Study Reveals Great Lakes Shift to New Climate Reality: More Extreme Events Ahead

The Great Lakes have officially transitioned into a new climate phase, and historical data can no longer be trusted as an accurate predictor for upcoming conditions.

That's the landmark finding in a new study by researchers at the University of Michigan, who concluded that in this new era, extremes increasingly will become more extreme.

The research, featured in Communications Earth and Environment, revealed that after examining eight decades of intense heatwaves and severe cold spells, scientists were able to identify when each of the five lakes—as well as the broader Great Lakes area—started transitioning to an altered state.

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“If we operate based on what we know, it’s not going to be applicable anymore,” said Ayumi Fujisaki Manome, co-author and climate modeler at the Cooperative Institute for Great Lakes Research at the University of Michigan. “That puts us in a very vulnerable situation.”

Fujisaki Manome stated that with more severe climate fluctuations becoming typical, the dangers are increasing for ecological systems, fish populations, water quality, as well as coastal facilities such as power stations and potable water systems.

Here are six key points from the research.

numerous alterations began following the El Niño occurrence in the late nineties.

The researchers utilized computer models usually applied to oceanic studies to examine the changes in surface temperatures of the Great Lakes over the last eighty years. Through this analysis, they identified the timeframe when the area—and each specific lake—transitioned into a different climatic phase.

According to Hazem Abdelhady, who co-authored the study and works as a postdoctoral researcher at the University of Michigan, the transition generally started around 1998. He pointed out that numerous alterations can be linked to the intense 1997–98 El Niño episode, which ranks among the strongest ever documented.

Abdelhady noted that since then, extreme heat and cold events have become progressively more severe.

The intensity of heat waves at Lake Superior has tripled, while those at Lake Michigan have doubled.

Over the past eight decades, the upper Great Lakes — Superior, Huron and Michigan — experienced the largest change in heat wave intensity. Heat waves becoming more intense could mean temperatures become hot faster, or lasting longer, Abdelhady explained.

The strength of Lake Superior’s heat waves has more than tripled, according to the study. Heat wave intensity in Lakes Huron and Michigan has more than doubled. Abdelhady said Lake Superior likely saw the greatest change because it’s one of the fastest warming lakes Across the globe, it has experienced a significant reduction in ice coverage.

In every lake, 1996 marked significant changes, with the exception of Lake Erie, where these alterations happened in 1991.

More: During wintertime, the waters of Lake Michigan and Lake Huron used to form distinct layers. That's not the case anymore. Do you know why?

Lake Erie facing severe cold spells

The study discovered that cold snaps—which indicate a sudden decrease in temperature or unusually frigid weather persisting over time—have increased in severity by more than double across all five of the Great Lakes. Specifically, in Lake Erie, these events have almost tripled in intensity.

Abdelhady stated that Lake Erie has experienced the most significant changes in cold snaps due to being the shallowest among the Great Lakes, allowing it to cool down and freeze at a faster rate.

The change in severity of cold spells occurred around 1976 in Lakes Erie and Ontario, 1991 in Lake Michigan, and 1996 in Lakes Superior and Huron.

More: Recent information indicates that winters in the Great Lakes area have shortened by at least two weeks since 1995.

The Great Lakes help regulate the area's climate and weather.

Extreme fluctuations will also be noticed beyond the Great Lakes due to how this extensive body of fresh water influences local weather conditions.

Unlike land, water retains heat for longer periods and releases it very gradually, aiding in cooler summers and milder winters.

Fujisaki Manome noted that areas located downwind from the lakes will particularly experience the effects of these climatic changes. She explained that lake-effect snow occurrences may intensify as a result. Such phenomena generally occur during late autumn and early winter when the lakes remain unfrozen and retain warmth. They usually take place on the leeward side of the bodies of water; this explains why places like Buffalo and Rochester, New York, have lately faced severe and significant snowstorms.

However, according to Fujisaki Manome, the research indicates that predicting such events, along with overall seasonal forecasts, will be significantly more challenging.

Extreme conditions affect supply chains, fishing industries, and coastal management.

Fujisaki Manome pointed out that the difficulty in producing dependable seasonal forecasts could render numerous sectors ill-prepared for quick environmental changes. As an example, he mentioned that unexpected drops in temperature and abrupt alterations in ice formations can interfere with transportation and logistics, resulting in hold-ups and potential hazards.

Abdelhady pointed out that extreme fluctuations in temperature also damage fisheries because the quick shifts do not allow fish sufficient time to adapt.

In Lake Superior, intensifying heat waves could worsen the growing problem of blue-green algae blooms, according to Fujisaki Manome. Though still a relatively new concern for the largest of the Great Lakes, algae blooms have been on the rise since the first major bloom appeared in 2012, which scientists attribute to rising water temperatures from climate change .

Some algae blooms are toxic, contaminating drinking water. But even if they aren't toxic, blooms can suck up the oxygen and block sunlight, which impacts the rest of the food web. Algae blooms are also eyesores that can damage coastal economies.

More: Frigid, snow-covered winters are integral to Wisconsin’s character. However, could these seasons be disappearing?

The climate change affecting the Great Lakes is indisputable.

The latest research contributes to the accumulating body of evidence showing how climate change is affecting the Great Lakes area.

Winter is warming at the quickest pace in the Great Lakes area, turning into increasingly warmer and wetter , experiencing reduced snowfall. The season has shortened by several weeks, and ice cover has steadily declined over the past 50 years.

Changes are even happening to the lakes themselves. For instance, a study published earlier this year found that Lakes Michigan and Huron do not always form distinct layers —or divide into layers—in the winter anymore.

More: Wisconsin's 2024 climate assessment: A season marked by extraordinary meteorological events, along with historic temperature peaks and troughs.

Caitlin Looby is a Report for America corps member focusing on environmental issues and the Great Lakes region. You can reach her at clooby@gannett.com , follow her on X @caitlooby and learn more about how she approaches her reporting .

This article originally appeared on Milwaukee Journal Sentinel: Landmark study finds Great Lakes have entered a new climate era, with more extreme events