How Climate Change Is Damaging The Great Lakes, With Implications For The Environment And The Economy

By Matt Kasper, Center for American Progress

Great Lakes Michigan and Huron set a new record low water level for the month of December, and in the coming weeks they could experience their lowest water levels ever. It’s becoming certain that, like the rest of the country, the Great Lakes are feeling the effects of climate change.

Last year was officially the warmest year on record for the lower-48 states. The hot summer air has been causing the surface water of the Great Lakes to increase in temperature. One might think this causes more precipitation around the lakes, but the warmer winter air is causing a shorter duration of ice cover. In fact, the amount of ice covering the lakes has declined about 71 percent over the past 40 years. Last year, only 5 percent of the lakes froze over –- compared to 1979 when ice coverage was as much as 94 percent.

Furthermore, the continuing effect of the historic drought in the Midwest is causing increased levels of evaporation. This combination of climate change side-effects results in low water levels for the Great Lakes.

The impact climate change has on the five lakes (Superior, Michigan, Huron, Erie, and Ontario) will have serious implications for aquatic life, as well as high economic costs for communities.

  • The Great Lakes stretch from Minnesota to New York. They account for over 80 percent of North America’s surface freshwater, and provide drinking water to 40 million U.S. and Canadian citizens.
  • Many industries in the region that depend on trade through the lakes will face navigation challenges, and will have to reduce the amount of cargo carried.
  • Tourism and recreational activities that are vital to coastal communities will surely feel the negative economic effects. Activity associated with recreational fishing alone is estimated to be at least $7 billion annually.
  • Infrastructure investments will need to occur, as the necessity for extending docks and dredging increases.
  • And the habitats of fish, birds, and other mammals will be altered.

The two maps below developed by the Great Lakes Environmental Assessment and Mapping project (GLEAM) illustrate the severity of the environmental impacts on the lakes, as well as the warming temperature of the lakes.

The researchers behind GLEAM note that water surface temperatures between 2000 and 2100 will warm at rates ranging from 0.37-0.93 degrees Celsius per decade in Lake Superior, and 0.20-0.60 degrees Celsius per decade in Lake Eire as a result of climate change. Research conducted by the University of Minnesota-Duluth’s Large Lakes Observatory (LLO) found that summer surface water temperatures on Lake Superior have increased 2.5 degrees Celsius between 1979 and 2006. As climate change continues, fueling more frequent and more extreme droughts, we will continue to see more reductions in the extent and duration of winter ice cover.

Researchers at GLEAM are not alone in this finding.

Several different climate models for the Great Lakes region all predict that lake levels will decline over the next century. The NOAA Great Lakes Environmental Research Laboratory (GLERL) uses two different modeling approaches, researching the net effect of precipitation due to climate change, and the warming lakes and air surrounding the lakes are leading to increased evaporation levels.

The Third National Climate Assessment draft, the most comprehensive peer-reviewed analysis of how climate change impacts regions and sectors across the United States, was released last week. It found that the likelihood of extreme events like intense heat waves, mild winters, and lack of ice cover on the lakes will occur with greater frequency. The draft also finds:

  • The Great Lakes are warming at rates faster than the world’s oceans. This will also stimulate blooms of harmful algae in the lakes, leading to toxic cyanobacteria.
  • Climate change will likely heighten the impact that invasive species have in the Great Lakes.

11 Responses to How Climate Change Is Damaging The Great Lakes, With Implications For The Environment And The Economy

  1. Joseph Ventolora says:

    Bring on the fuel-cell cars and get rid of big gasoline companies.

  2. Paul Magnus says:

    Things are happening way faster then people can comprehend…

    That spending followed a $1.2 million trial by the Adelaide City Council to improve water quality last summer.

  3. Lore says:

    I live in Michigan, near the Lake MI shoreline, there is concern that a large number of ports will be closed this summer to boat traffic due to the low lake levels. Federal funding for dredging the harbors will only satisfy the major ports of call, so, local harbor town communities are now taking up collections to keep their ports open.

    Forget the idea of a ever tapping the lakes as a water source to supply a burnt out SW.

  4. rjs says:

    last year we had record flooding & my basement stayed flooded almost all year…& that was blamed on climate change too…when you switch like that, you lose creditability…

  5. Thomas Moore says:

    @rjs Your house flooded because the Great Lakes flooded last year? How close to which lake is your house?

  6. prokaryotes says:

    Lake Temperatures — Changing Planet

  7. Maxine says:

    Lake Ontario levels were high in the spring of 2012, high winds and lack of ice pack caused damage and flooded many homes along the shores of Lake Ontario.

  8. You didn’t read the headline: Heat Waves, Storms, Flooding: Climate Change to Profoundly Affect U.S. Midwest in Coming Decades. The lowering lake water levels is part of the climate-change scenario. Many areas will expect increased rain/snowfall, while others much less. Your point is simplistic in the face of an enormously complicated situation. It’s happening!

  9. paulb says:

    glad to see folks reporting and talking about our home – the Great Lakes. but do folks think the current system of governance is going to get us anywhere? there is a growing movement organizing under the umbrella of a ‘commons’ approach. also integrates into the re-indigenization of our thinking. see more at Great Lakes Commons Map or google great lakes commons.

  10. Jim Olson says:

    At FLOW for Water, a Water and Public Trust Policy Center focused on law and policy that advances pubic trust and water law principles to bring about integrative and comprehensive solutions to address threats, like climate change, to Great Lakes and elsewhere, we’re evaluating how public trust doctrine will empower citizens to require governments and industry to reduce global warming gases because they impair and subordinate the public trust in the Great Lakes – recognized as fundamental right of each person, in shared use and enjoyment of water. This right cannot be subordinated or impaired. And if government doesn’t act, citizens can go to court to enforce the trust like any legal beneficiary of a trust.

  11. Jim Snyder-Grant says:

    The Chicago River, largely sewage now, would start flowing in to Lake Michigan if there’s another 15 cm of water level drop in the lake: