The Potential Impacts of Climate Change on the Great Lakes

Global climate change could have a significant impact on the Great Lakes. A number of studies of the potential effects of climate change on the Great Lakes were commissioned by the U.S. Environmental Protection Agency, using common scenarios of global warming derived mainly from general circulation models. These studies found that a doubling of carbon dioxide concentrations in the atmosphere could eventually lower Great Lakes water levels by 0.5 to 2.5m; reduce ice cover by 1 to 2 1/2 months; lengthen shipping seasons while increasing shipping and dredging costs; reduce dissolved oxygen levels in shallow lake basins; and increase fish productivity. Measures should be taken in the near future to anticipate many of these impacts and mitigate their effects or avoid costly political issues.