Climate Change and Great Lakes Shipping and Boating

Great Lakes Water Resources — Lake Levels

The Great Lakes/St. Lawrence Seaway is internationally shared resource used for shipping, transportation, fishing, and hydroelectric power generation. The Great Lakes are also one of the prime recreational boating areas in the country.

The CGCM1 model used in the current assessment suggests a trend toward lower Great Lakes levels — a drop of 1.5 to 3 feet on the various lakes within the next 30 years. Output from the HadCM2 model suggests no change to a slight increase in lake levels. Ice cover will also likely decrease, both in terms of days with ice cover and thickness of ice.

3 Unique findings from this assessment:
1) Using the transient models for the year 2030 shows that significant changes to the Great Lakes water resources could come sooner rather than later.
2) Although the use of the HadCM2 has indicated for the first time that there is a potential for slightly higher water levels under climate change—the prior nine model runs for the Great Lakes water resource studies, including the current CGCM1 have all indicated a major lowering of lake levels and a reduction of water supplies.
3) With the help of an interest satisfaction regulation model for Lake Ontario, we have the ability to assess impacts on specific interests using a variety of regulation scenarios.

Great Lake Regional Summary — Water Resources report (PDF) available here

Lake Michigan-Huron

Lake Michigan—Huron comparison from selected climate change studies. The size of the marker is keyed to the magnitude of the change in lake level. The color represents different studies: the lavender ones (1-4) were taken from previous studies at the Great Lakes Environmental Research Laboratory (GLERL); the yellow ones (5-8) were taken from a recent study by Phil Chao; and the green ones (9-12) were done most recently —specifically for this assessment.