As climate change drives higher temperatures and more frequent droughts around the world, many predict severe threats to agriculture and food security. But a new study aggregating several climate and crop models suggests that the primary driver of climate change, rising levels of carbon dioxide, may also prove beneficial to crops, mitigating a portion of the damage.
The study, published in Nature Climate Change and led by Delphine Deryng, an environmental scientist at the University of Chicago’s Computation Institute, Columbia University’s Center for Climate Systems Research and the NASA Goddard Institute for Space Studies, finds that higher atmospheric CO2 will increase the water productivity of staple crops including wheat, maize, rice, and soybean. Modeling data found that in 2080 the elevated CO2 will improve agricultural water efficiency and increase crop yield — but not enough to completely offset the expected decline from climate change.
“We find that there is a huge increase in crop water productivity, but if you look at the net effect on yield and production, there’s still a negative impact due to extreme heat and water stress conditions,” said Deryng, who works with the CI’s Center for Robust Decision-Making on Climate and Energy Policy (RDCEP). “But increases in biomass yield with less water have crucial implications for food and water security, as well as agricultural policy.”
The new study finds large regional differences in the effect of high CO2 on CWP, as well as significant differences in how it affects the four different crops studied. For instance, they projected that farms in arid regions, particularly those using primarily rainwater, will benefit more from the positive effect of elevated CO2. In addition to Deryng, the paper’s authors include Joshua Elliott of the University of Chicago, RDCEP and Computation Institute, Christian Folberth and Hong Yang of the Swiss Federal Institute of Aquatic Science and Technology, Christoph Muller, Dieter Gerten, and Sibyll Schaphoff of Potsdam Institute for Climate Impact Research, Thomas A. M. Pugh of Kahrlsruhe Institute of Technology, Kenneth J. Boote, James W. Jones of University of Florida, Declan Conway of London School of Economics, Alex C. Ruane and Cynthia Rosenzweig of NASA Goddard Institute for Space Studies, Nikolay Khabarov of International Institute for Applied Systems Analysis, Stefan Olin of Lund University, and Erwin Schmid of University of Natural Resources and Life Sciences.