A new climate model run by Purdue researchers shows that Great Lakes states could see up to 28 percent more precipitation by 2070. Much of that increase would be seen in the winter and spring and would likely lead to increased flooding. The model shows that though it may rain more overall, the summer and fall seasons will be drier This is troubling in that it could really have an adverse effect on agriculture by disrupting the planting season, while summer and fall droughts would also negatively impact crops and intensify water concerns.
Another serious issue is water quality. The increased heavy wet weather events could wreak havoc on local waterways from combined sewer overflows (CSOs). CSO's happen when rainwater overwhelms local sewer capacity and rainwater and sanitary waste overflows onto the waterways. Last year was the worst year in awhile with 37.2 billion gallons of CSOs in the Metro Detroit area. While those numbers are bad, there is an increased focus by municipalities on green infrastructure which looks at ways to redirect and filter rainwater naturally rather than having it go into the sewer systems.
The model was based off of the Intergovernmental Panel on Climate Change that gave predictions from 1950-2099. The model assumes warmer winters ranging between 2.7 and 5.4 degrees, and warmer summers ranging from 3.6 and 10.8 degrees. The projections were put into the Variable Infiltration Capacity Model which simulates rain patterns in land environments.
One of the recommendations is that though there won't be a shortage of water, ways to store excess water may need to be found. Some municipalities such as Rochester Hills, MI are already considering measures such as this. Though it is less of a response to global warming than it is towards using the reservoir for lawn irrigation so they can avoid peak water rates from the City of Detroit. Still though, it is the same principle, and the infrastructure will be useful for the future.
The report is published in the Journal of Great Lakes Research:
Hydrologic impacts of projected future climate change in the Lake Michigan region
Projection Shows Water Woes Likely Based on Warmer Temperatures