The realities of climate change — including more frequent floods, droughts, wildfires, heat waves, and more — are becoming ever more visible in every country. Agricultural producers face immediate impacts from these weather events. A marked increased in the incidence of pests and more challenging working conditions further harm their ability to grow plants and raise animals to feed people.
Global climate talks and national actions have focused on decarbonizing the power sector to address climate change, but policymakers, scientists, environmental groups, and farmers are increasingly looking at how to transform agriculture to help stabilize our climate. Our new book, Farming for Our Future: The Science, Law, and Policy of Climate-Neutral Agriculture, aims to provide the foundation that policymakers need to begin shifting agriculture so crop and animal production can both better handle climate change and contribute to mitigating it . While directed at U.S. policymakers, the lessons from the book are widely applicable in a global context.
Mitigating the harm of climate change
Russia’s invasion of Ukraine has demonstrated the interconnectedness of the world food system. The global food supply chain will feel impacts to and from Ukraine’s grain production for years. And while less dramatic in nature, policy incentives in the United States and elsewhere for farmers to grow animal feed and biofuel feedstock, rather than grains for direct human use, will also have geopolitical ramifications. This use of fertile land means less land is available to produce food more efficiently for people, thus increasing the possibilities of shortages.
Former President Donald Trump’s trade wars with China laid bare the close links between the U.S. and Chinese agriculture. The United States exports about a quarter of the food it produces and imports about a sixth of the food consumed by its population. China is the largest single market for U.S. agriculture, accounting for almost nine percent of total U.S. agricultural exports. China supplies 70 percent of the apple juice and 78 percent of the tilapia fish consumed in the United States as a part of $4.6 billion in food exported from China.
Food production technology also flows around the world. For example, other nations have adopted the U.S. model of large-scale concentrated animal feeding operations. Using this model, Latin America has since 2000 emerged as a major meat producer. Boasting only 8 percent of the world’s population, Latin American countries now produce a quarter of the world’s beef and poultry with enormous harm to the climate. Beef, along with leather and soy beans (mostly for cattle feed), are major export commodities in Brazil that also are driving tropical deforestation and loss of critical carbon sinks.
Global food systems are linked. Agriculture everywhere faces many of the same climate challenges, and agricultural producers around the world can employ similar strategies to increase resilience. Good practices, such as avoiding bare or overly disturbed ground, growing perennial plants, and increasing diversity, build resilience against extreme weather, mitigate climate change, and reduce water pollution. Yet these climate-friendly practices, here and abroad, are employed by farmers on only a tiny fraction of agricultural land; policy change will be critical to accelerating their adoption.
Agriculture’s contribution to climate change
Numerous studies highlight that the global food system as a whole contributes about a third of overall greenhouse gas emissions, and that agriculture itself contributes about a quarter, on a par with the transportation sector. Agriculture’s contributions to climate change largely come from methane, a powerful greenhouse gas about 85 times more potent in global warming over 20 years. Methane is generated by decomposition of manure and in the guts of cows and sheep. Agriculture’s other main greenhouse gas is nitrous oxide, released when nitrogen fertilizer is converted by soil microbes into this greenhouse gas. It is almost 300 times more potent than carbon dioxide. Healthy soils naturally hold a lot of carbon, but sadly most agricultural soils have now been stripped of much of that carbon, a process that also drives climate change.
Many opportunities are available to reduce methane and nitrous oxide emissions, while building up the amount of carbon stored in agricultural lands and plants. Soil can be restored to biological health and greater natural fertility by growing cover crops during the winter and by farming with longer crop rotations with plants that introduce a wider range of nutrients. This reduces the need for fertilizers and pesticides, saves costs for farmers, decreases the amount of nitrous oxide released into the atmosphere, and increases the carbon stored in the soil and plants.
Similarly, as Lixing Chengyang explained in a recent Environmental Law Institute webinar, agroforestry practices generally require less synthetic fertilizer, store larger amounts of carbon, and better withstand droughts and floods, because of the larger root systems of trees. Studies have shown that better crop and soil management through enhanced manure management and irrigation systems, improved grazing and animal feeding practices, and growing perennial crops brings benefits for both climate resilience and climate mitigation.