By Rob Mitchum
A warmer world is expected to have severe consequences for global agriculture and food supply, reducing yields of major crops even as population and demand increases. Now, a new analysis combining climate, agricultural, and hydrological models finds that shortages of freshwater used for irrigation could double the detrimental effects of climate change on agriculture.
Given the present trajectory of greenhouse gas emissions, agricultural models estimate that climate change will directly reduce food production from maize, soybeans, wheat and rice by as much as 43 percent by the end of the 21st century. But hydrological models looking at the effect of warming climate on freshwater supplies project further agricultural losses, due to the reversion of 20 to 60 million hectares of currently irrigated fields back to rain-fed crops.
“It’s a huge effect, and an effect that’s basically on the same order of magnitude as the direct effect of climate change,” said Joshua Elliott, a research scientist with the Computation Institute’s Center for Robust Decision Making on Climate and Energy Policy (RDCEP), Argonne National Laboratory, and lead author of the paper. “So the effect of limited irrigation availability in some regions could end up doubling the effect of climate change.”
The research was led by Elliott and colleagues from the Agricultural Model Intercomparison and Improvement Project (AgMIP), as part of the Inter-Sectoral Impacts Model Intercomparison Project (ISI-MIP). The paper is among 12 featured in a special feature dedicated to ISI-MIP research in Proceedings of the National Academy of Sciences, published online December 16…
Continue reading at the Computation Institute…