Experts expect global warming to have a negative impact on crop yields, but shortages of water for irrigation could make for double the trouble, according to a study published yesterday.
As described in ScienceDaily, “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.”
The study’s lead author, Joshua Elliot, said the analysis is the first of its kind to feature an in-depth comparison of agricultural and hydrological models, which resulted in dramatically different results from other research.
“It’s a huge effect, and an effect that’s basically on the same order of magnitude as the direct effect of climate change,” Elliott, a research scientist with the Computation Institute’s Center for Robust Decision Making on Climate and Energy Policy (RDCEP), Argonne National Laboratory, is quoted as saying. “So the effect of limited irrigation availability in some regions could end up doubling the effect of climate change.”
The “good” news, if any, is that some areas will most likely see more precipitation, which could mitigate some of the effects of shortages, the study says.
The study, entitled “Constraints and potentials of future irrigation water availability on agricultural production under climate change” and conducted under the auspices of the Agricultural Model Intercomparison and Improvement Project, as part of the Inter-Sectoral Impacts Model Intercomparison Project, was published in Proceedings of the National Academy of Sciences.