Climate Change and Great Lakes Water Resources (a 44 page PDF), a new report from the National Wildlife Federation, looks at threats to the Great Lakes from global warming and water diversion, and concludes that states need to approve the Great Lakes-St. Lawrence River Basin Water Resources Compact.

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Executive Summary

THE EARTH’S CLIMATE IS WARMING. This is the unequivocal conclusion of climate scientists. Despite the complexities of climatology, certain consistent themes emerge with implications for water availability: as the world gets warmer, it will experience increased regional variability in precipitation, more frequent heavy precipitation events, and will become more susceptible to drought.

These simple facts could have a profound impact on the
Great Lakes, as the warmer climate may reduce water supply and increase water demand within the region. Further, as other regions suffer from shortages in water supply and increased demand for water resources, they will look to divert
Great Lakes water to slake their thirst.

The science is compelling. Now the question for citizens and policymakers is whether existing laws and policies are adequate to protect the
Great Lakes from the new pressures of climate change. Unfortunately, the answer is, “No.” However, the
Great Lakes-St. Lawrence River Basin Water Resources Compact (“Great Lakes compact”),1 if enacted, would be an important step in improving
Great Lakes water resource policy to meet the challenge of climate change.

Part I of this report focuses on how climate change will impact water resources. It begins with a brief summary of climate change science. It then explores what a changing climate will mean for the Great Lakes, including possible lowering of lake levels, impacts on fisheries and wildlife, changes in
Great Lakes shorelines, and reduction of groundwater supplies. Climate change will also reduce water supplies in other parts of the country, creating increased pressure to divert
Great Lakes water to other regions. As the
Great Lakes and other regions struggle with loss of water supplies, demand for water is expected to increase unless water conservation laws and policies are adopted.

Taken together, the key findings of Part I present a major challenge to the
Great Lakes region:

• Spring and summer temperatures in the
Great Lakes region may increase by as much as 9º F (5º C) and 7.2º F (4º C), respectively, by 2050;

• According to one recent study, lake levels in Lake Michigan and
Lake Huron may drop by as much as 4.5 ft (1.38 m) due to a combination of decreased precipitation and increased air temperature/evapotranspiration;

• Groundwater will be impacted, as aquifer levels and recharge rates are expected to drop;

• Lower lake levels and rising temperatures (both in the air and water) will significantly impact fisheries, wildlife, wetlands, shoreline habitat, and water quality in the Great Lakes region;

• Tourism and shipping, which are critically important to the region, are especially vulnerable to climate change impacts; and

• Water shortages in other regions will raise the threat of
Great Lakes diversions.

Part II of this report focuses on policies to reduce greenhouse gas emissions that cause climate change and to adapt to the unavoidable impacts on water resources. It begins with a brief summary of recommendations to reduce emissions of greenhouse gases which cause climate change. It then evaluates the adequacy of existing
Great Lakes water resource policies for responding to the pressures of climate change. Unfortunately, current laws and policies intended to protect Great Lakes water resources from diversions (transfers of
Great Lakes water outside of the basin) and overuse within the basin are not up to the new challenges posed by climate change. The region can better protect and manage
Great Lakes water resources in a future of climate change by adopting new water resource policies that:

• Emphasize water conservation as water becomes more scarce and valuable;

• Protect aquatic habitat for fisheries and wildlife in changing conditions;

• Provide strong legal protections against diversions of
Great Lakes water to other regions; and

• Create regional governance institutions that can help adaptively manage water resources as new scientific information becomes available.

The report concludes by examining how the Great Lakes compact gives the region an opportunity to make these improvements in water resource policy and better protect the
Great Lakes from the pressures of climate change.

This is a 44 page PDF file, that might take a while to download...

From:

http://www.nwf.org/nwfwebadmin/binaryVault/2007-11-27ClimateChangeandGreatLakesWaterResourcesReportFINALAffiliates.pdf

Via: http://planning.co.cuyahoga.oh.us/blog/