Climate Crisis Will Bring Wetter Winters to Majority of U.S., Study Finds

Most people in the United States can expect wetter winters with more extreme weather and precipitation due to global heating, a new study has found.

The research team — led by Akintomide Akinsanola, an assistant earth and environmental sciences professor at the University of Illinois at Chicago (UIC) — used climate models to look at how winter precipitation in America will change this century.

“We found that, unlike summer and other seasons where projected changes in precipitation is highly uncertain, there will be a robust future intensification of winter precipitation,” Akinsanola said in a press release from UIC. “It will accelerate well past what we have seen in historic data.”

The study, “Robust future intensification of winter precipitation over the United States,” was published in npj Climate and Atmospheric Science.

The researchers found that, in some areas of the country, “very wet” winters — those ranking in the top five percent for total winter precipitation — would happen as frequently as once every four years.

Akinsanola pointed out that the changes — combined with snow shifting to rain in many areas — would dramatically impact flooding, water resources, agriculture and other climate-sensitive areas.

Nearly 20 Earth system models were used in the study to conduct an analysis across the seven subregions of the U.S., as defined in the National Climate Assessment Report.

The study compared predicted precipitation for 2070 to 2099 with 1985 to 2014. It found that there would be a mean winter precipitation increase across the country of approximately two to five percent for each degree of warming.

The Northwest and Northeast were projected to have the largest increases in terms of “absolute change,” the press release said. Very wet winters were expected more often in six out of the seven regions, with the most marked increases found in the Midwest and Northeast.

The only region where predicted changes were highly uncertain and very small was in Southern Great Plains states like Oklahoma and Texas.

Akinsanola explained that an increase in the frequency of extreme dry events in the region would outweigh or offset the increase of extreme wet events.

“The findings highlight that changes in winter precipitation will have a significant impact nationwide and, in some regions, more impact than expected changes in spring and summer precipitation,” the press release said.

It is also likely that the mix of precipitation will change in many areas. Earlier studies predicted that, as temperatures rise, precipitation will increasingly fall as rain instead of snow, leading to lower snow depth. The reduction in snowpack along with higher rainfall levels will put stress on existing systems, UIC said.

“There will be a need for updating or upgrading infrastructure, because we’re not just talking about the mean precipitation, we’re also talking about an increase in extreme events,” Akinsanola said in the press release. “Drainage systems and buildings will have to be improved to cope with potential floods and storm damage.”