Like the rest of the globe, the Midwest is expected to warm, but thus far scientists cannot clearly predict if the region will become wetter or drier. Even more perplexing, is the fact that temperatures in the Midwest have not yet significantly increased.
The puzzle is the subject of a study led by Dartmouth College assistant professor of geography Jonathan Winter.
He started digging into the Midwest while working on his PhD.
“There are only a couple of regions around the world that have not seen a significant increase in temperature due to climate change. And the Midwestern U.S. just happens to be one of them. And then when we look at the model projections, we see that yes, in fact, if we look out into the future, all of our models are forecasting an increase in temperature,” Winter says.
Winter says focusing on soil moisture proved to be an important tool for his study.
“One of the key differentiators of this study is that we were looking at soil moisture. Soil moisture is a good measurement of climate change impacts on agriculture because that’s what a plant cares about, how much water do I have access to in the soil order to grow and transpire,” Winter adds, "the reason why we feel confident looking at soil moisture is because we focused in on the state of Illinois which has a great three-decade-long data set, where they’ve been collecting soil moisture observations from around the state."
The Illinois State Water Survey based at the University of Illinois Champaign-Urbana collects the data.
He says more accurate projections will be critical because of the Midwest’s importance as an agricultural hub.
Winter says while in many part of the globe, scientists have a better idea whether soil moisture is likely to rise or fall, his Midwest research reveals uncertainty “some of the models predict we’re going to see an increase in soil moisture and others predict we’re going to see a decrease.”
Winter says the point of his study is to highlight the uncertainty.
“So we’re going to try to track this back to the atmospheric phenomenon that are driving it and see if we can’t explain better why we have this lack of warming and have that inform how we think about our future projections,” he says.
Winter says while the Midwest’s unique “warming hole” is yet to be fully understood, global climate change is not in question.
“The average global temperature is warming, and in fact NOAA has just released numbers for January-April temperature and 2015 is the hottest start to the year on record, Winter says.
He says we’re poised to experience record-breaking heat around the globe this year.
Winter’s study appears in the journal Water Resources Research.
