Iowa corn yield growth likely to slow by 2030 without urgent focus on climate adaptation

U.S. farmers have a long history of continually increasing crop yields. From the 1950s until now, farmers have turned to new technologies and other farming improvements to continually boost crop harvests and stay ahead of growing global food, fuel and fiber demand. It’s a remarkable feat of ingenuity and innovation.

That boom cycle won’t go bust any time soon, but it is starting to slow down. And that should concern us all.

The extreme heat and changing rainfall associated with climate change threaten to slow or reverse agriculture’s productivity growth as soon as 2030. A new study indicates that by the end of the decade, corn yields in Iowa are likely to be at least 5% lower than what they would be without climate change. More than half of Iowa counties will see yields dragged down by more than 10%.

Yes, warmer temperatures will lead to more days with favorable corn growing temperatures, but warmer temperatures also will lead to more killing-degree days when corn cannot grow. Detrimental impacts from hotter days and nights are predicted to outpace any opportunities from balmier temperatures.

Productivity declines are particularly concerning for two reasons. First, the reductions were modeled based on an optimistic climate future where carbon pollution peaks by 2050 then begins to decline. The world is not on track for that to happen, so climate impacts on crop yields could be substantially worse. Second, with the global population expected to increase 25% by 2050, it will be challenging to grow more food without further damaging the environment. If yields are slowing down on some of the most productive farmland in the world, warning signs are flashing red.

Fortunately, this future isn’t written in stone. If we take urgent action today to make agriculture more resilient to the climate impacts we can’t avoid, we can protect food supplies, farmer livelihoods and rural economies.

Adaptation options range from incremental to transformational, from farm-level to regionwide. Whether developing new seed varieties that can withstand warm nighttime temperatures, or equipping farmers across an entire sourcing region to grow more diverse crop rotations, change takes time.

Massive ships have to start turning long before they actually need to turn. Efforts must begin as soon as possible.

Policymakers and corporations must double down on research and development investments to maximize the likelihood of finding technological fixes that boost food production even in the face of climate change. The 5% yield slow down by 2030 assumes that the current level of public and private R & investment stays steady through 2030. That status quo is no longer enough.

Public-private partnerships, like those funded by the U.S. Department of Agriculture and the farm bill, can help build markets for more diverse and climate-resilient grains like oats and millet. Farmers are business people. If market infrastructure and consumer demand exist for a new type of crop, they’ll grow it.

We also need innovative new farm loan products that help farmers manage the financial risk and equipment costs they will incur when they start growing a new crop variety or using a different crop rotation.

Last but not least, the extension agents and other advisers who farmers already turn to for advice, will need to be knowledgeable about what climate resilience means for Iowa farms so that they can best help their farmer clients adapt.

These changes will require an all-hands-on-deck effort. Farmers, food and agribusiness companies, policymakers and politicians, nonprofits and universities all have key roles to play.

Adaptation is essential and urgent. It’s how we’ll ensure that Iowa farmers continue to help grow food for their local communities and for 10 billion people around the world, even as climate impacts make it harder to do so.

Britt Groosman is Vice President of Climate-Smart Agriculture at Environmental Defense Fund and an economist by training. Read the full research about climate impacts on crop yields in Iowa, Kansas and Minnesota at edf.org/climate-proofing-agriculture.

Opinion content represents the viewpoint of the author or The Gazette editorial board. You can join the conversation by submitting a letter to the editor or guest column or by suggesting a topic for an editorial to [email protected]