COP26 Universities Network Briefing / march 2021 Destination net zero: setting and delivering ambitious, credible targets Key messages • Stabilising global temperatures at any level requires reaching net zero emissions. Stabilising at 1.5°C would mean reaching net zero global emissions of CO2 by mid-century and substantial reduction of other greenhouse gas emissions; the Paris Agreement also commits to a balance in human-caused sources and sinks of all greenhouse gases in the second half of the century. • Net zero means balancing emissions (sources) with removals (sinks), which requires deep and widespread emissions cuts, as well as scaling up both nature-based and technological removal methods. • Allied to net zero targets, immediate reductions of greenhouse gas emissions are essential, as global temperature rise is driven by cumulative carbon dioxide emissions over time. Reductions in emissions at source (as opposed to offsets and removals) should form the bulk of action to achieve net zero targets. • Individual net zero targets and the pathways to achieve them should be driven by considerations of responsibility and capacity. To reflect their equity obligations under the Paris Agreement, industrialised nations should, as a matter of best practice, consider setting targets for delivering net zero before 2050. • In order to be truly comprehensive, net zero targets should include all seven greenhouse gas groups reported under national inventories (while ensuring net zero CO2 specifically) and cover all economic sectors of activity. • Plans should be specified for how an agreed net zero target will be delivered, and immediate policy action should be taken to put them on track. These plans should be published, as should regular updates on progress towards achieving them. • An encouraging number of net zero targets are being set by national governments, regional, local and city governments, businesses, universities and third sector organisations. COP26 is an opportunity for more commitments to be made, and for ensuring targets are backed up by plans for delivery. • Net zero targets and near-term actions to implement them can be expected to produce a range of benefits – as well as co-benefits – to those who adopt them. Introduction Agreement. They provide a clear deadline for creating a zero-carbon economy, giving certainty and clarity Net zero emissions targets have gained traction for planners, industry, investors and consumers. in the global effort to halt climate change1. In 2019, Similarly, businesses and other organisations benefit the UK became the first of the G7 nations to make from setting their own net zero targets by providing a legally binding commitment to reaching net zero accountability to their stakeholders that they are greenhouse gas emissions by 2050. Of the G20, China changing their operations at the scale and pace has recently committed to carbon neutrality by 2060, needed for alignment with the Paris Agreement. while South Korea and Japan have committed to net zero emissions by 2050. At least 53% of gross As the impacts of the COVID-19 crisis continue to be domestic product (GDP) is now produced in countries, acutely felt, a net zero emissions transformation can regions or cities where net zero emissions targets have also significantly aid economic recovery. Sustainable either been agreed or are being proposed2. recovery policies could, if well designed, create more jobs, deliver higher short-term returns per Setting strong, ambitious targets for achieving net pound spent and higher long-term cost savings, zero emissions enables governments at national, in comparison to traditional fiscal stimulus. regional and city level to clearly align with the Paris Briefing authors: | Katrine Petersen, Imperial College London | Chris Jones, University of Manchester | Myles Allen, University of Oxford | David Reay, University of Edinburgh | Chris Hilson, University of Reading | Steve Smith, University of Oxford Destination net zero: setting and delivering ambitious, credible targets 1 They could also produce clear ‘co-benefits’ in terms of e.g. reduced urban air pollution, which is Box 1: Net zero carbon emissions and associated with increased morbidity and mortality ‘carbon neutrality’ rates. All of this makes embedding net zero targets Stopping CO emissions from causing global into future economic planning an even more 2 warming is a minimum requirement for halting compelling approach3. total human-induced warming. This requires However, a net zero target is only as strong as the a global balance between CO2 emissions and action to deliver on it. Meeting the Paris Agreement CO2 removal (i.e. ‘net zero’ CO2 emissions); goal by setting a net-zero target is ultimately path also known as ‘carbon neutrality’. This balance dependent, and contingent on short term measures must be sustainable, permanent and resilient to reduce CO2 emissions sufficiently in line with the to climate change. global carbon budget4. Current approaches to achieving net zero CO2 This briefing sets out the science behind net zero often rely on balancing out fossil-fuel emissions targets and the considerations that policymakers with offsetting through biosphere carbon storage and industry leaders should take when adopting and (such as through afforestation). However, such implementing such targets to represent the highest large-scale conversion between fundamentally ambition in both planning and delivery. different carbon reservoirs may not be sustainable over multi-decadal timescales, particularly should The science of net zero global warming itself cause carbon stored in the 6 The Paris Agreement stipulates a long-term biosphere to be re-emitted to the atmosphere . temperature goal to keep global warming to well As such, reaching ‘sustainable and permanent below 2°C and to pursue efforts to limit it to 1.5°C net zero’ will require changes to future offsetting above pre-industrial levels. and removal strategies, including ensuring they are resilient to current and future impacts of Article 4 of the Agreement states that this must be climate change. achieved by reaching a balance between sources and sinks of greenhouse gases from human activities in the second half of this century;a,5 what is commonly continue to rise up to that point, and sea levels will 7 known as ‘net zero’ emissions. continue to rise for many years beyond . The impacts of the current 1°C of global warming – such as on wildfires, heatwaves and flooding – are The ‘net’ in net zero targets already playing out across the globe and will become The emphasis on ‘net zero’, rather than simply ‘zero’ more severe with any increases in global temperature. – i.e. ending greenhouse gas emissions fully at the Aiming for the more ambitious Paris Agreement source – stems from the difficulty of achieving the temperature target – namely 1.5°C above pre- latter by 2050. industrial levels – significantly reduces the risks and Even if all measures to reduce greenhouse gas impacts of further climate change4. emissions are rolled out immediately, it is likely that Answering the question of what it will take to achieve some emissions will remain difficult to phase out this, the Intergovernmental Panel on Climate Change’s completely, such as those from some industrial (IPCC) 2018 Special Report on the impacts of 1.5°C of activities, agriculture and aviation sectors. In a net global warming showed that global emissions must zero emissions future, any residual emissions would be reach their peak immediately and then fall rapidly balanced by removals from the atmosphere through technological and nature-based solutions8. over the following decades. CO2 emissions dominate the climate impact from human activities and have However, there are significant uncertainties in large- a cumulative effect on temperature, so they must scale removal of greenhouse gases. Technological reach net zero for global temperatures to stabilise at solutions such as Direct Air Carbon Capture and any given level. To limit warming to 1.5°C, this will need Storage (DACCS), a process in which carbon dioxide to happen by 2050. Other greenhouse gas emissions is chemically trapped from the air, concentrated, and will need to be reduced substantially by this point as piped to geological stores, are still expensive and are well and continue to fall thereafter, with the IPCC still untested for large-scale use. calculating that net zero greenhouse gas emissions will need to be achieved around 2065. For nature-based solutions, relying on tree planting to reach net zero targets would require large amounts of Importantly, targeting net zero emissions does not land, posing risks for biodiversity and food production9. negate the need for substantial efforts on adaptation In addition, there are issues of long-term sustainability and resilience-building measures. Even if the world of using biosphere carbon storage to offset fossil fuel achieves net zero emissions, global temperature will carbon emissions, as explained in Box 1. a How natural and human-caused fluxes are disentangled is still a point of discussion. Destination net zero: setting and delivering ambitious, credible targets 2 As such, any net zero target must ultimately When countries set their target dates for will depend involve a targeted plan to bring emissions down on their specific context. On the basis of the Paris as much as possible in absolute terms, across Agreement principles that developed nations all economic sectors, alongside innovating and should lead the effort on climate change, there testing technologies both for removal and for is a strong equity-based case for industrialised hard-to-treat emissions. nations to set net zero greenhouse gas emissions targets by an early date, such as the UK has done Net zero might now also be considered the minimum with its target for net zero greenhouse gas emissions target that is acceptable for industrialised countries, by 2050, and preferably achieve net zero carbon given their larger historical emissions and current dioxide emissions earlier than that. Such concerted contribution to climate change, as well as greater early action by these nations would provide the space capability to tackle current emissions.