Report: Climate change compounds agriculture’s environmental impact
Environmental harms from agriculture are likely to worsen with climate change, according to a comprehensive review published in the journal Science on September 6.
“Climate change is rapidly and significantly aggravating the environmental damages wrought by agricultural production,” said Chris Barrett, corresponding author of the paper and Stephen B. and Janice G. Ashley Professor of Applied Economics and Management in the Charles H. Dyson School of Applied Economics and Management at the Cornell SC Johnson College of Business.
The paper draws on 150 previously published works to explain how climate change and agriculture interact, linking changes in rainfall, soil erosion, pest outbreaks, carbon and nitrogen emissions from land clearing, energy-intensive irrigation, and more. These interactions compound and amplify negative environmental impacts.
“This is the first time these threads have been pulled together in a single place,” Barrett said. “That’s important to motivate some leaders to act.”
Yi Yang of Chongqing University in China led the work along with numerous other scholars including Ariel Ortiz-Bobea, associate professor of applied economics and policy in the Dyson School, and Mario Herrero, professor in Cornell’s College of Agriculture and Life Sciences.
The world’s population is growing and becoming wealthier, the authors wrote, which increases the demands on agriculture to produce more food, animal feed, fiber, and biofuels. That leads to more greenhouse gas emissions, water scarcity, soil erosion, and chemical pollution.
Experts expect climate change will exacerbate most of these impacts. For example, when droughts reduce crop yields, farmers are often compelled to clear more land to increase production. Such actions add more greenhouse gases to the atmosphere, creating a “potentially powerful climate change-reinforcing feedback loop.”
“Seemingly distant issues may be interacting more than they appear,” said Ortiz-Bobea. By bringing diverse findings together and collaborating with experts across various fields, these potentially large feedback loops become visible beyond specialized research areas.
Despite major challenges, existing practices and technologies can improve sustainability, productivity, and climate resilience, the authors wrote.
“We have tools at the ready that can help meet the growing demand for food while mitigating agriculture’s environmental consequences—we just need to address the various obstacles to uptake of existing solutions,” Barrett said. “There are many promising innovations that are rapidly approaching field viability that just need reinforcement through R&D investments.”
New crop varieties offer drought and pest resistance as well as increased yields, for example. But education, subsidies, and insurance are needed to increase awareness, fund adoption of and grower experimentation with new cultivars, and buffer losses while transitioning to new practices, the authors wrote, adding that efforts in these areas must be adapted to local circumstances; there is no one-size-fits-all approach to scale such solutions.
Emphasizing the need for increased innovation, the authors assert that “reallocating about a tenth of high-income country agricultural subsidies could more than double public agri-food research and development investments globally.”
Future research in artificial intelligence, remote sensing, and other technologies could help diagnose problems in real time and optimize irrigation and chemical applications. A better understanding of climate-agricultural feedback loops would help determine where environmental impacts will be most severe.
“Climate change poses surmountable challenges if we muster the political will and create the right economic incentives to respond robustly and urgently,” Barrett said.