What climate change means for our state
Climate change can be a confusing issue. Christopher Kucharik, head of the agronomy department at the University of Wisconsin-Madison, knows that well.
“People hear the term global warming and say to themselves, well, we didn’t get it this year,” he said. “That’s the difference between weather and climate. It’s still going to be cold periodically; it’s just that climate change more or less loads the dice in terms of the probabilities of having more heavy rainfall events or warmer stretches during the winter when we’ll have a higher likelihood of rain vs. snow failing.”
And it’s not just the scientists who are noticing the longer-term trends.
“If you are writing down the date on the first day in spring when you see a robin — over 30 years — you’ll see that they are arriving three weeks earlier than they were back in the 1970s.”
With a background in atmospheric science, ecology, biology and agricultural systems, Kucharik studies how a changing climate impacts, among other things, “the production of crops and how they function and behave in the landscape, and how that might change in the future.”
He also looks at how those impacts might be felt on “our natural resources such as water quality and the amount of carbon we have in our soils.”
He and his researcher colleagues look at things on “a more policy-relevant scale because the Wisconsin Legislature isn’t going to implement some new plant nutrient policy, or whatever it might be, based on what one person found at an individual research station. They want to see results across a broad scale where it’s known to impact 2 million people.”
Here are some points he made during a recent interview about climate change and Wisconsin agriculture:
In the Midwest, temperatures are projected to be four to nine degrees warmer by the middle or later part of this century.
Nighttime low temperatures are warming faster than daytime highs. And the most significant warming has been happening in winter and springtime. Putting the polar vortex aside as a “blip,” he said that the frequency of very cold nights — those that reach below zero — has been on a significant decline over the last 70 years or so.
There's been a general trend toward wetter conditions in Wisconsin, with an increase in the frequency of heavy rainfall events, particularly over the last three decades.
It's going get harder and harder under a changing climate to clean up water. For example, if you add fertilizer in the spring to get things going and there’s a heavy rainfall event, a lot of the fertilizer is going to wash through and into the groundwater — or it will get carried through the landscape to a river or stream.
The growing season, particularly in the central and northern part of the state, has expanded by about one to three weeks. Plant hardiness zones have also moved farther north, so some of the types of plants that can survive have been changing.
One thing that may be less readily apparent: As we get warmer, there may be pests and diseases that weren’t here previously that have moved here from places farther south.
University scientists continue to develop adaptations for farmers, such as varieties of crops that are more wateruse efficient or more nutrient-use efficient.