton Council.
2.3.8 In March 2019, at the time that the task force was being established, Public Health England produced a further piece of timely evidence on the health risks arising from poor air quality and the interventions that would best address this – a “Review of interventions to improve outdoor air quality and public health”.
2.3.9 It provides evidence-based advice on actions available locally and nationally to reduce air pollution and its impact on our health. It also challenges the view that actions to reduce air pollution run counter to economic growth and development, arguing that this is an opportunity for better air quality and economic prosperity to go hand in hand. This is consistent with the emerging vision in the Local Industrial Strategy around health and wellbeing, linked integrally to clean growth.
2.3.10 The following are highlighted as effective interventions to address traffic-related emissions:-
Reducing emissions from existing vehicles (e.g. retrofitting) planning for active travel and public transport use Promoting low emission vehicles and reducing demand for more polluting forms of transport. Using the planning process to reduce sources and exposure to pollution. (e.g. reducing the need for vehicle use by design and increasing the use of public transport and active travel)
2.3.11 Public Health England‟s highlighted interventions align closely with issues identified in 2018 by the Overview and Scrutiny Committee and high-level recommendations to the Combined Authority. They also add further weight and validity to the measures identified in this action plan.
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3. Structuring this into an action plan
3.1 Drawing the above considerations together, the action plan that follows is divided into three main sections:-
1. Actions by the Combined Authority 2. Recommended actions to local authorities and our partners 3. Actions for the LCR‟s residents, communities and businesses; and 4. Recommended actions to Central Government and its agencies
3.2 Where appropriate these are then divided into short term and longer term actions:-
Short term – for action or delivery immediately or within the next 12 months Longer term – for action or delivery with the next 24-36 months
3.3 It is reiterated that this is an interim plan which will be refined further over the coming six months, but provides an important starting point for action to be taken by the Combined Authority and by partners.
3.4 This process of refinement and engagement will also help to strengthen emerging recommendations in the plan, recognising that many need further testing and exploration in order to make harder-hitting and more precise, to have the desired effect. Equally, issues arising from detailed clean air options-testing work within Liverpool will be factored into the draft final plan.
3.5 Importantly, it is an important start in drawing together partners across the city region as a whole together, and coalescing around a shared vision and action plan.
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THE LIVERPOOL CITY REGION’S INITIAL AIR QUALITY ACTION PLAN
(1) Actions by the Combined Authority Short term actions (within the next 12 months) Means to achieve or resource implications Supporting our partners to clean the air We will utilise the skills of the LCR‟s Air Quality Technical Group and We will work with Liverpool on the development of options around poor air quality and existing CA resources potential clean air zones as part of the “mandated” work with Defra, and seek to secure synergies and common approaches We will maintain close co-operation We will work with our colleagues at the Greater Manchester Combined Authority to via the Air Quality Task Force and understand the impact their clean air plans on the Liverpool City Region, to support equivalent bodies and networks complementary proposals. This will seek to avoid any unintended consequences, such as displacement and avoid adverse effects on the Liverpool City Region We will undertake a skills map of all local authority and Combined Authority staff working in the air quality area to identify where there is potential to share resources and support peaks in workloads or demand across the area. We will foster stronger links with the health sector to develop collective approach to measuring and taking action in response to poor air quality across the city region, building on the preventative principles and a shared approaches to data and evidence Better data to support decision-making We will investigate options around direct funding support to collect new We will supporting our local authorities in their duties to monitor and improve air and improved data, or else reform quality, and seek to foster a more “high tech”, consistent and extensive air quality existing data-related contractual monitoring regime across the LCR. This will include air quality modelling (including frameworks that are already in modelling of carbon emissions) and data management capabilities, to allow scenarios place. to be tested and to inform decision-making processes.
With Public Health England, we will develop a more nuanced local model for air quality We will utilise processes such as the impacts that can be run to forecast the likely outcome of numerous policy choices and SIF evaluation process to measure
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(1) Actions by the Combined Authority Short term actions (within the next 12 months) Means to achieve or resource implications provide greater certainty about impacts on air quality in decision-making processes and better understand impacts We will help to build evidence around other potential pollutants of concern, including particulate matter (PM) and sulphur dioxide from all relevant sources (including shipping) and which could present future risks or problems Effective plans and strategies to create clean, liveable and healthy places We will build the evidence gleaned on air quality into our strategies and In developing our plans and projects as a Combined Authority, we will ensure that plans and develop systems to issues of air quality are not considered in isolation and are fully woven into assess the impact of policies and conversations and actions how we will deliver low carbon, clean and inclusive growth. programmes on air quality. This will Specifically, we will do this as a core part of our emerging Local Industrial Strategy, involve existing LCRCA staff and which will be focused around four priorities resources. o Good work, health and wellbeing for all; o Vibrant and connected communities; We will target the use of funds that o More businesses innovating and growing; we manage as a CA to support the o Clean growth clean growth and clear air agenda These principles will be considered and woven fully into the development of other key and ensure that these are strategies, such as the Spatial Development Strategy, Housing Statement and a future imperatives and not platitudes or Mayoral Transport Plan tokenistic measures. We commit to championing the delivery of agreed policy statements (e.g. the 2019 Combined Authority Transport Plan) on the imperative to deliver sustainable transport enhancements and create a shift from polluting forms of transport to clean, zero carbon forms of transport as significant contributors to better air quality locally.
Boosting active travel (walking and cycling) levels, especially for short trips This will be commissioned through the £172m Transforming Cities We will commission and support the delivery of a radical and comprehensive Funding programme.
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(1) Actions by the Combined Authority Short term actions (within the next 12 months) Means to achieve or resource implications programme of walking and cycling upgrades within the next 4 years, linked to the Transforming Cities Funding programme and the development of a Local Cycling and This work will also be supported by Walking Investment Plan (LCWIP). The focus will be on a network of dedicated cycle our LRC Cycling and Walking routes, which are segregated from traffic, to encourage the switch from cars to bikes Commissioner for short journeys. . We will investigate measures to boost investment in behavioural change campaigns and initiatives to complement this investment.
Promoting clean fuels and technologies We are working to identify additional staff resources and sources of We will accelerate plans to roll-out a network of alternative fuel facilities across the expertise amongst our local region, building on previous good examples such as the Project Charge electric authority partners vehicle charging facility, and also hydrogen fuelling facilities, linked to a £6.4 million OLEV grant from government for a pilot hydrogen bus fleet We will engage with the local university sector and bodies such as the Heseltine Institute to establish further research opportunities in this area to inform our plans and policies and support our local authority partners in tackling complex problems We will work with Highways England to explore the scope of rolling-out their electric van pilot scheme, working closely with all parties, including local Chambers of Commerce to engage local small businesses and end users
(1) Actions by the Combined Authority Longer term actions (within the next 24-36 months) Means to achieve or resource implications
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(1) Actions by the Combined Authority Longer term actions (within the next 24-36 months) Means to achieve or resource implications A well-managed Key Route Network We will test options for traffic control systems using Transforming Cities We will help develop and deliver improved urban traffic control systems across the city Funding initially region to better co-ordinate traffic movement and give intelligent priority, particularly for public transport and for active travel users. We will test and use our co-ordinating and funding powers over a Key Route Network to better plan and deliver measures across the city region that prioritise clean forms of transport over polluting forms of transport and that support modal shift to sustainable forms of travel. Joint working with Highways England to reduce emissions on the Strategic Road We will engage closely with HE staff Network and also identify opportunities through HE discretionary funds to We will investigate the potential expansion of the electric van pilot (under “Promoting support the implementation of clean fuels and technologies”) into a hydrogen HGV pilot, reflecting the LCR‟s role as measures a major port and logistics centre We will work with HE on a programme to develop prominent signage to Park and Ride sites from the strategic road network, to complement the development of new transport facilities and services (e.g. at Birkenhead North, Bidston, Newton-le-Willows and Maghull North) and to maximise the success of the new Merseyrail train fleet that is being introduced in 2019/20 Bus, rail and ferries as the modes of choice for longer distance trips Funding options for bus delivery re core to the options development We are in the process of investigating alternative models of bus delivery to best serve work underway. the needs of the city region and improve air quality and will begin to implement the preferred option over the lifetime of this action plan Transforming Cities funding could Through the Transforming Cities Fund‟s Green Bus Route proposals, we will develop be an appropriate use of funding to a new, holistic approach to bus quality, convenience and punctuality, by giving buses deliverer enhancements to the
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(1) Actions by the Combined Authority Longer term actions (within the next 24-36 months) Means to achieve or resource implications the right priority on our highways to make bus travel a more attractive opportunity sustainable transport network We will explore lower-cost ways to cross the river by bus. We are procuring new cleaner, greener Mersey Ferries vessels that will replace the existing, 60-year old vessels and which provide a vital link between Wirral and Liverpool, especially for cyclists As part of the introduction of the new Merseyrail rolling stock, we will further enhance the Merseyrail cycle locker scheme to encourage many more short trips to rail stations to be made by bike We will work to integrate new and existing cycle hire schemes within the new smartcard and ticketing system in development, to allow people to pay for their journeys quickly and easily and to „mix and match‟ with other forms of travel We will investigate and implement where appropriate, new park and ride sites or extend existing sites where these remove or reduce polluting journeys by private car by intercepting vehicles from the strategic road network Vehicle scrappage and incentives to use clean vehicles, esp. taxis & light vans Funding sources and models and means of delivery will be central to We will investigate options for an LCR scrappage scheme, working with LAs to look at this investigative work. There may phasing out dirty vehicles. This will include the examination of a scrappage scheme also be „clean air‟ funding available for taxis, private hire vehicles, and light goods vehicles, targeted at small local through Government. businesses. These could take the form of a leasing scheme, whereby clean vehicles are procured centrally, whether by the CA/LAs, a joint venture or privately, and leased Work on taxi standards would be to local business, to incentivise uptake and usage. policy-based and would not seek to We will champion greater consistency of taxi and private hire vehicle standards across change the governance of taxi and the city region, to create higher environmental standards overall, building on earlier PHV licensing at a local authority scoping work led by sefton MBC in 2018. level. Tackling domestic emissions to clean the air Funding sources and models and means of delivery will be central to
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(1) Actions by the Combined Authority Longer term actions (within the next 24-36 months) Means to achieve or resource implications We will investigate options and measures to improve our housing stock and domestic this investigative work (e.g. part of emissions. Potentially, this could be around an energy retrofit programme and LCR the Strategic Investment Fund (SIF) domestic boiler scrappage scheme to help local residents reduce domestic process. This will also link to the consumption and tackle particulate matter emissions. This would also be through an CA‟s emerging Housing Statement approach targeted to help least affluent residents first, in order to address fuel poverty. and Local Industrial Strategy. Reducing freight emissions Funding sources and models and means of delivery will be central to We will develop with local authorities a local approach to make freight and logistics as this investigative work sustainable as possible. This will include joint work with the National Infrastructure Commission and the development of local pilots linked to e.g. local supermarket This will include engagement with delivery chains and last mile logistics, to explore the scope for rationalisation or relevant local authorities through increase uptake of shopping deliveries to home instead of car trips to supermarkets. the National Infrastructure This will also include actions to promote locally-sourced goods and produce that Commission‟s joint learning reduce ”food miles” programmes, to learn from best As part of the above, we will investigate models for urban consolidation for movement practice and innovation of goods focusing on options for „last mile‟ delivery. With partners, we will seek to take forward a city region-wide vehicle accreditation schemes being effectively applied in selected local authorities, notably scheme in Sefton.
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(2) Recommended actions by the local authorities and our partners Short term actions Means to achieve or resource implications Joined-up communications and campaigns Though pooled resources and early engagement Collectively, we recommend developing and delivering a consistent marketing campaign on Air Quality, including public information and an agreed calendar of events linked to consistent press and PR messaging (e.g. „Let‟s Clean the LCR‟s Air‟) This will include a pilot across all local authorities of at least 2 schools per district to reduce the private car school run and associated emissions. A co-ordinated approach will be required to ensure that different approaches and different type of schools are being included (e.g. scoping a trial of staggered school hours to tackle peaks and troughs of demand). This could lead to a longer term strategy to extend this approach to all schools Local planning powers and the creation of create clean, liveable and safe places Through LCR Chief Planning Officers‟ Group We recommend and support the development of LCR-wide, consistent planning conditions and guidance for air quality that are agreed by each authority, e.g. policies around the sustainable design of new developments and means of access, management of car parking and vehicle movements, installation of low emission boilers, electric vehicle charging points, dust suppression controls during building stage etc. This will also be considered as part of the development of the Combined Authority‟s Spatial Development Strategy. We consider that the profile of health, air quality and “climate emergency” considerations should be clearly factored into the policies, designations and major planning decisions made by local planning authorities. Enforcement of idling vehicles to reduce pollution at source Through the LCR Air Quality Technical Group We recommend the co-ordination of a consistent and collective approach to enforcing and ultimately, reducing numbers of idling vehicles, particularly around schools and at taxi ranks, to strengthen public messaging, and to tackle a root cause of emissions.
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(2) Recommended actions by the local authorities and our partners Longer term actions (within the next 24-36 months) Means to achieve or resource implications Green infrastructure and the mitigation of pollution We will work with expert bodies such as the Mersey We recommend the piloting of an approach to greening development across all districts and Forest and relevant partners where further greening can be part of this approach, e.g. targets for tree planting as part of new development or interventions, green walls, green roofs, tree planting and soft landscaping. This will also be considered as part of the development of the Combined Authority‟s Spatial Development Strategy. We recommend the investigation of Air Quality Barriers where appropriate on parts of the KRN and or the Highways England‟s network that are close to schools and housing To work to „green‟ existing public infrastructure, including bus shelters and railway stations To work to mitigate against poor air quality outside schools with greening-up and planting on a consistent footing across the city region Speed management to encourage modal shift and cleaner air Through the Merseyside Road Safety Partnership We encourage all LCR local authorities to test and adopt a policy of 20mph on all local Group and the Transport residential roads following on from positive outcomes experienced in Liverpool and parts of Advisory Group Sefton, to encourage walking and cycling, especially for short trips.
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(3) Recommended actions for residents, communities and businesses Short term actions Means to achieve or resource implications Joined-up communications and campaigns – “we’re all doing our bit” Though pooled resources and early engagement Through the umbrella of the Air Quality Task Force, we will work together to align our public- facing communication and publicity plans to secure greater targeting of messages and co- Through our joint campaigns ordination of public campaigns, messages and incentives on means to take action to improve and marketing initiatives air quality. The public sector will maintain effective engagement with businesses on the air quality agenda As part of the plans that we and on the benefits of “responsible business” that reduces air quality emissions. This will make for building a legacy include early and meaningful engagement and consultation on publicly funded proposals that from 2019‟s Year of the have a significant bearing on movement or business operations across the city region. Environment activities. Members of the Air Quality Task Force will work with Chambers of Commerce to seek to establish air quality “consultancy” and awareness-raising sessions for local businesses so that Through the identification they can understand the need to change behaviour or practices, and the cost and business and creation of a community opportunities associated with this. This will be aligned with existing business support or fund or similar outreach activities. With our Chambers of Commerce and business support groupings, we will engage local small businesses and end users on clean vehicle fleets and recuing air quality form their activities, linked to the Highways England electric van trial scheme as an example. Members of the Air Quality Task Force will support grassroots and community groups with the provision of factual information, advice and joint campaigns and communications in order to take action to improve local air quality (e.g. Car Free Days, walking buses, green infrastructure, home insulation and energy efficiency). We recommend joint action to raise the profile amongst residents and businesses of wood burning stoves and their implications on particulate matter emissions, linked to the need for better national regulations on definitions and standards.
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(4) Recommended Actions by Central Government and its agencies Longer-term actions (within the next 24-36 months) Means to achieve or resource implications Joint work with Highways England Engagement with Highways England and with Central We recommend an investigation into the potential for speed reductions on the local motorway Government network, to reduce emissions at source, leading to potential ask of Government to implement We will engage HE to invest in prominent signage to public transport park and ride sites from the HE network to coincide with the introduction of complementary public transport enhancements Long term funding confidence to support clean air interventions and modal shift With influencing umbrella bodies such as UK100, BCC, We will work with Government and through our collective network groups to make the case The Urban Transport Group, for long-term funding certainty to support the delivery of measures that support clean air and other Metro Mayoral areas extend above and beyond compliance standards, so as to support wider quality of life and and Core Cities Group wellbeing objectives. This includes both capital and revenue spend. Streamlining local enforcement of pollution and emissions Engagement with Central Government and through the We will engage with government to encourage the timely introduction of updated national provision of input to the regulations and guidance to address issues such as idling vehicle engines, dark smoke and development of the smoke control areas, as identified in the clean air strategy 2019. This is to address existing Environment Bill cumbersome legislative provisions that can make local enforcement complex or bureaucratic. Fiscal support for low emission vehicles With influencing umbrella bodies such as UK100, BCC, We will make the case for financial incentives to be made available to freight and public The Urban Transport Group, service fleet operators to invest in low emissions vehicles, scarp existing “dirty vehicles” or to other Metro Mayoral areas retrofit existing polluting engines through a targeted programme and Core Cities Group We will work with the government to ensure that taxation and regulatory systems support the uptake of clean vehicles and clean fuels, through regimes such as the Bus Services Operators Grant (BSOG), which currently incentivise the use of diesel rather than hydrogen
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(4) Recommended Actions by Central Government and its agencies Longer-term actions (within the next 24-36 months) Means to achieve or resource implications or electrical power We will engage government and industry on initiatives to remove the oldest and dirtiest engines from the vehicle fleet through scrappage schemes or similar for domestic vehicles. Building on experiences of the past, this must be done in ways that do not lead to unintended consequences (e.g. social exclusion, the creation of incentives to drive or be car-dependent, or that creates displacement from one pollutant to another). Aiding co-ordination and communication on clean air With influencing umbrella bodies such as UK100, The We will impress upon Government the need to urgently embed air quality and climate Urban Transport Group, emergence more effectively across government departments and on a “prevention is better BCC, other Metro Mayoral than cure” principle to actively avoid the creation of emissions at source whether from areas and Core Cities Group industry, from homes or from transport. We will seek support from central government, NHS and health bodies to bring greater cohesion to LCR health boundaries and a “single voice” with the health sector, to work more effectively across currently complex health boundaries and aligns budgets more effectively Cleaner, greener national and inter-city connectivity With Transport for the North, industry and with Central We will reiterate our evidenced work on the importance of national and inter-regional Government enhancements to our rail networks to facilitate modal switch to rail and reduce emissions, through schemes such as High Speed 2, Northern Powerhouse Rail. We will reiterate the role that enhanced northern rail capacity and connectivity plays in supporting the rebalancing of the UK‟s economy and in reducing wasteful haulage-related emissions from an over- reliance on south eastern ports. With other relevant local authorities and alliances, we will formulate an approach to reduce emissions from local aviation and from shipping (freight and cruise liners), particularly through measures that support the use of low emission fuels when taxiing/idling airside or berthed in port, respectively.
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(4) Recommended Actions by Central Government and its agencies Longer-term actions (within the next 24-36 months) Means to achieve or resource implications
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4. Next steps
4.1 This interim plan coincides with the end of the Air Quality Task Force‟s initial 6-month work programme. It is considered a programmatic and robust approach that guides the work of the Combined Authority and its partners in the imperative to tackle the cause and effect of poor air quality. It also forms a key input to other Combined Authority‟s emerging plans and programmes, notably the Local Industrial Strategy, Climate Change Action Plan, Housing Statement and Spatial Development Strategy, as prominent examples.
4.2 This plan has been informed and overseen by the LCR‟s Air Quality Task Force and will be presented to the Combined Authority in November 2019. Recognising the important work undertaken by the Combined Authority‟s Overview and Scrutiny Committee on air quality in 2018, and the transposition of this work into the this action plan, this interim plan will also be presented a future meeting of the Overview and Scrutiny Committee. This will be ahead of its finalisation by the Task Force and by the Combined Authority and its partners at the end of the current financial year.
4.3 A critical issue recognised in this plan concerns the importance of joint working and a collaborative approach. This stems from the clear realisation that no single body can resolve poor air quality in isolation. As such, it is recommended that this plan and the recommendations contained within it, are progressed through the governance and reporting structures of the Task Force‟s partner authorities in due course. This could also include local Health and Wellbeing Boards and the Combined Authority‟s Fairness and Social Justice Advisory Board (FASJAB), to secure the buy-in and alignment that is vital to deliver practical change.
4.4 This interim plan will be refined further ahead of the end of the financial year and updated in light of new considerations. These wider considerations include the “mandated” air quality study underway in Liverpool and which is likely to have the biggest impact on the shape of the plan. The plan will also be refined in light of legislative change, budgetary changes locally and nationally and also “Climate Emergency” responses and that cannot be considered in isolation of air quality considerations. It will then take the form of a Final Action Plan by March 2020 that will be kept under regular review.
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Appendix Recap on Air Quality Recommendations Agreed by LCRCA in June 2018
1. That the Metro Mayor, on behalf of Combined Authority, acts as a political “champion” for a series of long term measures to improve air quality across the Liverpool City Region, involving a wide range of influential bodies and decision makers. The preliminary air quality feasibility study which is in the process of being finalised, and the action plan that needs to be developed in response, should be formally considered by the Overview and Scrutiny Committee in due course. This will come ahead of consideration by the Combined Authority.
2. 2. Allied to this, the Metro Mayor and the Combined Authority should champion a communications plan to set out a commitment to engage with people across the LCR. This should be targeted as follows:-
a) to engage with schools and young people who are particularly vulnerable to the effects of poor air quality, aided by consistent educational materials and best practice across the LCR; b) to engage with the public protection and public health sectors to jointly raise awareness, which could be through roadshows and events, as examples; and; c) To promote National Clean Air Day and related campaigns.
3. The communications plan needs to explain clearly that the LCR has a problem and set out what can be done to both alleviate symptoms, and help address the root of the problem.
4. he Combined Authority needs to fully utilise and align its funding, transport, planning and economic development powers to create an environment where people have reduced reliance on road transport and make greater use of walking, cycling and public transport. For example, this could be linked to the Authority‟s emerging digital strategy and the powers that it has over a Key Route Network of local roads. This also needs to be consistently applied through the Authority‟s plans and strategies, e.g. through the Freight Strategy and Local Journeys Strategy.
5. The Combined Authority should use its emerging Spatial Development Strategy to address poor air quality and to raise air quality as a policy consideration.
6. The Combined Authority should give prominent and consistent consideration to air quality implications in its decision-making processes and in its investment decisions. This could include much better “before and after‟ analysis in project and programme evaluations.
7. The Combined Authority should support the six constituent local authorities in their statutory duties to monitor and address air quality, and seek to foster a more “high tech”, consistent and extensive air quality monitoring regime across the LCR. The Combined Authority also needs to work collectively with the constituent local authorities and with central government to tackle the problems caused by vehicles and engines that create the most pollution. This should take the form of an LCR air quality task force, convened by the Authority, comprising officers from the local authorities, Combined Authority and public health bodies, to progress the actions needed in order to improve air quality.
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Appendix 2 AECOM Air Quality Feasibility Study - Ranking of measures
Measure Rank score Urban Traffic Management Control 72 Supplementary Planning Guidance 72 Engagement & Education 72 Building Standards 72 Cross Boundary Travel 64 Bus Fleet Upgrades 48 Mersey Toll 48 Fleet Management 48 Travel Cards 48 Web Resources 48 Domestic Solid Fuel Burning 48 NRMM ULEZ 48 Diesel Generators 48 Fleet Recognition Scheme 36 Car Clubs 36 Pollution Event Forecasting 36 Segregated Bus Corridors 32 Red Routes 32 Renewable Micro Energy Generation 32 Freight Coordination 24 Taxi Management 24 Real-time Passenger Info 24 Travel Planning Resources 24 Green Infrastructure 24 Commercial & Domestic Boilers 24 Air Quality Neutral 24 Variable Parking Charges 24 Cycling Infrastructure 24 Clean Air Zone 18 Construction Emissions 18 Street Works 18 Bus Layover Facilities 16 School Audits 16 Business Engagement 16 Shipping Emissions 12 Sustainable Procurement 12 Alt Fuel Infrastructure 12 Shared Space 8 Agricultural Emissions 8 Air Traffic Emissions 8
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Air Quality Plan for tackling roadside nitrogen dioxide concentrations in Liverpool Urban Area (UK0006)
July 2017 © Crown copyright 2017
You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence v.3. To view this licence visit www.nationalarchives.gov.uk/doc/ open-government-licence/version/3/ or email [email protected]
Any enquiries regarding this publication should be sent to us at: [email protected] www.gov.uk/defra
1 Contents
1 Introduction 3
1.1 This document ...... 3
1.2 Context ...... 3
1.3 Zone status ...... 3
1.4 Plan structure ...... 4
2 General Information About the Zone 4
2.1 Administrative information ...... 4
2.2 Assessment details ...... 6
2.3 Air quality reporting ...... 8
3 Overall Picture for 2015 Reference Year 8
3.1 Introduction ...... 8
3.2 Reference year: NO2_UK0006_Annual_1 ...... 8
4 Measures 13
4.1 Introduction ...... 13
4.2 Source apportionment ...... 13
4.3 Measures ...... 13
4.4 Measures timescales ...... 14
5 Baseline Model Projections 14
5.1 Overview of model projections ...... 14
5.2 Baseline projections: NO2_UK0006_Annual_1 ...... 15
Annexes 20
A References ...... 20
B Source apportionment graphs ...... 21
C Tables of measures ...... 23
2 1 Introduction
1.1 This document
This document is the Liverpool Urban Area agglomeration zone (UK0006) updated air quality plan for tackling roadside nitrogen dioxide (NO2) concentrations. This is an update to the air quality plan published in December 2015 (https://www.gov.uk/government/collections/air-quality-plan-for-nitrogen- dioxide-no2-in-uk-2015).
This plan presents the following information:
• General information regarding the Liverpool Urban Area agglomeration zone
• Details of NO2 exceedance situation within the Liverpool Urban Area agglomeration zone
• Details of local air quality measures that have been implemented, will be implemented or are being considered for implementation in this agglomeration zone
This air quality plan for the Liverpool Urban Area agglomeration zone should be read in conjunction with the separate UK Air Quality Plan for tackling roadside nitrogen dioxide concentrations (hereafter referred to as the overview document) which sets out, amongst other things, the authorities responsible for delivering air quality improvements and the list of UK and national measures that are applied in some or all UK zones. The measures presented in this zone plan, and the accompanying UK overview document show how the UK will ensure that compliance with the NO2 limit values is achieved in the shortest possible time. This plan should also be read in conjunction with the supporting UK Technical Report which presents information on assessment methods, input data and emissions inventories used in the analysis presented in this plan.
1.2 Context
Two NO2 limit values for the protection of human health have been set in the Air Quality Directive (2008/50/EC). These are:
• The annual mean limit value: an annual mean concentration of no more than 40 µgm-3
• The hourly limit value: no more than 18 exceedances of 200 µgm-3 in a calendar year
The Air Quality Directive stipulates that compliance with the NO2 limit values will be achieved by 01/01/2010.
1.3 Zone status
The assessment undertaken for the Liverpool Urban Area agglomeration zone indicates that the annual limit value was exceeded in 2015 but is likely to be achieved by 2020 through the introduction of measures included in the baseline.
3 1.4 Plan structure
General administrative information regarding this agglomeration zone is presented in Section 2.
Section 3 then presents the overall picture with respect to NO2 levels in this agglomeration zone for the 2015 reference year of this air quality plan. This includes a declaration of exceedance situations within the agglomeration zone and presentation of a detailed source apportionment for each exceedance situation.
An overview of the measures already taken and to be taken within the agglomeration zone both before and after 2015 is given in Section 4.
Baseline modelled projections for each year from 2017 to 2030 for each exceedance situation are presented in Section 5. The baseline projections presented here include, where possible, the impact of measures that have already been taken and measures for which the relevant authority has made a firm commitment to implement. However, it has not been possible to quantify the impact of all the measures. This section therefore also explains which measures have been quantified, and hence included in the model projections, and which measures have not been quantified.
2 General Information About the Zone
2.1 Administrative information
Zone name: Liverpool Urban Area Zone code: UK0006 Type of zone: agglomeration zone Reference year: 2015 Extent of zone: Figure 1 shows the area covered by the Liverpool Urban Area agglomeration zone. Local Authorities within the zone: Figure 2 shows the location of Local Authorities within the agglomeration zone. A list of these Local Authorities is also given below. The numbers in the list correspond to the numbers in Figure 2.
1. Knowsley Metropolitan Borough Council
2. Liverpool City Council
3. Sefton Metropolitan Borough Council
4. St Helens Metropolitan Borough Council
(Note: Local Authority boundaries do not necessarily coincide with zone boundaries. Hence Local Authorities may be listed within more than one zone plan.)
4 Figure 1: Map showing the extent of the Liverpool Urban Area agglomeration zone (UK0006).
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Figure 2: Map showing Local Authorities within the Liverpool Urban Area agglomeration zone (UK0006).
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5 2.2 Assessment details
Measurements
NO2 measurements in this zone were available in 2015 from the following national network monitoring stations 1 (NO2 data capture for each station in 2015 shown in brackets):
1. Liverpool Queen’s Drive Roadside GB0922A (96%)
2. Liverpool Speke GB0777A (98%)
Full details of monitoring stations within the Liverpool Urban Area agglomeration zone are available from http: //uk-air.defra.gov.uk/networks/network-info?view=aurn.
Modelling Modelling for the 2015 reference year has been carried out for the whole of the UK. This modelling covers the following extent within this zone:
• Total background area within zone (approx): 198 km2
• Total population within zone (approx): 744,225 people
Zone maps
Figure 3 presents the location of the NO2 monitoring stations within this zone for 2015 and the roads for which
NO2 concentrations have been modelled. NO2 concentrations at background locations have been modelled across the entire zone at a 1 km x 1 km resolution.
1Annual data capture is the proportion of hours in a year for which there are valid measurements at a monitoring station, expressed in this document as a percentage. The Implementing Provisions on Reporting (IPR) guidance requires that a minimum data capture of 85% is required for compliance reporting (that is 90% valid data, plus a 5% allowance for data loss due to planned maintenance and calibration). Monitoring stations with at least 75% data capture have been included in the modelling analysis to ensure that a greater number of operational monitoring sites have been used for model calibration and verification purposes. For more information on compliance reporting under European Directives see Section 2.3.
6 Figure 3: Map showing the location of the NO2 monitoring stations with valid data in 2015 and roads where concentrations have been modelled within the Liverpool Urban Area (UK0006) agglomeration zone.
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7 2.3 Air quality reporting
From 2001 to 2012 the UK has reported annually on air quality concentrations using a standard Excel questionnaire (Decision 2004/461/EC). These questionnaires are available online from http://cdr.eionet. europa.eu/gb/eu/annualair. Since 2013 reporting has been via an e-reporting system (Decision 2011/850/EU) http://cdr.eionet.europa.eu/gb/eu/.
In addition, the UK has reported on air quality plans and programmes (Decision 2004/224/EC) since 2003. The most recent previous UK air quality plan for nitrogen dioxide was published in 2015. The plan and supporting documents are available at https://www.gov.uk/government/collections/air-quality-plan-for-nitrogen- dioxide-no2-in-uk-2015 and the submission of this plan via e-reporting is published at http://cdr.eionet.europa. eu/gb/eu/aqd/h/envvryhbq/. Historic plans and programmes are available on http://cdr.eionet.europa.eu/gb/eu/ aqpp.
3 Overall Picture for 2015 Reference Year
3.1 Introduction
There are two limit values for the protection of health for NO2. These are:
• The annual limit value (annual mean concentration of no more than 40 µgm-3)
• The hourly limit value (no more than 18 hourly exceedances of 200 µgm-3 in a calendar year)
Within the Liverpool Urban Area agglomeration zone the annual limit value was exceeded in 2015. Hence, one exceedance situation for this zone has been defined, NO2_UK0006_Annual_1, which covers exceedances of the annual limit value. This exceedance situation is described below.
3.2 Reference year: NO2_UK0006_Annual_1
The NO2_UK0006_Annual_1 exceedance situation covers all exceedances of the annual mean limit value in the Liverpool Urban Area agglomeration zone in 2015.
Compliance with the annual limit value in this exceedance situation has been assessed using a combination of air quality measurements and modelling. Table 1 presents measured annual concentrations at national network stations in this exceedance situation since the 1st Daughter Directive (1999/30/EC) came into force in 2001. This shows that there were no measured exceedances of the annual limit value in this zone in 2015. Table 2 summarises modelled annual mean NO2 concentrations in this exceedance situation for the same time period. This table shows that, in 2015, 25.3 km of road length was modelled to exceed the annual limit value. There were no modelled background exceedances of the annual limit value. The maximum measured concentration in the zone varies due to changes in emissions and varying meteorology in different years. However, the models are also updated each year to take into account the most up-to-date science, so the modelled results for different years may not be directly comparable. Maps showing the modelled annual mean NO2 concentrations for 2015 at background and at roadside locations are presented in Figures 4 and 5 respectively. All modelled exceedances of the annual limit value are coloured orange or red in the maps.
The modelling carried out for this exceedance situation has also been used to determine the annual mean NOX source apportionment for all modelled locations. Emissions to air are regulated in terms of oxides of nitrogen
8 (NOX), which is the term used to describe the sum of nitrogen dioxide (NO2) and nitric oxide (NO). Ambient
NO2 concentrations include contributions from both directly emitted primary NO2 and secondary NO2 formed in the atmosphere by the oxidation of NO. As such, it is not possible to calculate an unambiguous source apportionment specifically for NO2 concentrations; therefore the source apportionment in this plan is presented for NOX, rather than for NO2 (for further details please see the UK Technical Report). Table 3 summarises the modelled NOX source apportionment for the section of road with the highest NO2 concentration in this exceedance situation in 2015. This is important information because it shows which sources need to be tackled at the location with the largest compliance gap in the exceedance situation.
Figure B.1 in Annex B presents the annual mean NOX source apportionment for each section of road within the
NO2_UK0006_Annual_1 exceedance situation (i.e. the source apportionment for all exceeding roads only) in 2015.
9 -3 Table 1: Measured annual mean NO2 concentrations at national network stations in NO2_UK0006_Annual_1 for 2001 onwards, µgm (a). Data capture shown in brackets.
Site name (EOI code) 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Liverpool Centre 38 36 (GB0594A) (93) (68) Liverpool Queen’s 40 38 37 35 30 34 34 34 Drive Roadside (100) (99) (99) (99) (56) (64) (99) (96) (GB0922A) Liverpool Speke 27 23 24 22 24 22 (95) 22 30 24 25 23 25 22 (GB0777A) (57) (98) (98) (92) (96) (94) (94) (97) (86) (95) (91) (98)
(a) Annual Mean Limit Value = 40 µgm-3
Table 2: Annual mean NO2 model results in NO2_UK0006_Annual_1 for 2001 onwards.
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 10 Road length exceeding 175.1 65.9 155.8 120.1 121.0 120.9 129.9 72.3 67.3 100.5 64.5 60.3 38.6 33.6 25.3 (km) Background exceeding 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 (km2) Maximum modelled 63.2 53.3 63.3 67.9 84.1 76.2 87.4 81.7 78.3 88.0 79 80 57 54 50 concentration (µgm-3) (a)
(a) Annual Mean Limit Value = 40 µgm-3 -3 Table 3: Modelled annual mean NOX source apportionment at the location with the highest NO2 concentration in 2015 in NO2_UK0006_Annual_1 (µgm ) traffic count point 37905 on the A57; OS grid (m): 334400, 390600) .
Spatial scale Component Concentration at highest road link (a)
Total 4.2 Regional background sources NOx (i.e. contributions from From within the UK 2.2 distant sources of > 30 km from the receptor). From transboundary sources (includes shipping and other EU 2.1 member states) Total 40.1 From road traffic sources 25.8 From industry (including heat and power generation) 2.4 From agriculture NA Urban background sources NOx (i.e. sources From commercial/residential sources 8.4 located within 0.3 - 30 km from the receptor). From shipping 1.5 From off road mobile machinery 1.8 From natural sources NA From transboundary sources NA From other urban background sources 0.2 11 Total 95.3 From petrol cars 3.1 From diesel cars 13.6 From HGV rigid (b) 5.7 Local sources NOx (i.e. contributions from sources From HGV articulated (b) 0.1 < 0.3 km from the receptor). From buses 63.0 From petrol LGVs (c) 0.0 From diesel LGVs (c) 9.9 From motorcycles 0.0 From London taxis 0.0 Total NOx (i.e. regional background + urban background + local components) 139.6
Total NO2 (i.e. regional background + urban background + local components) 50
(a) Components are listed with NOX concentration of NA when there is no source from this sector.
(b) HGV = heavy goods vehicle
(c) LGV = light goods vehicle Figure 4: Map of modelled background annual mean NO2 concentrations 2015. Modelled exceedances of the annual limit value are shown in orange and red.
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Figure 5: Map of modelled roadside annual mean NO2 concentrations 2015. Modelled exceedances of the annual limit value are shown in orange and red.
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12 4 Measures
4.1 Introduction
This section gives details of measures that address exceedances of the NO2 limit values within Liverpool Urban Area agglomeration zone. This includes both measures that have already been taken and measures for which there is a firm commitment that they will be taken.
Section 5 then explains the extent to which it has been possible to incorporate the impacts of these measures into the baseline modelling carried out for this assessment.
4.2 Source apportionment
It is important to understand which sources are responsible for causing the exceedance in order to most effectively tailor measures to address the NO2 exceedance situation described in Section 3 above. This can be achieved by considering the source apportionment for the exceedance situation, also presented in Section 3. A summary of what the source apportionment shows and the implications for which measures would therefore be appropriate is given here.
Local road traffic was the dominant source in this exceedance location in the reference year. The largest -3 contribution was from buses at the location of maximum exceedance with a contribution of 63 µgm of NOX -3 out of a total of 139.6 µgm of NOX. Diesel cars and diesel LGVs were important sources on the motorway roads with the highest concentrations in this exceedance situation. Diesel cars, diesel LGVs and on some roads HGVs or buses were important sources on the primary roads with the highest concentrations. Articulated HGVs, diesel cars, diesel LGVs and rigid HGVs were important sources on the trunk roads with the highest concentrations.
This indicates that appropriate measures should impact on local road traffic sources in this zone. Other measures to address the urban background sources may also be beneficial.
4.3 Measures
Measures potentially affecting NO2 in this agglomeration zone have been taken and/or are planned at a range of administrative levels. These are:
• European Union
• National (i.e. England, Scotland, Wales, Northern Ireland or whole UK)
• Local (i.e. UK Local Authorities)
Details of European Union measures (e.g. Euro Standards, Fuel Quality Directives, Integrated Pollution Prevention and Control) can be found on the European Commission’s website (http://ec.europa.eu/environment/ air/index_en.htm). Details of national measures are given in the UK overview document.
Relevant Local Authority measures within this exceedance situation are listed in Table C.1 (see Annex C). Table C.1 lists measures which a local authority has carried out or is in the process of carrying out, plus additional measures which the local authority is committed to carrying out or is investigating with the expectation of carrying out in the future.
13 Measures by local authorities in the Liverpool Urban Area include, for example, a low emission strategy that includes policies on reducing congestion and pollution. The intention is to encourage a shift away from using cars e.g. to cycling and walking for travelling to work or school. There is action underway to improve the emission standard of buses via voluntary bus quality partnerships. Freight and taxi quality partnership initiatives are also in place. Traffic planning has also been utilised to improve traffic flow.
Between 2013 and 2016 the Liverpool City Region (LCR) has been awarded £1.35 million through the clean Bus Technology Fund whereby 130 buses have had retrofits to bring them up to Euro VI standard.
Funding for Recharging Points was secured from the Office for Low Emission Vehicles (OLEV) to install a network of electric vehicle charging points across the LCR. Phase 2 of the scheme is now underway, funded by the Local Growth Deal funding. The LCR also secured funding from OLEV to introduce 23 ultra-low emission vehicles (ULEV’s) into local authority fleets across the City Region.
The City Council launched a city bike hire scheme in 2014. This has had 170,000 hires in the first two years of operation.
The Local Transport Plan for the area also promotes the implementation of a low emissions strategy. The aim is to improve air quality and health and provide a stimulus to the creation of new technologies in support of a Regional low carbon economy.
4.4 Measures timescales
Timescales for national measures are given in the UK overview document.
Local Authorities report on progress with the implementation of their action plans annually and review action plan measures regularly. Information on local measures was collected in February/March 2015. Local authorities were asked to review and, where necessary, provide updates to measures in March/April 2017. Hence, any Local Authority action plans and measures adopted by Local Authorities after this time have not been included in this air quality plan, unless additional information was provided during the consultation process.
The reference year for this air quality plan is 2015. Where measures started and finished before 2015, then the improvement in air quality resulting from these measures will have already taken place before the reference year and the impact of these measures will have been included in the assessment where the measure has had an impact on the statistics used to compile the emission inventory. Many measures started before the reference year and will continue to have a beneficial impact on air quality well beyond the reference year. Measures with a start date before 2015 and an end date after 2015 may have an impact on concentrations in the reference year and a further impact in subsequent years. Where the Status column in Annex C is ‘Implementation’, this shows that this measure is already underway or that there is a commitment for this measure to go ahead. Where the Status is ‘Planning’, ‘Preparation’ or ‘Other’ the level of commitment is less clear and it is possible some of these measures may not go ahead.
5 Baseline Model Projections
5.1 Overview of model projections
Model projections for each year from 2017 to 2030, starting from the 2015 reference year described in Section
3, have been calculated in order to determine when compliance with the NO2 limit values is likely to be achieved on the basis of EU, regional and local measures currently planned. Details of the methods used for the baseline emissions and projections modelling are provided in the UK technical report.
14 For national measures, it has not been possible to quantify the impact of all measures on emissions and ambient concentrations. The impact for all quantifiable measures has been included in the baseline projections.
The impacts of the individual Local Authority measures have not been explicitly included in the baseline model projections. However, measures may have been included implicitly if they have influenced the traffic counts for 2015 (used as a basis for the compilation of the emission inventory) or in the traffic activity projections to 2020 and beyond (used to calculate the emissions projections). It should be recognised that these measures will have a beneficial impact on air quality, even if it has not been possible to quantify this impact here.
5.2 Baseline projections: NO2_UK0006_Annual_1
Table 4 presents summary results for the baseline model projections for each year from 2017 to 2030 for the
NO2_UK0006_Annual_1 exceedance situation. This shows that the maximum modelled annual mean NO2 concentration predicted for 2020 in this exceedance situation is 40 µgm-3. Hence, the model results suggest that compliance with the NO2 annual limit value is likely to be achieved by 2020 under baseline conditions.
Figure 6 and 7 presents maps of projected annual mean NO2 concentrations at background and roadside locations respectively in 2020, the year at which compliance is achieved. For reference Figures 8 and 9 show maps of projected annual mean NO2 concentrations in 2020, 2025 and 2030 for background and roadside locations respectively.
It should be noted that the baseline projections presented here include the impacts of some measures, where they can be quantified, that have already been or will be implemented.
15 Table 4: Annual mean NO2 model results in NO2_UK0006_Annual_1.
2015 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
Road length exceeding 25.3 12.1 2.3 1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 (km) Background exceeding 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (km2) Maximum modelled 50 46 44 42 40 38 36 34 32 30 29 28 26 26 25 -3 concentration NO2 (µgm ) (a) Corresponding modelled 140 112 105 99 92 85 79 73 68 64 60 57 54 52 49 concentration NOx (µgm-3) (b)
(a) Annual Mean Limit Value = 40 µgm-3
(b) NOX is recorded here for comparison with the NOX source apportionment graphs for 2015 presented in Annex B of this plan. Limit values for EU directive purposes are based on NO2. 16 Figure 6: Background baseline projections of annual mean NO2 concentrations in 2020, the year at which compliance is achieved under baseline conditions. Modelled exceedances of the annual limit value are shown in orange and red.
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Figure 7: Roadside baseline projections of annual mean NO2 concentrations in 2020, the year at which compliance is achieved under baseline conditions. Modelled exceedances of the annual limit value are shown in orange and red.
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17 Figure 8: Background baseline projections of annual mean NO2 concentrations in 2020, 2025 and 2030. 2015 is also included here for reference. Modelled exceedances of the annual limit value are shown in orange and red. 18
© Crown copyright. All rights reserved Defra, License number 100022861 [2017] Figure 9: Roadside baseline projections of annual mean NO2 concentrations in 2020, 2025 and 2030. 2015 is also included here for reference. Modelled exceedances of the annual limit value are shown in orange and red. 19
© Crown copyright. All rights reserved Defra, License number 100022861 [2017] Annexes
A References
1st Daughter Directive 1999/30/EC. Council Directive 1999/30/EC, of 22 April 1999 relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air (The First Daughter Directive). From the Official Journal of the European Communities, 29.6.1999, En Series, L163/41.
Air Quality Directive 2008/50/EC. Council Directive 2008/50/EC, of 21 May 2008. On ambient air quality and cleaner air for Europe. From the Official Journal of the European Union, 11.6.2008, En Series, L152/1
Air Quality Expert Group (AQEG, 2004). Nitrogen Dioxide in the United Kingdom. http://uk-air.defra.gov.uk/ library/aqeg/publications
CDR Central Data Repository. http://cdr.eionet.europa.eu/
Decision 2004/224/EC. Commission Decision of 20 February 2004 laying down arrangements for the submission of information on plans or programmes required under Council Directive 96/62/EC in relation to limit values for certain pollutants in ambient air. From the Official Journal of the European Union, 6.3.2004, En Series, L68/27
Decision 2004/461/EC. Commission Decision of 29 April 2004 laying down a questionnaire to be used for annual reporting on ambient air quality assessment under Council Directives 96/62/EC and 1999/30/EC and under Directives 2000/69/EC and 2002/3/EC of the European Parliament and of the Council. From the Official Journal of the European Union, 30.4.2004, En Series, L156/78
Decision 2011/850/EU. Commission Implementing Decision of 12 December 2011 laying down rules for Directives 2004/107/EC and 2008/50/EC of the European Parliament and of the Council as regards the reciprocal exchange of information and reporting on ambient air quality. From the Official Journal of the European Union, 17.12.2011, En Series, L335/86
IPR 2013. Guidance on the Commission Implementing Decision laying down rules for Directives 2004/107/EC and 2008/50/EC of the European Parliament and of the Council as regards the reciprocal exchange of information and reporting on ambient air (Decision 2011/850/EU). http://ec.europa.eu/environment/air/quality/ legislation/pdf/IPR_guidance1.pdf
UK Air Quality Plan for tackling roadside nitrogen dioxide concentrations and the UK technical report are available at: http://www.gov.uk/defra.
20 B Source apportionment graphs
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21 Figure B.1: Annual mean roadside NOX source apportionment plots for all roads exceeding the annual mean NO2 limit value in 2015.
300 Liverpool Urban Area (UK0006): 2015 London taxis HGVr Motorcycles Cars diesel LGVs diesel Cars petrol LGVs petrol UB: Traffic ) 3 250
− Buses UB: Non traffic HGVa Regional background gm µ , 2 200 as NO X 150 concentration (NO concentration X 100 22 Modelled NO 50 0 PU,A59,7859,43 PU,A565,7861,41 PU,A57,37905,50 PU,A59,75290,49 PU,A580,7862,45 PU,A59,56612,43 PU,A59,48332,41 PU,A59,47911,41 PU,A580,7297,41 PU,A57,18444,41 MU,M62,27892,43 PU,A565,27302,41 PU,A561,77850,47 PU,A580,28563,47 PU,A580,37794,45 PU,A565,75288,44 PU,A580,70144,44 PU,A580,28238,43 TU,A5036,17655,46 TU,A5036,47741,46 TU,A5036,58149,43 PU,A5047,81361,42 PU,A5047,81581,42 PU,A5039,70133,42 PU,A5047,38294,42 PU,A5049,81363,42 PU,A5047,47917,41 PU,A5047,81580,41 PU,A5036,27745,41 PU,A5080,18508,49 PU,A5036,17657,49 PU,A5038,46588,48 PU,A5047,81362,46 PU,A5080,47919,45 PU,A5036,70146,44 PU,A5038,70142,44 PU,A5058,37334,43
−3 Road class (MU = motorway, PU = primary road, TU = trunk road), road number, census id 15 and modelled NO2 concentration (µgm ) C Tables of measures
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23 Table C.1 Relevant Local Authority measures within Liverpool Urban Area (UK0006)
Measure code Description Focus Classification Status Other information
Liverpool City Council_1.1 Voluntary Bus Quality Partnership Five corridors will come under the Traffic planning and management: Implementation Start date: 2013 (VQBP) VBQP, but the first one will be Route Improvement of public transport Expected end date: 2013 10. Agreed conditions will apply to Spatial scale: Local bus operators, Mersey travel and Source affected: Transport LCC Indicator: Number of Voluntary BQP Target emissions reduction: Once the corridors are fully compliant, expected emission reduction has the potential to be significant. Liverpool City Council_1.2 Improve Euro Standard Buses The Euro Standard for new buses Public procurement: New vehicles, Implementation Start date: 2013 will be a condition within the VBQP including low emission vehicles Expected end date: 2013 Spatial scale: Local Source affected: Transport Indicator: % of compliant buses on the corridors Target emissions reduction: Emission reduction will be within that estimated above Liverpool City Council_1.3 Signal enhancement Signal enhancement at junctions Traffic planning and management: Implementation Start date: 2009 along bus corridors to include Other measure Expected end date: 2030 24 enhanced phasing, selective vehicle Spatial scale: Local detection and in some cases new Source affected: Transport signals Indicator: Number of junctions upgraded Target emissions reduction: Emission reduction will be within that estimated above Liverpool City Council_1.4 Enforcement of vehicle idling Council officers will be asked to Traffic planning and management: Implementation Start date: 2008 regulations enforce the vehicle idling regulations Other measure Expected end date: 2030 focusing on buses and taxis. Spatial scale: Local Source affected: Transport Indicator: Number of enforcement interventions Target emissions reduction: Depends on scale of enforcement activity, but could reduce NOx concentrations by a few micrograms at areas where idling is a problem. Measure code Description Focus Classification Status Other information
Liverpool City Council_2.1 Trial of MOTE system A trial will be carried out to assess Traffic planning and management: Implementation Start date: 2006 using real time Mote sensor systems Other measure Expected end date: 2030 to feed air pollution data into Spatial scale: Local Liverpool’s traffic management Source affected: Transport systems. The systems will use this Indicator: Congestion data from trial information to develop strategies to junctions manage congestion and avoid peaks Target emissions reduction: The in concentrations. system is being trialled in Liverpool and indications are that it could reduce concentrations of NOx by several micrograms. Liverpool City Council_2.2 Continual development of Maximise efficiency of network Traffic planning and management: Implementation Start date: 2006 UTMC/SCOOT systems utilisation and therefore manage Other measure Expected end date: 2030 congestion by upgrading systems on Spatial scale: Local an ongoing basis. Source affected: Transport Indicator: Congestion data from key junctions Target emissions reduction: Will vary by location and type of improvement. Liverpool City Council_2.3 Day to day operation of High levels of investment has led to Traffic planning and management: Implementation Start date: 2006 UTMC/SCOOT centre significant work being done in the Other measure Expected end date: 2030 past few years and Liverpool’s Spatial scale: Local
25 advanced systems are preventing Source affected: Transport congestion and therefore reducing Indicator: Congestion data from key polluting emissions now. junctions Target emissions reduction: May not directly improve air quality outside of the interventions listed above, but is central to preventing air quality from getting appreciably worse in Liverpool in the context of growing traffic levels. Liverpool City Council_3.1 Travel Plans in workplaces, schools, TravelWise offer advice to Traffic planning and management: Implementation Start date: 2005 new developments organisations in Liverpool on Encouragement of shift of transport Expected end date: 2030 implementing Travel Plans. modes Spatial scale: Local Source affected: Transport Indicator: Number of organisations/individuals actively engaged in travel planning. Target emissions reduction: It is not possible to quantify for a city wide AQMA as data will first have to be generated for the city wide activity of current and future Travel Plans, not merely the number that have been developed. Measure code Description Focus Classification Status Other information
Liverpool City Council_3.2 Walking The Merseyside Local Transport Traffic planning and management: Implementation Start date: 2005 Plan partners are working to make Encouragement of shift of transport Expected end date: 2030 walking around Merseyside easier modes Spatial scale: Local and more enjoyable. This includes Source affected: Transport improvementsto public spaces and Indicator: Improvements to existing pavements as well as signposts and infrastructure and facilities better provision for disabled people. Target emissions reduction: It is not possible to quantify for a city wide AQMA as data will first have to be generated for city wide mode shifts to walking. Liverpool City Council_3.3 Cycling An agreement between Liverpool Traffic planning and management: Implementation Start date: 2010 Primary Care Trust and Merseyside Encouragement of shift of transport Expected end date: 2030 Transport Partnership sets out to modes Spatial scale: Local generate a 10% increase in trips Source affected: Transport made by bike before the end of Indicator: Improvements to existing March 2011, compared to journeys in infrastructure and facilities 2006. Target emissions reduction: The share of journeys taken by bicycle is still very small in Liverpool, and a 10% increase will not impact measurably on ambient air quality,
26 though some estimate of emission savings could be undertaken when robust activity data is available. Liverpool City Council_4.1 Enhanced design of Live Air website To redesign the website including a Public information and Education: Preparation Start date: 2008 strong educational element to the Internet Expected end date: 2030 site to increase usage and public Spatial scale: Local awareness Source affected: Transport Indicator: Relaunch of site, number of hits on the site per month Target emissions reduction: This is likely to have negligible impact in the short term but over the longer term it will encourage sustainable travel options Liverpool City Council_4.2 Airtext Alert system A three year trial, whereby registered Public information and Education: Implementation Start date: 2008 members receive a text when Other mechanisms Expected end date: 2010 pollution levels are high Spatial scale: Local Source affected: Transport Indicator: Launch of the service, number of registered members Target emissions reduction: Aim is to provide a health warning to susceptible people when pollution is high. No impact on reducing emissions Measure code Description Focus Classification Status Other information
Liverpool City Council_5.1 Enhance design of air quality There are currently several schemes Traffic planning and management: Other Start date: 2011 monitoring network aimed at reducing congestion the Other measure Expected end date: 2030 current monitoring network is not Spatial scale: Local optimised to track the air quality Source affected: Transport effects of these schemes. Indicator: Monitoring data from key corridors and junctions Target emissions reduction: No reduction will be invoked directly but a better understanding of policy effects on air quality would be gained. Sefton Metropolitan Borough A565 RMS Action Plan Reduce emissions by measures in Traffic planning and management: Implementation Start date: 2009 Council_AQMA 1 No 1 the A565 Route Management Other measure Expected end date: 2012 Strategy Action Plan to ease Spatial scale: Local congestion Source affected: Transport Indicator: Compliance with the PM10 air quality Objectives. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Port booking system Reduce emissions using efficient Traffic planning and management: Implementation Start date: 2009 Council_AQMA 2 No 1 HGV booking system Other measure Expected end date: 2009 Spatial scale: Local
27 Source affected: Transport Indicator: Feedback on effectiveness of booking system via Port liaison meetings. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Port mitigation Offset emissions from HGVs due to Traffic planning and management: Planning Start date: 2016 Council_AQMA 2 No 2 port expansion Other measure Expected end date: 2022 Spatial scale: Local Source affected: Transport Indicator: Compliance with the NO2 air quality Objectives. Measure implemented to timescale. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough EcoStars fleet recognition Reduce emissions from HGVs using Other measure: Other measure Implementation Start date: 2013 Council_AQMA 2 No 3 port access routes Expected end date: 2015 Spatial scale: Local Source affected: Transport Indicator: Number of operators recruited to scheme Target emissions reduction: Difficult to estimate no target set Measure code Description Focus Classification Status Other information
Sefton Metropolitan Borough Hurry Call Reduce emissions by facilitating Traffic planning and management: Implementation Start date: 2011 Council_AQMA 3 No 1 HGVs passage through traffic lights Other measure Expected end date: 2011 on incline at Millers Bridge Spatial scale: Local Source affected: Transport Indicator: Number of activations of hurry call outside peak hours Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Regulatory control Port Industry Reduce dust emissions from Port Permit systems and economic Implementation Start date: 2011 Council_AQMA 3 No 2 Industrial processes instruments: Other measure Expected end date: 2011 Spatial scale: Local Source affected: Transport Indicator: Compliance results from Local Authority and Environment Agency site inspection visits to permitted industrial sites within the Port of Liverpool and the number of exceedances of the PM10 daily mean standard when predominantly north westerly winds. Target emissions reduction: Difficult to estimate no target set
28 Sefton Metropolitan Borough A565 RMS Action Plan Reduce emissions by measures in Traffic planning and management: Implementation Start date: 2009 Council_AQMA 4 No 1 A565 Route Management Strategy Other measure Expected end date: 2016 Action Plan to ease congestion Spatial scale: Local Source affected: Transport Indicator: Compliance with the NO2 air quality Objectives. RMS actions implemented to timescale. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Port mitigation Offset emissions from HGVs due to Traffic planning and management: Planning Start date: 2016 Council_AQMA 5 No 1 Port expansion Other measure Expected end date: 2022 Spatial scale: Local Source affected: Transport Indicator: Compliance with the NO2 air quality Objectives. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough EcoStars fleet recognition Reduce emissions from HGVs using Other measure: Other measure Implementation Start date: 2013 Council_AQMA 5 No 2 Port access routes Expected end date: 2015 Spatial scale: Local Source affected: Transport Indicator: Number of operators recruited to scheme Target emissions reduction: Difficult to estimate no target set Measure code Description Focus Classification Status Other information
Sefton Metropolitan Borough Optimisation of SCOOT Reduce emissions by optimising Traffic planning and management: Implementation Start date: 2010 Council_GM1 SCOOT system Other measure Expected end date: 2010 Spatial scale: Local Source affected: Transport Indicator: Optimisation of SCOOT Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough AQ information using VMS Reduce emissions using message Public information and Education: Implementation Start date: 2013 Council_GM2 boards to ease congestion Other mechanisms Expected end date: 2013 Spatial scale: Local Source affected: Transport Indicator: Ensure system operating effectively Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Work place travel plans Reduce emissions through travel Traffic planning and management: Implementation Start date: 2010 Council_GM3 plans Encouragement of shift of transport Expected end date: 2010 modes Spatial scale: Local Source affected: Transport Indicator: Number of work place travel plans implemented Target emissions reduction: Difficult
29 to estimate no target set Sefton Metropolitan Borough School travel plans Reduce emissions through travel Traffic planning and management: Implementation Start date: 2010 Council_GM4 plans Encouragement of shift of transport Expected end date: 2010 modes Spatial scale: Local Source affected: Transport Indicator: Percentage of schools in Sefton with a travel plan. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Encourage walking & cycling Reduce emissions by encouraging Traffic planning and management: Implementation Start date: 2010 Council_GM5 cycling and walking Encouragement of shift of transport Expected end date: 2010 modes Spatial scale: Local Source affected: Transport Indicator: Increase in participation. Target emissions reduction: Difficult to estimate no target set Measure code Description Focus Classification Status Other information
Sefton Metropolitan Borough Land use planning system Mitigate emissions through planning Other measure: Other measure Implementation Start date: 2010 Council_GM6 system Expected end date: 2010 Spatial scale: Local Source affected: Other, please specify Indicator: Percentage of planning permissions granted where the submitted air quality assessment shows no action was required or the air quality impact of a development was mitigated. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Low Emission Strategy measures Mitigate/reduce emissions through Other measure: Other measure Implementation Start date: 2010 Council_GM7 low emissions strategies Expected end date: 2010 Spatial scale: Local Source affected: Transport Indicator: Number of LES measures implemented Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Tree planting Reduce emissions by planting trees Other measure: Other measure Implementation Start date: 2010
30 Council_GM8 Expected end date: 2010 Spatial scale: Local Source affected: Transport Indicator: Number of trees planted within AQMA. Compliance with the PM10 air quality Objectives Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough AQ awareness Reduce emissions through Public information and Education: Implementation Start date: 2010 Council_GM9 awareness information & education Internet Expected end date: 2010 Spatial scale: Local Source affected: Transport Indicator: Maintenance of Sefton Council air quality website. Number of AQ awareness events held. Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Freight Quality Partnership Reduce emissions from freight Traffic planning and management: Implementation Start date: 2010 Council_GM10 Freight transport measure Expected end date: 2010 Spatial scale: Local Source affected: Transport Indicator: Number of meetings held. Number of AQ initiatives undertaken Target emissions reduction: Difficult to estimate no target set Measure code Description Focus Classification Status Other information
Sefton Metropolitan Borough Taxi Quality Partnership Reduce emissions from taxis Permit systems and economic Implementation Start date: 2013 Council_GM11 instruments: Introduction/increase of Expected end date: 2013 environment taxes Spatial scale: Local Source affected: Transport Indicator: Number of operators participating Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Intensive road cleaning/pavement Reduce dust resuspension Traffic planning and management: Implementation Start date: 2011 Council_AQMA 1 No 2 washing Other measure Expected end date: 2013 Spatial scale: Local Source affected: Transport Indicator: Comparison of ratio of PM10 levels at site within AQMA to background site Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough ANPR study Gain information on HGV fleet using Traffic planning and management: Implementation Start date: 2012 Council_AQMA 2 No 4 A5036 to inform action plan Other measure Expected end date: 2012 Spatial scale: Local Source affected: Transport Indicator: Analysis of information and
31 interpretation of data to further inform Action Plan. Target emissions reduction: Information gathering exercise Sefton Metropolitan Borough Intensive road cleaning/pavement Reduce dust resuspension Traffic planning and management: Implementation Start date: 2010 Council_AQMA 3 No 3 washing Other measure Expected end date: 2013 Spatial scale: Local Source affected: Industry including heat and power production Indicator: Comparison of ratio of PM10 levels at site within AQMA to background site Target emissions reduction: Difficult to estimate no target set Sefton Metropolitan Borough Feasibility Study for Natural Gas and Reducing emissions from HGVs on Traffic planning and management: Preparation Start date: 2015 Council_1 other alternative fuels refuelling Port access routes Freight transport measure Expected end date: 2015 facilities in the Liverpool City Region Spatial scale: Whole agglomeration Source affected: Transport Indicator: Recommendations will be made by consultant in study report Target emissions reduction: Not estimated but savings greater than 80% NOx & PM10 emissions savings by HGVs running on LNG compared to diesel Measure code Description Focus Classification Status Other information
St Helens Metropolitan Borough Acoustic Barrier N/A Traffic planning and management: Evaluation Start date: 2014 Council_1 Other measure Expected end date: 2014 Spatial scale: Local Source affected: Transport Indicator: Monitored results Target emissions reduction: Medium St Helens Metropolitan Borough Use of hard shoulder running N/A Traffic planning and management: Evaluation Start date: 2014 Council_2 Other measure Expected end date: 2014 Spatial scale: Whole agglomeration Source affected: Transport Indicator: Monitored results Target emissions reduction: Medium St Helens Metropolitan Borough Traffic Regulation Order N/A Traffic planning and management: Other Start date: 2014 Council_3 Other measure Expected end date: 2014 Spatial scale: Local Source affected: Transport Indicator: Monitored results Target emissions reduction: N/A St Helens Metropolitan Borough Vehicle Idling N/A Public information and Education: Preparation Start date: 2014 Council_4 Leaflets Expected end date: 2014 Spatial scale: Local Source affected: Transport
32 Indicator: Monitored results Target emissions reduction: Low St Helens Metropolitan Borough Optimise flow on key routes N/A Traffic planning and management: Other Start date: 2012 Council_5 Encouragement of shift of transport Expected end date: 2013 modes Spatial scale: Local Source affected: Transport Indicator: Monitored results Target emissions reduction: Low St Helens Metropolitan Borough Travel awareness campaign N/A Traffic planning and management: Implementation Start date: 2012 Council_6 Encouragement of shift of transport Expected end date: 2014 modes Spatial scale: Whole town or city Source affected: Transport Indicator: Uptake Target emissions reduction: Low St Helens Metropolitan Borough Freight quality partnership N/A Traffic planning and management: Implementation Start date: 2013 Council_7 Freight transport measure Expected end date: 2016 Spatial scale: National Source affected: Transport Indicator: Uptake and monitored results Target emissions reduction: Low St Helens Metropolitan Borough Green Council fleet N/A Other measure: Other measure Implementation Start date: 2012 Council_8 Expected end date: 2014 Spatial scale: Whole town or city Source affected: Transport Indicator: Annual fuel records Target emissions reduction: Low Measure code Description Focus Classification Status Other information
St Helens Metropolitan Borough Green taxi fleet N/A Other measure: Other measure Planning Start date: 2016 Council_9 Expected end date: 2024 Spatial scale: Whole town or city Source affected: Transport Indicator: Calculated Target emissions reduction: Low St Helens Metropolitan Borough Supplementary planning guidance N/A Other measure: Other measure Preparation Start date: 2016 Council_10 Expected end date: 2016 Spatial scale: Whole town or city Source affected: Other, please specify Indicator: Monitored results Target emissions reduction: Medium St Helens Metropolitan Borough Raise awareness of AQ issues N/A Public information and Education: Implementation Start date: 2012 Council_11 Other mechanisms Expected end date: 2030 Spatial scale: Whole town or city Source affected: Other, please specify Indicator: Monitored results Target emissions reduction: Low 33 LIVERPOOL CITY REGION COMBINED AUTHORITY OVERVIEW AND SCRUTINY COMMITTEE
REVIEW INTO AIR QUALITY ACROSS THE LIVERPOOL CITY REGION
FINAL REPORT BY THE TASK AND FINISH GROUP
1 Chair’s Introduction
This review was chosen by Members in recognition of the air quality issues which were evident across the Liverpool City Region, with 11 Air Quality Management Areas in place. Furthermore, this review sought to examine and challenge the Combined Authority‟s strategic role in addressing poor air quality across the City Region.
This Task and Finish Group met five times during February 2018 and April 2018. Members heard extensive evidence from a number of high profile witnesses which included those with expertise in the monitoring and management of air quality across the City Region, a panel of witnesses which comprised of experts from public health and medical and the final panel of experts who explained how policies, plans and funding programmes from Merseytravel, Constituent Local Authorities and the Combined Authority could influence improvements to Air Quality.
The extensive evidence and insight gained enabled the Task and Finish Group to identify six recommendations and sought to complement the air quality feasibility study which was being developed by the Combined Authority.
2 Background to the Review
Action to manage and improve air quality is largely driven by European legislation, which sets legally binding limits for air pollutants that impact on public health, such as particulate matter and nitrogen dioxide. Related UK legislation requires local authorities in the UK to review air quality in their area and designate air quality management areas (AQMAs) where pollution levels exceed these limits. The legislation does not directly apply to the Combined Authority. The briefing paper in Appendix 1 summarises the legislation and legal powers.
Across the UK, road transport has been identified as the most significant source of emissions locally, related to transport. Nitrogen dioxide (NO2) and particulate matter (PM10s) are the main pollutants breaching legal limits, mainly stemming from the combustion of diesel fuel.
Where AQMAs are designated, local authorities are required to work towards improvement, and an Air Quality Action Plan (AQAP) must be developed. The
Page 21 City Region currently has 11 Air Quality Management Areas (AQMAs), and all of Liverpool City Council is designated an AQMA on account of its poor air quality. Many of these designations have been in existence for over a decade, and the problems associated with poor air quality are, generally, worsening rather than improving. The briefing paper in Appendix 2 provides additional information on the local air quality problem.
Linked to the City Region‟s Devolution Deal, and related commitments in the Metro Mayor‟s 100 Day Plan from the summer of 2017, the Liverpool City Region (LCR) is currently finalising an initial feasibility study to test, model and evaluate a range of measures that could improve air quality across the LCR, and to test their costs, relative benefits. This work commenced before the Task and Finish Group‟s work began, and it was possible to engage the feasibility study‟s lead consultant in this review. The Task and Finish Group‟s brief is considered wholly complementary with the scope of the technical feasibility work.
3 Developing the Scoping Document
An initial scoping meeting of the Task and Finish Group took place on 7 February 2018, where members were briefed on the current position relating to air quality management in the Liverpool City Region.
Members discussed the complexity of the issues at stake, and the large number of factors that affected air quality, such as traffic, freight, shipping, industrial pollution from commercial premises. Equally, it was appreciated that responsibilities fell to many organisations and indeed, to individuals, whose travel choices affect air quality.
Members considered the universities‟ involvement in the work to be important, specifically referencing air quality studies which had been undertaken across the City Region.
The effect of air pollution on health was highlighted and it was suggested that health professionals should be invited to provide statistics on related illnesses. It was noted that there was a correlation between low income areas and poor air quality and more information on this was requested.
Members were also keen to understand variations in air quality across the boroughs with a view to understanding how requirements stemming from European Regulations could be exceeded.
It was agreed that the aim of the review would be as follows:-
To examine and challenge the Combined Authority’s strategic role in addressing poor air quality across the Liverpool City Region, aided by an understanding of the risks to public health that are presented, and the plans, policies and proposals of both Authority and the six constituent local authorities in seeking to address these air quality problems.
Page 22 The review would go on to examine and make recommendations on:-
The context to the local air quality management regime, legal requirements and the causes and effects of poor air quality locally; Existing approaches locally and across the city region in tacking poor air quality, including initiatives by the Liverpool City Mayor, Merseytravel, and Public Health practitioners; The commitment in Liverpool City Region‟s follow-on Devolution Deal, that has led to the commissioning of an (ongoing) Preliminary Air Quality Feasibility Study, due to complete in March 2018 ; Approaches and best practice from others towns and cities across the UK and beyond; and Other actions and priorities that the Combined Authority could explore in the context of improving air quality.
4 What we did and who we spoke to
The panel was fortunate to hear evidence from a sizeable, highly proactive group of prominent experts in the field. The evidence gathering sessions ran for over six hours in total, in response to members‟ questions and ensuing discussions, linked to the interest in the issues at stake.
As noted in the scoping document, the review comprised three evidence sessions:-
a) The first session heard from witnesses with expertise of the air quality monitoring and management regime across the city region:-
Paul Farrell, Public Protection at Liverpool City Council Vicky Jackson, Atmospheric Emissions Officer, Merseytravel/Sefton MBC Duncan Urquhart, AECOM (consultant commissioned by Merseytravel to develop the preliminary air quality feasibility study)
b) The second session examined the impacts of poor air quality of health and comprised a panel of public health and medical experts on the issues:-
Dr Emer Coffey – Liverpool City Council Dr Richard Jarvis - Public Health England Dr Ben Barr – University of Liverpool Linda Turner – Sefton MBC Public Health Dr Rob Barnett – General Practitioner within the LCR
c) The final evidence session looked at the policies, plans and funding programmes that were being taken forward across the LCR:- Mick Noone – Director of Integrated Transport Merseytravel and Chair of the Transport Advisory Group (TAG)
Page 23 Colleen Martin - Liverpool City Council Dr Stephen Birch – Sefton MBC Matt Goggins – Head of Bus, Merseytravel Mark Dickens- LCRCA Planning Lead
A representative from the Society of Motor Manufacturers and Traders Limited (SMMT) was invited to give evidence, and whilst fully willing to participate, was unable to attend the planned evidence session due to prior commitments. However, SMMT have been approached for further written information which is being circulated to members separately, for their consideration.
5 What did we hear and from whom?
a) Evidence session one
This session sought to set the scene from a factual and regulatory context, to understand the location, extent and causes of poor air quality across the Liverpool City Region, together with an understanding of the local air quality management system.
Witnesses set out changes to air quality trends from the 1960s through to the present day and explained the changes seen in the composition of air pollution. For example, there has been a downward trend in pollutants like lead and sulphur dioxide, but Nitrogen Dioxide (NO2) and PM10 emissions in England remain a cause for concern. This comes as a result of the growth in vehicle use, despite an improvement in engine and emissions standards.
Air Quality is monitored through automatic monitoring stations and diffusion tubes located on street furniture across the City Region to undertake the required air quality management assessments. The Atmospheric Emission Inventory (AEI) that the LCR has invested in also provides a valuable tool for quantifying emissions of pollutants and assessing the impact of activities that release them.
b) Evidence session two
This session sought to understand the public health context arising from poor air quality stemming from transport emissions across the Liverpool City Region.
Poor air quality has a stark impact on public health. Air pollution can cause a range of cardiovascular diseases, lung cancer, respiratory diseases, asthma as well as eye and throat irritations, leading to premature deaths. The graph overleaf was presented by Dr Coffey as context:-
Page 24
Dr Coffey showed that, across the LCR, 1 in 3 die young (defined as less than 75 years), which translates as some 6,000 deaths each year. This is linked to a range of factors, including high rates of asthma, chronic bronchitis and coronary heart disease. Life expectancy is significantly reduced in more deprived areas. The LCR‟s health gap compared to the rest of the UK is widening. Improving socio-economic conditions in the LCR is key to improving people‟s health, building on earlier “health is wealth” studies and evidence.
Dr Barr referenced research by the University of Liverpool, which sought to quantify the savings to the health service if air pollution could be reduced.
Dr Jarvis considered there to be a need to invest in sustainable travel infrastructure and encourage the population to walk, cycle and exercise more as this has a contributing effect on pollution. Levels of pollution breathed in by cyclists are less than for those sitting in a car, for example.
The panel of experts considered there to be an urgent need to inform the public in terms of the impact that air pollution is having on health. In summary, the panel‟s evidence informed the Task and Finish Group that the
Page 25 city region should build a coalition of stakeholders and establish an air quality network, to help provide simple consistent messages. Recognising that air pollution needs to be tackled in partnership with a wide range of bodies and not just the local government, underpinned by senior level, long term commitments.
c) Evidence session three
The session sought to understand and assess the plans, policies and activities that are being developed and/or implemented across the city region that have the aim of addressing poor air quality. A large number of transport- related policies exist, with the overriding aim of promoting more sustainable travel choices, such as walking, cycling and public transport. Funds are available that could support the roll-out of such measures, such as the Transforming Cities fund and to promote the uptake of alternative fuels in the bus fleet. More needs to be done to encourage people to change their travel choices in practice, however.
Liverpool City Council had received a ministerial direction to advance improvements on air quality before 2020. The City Council had identified a range of areas to improve emissions e.g., changing LCC fleet to non-diesel alternatives and commitments to a diesel free city centre.
Sefton Council had also received ministerial direction and has identified a series of measures to address the problem through an Action Plan, a communications strategy, an air quality study as examples. Growth and development in the Port of Liverpool is a big issue for air quality as a result of an increase in container ship traffic. Better rail infrastructure and more use of inland and coastal shipping is needed to reduce these traffic levels. The Manchester Ship Canal is considered an important asset, but a balance needs to be struck between promoting greater use of the canal for the carriage of freight, and the impacts caused by the opening of swing bridges in Warrington upstream.
Merseytravel set out how the bus is part of the solution to improving air quality. For example, the LCR has the biggest electric bus fleet outside of London. Increased use of the bus is needed to reduce private car use and cut down on congestion and pollution. Prioritising bus services above general traffic is essential to do this, and measures such as bus lanes, red routes and intelligent traffic signals are considered part of the solution in order to attract people from their cars. Improved bus punctuality and reliability also reduces the number of busies needed to maintain a service, offering cost and environmental benefits.
More detailed summaries of the three evidence sessions are set out in Appendices 4, 5 and 6.
Page 26 6 What conclusions did we reach?
From the evidence sessions the following conclusions were reached:-
1. Although the Combined Authority is not specifically covered by local air quality management legislation, it can and must act in response and in order to raise the profile of the issue. The main cause of NO2 exceedances locally stem from transport emissions and as the Combined Authority has statutory responsibilities for transport policy and funding, the policies and priorities of the Combined Authority have a direct bearing on transport, and thus on transport emissions and local air quality management. Likewise, the role of the Authority‟s Spatial Development Strategy needs to be maximised in terms of its emerging policies on air quality.
2. The problems and risks associated with poor air quality from NO2 emissions should be a higher priority, and awareness needs to be raised. The problem is not as visible as it was in the past, when smog and soot from coal burning blackened building across the region. As a result, the health and social implications of the problem are not fully realised or appreciated. Much better communication and education is needed across the city region to raise awareness. The Combined Authority should promote best practice in this respect and seek to encourage a more consistent approach across the LCR to working with schools, communicating with the public and stakeholders and so forth, so as to allow people to take appropriate action.
3. Further work is needed to improve the air quality monitoring and modelling processes across the LCR, to make them “real time” and consistent, given the manual processes associated with collecting data from diffusion tubes on street furniture.
4. There needs to be greater commitment by the Combined Authority and a wide range of bodies alike towards the delivery of measures that support cleaner air and which reduce emissions from vehicles. Promoting more walking, cycling and public transport use is essential and there is an urgent need to actively plan for, and create a Liverpool City Region that fosters more sustainable travel choices. Land use planning guidance is considered vitally important in this respect, in order to future-proof new development and to promote sustainable design and “place-making”. Supplementary Planning Documents, produced by the local authorities are considered important to translate these principles into action.
5. The Combined Authority has an important role to play in terms of acting as a champion for the range of potential solutions available. Its emerging air quality preliminary feasibility study will be an important springboard for further action. This action plan should be considered in more depth by the Overview and Scrutiny Committee at a later date.
Page 27 7 What recommendations are we making?
1. That the Metro Mayor, on behalf of Combined Authority, acts as a political “champion” for a series of long term measures to improve air quality across the Liverpool City Region, involving a wide range of influential bodies and decision-makers. The preliminary air quality feasibility study which is in the process of being finalised, and the action plan that needs to be developed in response, should be formally considered by the Overview and Scrutiny Committee in due course. This will come ahead of consideration by the Combined Authority.
2. Allied to this, the Metro Mayor and the Combined Authority should champion a communications plan to set out a commitment to engage with people across the LCR. This should be targeted as follows:-
a) to engage with schools and young people who are particularly vulnerable to the effects of poor air quality, aided by consistent educational materials and best practice across the LCR;
b) to engage with the public protection and public health sectors to jointly raise awareness, which could be through roadshows and events, as examples; and
c) to promote National Clean Air Day and related campaigns.
The communications plan needs to explain clearly that the LCR has a problem and set out what can be done to both alleviate symptoms, and help address the root of the problem.
3. The Combined Authority needs to fully utilise and align its funding, transport, planning and economic development powers to create an environment where people have reduced reliance on road transport and make greater use of walking, cycling and public transport. For example, this could be linked to the Authority‟s emerging digital strategy and the powers that it has over a Key Route Network of local roads. This also needs to be consistently applied through the Authority‟s plans and strategies, e.g. through the Freight Strategy and Local Journeys Strategy.
4. The Combined Authority should use its emerging Spatial Development Strategy to address poor air quality and to raise air quality as a policy consideration.
5. The Combined Authority should give prominent and consistent consideration to air quality implications in its decision-making processes and in its investment decisions. This could include much better „before and after‟ analysis in project and programme evaluations.
6. The Combined Authority should support the six constituent local authorities in their statutory duties to monitor and address air quality, and
Page 28 seek to foster a more “high tech”, consistent and extensive air quality monitoring regime across the LCR. The Combined Authority also needs to work collectively with the constituent local authorities and with central government to tackle the problems caused by vehicles and engines that create the most pollution. This should take the form of an LCR air quality task force, convened by the Authority, comprising officers from the local authorities, Combined Authority and public health bodies, to progress the actions needed in order to improve air quality.
Page 29 List of Appendices
Appendix One – Supplementary Note – Air Quality Management Legislative background – considered by the Task and Finish Group at their meeting on 28 February 2018
Appendix Two – Supplementary Note – A brief introduction to air quality issues across the Liverpool City Region – considered by the Task and Finish Group at their meeting on 21 February 2018
Appendix Three – Map showing the location of Air Quality Management Areas (AQMAs) across the Liverpool City Region
Appendix Four – Air Quality Task and Finish Summary Note for the evidence session held on 21 February 2018
Appendix Five – Air Quality Task and Finish Summary Note for the evidence session held on 7 March 2018
Appendix Six – Air Quality Task and Finish Summary Note for the evidence session held on 21 March 2018
Appendix Seven – Links to additional documents outlined by expert witnesses
Page 30 Appendix One
TOPIC: Supplementary Note – Air Quality Management Legislative Background DATE: 28th February 2018 FAO: Scrutiny Panel Task and Finish Group on Air Quality AUTHOR: Huw Jenkins, LCRCA
1. This note provides a brief summary of the legislative background concerning local air quality management across the UK. It has been written from a policy perceptive and should not be taken as a definitive statement of the law.
2. The Environment Act 1995 and the “National UK Air Quality Strategy” from March 1997 sets hourly and annual mean objectives for eight pollutants :
Nitrogen Dioxide (NO2) Sulphur Dioxide (SO2) Carbon Monoxide (CO) Lead (Pb) Fine Particulate Matter (PM10) Benzene (C6H6) 1,3–Butadiene Ozone (O3)
3. The Environment Act 1995 requires local authorities to conduct periodic reviews and assessments of air quality. The first stage of review and assessment was undertaken in 2001 By 2005 LAs were required to designate an Air Quality Management Area (AQMA) where objectives were not being achieved, and thereafter produce an Action Plan to reduce emissions. Local Authorities must also submit regular progress reports to Government. Just as AQMAs can be declared when emissions exceed prescribed standards, they can also be revoked when standards are met.
4. Under EU law, which in turn has informed the UK‟s legislative framework, the UK Government is required to comply with emissions standards by 2020. Court proceedings have been brought against the UK Government by Client Earth on three occasions for non-compliance. Any action and fines from the EU would be levied against the UK Government (and the devolved administrations), though these fines could be levied against offending local authorities under the Localism Act 2011.
5. The Combined Authority is not specifically covered by local air quality management legislation, being a duty that falls to the constituent local authorities. However, as the main cause of NO2 exceedances in the LCR stem from
Page 31 transport emissions, and as the Combined Authority has statutory responsibilities for transport policy and funding, it will be appreciated that there is a link between the CA‟s responsibilities and those of the constituent local authorities. In other words, the policies and priorities of the Combined Authority have a bearing on transport, which in turn has a bearing on transport emissions and local air quality management.
6. Turning to issues of shipping and impacts on air quality, then the Mersey Port Health Authority has influence over the Mersey waterfront within Liverpool, Sefton and Wirral. Of particular concern to the Authority is dark smoke emitted from shipping, and which is an offence under the Clean Air Act 1993. Regulations permit dark smoke to be emitted for limited periods and in particular circumstances. Complaints related to ship operations or port areas will normally be the subject of a joint approach by the local authority and the Port Health Authority, with legal enforcement being undertaken by the local authority.
7. The Maritime and Coastguard Agency exercises further powers over coastal waters, extending to within 12 miles of the shore. Emissions from ships are covered by 1997 Protocol to the International Convention on the Prevention of Pollution from Ships (known as the MARPOL Convention).
8. MARPOL Annex VI, adopted in 1997, limits the main air pollutants in exhaust gases, including sulphur oxides (SOx) and nitrous oxides (NOx), and prohibits deliberate emissions of ozone depleting substances.
Page 32 Appendix Two
TOPIC: A brief introduction to air quality issues across the Liverpool City Region DATE: February 2018 FAO: LCRCA Scrutiny Panel Task & Finish Group on Air Quality AUTHOR: Huw Jenkins, Liverpool City Region Combined Authority
Tel: 0151 330 1393
1. Introduction
1.1 Action to manage and improve air quality is largely driven by European legislation, which sets legally binding limits for air pollutants that impact on public health, such as particulate matter and nitrogen dioxide.
1.2 In England, the Department for Environment, Food and Rural Affairs (Defra) has responsibility for meeting the values in England and co-ordinates assessment and air quality plans for the UK as a whole. The legislation requires local authorities in the UK to review air quality in their area and designate air quality management areas (AQMAs) where pollution levels exceed these limits.
1.3 Across the UK, road transport has been identified as the most significant source of emissions locally. Defra figures state that that 70% of air quality emissions are related to transport and nitrogen oxides (NOx) and particular matter (PM10s) are the main pollutants breaching legal limits, mainly stemming from the combustion of diesel fuel.
1.4 Where AQMAs are designated, local authorities are required to work towards improvement, and an Air Quality Action Plan (AQAP) describing the pollution reduction measures must be developed. These plans should contribute to the achievement of air quality limits at a local level.
1.5 Notwithstanding uncertainties surrounding „Brexit‟, the EU has the power to take action against non-compliant member states in the form of fines. There remains a real risk that fines could be levied on the UK for not having a „credible plan‟ to meet air quality standards, and these could be passed down to local authorities to pay. This is now recognised as a potential risk to local authorities, in addition to the serious health risks caused by poor air quality.
1.6 These health risks are wide ranging and well documented, including heart and lung disease, autism, brain development, cancer and overall reduced life expectancy. The premature death toll caused by road traffic pollution is suggested to be around 29,000 people or 5% of all annual UK deaths and the
Page 33 UK has the second-highest number of deaths from nitrogen dioxide pollution in Europe.
2. The UK plan for tackling roadside nitrogen dioxide
2.1 Following earlier court cases against the UK Government for non-compliance against EU air quality targets, the Government published a draft Air Quality Plan for Nitrogen Dioxide in May 2017. The LCR Combined Authority considered and approved its response to this consultation in June 2017. The covering report and draft response is available here. The Government issued its final plan ahead of the legal deadline of end July 2017, and the document is available here.
2.2 The plan lists Knowsley, Liverpool and Sefton Councils as having roads with concentrations of NO2 forecast above legal limits. Despite being listed in the plan, it states that these areas are not required to conduct a Clean Air Zone (CAZ) feasibility study, as has been the case in other cities and city regions. As per the approach with London‟s T charge, a CAZ could seek to ban or levy charges against the most polluting vehicles, or else provide incentives to use less polluting forms of travel. Halton Borough Council is also cited in the plan as having roads with exceedances of nitrogen dioxide, which it states will be resolved by the opening of the Mersey Gateway Bridge. Again, a feasibility study is not mandated.
2.3 Despite not being mandated to look at Clean Air Zones specifically in the Government‟s national plan, Government still requires local action to achieve improvements in air quality ahead of the 2020 deadline imposed by Europe. The plan also signals the availability of further funding to assist local areas in tacking poor air quality, which could include a Clean Air Fund.
3. The air quality position across the LCR
3.1 The Liverpool City Region currently has 11 Air Quality Management Areas (AQMAs), and all of Liverpool City Council is an AQMA on account of its poor air quality. The map at the back of this briefing note shows the declared AQMAs across the city region.
3.2 In view of the clear links between transport and poor air quality, improving air quality is a core aim of the Liverpool City Region‟s statutory Local Transport Plans, to reduce emissions from transport sources, and promote a clean, low emission transport system. These plans also draw upon best practice from other European cities, where sustainable mobility, clear air and a healthy population are all recognised as core components of the creation of a strong and prosperous economy – “clean growth”. 3.3 Many of the city region‟s AQMAs have been in existence for over a decade, and it is fair to assert that poor air quality has been seen as a low priority, or else an inevitable consequence of growth. This in part stems from the complexity of the problems and solutions at stake, and the need for action by a very wide range of local authority departments, public health departments,
Page 34 the NHS, Public Health Departments, property developers, the private sector, motor manufacturers, local residents and so forth. In other words, it is a problem that does not sit neatly with any individual local authority department or public or private body.
3.4 The Liverpool City Region‟s 2016 Devolution Deal agreed between government and the Combined Authority commits to further devolution to the Authority, linked to the election of a directly elected Metro Mayor. In respect of air quality, it states that:
“The government will work with the Liverpool City Region Combined Authority to explore ways in which the Liverpool City Region Combined Authority Mayor can be enabled to implement Clean Air Zones in the Combined Authority area. This will help achieve Air Quality Plan objectives at both the national and local level.”
3.5 Building on the above, and as per the related commitment in the Metro Mayor‟s 100 Day Plan, the LCR is currently embarking on an initial study to test, model and evaluate a range of measures that could improve air quality across the LCR, and to test their costs, relative benefits. The work being commissioned will greatly enhance the LCR‟s understanding of the effectiveness of likely solutions. These options will also include an examination of Clean Air Zones (CAZs).
3.6 The commission for the study was awarded, following a competitive tendering process, to AECOM (led by Duncan Urquart). It is being steered on behalf of the Combined Authority by Merseytravel and the constituent local authorities. The work will be complete by the end of March 2018, and key issues will be reported to the local authorities and to the Combined Authority.
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Appendix Three - Map showing location of Air Quality Management Areas (AQMAs) across the Liverpool City Region
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Appendix Four
LIVERPOOL CITY REGION COMBINED AUTHORITY OVERVIEW & SCRUTINY COMMITTEE
SUMMARY NOTE
AIR QUALITY TASK & FINISH GROUP Evidence Session 1 21 February 2018
Attendees
Councillors Witnesses
Sue McGuire Paul Farrell, Liverpool City Council Denise Dutton Vicky Jackson, Merseytravel Pauline Sinnot Duncan Urquhart, AECOM Carla Thomas Bill Woolfall Supporting Officers Gillian Wood Paula Murphy Huw Jenkins, Liverpool City Region Combined Tricia O‟Brien Authority
1. Presentation from Paul Farrell, Vicky Jackson and Duncan Urquhart
Officers provided a presentation which highlighted the following:-
Set out the air quality trends from the 1960‟s through to the present day and explained the sources of air pollution which people were currently exposed too;
Outlined the trend of the various pollutants across England which demonstrated that until recently they had been on a downward trend (e.g. lead and sulphur dioxide).
Highlighted that Nitrogen Oxide and PM10 emissions in England have plateaued and remain a cause for concern as a result of the growth in vehicle use, despite an improvement in engine and emissions standards;
Explained the Air Quality legislation and the legislative framework which Local Authorities worked within;
Explained how Air Quality was monitored through automatic monitoring stations and Diffusion Tubes;
Outlined where automatic monitoring stations and diffusion tubes where situated across the City Region;
Explained the purpose of an Air Quality Management Assessment (AQMA) and highlighted the number of them in operation across the UK, with 11 situated across the City Region;
Summarised the purpose of an Atmospheric Emission Inventory (AEI) which provided a Page 37 valuable tool for quantifying emissions of pollutants and assessing the impact of activities that release them;
Provided examples of how the AEI identified the pollutant emissions for each source and how this information was able to support interventions to reduce air quality;
Considered a map of the City Region which highlighted the areas according to the indices of multiple deprivation; and
Compared the annual emissions for NO2 and PM10 for 2016 and through to 2020.
Summary of issues raised
Clarity was sought on whether this Task and Finish Group would have an opportunity to influence the Air Quality feasibility study which was currently being undertaken?
The Group was informed that the work of this Group would complement the feasibility study and that some issues being examined by the group went beyond the scope of the feasibility study.
A number of concerns were expressed regarding the vessels coming into the Port of Liverpool and the impact this had on air quality. In particular, Members sought clarity on the process of monitoring Cruise Liners to ensure they switched from dirty to clean fuel as they were coming into Port and what enforcement action was available if a Cruise Liner was found not to be switching from dirty to clean fuel.
It was suggested that Cruise Liners would be monitored by Marine regulations. However, further information would be sought to confirm if this was the case and that a supplementary note summarising the legislative framework would be produced.
It was noted that the presentation highlighted that the pollutants from rail were a concern and wasn‟t the preferred method of moving freight to rail causing greater problems to emissions.
Members were informed that the operation of rail diesel was a contributing factor towards increased emissions. However, with the continued electrification of rail lines and move to alternative fuel sources, this would seek to reduce the emissions from rail diesel.
A summary of how the Automatic Monitoring Station operated and the varying emissions it could measure was provided to Members.
A Member referenced Section 87 of the Planning and Environment Act and sought clarity on whether there had been any cases which had been prosecuted using this legislation in the City Region?
It was noted that no local authorities had been prosecuted under this legislation, but that the UK Government as a whole was in breach of the EU‟s air quality compliance targets. This had resulted in court cases against the Government by Client Earth, and the requirement for Government to produce an updated air quality plan. There remains a risk that any EU fines could be passed down to offending local authorities by the UK Government.
An explanation of how DEFRA sourced the data from the Automatic Monitoring Station was provided to the Group. This highlighted the frequency with which the data was Page 38 collected and how this was then verified through a manual process. The Group was also informed that the data contained in the Diffusion Tubes was collected on a fortnightly basis. It was noted that there are differences between local air quality data and DEFRA‟s data.
It was recognised that particulates had impacted upon air quality since the 1940‟s, however due to the developments in science and the reduction in sulphur dioxide and carbon monoxide they had come to prominence more recently been identified.
How was the location of air quality monitoring stations determined?
Members were informed that each Local Authority would determine the location of their stations. The decision was often influenced by the volume of traffic and other information.
With regards to emissions produced by shipping it was noted that the statistics highlighted that this could be on a par with road traffic.
In considering the presentation from Duncan Urquhart, AECOM, who was undertaking the air quality feasibility study on behalf of the LCR Combined Authority, Members noted that to understand the age of the vehicle fleet and the types of engines in use, automatic number plate recognition devices would support this and be able to inform the actions to address this. The importance of addressing exposure by individuals, rather than overall emission levels was also noted.
Members were advised that AECOM considered the monitoring of air quality across the City Region to be of a good standard.
Concern was noted over the national data used by Central Government which indicated that in 2020 the issue of poor air quality would have been significantly reduced. However, local data contradicted and it was envisaged that the feasibility study would confirm the local data and present a range of actions that could be introduced to best tackle the problem.
Page 39 Appendix Five
LIVERPOOL CITY REGION COMBINED AUTHORITY OVERVIEW & SCRUTINY COMMITTEE
SUMMARY NOTE
AIR QUALITY TASK & FINISH GROUP Evidence Session 2 7 March 2018
Attendees
Councillors Witnesses
Sue McGuire Emer Coffey – Liverpool City Council Denise Dutton Richard Jarvis - Public Health Pauline Sinnott Ben Barr – University of Liverpool Carla Thomas Linda Turner – Sefton MBC Bill Woolfall Dr Rob Barnett – GP, British Medical Gillian Wood Association Paula Murphy Kevan Wainwright Supporting Officers
Huw Jenkins - Liverpool City Region Combined Authority Rachel Farnan - Merseytravel
1. Presentation from Dr Emer Coffey, Dr Richard Jarvis, Dr Ben Barr, Linda Turner, with contributions from Dr Rob Barnett
Officers provided a presentation which highlighted the following:-
6,000 people in LCR die every year due to Air Pollution. 64 Years is the life expectancy of the average person in Knowsley and wider spread areas that are deprived in the LCR. The admission rate in Knowsley is more than double the rate in Wirral The premature respiratory mortality rate in LCR has increased by 13% since 2009/10. The gap with England has widened from 44% in 2007/09 to 65% in 2014/16. Global Burden Disease of risk factors of deaths in the North West. Air Pollution can cause Cardiovascular disease, Lung Cancer, Respiratory disease, Asthma as well as Eye and Throat Irritations. Improving socio-economic conditions in the LCR is key to improving people‟s health – “health is wealth” Richard Jarvis explained the different types of pollution. Need to look at investing in infrastructure and encourage the population of the North West to cycle and exercise more as this had a contributing risk to pollution. Amount of pollution taken in by cycling is a lot less than being sat in a car. Need to inform the public what impact Air Pollution is having on health and state that deprivation is also a contributing factor. Need to be mindful of how individuals with disabilities can tackle air pollution Potential to take a more consistent approach to use of supplementary planning guidance across LCR and to encourage active community engagement on planning applications. Page 40 Need to build a coalition of stakeholders and establish an air quality network across region and simple consistent messages to the public. There would be a £1.5million in prescription and medication costs saving if air pollution was reduced by 20% over 5 years within the LCR. Air Pollution needed to be tackled in partnership with NHS etc; not just the local government. The question was raised as to what the contribution of nitrogen dioxide had to deaths. It was reported that it reduced a person‟s lifespan of 6 months and a study was currently being carried out regarding this. When the report is published it would be able to be broken down to show the effects. A question was also raised as to what affect shipping had on air pollution and the distance it would spread. Richard Jarvis explained that due to shipping using high sulphur fuels; it would contribute to air pollution. A recommendation was put in place to contact the Port Authority to seek any data they have in relation to air pollution. A question was raised by Cllr Thomas as to whether there were any statistics showing what factor Carbon Monoxide had on air pollution. Richard Jarvis would seek the answer in relation to this and report back to Cllr Thomas. Richard Jarvis provided a list of what the LCR could do to tackle air pollution: - Leadership and Commitment from Members and Local Districts - Think about what needs to be done long term – and keep at it - Work out what suited the LCR best recognising that there are lots of potential solutions available - Need to achieve creating an environment where people could have reduced reliance on road transport and greater use of walking, cycling and public transport and tackle vehicles that cause the most pollution - Engage more with schools, public and bring in the Public Sector. In Sefton a local communications plan is due to begin in schools, taxis and eco- centres. Liverpool are developing a behavioural chance campaign and planning education work with schools. Work is also being carried out in schools in Wirral and perceptions of local air quality is being carried out in Halton.
Summary of issues raised
It was raised as to whether cycling was healthy due to congestion and being exposed to car emissions. However it was clarified that it was a risk benefit and we needed to do what we could to reduce an individual‟s exposure to pollution. The LCR needed to be promoting the effects of what air pollution has on an individual‟s health, invest in walking and cycling infrastructure, NHS need to be acting as champions and to engage with the public to make them aware that air pollution is a serious issue and contributes to deaths. In regards to children, it was suggested that it may be beneficial speaking with pram manufacturers in order to protect children from car emissions. A recommendation was put in place to contact l Port Authority to seek any data they had in relation to air pollution from shipping. It was recommended that Huw Jenkins ask representatives that attend the previous Air Quality Meeting what their opinion was on re-opening bus lanes and extending this to cycle lanes as this may benefit reducing air pollution and get the public cycling and using public transport. Planning needs be taken into account i.e. housing estates and being able to have easy accessibility to see a doctor or nurse, pharmacy and public transport. Huw Jenkins suggested bringing a planning representative to the next Air Quality task and finish group meeting.
Page 41 Appendix Six
LIVERPOOL CITY REGION COMBINED AUTHORITY OVERVIEW & SCRUTINY COMMITTEE
SUMMARY NOTE
AIR QUALITY TASK & FINISH GROUP Evidence Session 3 21 March 2018
Attendees
Councillors Witnesses
Sue McGuire (Chair) Mick Noone – Director of Integrated Transport Pauline Sinnott Merseytravel and Chair of the Transport Carla Thomas Advisory Group (TAG) Bill Woolfall Coleen Martin- Liverpool City Council Gillian Wood Stephen Birch – Sefton MBC Paula Murphy Matt Goggins –Head of Bus At Merseytravel Kevan Wainwright Mark Dickens- LCRCA Land Use Planning
Supporting Officers
Sue Jarvis- Liverpool City Region Combined Authority Shauna Phillips- Merseytravel Democratic Services
1. Verbal Presentations from Mick Noone, Coleen Martin, Stephen Birch, Matt Goggins and Mark Dickens
Mick Noone – Director of Integrated Transport and Chair of TAG : The STEP programme was in its second phase and delivered cycling and walking schemes to lessen private care use. Transforming Cities funding ideas were being developed with Steve Rotheram taking the lead. There was discussion on the state of the KRN with acknowledgement that it affected public transport, cyclists and pedestrians alike with 25% of the KRN being „structurally unsound‟. The City Region „Freight Logistics Strategy‟ took into consideration Air Quality looking to encourage low emission vehicle use, multi-distribution points and last mile low emission. The „Local Journeys Strategy‟ also focused on walking and cycling as did the „Right of Way Improvement Plan‟ and the TfN „Strategy Transport Plan‟. The capabilities of the Rail network to transport freight were also discussed with focus on the significant rail capacity constraints. The potential for a Clean Air Zone under the Devolution Agreement was queried by Councillor Sinnott. Issues around funding within the NHS and Education Sector were highlighted through questions raised by Councillors Wood and Murphy.
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Coleen Martin – Liverpool City Council Air Quality Expert: Coleen explained there had been ministerial direction to Tier 3 Councils to advance improvements on Air Quality before 2020 – Liverpool City Council had identified 6 areas to improve. Short term and Long Term measures included: salary sacrifice for car leasing/bikes, bus pass schemes, changing LCC fleet to non-diesel alternatives, commitment to a diesel free city centre, no – idling policies, hackney cab schemes to address diesel retrofitting. 21st June had been identified as „Clean Air Day‟ and it was hoped all the districts would be involved in sharing messages about cleaner air. Work had also been undertaken with Scottish Power to look at how uptake in electric vehicle usage could affect infrastructure. LCC were also inserting development requirements regarding electric vehicle charging points into contracts for new builds e.g. office buildings and housing estates. Further work was needed to improve the monitoring and review process in place to ensure they are more effective especially in regards to „before and after‟ analyses on projects like City Centre Connectivity. It was noted that theoretical modelling had been done to identify ways in which people could charge Electric Vehicles but there would be behavioural variances that would not be apparent yet. The price to charge would also vary dependent on the speed, location etc. Mick Noone suggested inviting Colleen to a TAG meeting to push Air Quality further up the agenda. Councillor McGuire queried if there was any training undertaken with drivers to address negative attitudes towards cyclists. Coleen stated there was work done with the Waste Collection Drivers and sensors had been fitted on their wagons to detect cyclists. Coleen offered to update with further information post meeting.
Stephen Birch- Sefton Council: Sefton Council had also received ministerial direction to improve its Air Quality and had identified 4 areas in which to do so: 2 on the A5036 and 2 on the A565. Measures included: the formation of an Air quality Strategy Group, an Action Plan, a Communications Strategy, an Air Quality study looking at the feasibility of a Clean Air Zone, Local Plan amendments specifying requirements to create charging infrastructure in new builds, Air Quality Initiatives in primary Schools utilising characters such as the „pollutants‟ and the Ecostars Fleet Recognition Scheme which awarded star ratings to companies dependent on improvements to their fleet in accordance with Air Quality measures. Growth and development in the Port was highlighted as a big issue for Air Quality in the region as there were significant expansion plans for a Deep Water Berth which would create an increase in container ship traffic. A City Region Port Assessment Steering Group looked at options for Rail, inland shipping on the MSC and Coastal Shipping. It was noted that potentially 75% of traffic from new containers could be transported onto the roads.
Matt Goggins- Head of Bus, Merseytravel: Bus as part of the solution to Air Quality issues was emphasized throughout Matt‟s presentation with 8/10 journeys being made by bus and the Region bucking the National trend of passenger decline with 16.2% growth. Increased use of Bus was highlighted as a measure to reduce private car use and cut down on congestion and pollution given the Euro6 standards of the fleet. Prioritising bus services as cost effective for the Public Sector was also noted given the decline in retail spend when the bus services are suspended. KPMG had done a study which showed for every £1 of public money invested in bus there would be a £3 return. However, this varied if punctuality and reliability dropped with extra buses being put in to
Page 43 maintain the schedule at extra cost. There was further discussion on Bus Lanes with a recent Intelligent Traffic Signals Trial being highlighted as potential solution. Matt noted locally Arriva had 72 hybrid electric and bio methane buses and the Region had the biggest electric bus fleet outside of London with the 27 route 100% electric. Actions taken by Bus were as follows: £40million invested in the bus fleet to ensure Euro 6 standard, £5million OLEV bid, stop/start technology on Stagecoach to combat idling, 7 year average age of fleet, smarter ticketing advances to speed up journey times and a £3million spend from Defra funding to retrofit 150 buses to better standard.
Mark Dickens – LCRCA Land Planning:
Mark referenced the Air Quality Strategic Policy and Air Quality Planning consideration in recommendations on spatial planning. Setting out charging points in planning regulations was also discussed. The group discussed creating an Air Quality Policy in SDS.
Summary of issues raised The cost of bus fares was noted as potentially hindering people from using the service and there was discussion on how this could be addressed. Potential for a Clean Air Zone. Driver training around cyclist in the districts and potentially lobbying for alterations to the Highway Code were discussed. Growth in the Port and how this can be managed with Air Quality in mind. Issues around the KRN and how these can be addressed to the betterment of all were raised. Concerns on the capacity of the rail network to carry freight were raised with emphasis on how these can be addressed. Working in partnership with the Hackney cabs was important to improving Air Quality and was being explored by LCC.
Page 44 Appendix Seven Links to additional documents outlined by expert witnesses
“Air Quality - A Briefing for Directors of Public Health” https://www.local.gov.uk/air-quality-briefing-directors-public-health
LCR Road Safety Strategy https://www.merseytravel.gov.uk/about-us/local-transport- delivery/Documents/LCR%20Road%20Safety%20Strategy%20FINAL%20v10%20- %20July%202017.pdf
LCR Long Term Rail Strategy https://www.merseytravel.gov.uk/Site%20Documents/LCR%20LTRS_Strategy%20 Summary_01_08_14_Final%20Issue%20%286%29_MTravel.pdf
LCR Rights of Way Improvement Plan https://www.merseytravel.gov.uk/about-us/local-transport- delivery/Documents/ROWIP%202%202018-2028%20final-March%202018.pdf
LCR Bus Strategy https://www.merseytravel.gov.uk/Site%20Documents/9560%20Bus%20Strategy%2 0FINAL%20WEB.pdf
LCR Local Journeys Strategy http://councillors.knowsley.gov.uk/documents/s49767/Item%206%20- %20Appendix.pdf?StyleType=standard&StyleSize=none
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