Harvard Animal Law & Policy Fellow Helen Harwatt and a team of colleagues have published a call to action in The Lancet Planetary Health. It urges climate ministers from high and middle income countries to consider including four overarching measures related to animal agriculture in revised commitments to the Paris Agreement. The call was published on December 11, 2019 to coincide with the United Nations Climate Change Conference (COP25) happening in Madrid this month.

The scientific consensus states CO2 emissions must be limited to 420 billion tonnes and approximately 720 billion tonnes of CO2 must be removed from the atmosphere to limit global warming to 1·5°C with 66% probability.1 Restoring natural vegetation, such as forest, is currently the best option at scale for removing CO2 from the atmosphere,2 and must begin immediately to be effective within the required timescale of reaching net zero emissions by 2050.1

The livestock sector, having largely displaced natural carbon sinks, continues to occupy much of the land that must be restored.3 Without such land restoration, CO2 removal from the atmosphere relies on methods currently unproven at scale, increasing the risk of temperatures rising high enough to tip various Earth systems into unstable states. This instability could result in the loss of coral reefs and major ice sheets, and increases the uncertainty of maintaining life-supporting ecosystems.4

If the livestock sector were to continue with business as usual, this sector alone would account for 49% of the emissions budget for 1·5°C by 2030,5 requiring other sectors to reduce emissions beyond a realistic or planned level. Since the first Intergovernmental Panel on Climate Change assessment report in 1990, the production of meat, milk, and eggs increased from 758 million tonnes to 1247 million tonnes in 2017,6 and is projected to further increase.7 Continued growth of the livestock sector increases the risk of exceeding emissions budgets consistent with limiting warming to 1·5°C and 2°C, limits the removal of CO2 from the atmosphere through restoring native vegetation, and threatens remaining natural carbon sinks where land could be converted to livestock production.3,5,7

To help reduce the risk of global temperature rising beyond 1·5°C or 2°C, we call on high-income and middle-income countries to incorporate four measures into their revised commitments to meeting the Paris Agreement, from 2020 onwards. First, declare a timeframe for peak livestock—ie, livestock production from each species would not continue to increase from this point forward. Second, within the livestock sector, identify the largest emissions sources or the largest land occupiers, or both, and set appropriate reduction targets for production. This process would be repeated sequentially, to set reduction targets for the next largest emitter or land occupier. Third, within a reconfiguration of the agriculture sector, apply a best available food strategy to diversify food production by replacing livestock with foods that simultaneously minimize environmental burdens and maximize public health benefits—mainly pulses (including beans, peas, and lentils), grains, fruits, vegetables, nuts, and seeds.5,8 Fourth, when grazing land is not required or is unsuitable for horticulture or arable production, adopt a natural climate solutions approach where possible, to repurpose land as a carbon sink by restoring native vegetation cover to its maximum carbon sequestration potential,2 with additional benefits to biodiversity.9

We propose that in creating Paris-compliant agriculture sectors, high-income and middle-income countries do not outsource their livestock production to other countries, and instead reduce demand for livestock products.

Although our suggestions are not a full list of mitigation actions for the agriculture sector, they are necessary to adhere to the equity component of the Paris Agreement, and are considered part of a suite of measures that are needed across all sectors to reduce the risk of reaching temperature levels beyond the Paris goals. We will provide further scientific evidence about these important topics during the ongoing revision of Nationally Determined Contributions to the Paris Agreement.

We declare no competing interests. Signatories speak on their own behalf, and not on behalf of their affiliated institutions.

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Helen Harwatt

Animal Law and Policy Program, Harvard Law School, Cambridge, Massachusetts, USA

William J. Ripple

Department of Forest Ecosystems and Society, Forest Biodiversity Research Network, Oregon State University, Corvallis, Oregon, USA.


Abhishek Chaudhary

Department of Civil Engineering, Indian Institute of Technology, Kanpur, India.

Matthew G. Betts

Department of Forest Ecosystems and Society, Forest Biodiversity Research Network, Oregon State University, Corvallis, Oregon, USA.

Matthew N. Hayek

Department of Environmental Studies, New York University, New York, USA.

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List of Co-signatories

  • Dr Ezequiel Arrieta, National Council of Scientific and Technical Research, Argentina
  • Dr Bojana Bajzelj, Swedish University of Agricultural Sciences, Sweden
  • Professor Andrew Balmford, University of Cambridge, UK
  • Dr Phoebe Barnard, Conservation Biology Institute, and Universities of Washington and Cape Town, USA and South Africa
  • Dr Sébastien Barot, Senior Scientist, Institute of Ecology and Environmental Sciences-Paris, France
  • Jorge Barrasa Fano, KU Leuven, Belgium
  • Professor Laurent Begue, University Grenoble Alpes, France
  • Felicitas Beier, Researcher, Potsdam Institute for Climate Impact Research (PIK), Germany
  • Dr Alberto Bernués, Agrifood Research and Technology Centre of Aragón, Spain
  • Professor Rachel Bezner Kerr, Cornell University, USA
  • Dr Benjamin Leon Bodirsky, Potsdam Institute for Climate Impact Research (PIK), Germany
  • Professor Sir Ian Boyd, University of St Andrews, UK
  • Ruth Buckley-Salmon, Researcher, University of Southampton, UK
  • Dr Aurelio Cabello-Garrido, University of Malaga, Spain
  • Dr Richard Carmichael, Imperial College London, UK
  • Dr Maud Carron, World Organisation for Animal Health, France
  • Nicholas Carter, Researcher, School of Environment & Sustainability | Royal Roads University, Canada
  • Dr Michael Clark, University of Oxford, UK
  • Professor David A Cleveland, The University of California, Santa Barbara, USA
  • Professor Wolfgang Cramer, CNRS – Mediterranean Institute for Biodiversity and Ecology (IMBE), France
  • Professor Alexis Cranberg, University of Amans In Ascam, Hungary
  • Professor Miguel Delibes, National Council of Research, Spain
  • Professor Karlheinz Erb, Institute of Social Ecology, University of Natural Resources and Life Sciences, Vienna, Austria
  • Dr Erasmus zu Ermgassen, Earth and Life Institute, UC Louvain, Belgium
  • Professor Gidon Eshel, Research Professor, Bard College, USA
  • Professor Robert Ewers, Imperial College London, UK
  • Professor Nele Famaey, KU Leuven, Department of Mechanical Engineering, Belgium
  • Mark Fisher, Research Associate, Wildland Research Institute, University of Leeds, UK
  • Professor Christopher Gardner, Stanford Prevention Research Center/Stanford Woods Institute for the Environment, Stanford University, California, USA
  • Dr Tara Garnett, University of Oxford, UK
  • Professor Jose M. Gil, Technical University of Catalonia (UPC), Spain
  • Dr Jan Gojda, Charles University, Third Medical Faculty, Prague, Czech Republic
  • Professor Dave Goulson, Professor of Biology, University of Sussex, UK
  • Professor Rosemary Green, London School of Hygiene & Tropical Medicine, London, UK
  • Dr Jillian Gregg, College of Agricultural Sciences, Oregon State University, Corvallis, Oregon, USA
  • Dr Helena Greter, University of Basel, Switzerland
  • Professor Helmut Haberl, Institute of Social Ecology, University of Natural Resources and Life Sciences, Vienna, Austria
  • Dr Michalis Hadjikakou, Deakin University, Australia
  • Professor Danny Harvey, Department of Geography, University of Toronto, Canada
  • Dr Lucy Haurisa, Raffles Medical, HOPE Worldwide, Germany
  • Dr Georg Heiss, Freie Universität Berlin, Germany
  • Dr Martin Heller, Center for Sustainable Systems, University of Michigan, USA
  • Dr Kathrin Herrmann, Johns Hopkins Bloomberg School of Public Health, USA
  • Tobias Herzfeld, M.Sc, Potsdam-Institute for Climate Impact Research, Germany
  • Professor Nick Hewitt, Lancaster University, UK
  • Dr Almira Hoogesteijn, Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Mexico
  • Professor Dale Jamieson, Professor of Environmental Studies and Philosophy, New York University, USA
  • Professor Aled Jones, Global Sustainability Institute, Anglia Ruskin University, UK
  • Dr Daniel Jones, Kings College London, UK
  • Dr Laura Kehoe, The Nature Conservancy, UK
  • Professor Kathleen Kevany, Faculty of Agriculture, Business and Social Sciences, Dalhousie University, Canada
  • Professor Marianne Krasny, Director of Civic Ecology Lab, Natural Resources, Cornell University, USA
  • Dr Tilman Kuehn, German Cancer Research Center, Germany
  • Professor Kate Lajtha, Oregon State University, Corvallis, Oregon, USA
  • Professor Tim Lang, Professor of Food Policy, City, University of London, UK
  • Dr. Beverly E. Law, Oregon State University, Corvallis, Oregon, USA
  • Dr Adrian Leip, European Commission, Joint Research Centre, Italy
  • Professor Benoît Leroux, Université de Poitiers, France
  • Professor Simon Lewis, University College London, UK
  • Dr Brent Loken, EAT, Sweden
  • Professor Heidi Lynch, Point Loma Nazarene University, USA
  • Dr Raphaël Manlay, AgroParisTech, France
  • Professor Sandrine Mathy, Université grenoble Alpes, France
  • Professor Clive McAlpine, The University of Queensland, Australia
  • Dr David McBey, University of Aberdeen, UK
  • Professor Andrew McGregor, Macquarie University, Australia
  • Professor Ron Milo, Weizmann Institute of Science, Rehovot, Israel
  • Quinn Montana, Department of Environmental Dynamics, University of Arkansas, USA
  • Dr Adrian Muller, Research Institute of Organic Agriculture FiBL, Switzerland
  • Dr Christoph Müller, Potsdam Institute for Climate Impact Research, Germany
  • Dr Samuel Myers, Principal Research Scientist, Planetary Health Alliance, Harvard School of Public Health, Cambridge, MA, USA
  • Professor Jonathan Nash, College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, USA
  • Professor Lorenzo Pagliano, Politecnico di Milano, Italy
  • Professor Mercedes Pardo Buendía, Sociology of Climate Change and Sustainable Development, University Carlos III of Madrid, Spain
  • Ronald Parry, Emeritus Professor of Chemistry, Rice University, USA
  • Professor Carlos Peres, Professor of Ecology, University of East Anglia, UK
  • Dr Benjamin Phalan, Parque das Aves, Brazil
  • Dr Prajal Pradhan, Potsdam Institute for Climate Impact Research (PIK), Germany
  • Professor Navin Ramankutty, University of British Columbia, Canada
  • Professor Dave Reay, Professor of Carbon Management, University of Edinburgh, UK
  • Dr Marta G. Rivera-Ferre, Chair Agroecology and Food Systems, University of Vic-Central University of Catalonia, Spain
  • Professor Diego Rose, Director of Nutrition, Tulane University, USA
  • Professor Antonio Ruiz de Elvira, Universidad de Alcala, Spain
  • Professor John Sanbonmatsu, Worcester Polytechnic Institute, USA
  • Karen Saunders, Researcher, Antioch University New England, USA
  • Professor Peter Scarborough, University of Oxford, UK
  • Dr Wes Sechrest, CEO and Chief Scientist, Global Wildlife Conservation, Austin, Texas, USA
  • Dr Alon Shepon, Harvard T.H Chan School of Public Health, USA
  • Professor Drew Shindell, Nicholas School of the Environment, Duke University, USA
  • Professor Pete Smith, Professor of Soils & Global Change, FRS, FRSE, University of Aberdeen, UK
  • Professor Phillip Sollins, College of Forestry, Oregon State University, Corvallis, Oregon, USA
  • Dr Marco Springmann, Senior researcher, University of Oxford, UK
  • Dr Cristina Tirado von der Pahlen, Department of Political Science & International Relations, Loyola Marymount University, Spain/USA
  • Professor Nigel Unwin, Director of Research in Global Public Health Research and Professor of Diabetes, University of Cambridge and University of Exeter, UK
  • Professor Hans Van Oosterwyck, KU Leuven, Belgium
  • Dr Petra Verdonk, Amsterdam UMC, dept Medical Humanities, The Netherlands
  • Professor Jonathan Verschuuren, International and European Environmental Law, Tilburg University, Netherlands
  • Professor Paul West, Institute on the Environment, University of Minnesota, USA
  • Professor Walter Willett, Professor of Epidemiology and Nutrition, Harvard T. H. Chan School of Public Health, USA
  • Professor Stefan Wirsenius, Chalmers University of Technology, Sweden
  • Stephanie Wunder, Senior Fellow, Ecologic Institute, Germany
  • Heidi Zamzow, Researcher, London School of Economics and Political Science, UK
  • Leslie Zubieta, Marie Curie Fellow, Universitat de Barcelona, Spain


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Copyright © 2020 The Author(s). Published by Elsevier Ltd.

This is an Open Access article under the CC BY-NC-ND 4.0 license. Gold OA CC BY-NC-ND 4.0 license.

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DOI: https://doi.org/10.1016/S2542-5196(19)30245-1

Article link: http://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(19)30245-1/fulltext

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