Global trends of methane emissions and their impacts on ozone concentrations Van Dingenen, R., Crippa, M., Maenhout, G., Guizzardi, D., Dentener, F. 2018 EUR 29394 EN This publication is a Science for Policy report by the Joint Research Centre (JRC), the European Commission’s science and knowledge service. It aims to provide evidence-based scientific support to the European policymaking process. The scientific output expressed does not imply a policy position of the European Commission. Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use that might be made of this publication. Contact information Name: R. Van Dingenen Address: European Commission, Joint Research Centre, via E. Fermi 2749, I-21027 Ispra, ITALY Email: [email protected] JRC Science Hub https://ec.europa.eu/jrc JRC113210 EUR 29394 EN PDF ISBN 978-92-79-96550-0 ISSN 1831-9424 doi:10.2760/820175 Print ISBN 978-92-79-96551-7 ISSN 1018-5593 doi:10.2760/73788 Luxembourg: Publications Office of the European Commission, 2018 © European Union, 2018 The reuse policy of the European Commission is implemented by Commission Decision 2011/833/EU of 12 December 2011 on the reuse of Commission documents (OJ L 330, 14.12.2011, p. 39). Reuse is authorised, provided the source of the document is acknowledged and its original meaning or message is not distorted. The European Commission shall not be liable for any consequence stemming from the reuse. For any use or reproduction of photos or other material that is not owned by the EU, permission must be sought directly from the copyright holders. All content © European Union 2017, except: cover, 2017. 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How to cite this report: Van Dingenen, R., Crippa, M., Maenhout, G., Guizzardi, D., Dentener, F., Global trends of methane emissions and their impacts on ozone concentrations, EUR 29394 EN, Publications Office of the European Union, Luxembourg, 2018, ISBN 978-92-79-96550-0, doi:10.2760/820175, JRC113210 Contents Abstract ............................................................................................................... 1 Foreword .............................................................................................................. 2 Acknowledgements ................................................................................................ 3 Executive summary ............................................................................................... 4 1 Introduction ...................................................................................................... 8 2 The global methane budget, trends, and changing background ozone ...................... 9 2.1 . The global methane (CH4) budget .................................................................. 9 2.2 . Observationally derived CH4 trends ................................................................ 9 2.3 . Ozone (O3) trends in Europe and the world ................................................... 11 2.3.1 O3 observations ................................................................................. 11 2.3.2 Model attribution of O3 trends to CH4 emissions ..................................... 13 3 Trends of anthropogenic CH4 emissions .............................................................. 16 3.1 . Past CH4 emissions .................................................................................... 17 3.1.1 Europe, USA and other OECD countries ................................................ 17 3.1.2 Russia, China and India and other countries in transition ........................ 19 3.2 . Sectoral break-down of the anthropogenic CH4 emissions ............................... 20 3.2.1 Emissions from agricultural soils, livestock and other agricultural sources . 20 3.2.2 Fugitive emissions from fossil fuel production, transport by pipelines and other energy industries ................................................................................ 21 3.2.3 Solid waste and waste water emissions ................................................ 23 3.2.4 Other remaining sources ..................................................................... 23 3.3 . Future CH4 emissions ................................................................................. 25 3.3.1 Mitigation potentials ........................................................................... 25 3.3.2 Emission scenarios ............................................................................. 30 4 Air quality impacts of CH4 emissions .................................................................. 39 4.1 . Current O3 exposure patterns ...................................................................... 39 4.2 . Future trends in background O3 from CH4 emissions ....................................... 40 4.3 . Future health impacts from CH4-induced O3 .................................................. 42 4.4 . Future crop impacts from CH4-induced O3 ..................................................... 45 4.5 . Role of CH4 in closing the GHG emissions gap................................................ 47 4.6 . Summary of impacts .................................................................................. 48 5 Conclusions and way forward ............................................................................ 49 5.1 . Current understanding of observed changes of CH4 and O3 concentrations ........ 49 5.2 . Current knowledge on the geographical distribution of CH4 emissions and on the contributing sources ......................................................................................... 50 5.3 . Policy-relevant CH4 emission scenarios until 2050 and contributions to O3 concentrations in Europe and other parts of the world .......................................... 51 i 5.4 . Benefits for human health, crops and climate of CH4 emission reductions in the EU alone, and through collaboration with other parties .............................................. 51 5.5 . Promising economic sectors to effectively achieve CH4 emission reductions ....... 52 5.6 . The way forward ........................................................................................ 53 References ......................................................................................................... 55 List of abbreviations and definitions ....................................................................... 66 List of figures ...................................................................................................... 68 List of tables ....................................................................................................... 71 ANNEXES ........................................................................................................... 72 Annex 1. The EDGAR v4.3.2 CH4 emissions ............................................................. 72 A.1.1.1 EDGAR-IPCC sector aggregration............................................................ 72 A.1.1.2 Agricultural soils and livestock ............................................................... 73 A.1.1.3 Fugitive emissions from fossil fuel production and transmission .................. 73 Annex 2. Future emission scenario families ............................................................. 78 Annex 3. World regions aggregation ...................................................................... 85 Annex 4. Modelling O3 responses from CH4 emissions ............................................... 87 Annex 5. O3 impact on health and crop yields ......................................................... 93 ii Abstract Methane is a greenhouse gas and air pollutant producing health damaging tropospheric ozone. By 2050 in Europe 6,000 to 11,000 ozone-related premature deaths can be avoided per year (worldwide 70,000 to 130,000) when implementing ambitious methane reduction strategies worldwide. This works informs Europe’s forthcoming methane strategy. 1 Foreword Methane is the 2nd most important anthropogenic greenhouse gas after carbon dioxide. Since the pre-industrial era, methane concentrations have more than doubled, and at present sources related to human activities are about 50% larger than natural ones. After a period of stagnation, methane concentrations are increasing again since the last decade, and by 2020, may reach levels that match the most pessimistic projections used in the IPCC AR5 report. There are contrasting scientific hypotheses on the reasons for this uptick in methane, with a number of studies pointing to increasing emissions from agriculture, fossil fuel production and distribution, and in developing countries, solid waste in landfills and wastewater management. It is often forgotten by policymakers that methane is also an important precursor of ozone in the troposphere. Ozone itself is a greenhouse gas and short-lived climate forcer, but it is also an atmospheric pollutant responsible for harmful impacts on human health and damage to crops and vegetation and for which air quality standards have been established. In various parts of the world environmental policies aim to reduce ground level ozone, but there is a risk that increasing methane emissions will counteract those regional efforts. Because methane stays about 10 years in the atmosphere, chemical mechanisms that lead to widespread ozone formation involve methane sources from everywhere in the world and mitigation efforts must