Scientists call for renewed Paris pledges to transform agriculture
Authors: Helen Harwatt, William J Ripple, Abhishek Chaudhary, Matthew G Betts, Matthew N Hayek
Journal: The Lancet Planetary Health (2019)

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.1Intergovernmental Panel on Climate ChangeSummary for policymakers.in: Masson-Delmotte VP Zhai H-O Pörtner D Global warming of 1·5°C. An IPCC Special Report on the impacts of global warming of 1·5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty World Meteorological Organization. IPCC, Geneva2018Google Scholar Restoring natural vegetation, such as forest, is currently the best option at scale for removing CO2 from the atmosphere,2Lewis SL Wheeler C Mitchard E Koch A Restoring natural forests is the best way to remove atmospheric carbon.Nature. 2019; 568: 25-28Crossref PubMed Scopus (320) Google Scholar and must begin immediately to be effective within the required timescale of reaching net zero emissions by 2050.1Intergovernmental Panel on Climate ChangeSummary for policymakers.in: Masson-Delmotte VP Zhai H-O Pörtner D Global warming of 1·5°C. An IPCC Special Report on the impacts of global warming of 1·5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty World Meteorological Organization. IPCC, Geneva2018Google Scholar The livestock sector, having largely displaced natural carbon sinks, continues to occupy much of the land that must be restored.3Poore J Nemecek T Reducing food's environmental impacts through producers and consumers.Science. 2018; 360: 987-992Crossref PubMed Scopus (1644) Google Scholar 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.4Steffen W Rockstrom J Richardson K et al.Trajectories of the Earth System in the Anthropocene.Proc Natl Acad Sci USA. 2018; 115: 8252-8259Crossref PubMed Scopus (1232) Google Scholar 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 2030,5Harwatt H Including animal to plant protein shifts in climate change mitigation policy: a proposed three-step strategy.Climate Policy. 2018; 19: 533-541Crossref Scopus (28) Google Scholar 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 2017,6Food and Agriculture Organization of the UNLivestock primary. World meat, egg and dairy production (excluding indigenous products and nes where items are not reported seperately) 1990 and 2017.http://www.fao.org/faostat/en/#data/QLDate: 2019Date accessed: November 14, 2019Google Scholar and is projected to further increase.7Springmann M Clark M Mason-D'Croz D et al.Options for keeping the food system within environmental limits.Nature. 2018; 562: 519-525Crossref PubMed Scopus (1134) Google Scholar 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.3Poore J Nemecek T Reducing food's environmental impacts through producers and consumers.Science. 2018; 360: 987-992Crossref PubMed Scopus (1644) Google Scholar, 5Harwatt H Including animal to plant protein shifts in climate change mitigation policy: a proposed three-step strategy.Climate Policy. 2018; 19: 533-541Crossref Scopus (28) Google Scholar, 7Springmann M Clark M Mason-D'Croz D et al.Options for keeping the food system within environmental limits.Nature. 2018; 562: 519-525Crossref PubMed Scopus (1134) Google Scholar 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 minimise environmental burdens and maximise public health benefits—mainly pulses (including beans, peas, and lentils), grains, fruits, vegetables, nuts, and seeds.5Harwatt H Including animal to plant protein shifts in climate change mitigation policy: a proposed three-step strategy.Climate Policy. 2018; 19: 533-541Crossref Scopus (28) Google Scholar, 8Springmann M Wiebe K Mason-D'Croz D Sulser TB Rayner M Scarborough P Health and nutritional aspects of sustainable diet strategies and their association with environmental impacts: a global modelling analysis with country-level detail.Lancet Planet Health. 2018; 2: e451-e461Summary Full Text Full Text PDF PubMed Scopus (317) Google Scholar 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,2Lewis SL Wheeler C Mitchard E Koch A Restoring natural forests is the best way to remove atmospheric carbon.Nature. 2019; 568: 25-28Crossref PubMed Scopus (320) Google Scholar with additional benefits to biodiversity.9Diaz S Settele J Brondízio E et al.Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. IPBES secretariat, Bonn, Germany2019Google Scholar 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. The list of signatories supporting our call can be found in appendix 2. Additional signatures from scientists and researchers are very welcome via our online portal. Download .pdf (.21 MB) Help with pdf files Spanish translation of appendix 1 Download .pdf (.45 MB) Help with pdf files Supplementary appendix 2 A "super-year" for the environmentAs we enter a new year and decade, it is natural to reflect on past progress and goals for the future. It's not surprising then that 2020 is shaping up to be a critical year in establishing ambition for climate and biodiversity action. There is much optimism and anticipation that this year could be a turning point in our relationship with nature, leading to the notion of 2020 being a "super year" for the environment. But this will only happen through conscious effort, if we drift on as we are, it will be far from super for people or the planet. 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