How Climate Changes Affect Wisconsin Agriculture

  • Hay Bales

by Dan Dieterich

You’d think that global warming would be good for Wisconsin farmers, wouldn’t you?

After all, it means a longer growing season. In central and northwest Wisconsin, the growing season is already 20 days longer than it was in 1950. Global warming is also giving us warmer spring soil temperatures, less risk of frosts in late spring and early fall, and higher demand for food production. All of that’s good news for Wisconsin agriculture!

So, what’s the problem?

Our atmosphere is getting hotter, which is causing more droughts and wildfires. But the warm air also holds more moisture, which means bigger, more intense rainstorms and snowstorms that cause bigger and more frequent floods. All these affect agriculture.

Over the past 50 years, Wisconsin’s average temperature has increased 2.5° Fahrenheit, with Northern Wisconsin temperatures increasing more than Southern Wisconsin’s. Wisconsin temperatures are predicted to rise faster during the next 50 years: another 6° by mid-century.

How will this affect Wisconsin crops?

We’ll have hotter summer nights, stressing plants and reducing yields. A study by Stanford University scientists found that for each 1.8° rise in temperature above the norm during the growing season, yields of corn and soybeans declined by 17 percent. Corn fails altogether if 95° heat lasts long enough. And, in the next few decades, three-day periods with temperatures above 95° are predicted to occur in three of every four years.

Crops will also have more competition because the heat will bring more kinds of weeds to Wisconsin, and weeds will grow more vigorously. Insect pests will overwinter and cause additional damage.

Changes in precipitation will also affect farming. We’ll have more frequent droughts that, like the drought of 2012, reduce crop yields, stress livestock, and increase costs for irrigation and to feed/water livestock.

More rain in spring will compact the soil and delay planting, reducing yields. Storms will be more intense too, which means more replanting and less soil productivity. Torrential rainfalls won’t actually recharge the water system either because the rain will flow off the top of the soil.  Increased flooding will reduce our soil productivity and increase our replanting costs.

Higher heat and humidity will lead to more disease and fungus, also reducing yields.

The health of Midwest farmers will also be at risk. Instead of experiencing less than 3 days of over 95° heat each year, as they have for the past 40 years, by 2050 they will experience an additional 20 to 75 extreme-heat days each year. When combined with high humidity levels, such high temperatures can lead to heat stroke.

To reduce the global warming causing all this, we must reduce the greenhouse gases we emit by burning fossil fuels. To do that, we must put a price on carbon! Contact Senators Baldwin and Johnson as well as your Representative (either Kind or Duffy) during this August recess. Ask them to pass a bill establishing a revenue-neutral carbon fee.

All money raised by such a bill would go in equal amounts to American families so that we can pay the increased costs of fuel.

By helping to get such a bill passed, you will enable Wisconsin farmers to continue to produce the food that Wisconsinites and people in the rest of the world need.



“ClimateChange to Affect Wisconsin Crops,” by Taylor W. Anderson. Wisconsin State Journal, May 6, 2014.’article_c941067f-0369-5150-af2a-c0a048c162d6.html

Wisconsin’s Changing Climate: Impacts and Adaptation.  2011. Wisconsin Initiative on Climate Change Impacts. Nelson Institute for Environmental Studies, University of Wisconsin-Madison and the Wisconsin Department of Natural Resources, Madison, Wisconsin, pp. 96 & 98.

Pay Now, Pay Later: Wisconsin American Security Project.  ]

Risky Business: The Economic Risks of Climate Change in the United States. June 24, 2014.