The Great Lakes region already is warming and changing faster than much of North America - and will continue to do so as global warming increases.
That was the summary finding of a new report, released Thursday, compiled by 18 scientists from across the region, both U.S. and Canadian.
The scientists gathered data from a broad range of previous studies that looked at ecosystems, economics, climate, agriculture and human health. It was called the most comprehensive assessment of climate impact on the region ever compiled.
The authors said the Great Lakes will see more algae blooms, more harmful bacteria in the water, more intense storms and warmer temperatures - all of which will impact humans, fish and wildlife as ecosystems reel under the stress.
The changing climate is impacting snowfall, ice cover - both how much and how long it lasts - and rainfall as well as water levels and storm damage around the lakes.
Lake Superior has seen several "unprecedented"' algae blooms in recent years due to warmer water temperatures and storms, said Lucinda Johnoson, associate director of the Natural Resources Research Institute at UMD and one of the report's leaders.
The Lake Superior region has seen three different "500 year storms" since 2012 alone, Johnson noted, causing widespread economic and ecological damage from wind, waves and flooding. But the big storms also bring runoff into the water that, when the waters calm, spurs algae, something that hadn't previously happened in Lake Superior.
So far the Lake Superior algal blooms have not turned toxic as they have in Lake Erie. But Bradley Cardinale, director of the Cooperative Institute for Great Lakes Research at the University of Michigan, said he suspects they probably will if water temperatures continue to increase.
The 71-page report says scientific studies predict the number of winter days that remain below freezing all day will drop significantly; Areas within the Great Lakes Basin could see an increase of 17 to 40 extremely warm days, with temperatures above 90 degrees, by century's end; more spring flooding and rainfall in extreme precipitation events could occur, disrupting agriculture and causing expensive infrastructure damage and runoff into rivers and lakes that leads to beach closings and algae blooms.
Among the report's key findings:
• The Great Lakes region has warmed more than other areas - up 1.6 degrees in annual mean temperature compared to a 1.2-degree increase for the rest of the continental U.S. (By the end of the century, global average temperatures are projected to rise another 2.7 to 7.2 degrees, depending on how much greenhouse gas emissions are produced. The authors said the Great Lakes will experience corresponding changes.)
• Great Lakes states should prepare for the likelihood of more extreme weather events: more flooding early in the year; more heat waves and drought in hotter months; an overall decrease in snowfall and snow cover, but more lake-effect snowstorms of significant magnitude.
• Drinking water from the lakes will be impacted. Warming trends have already increased bacteria levels in the lakes, and changes to the lakes' ecosystems will increase the number and severity of algae blooms which leave water unsafe to drink. Both bacteria and algae blooms dramatically increase the costs of water treatment, and can make water unsafe for swimming.
• Agriculture in the Great Lakes basin will see significant impacts. Changes in seasonal precipitation are already affecting farmers in Midwestern states, with planting delays caused by spring flooding and excessively wet soil. Delayed planting puts crops at greater risk during hotter and drier conditions later in the growing season. This increases the demand for irrigation to mitigate crop losses. Even with increased water management, it is projected that crop yields for both soybean and corn will decrease by 10-30 percent by the end of the century.
• Beaches, dunes and shorelines will be more vulnerable to coastal erosion as a result of changing weather patterns and the increased incidence of severe storm events.
The report comes on the heels of an Associated Press investigative report released this week that found the U.S. has experienced more than twice as many hot weather records than cold weather records in recent decades.
Johnson and Don Wuebbles, professor of atmospheric science at the University of Illinois and lead author of the report, said the Great Lakes have faced significant impacts over the past 200 years including invasive species, development on shorelines, urban and agricultural pollution and more.
"Climate change is now adding more challenges and another layer of stress," Wuebbles said. "This report paints a stark picture of changes in store for the lakes as a result of our changing climate."
The Chicago-based Environmental Law & Policy Center commissioned the report in coordination with the Chicago Council on Global Affairs. The report can be found at elpc.org/glclimatechange.
Officials said they will share the report with officials in each state and provincial government and with members of Congress but held out little hope the Trump administration would help implement solutions.
Changes suggested include advancing renewable solar, storage and wind energy development to create jobs and spur economic growth while avoiding carbon pollution; Improving energy efficiency, which saves residential and business consumers money on their utility bills, creates new installation and retrofit jobs, and keeps energy dollars in the Great Lakes region instead of draining energy dollars to places where more coal, natural gas and uranium are mined.