Here are a couple stories on U.S. corn yields:
From the “Risky Business Project“:
Shifting agricultural patterns and crop yields, with likely gains for Northern farmers offset by losses in the Midwest and South.
-
As extreme heat spreads across the middle of the country by the end of the century, some states in the Southeast, lower Great Plains, and Midwest risk up to a 50% to 70% loss in average annual crop yields (corn, soy, cotton, and wheat), absent agricultural adaptation.
-
At the same time, warmer temperatures and carbon fertilization may improve agricultural productivity and crop yields in the upper Great Plains and other northern states.
-
Food systems are resilient at a national and global level, and agricultural producers have proven themselves extremely able to adapt to changing climate conditions. These shifts, however, still carry risks for the individual farming communities most vulnerable to projected climatic changes.
From Ceres:
- 87% of irrigated U.S. corn is grown in regions with high or extremely high water stress, meaning there is limited additional water available for expansion of crop irrigation. The most vulnerable regions are in Nebraska, Kansas, California, Colorado and Texas.
- 27% of rainfed corn is grown in regions with high or extremely high water stress, meaning that there is limited water available should climate change make irrigation necessary. The most vulnerable regions are in Illinois, Wisconsin and Michigan.
- Twelve ethanol refineries above the High Plains aquifer – with nearly $1.7 billion in annual corn ethanol production capacity – are sourcing corn in areas experiencing cumulative declines in groundwater levels. Six of these refineries are in regions of extreme water-level decline (between 50-150 feet).
To me, this sounds like a lot of today’s productive farmland may not stay that way due to a combination of higher temperatures and drought. Can we really open up enough farmland and/or increase yields in “Northern States” to make up the difference? I suppose maybe there are areas of Canada that could go from ice-covered to prime farmland, as long as they stay wet enough.