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USA - Great Lakes water levels could increase on average from 7.5 to 17 inches in next few decades, study says

New research into Great Lakes water levels looks farther into the future to predict how much climate change will increase lake levels in four of the five Great Lakes.

The predictions for the levels between now and 2050 show average increases from 2010-2019 levels of Lake Superior rising 19 centimeters (7.5 inches), Lake Erie 28 centimeters (11 inches) and lakes Michigan and Huron by 44 centimeters (17.3 inches). Lake Ontario wasn’t included because the outflow from the lake is regulated and at the time, the model used did not incorporate the regulation plans of Lake Ontario.

These forecasts are a big departure from others, many of which only extend less than a year. The U.S. Army Corps of Engineers, for example, puts out a six-month forecast bulletin every month based on current conditions and anticipated future weather.

The reason these new projections can go out so far and so confidently is the advanced modeling used in the study, applied for the first time to the Great Lakes.

Presented at the Frontiers in Hydrology Meeting on Thursday and awaiting publication, the research – led by Michigan Technological University associate professor Pengfei Xue – used advanced climate modeling with a 3D hydrodynamic model to simulate the lakes more accurately. The modeling Xue used is more typically applied to oceans.

“We were able to develop a coupled modeling system that not only accounts for the interactions between the lakes, atmosphere and surrounding land, but also presented a more realistic and accurate representation of the Great Lakes hydrodynamic processes in climate modeling,” Xue said. “This is a necessary step to ultimately improve the long-term lake level projections.”

Great Lakes residents already struggles with erosion and flooding – common impacts of high water levels – especially after the record-high water levels in 2019 and 2020. And even though water levels are no longer at record-highs, erosion and flooding remain huge problems.

“Climate-driven change to Great Lakes water levels is a prospect we take seriously,” Jeff Johnson, a public information officer with Michigan’s Department of Environment, Great Lakes, and Energy, said in an email. “It’s one reason to work toward a carbon-neutral Michigan by 2050 through the MI Healthy Climate Plan… I’m confident we will be proactive and responsive to challenges if these predicted high water levels come to pass.”

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