Climate Change Will Put a Drag on U.S. Corn, Soy and Wheat Harvests by 2030

By Britt Groosman and Eileen McLellan et.al

For more than 50 years, U.S. farmers have steadily increased productivity, getting bigger harvests from the same land. That has made U.S. agriculture an economic engine and important contributor to global food supplies. Climate change may mean those days of unbridled productivity gains are over.

Without urgent action to make agriculture more resilient, climate impacts like higher temperatures and changing rainfall are likely to curb productivity growth as soon as 2030, with even bigger effects by 2050, according to a new report from Environmental Defense Fund, with modeling and analysis from Two Degrees Adapt, that looked at corn in Iowa, soybeans in Minnesota and winter wheat in Kansas.

“Farming amid climate change is like walking into the wind. You can still move forward, but at a much slower pace. In the same way, crop yields can still grow, but climate change will make productivity gains that much harder,” said Britt Groosman, vice president of Climate-Smart Agriculture at EDF. “This report gives us a sense of the headwinds that adaptation efforts will need to overcome to protect food supplies and maintain farmer livelihoods.”

How Climate Change Will Impact U.S. Corn, Soybean and Wheat Yields: A county-level analysis of climate burdens and adaptation needs in the Midwest used an ensemble of 20 climate models to predict how climate change would affect county-level yields of staple crops by 2030 and 2050. The models predict that by the end of this decade:

• Nearly all counties in Iowa will see corn yields that are more than 5% lower than they would have been without climate change. More than half will see declines of 10% or greater.
• More than half of Minnesota counties will see soybean yields drop by more than 5% from what they would have been without climate change. Seventeen-percent will see declines of more than 10%.
• Eight-percent of Kansas counties will see winter wheat yields drop by more than 5% from what they would otherwise be without climate change.  

The predicted slowdown in yield growth is especially concerning as the world will need to feed 10 billion people by 2050, a 25% increase over today’s global population.

“Our report looked at some of the most productive farmland in the entire world. If even those regions will struggle to boost yields, it will be challenging to grow more food without further damaging the environment,” said Eileen McLellan, lead senior scientist and report co-author at EDF. “Fortunately, adaptation efforts can help farmers stay ahead of climate impacts on yields, but we have to start immediately.”

“When we talk about adaptation, we’re talking about tangible things like new crop varieties or crop rotations that can help farmers keep farming in a changing climate,” said Kelly Suttles, senior research analyst and report co-author at EDF. “These approaches will need to be tailored to local needs to be successful. That’s why having results modeled down to 4,000-square miles is so important.”

Climate impacts will vary county by county, and adaptation efforts will be necessary on individual farm fields and across entire farming regions.