Study: Warming could drain lakes more
By John Flesher
Posted on MLive.com on November 28, 2007
TRAVERSE CITY -- Climate change appears likely to reduce already low Great Lakes water levels even more, making it more urgent to approve a regional compact protecting them from diversion and overuse, environmentalists said Tuesday.
Research suggests warming temperatures might bring less snowfall to the region while boosting evaporation rates, driving down the lakes and the streams and groundwater that feed them, the National Wildlife Federation said.
At the same time, the lakes might become an even more tempting target for water-starved regions, such as the desert Southwest, the group said in a newly released report.
"We do not have the luxury of waiting," said Molly Flanagan, the federation's water program manager. "If we do not act to protect our water, others may decide to take action for us and they may not make the same choices we would make."
Governors of the eight states on the Great Lakes signed a compact in 2005 that would outlaw most diversions of water from the region's drainage basin and require the states to set water-use policies.
The pact needs approval of the eight state legislatures and Congress to take effect. Lawmakers in Minnesota and Illinois have endorsed it, while ratification bills are pending in Indiana, Michigan, New York and Pennsylvania.
Significant opposition has arisen in Ohio, where critics say the compact could hamper economic development and property rights, and in Wisconsin, where cities just outside the basin fear it could prevent them from tapping into Lake Michigan for municipal water supplies.
Supporters of the compact have focused on what Flanagan called the region's "primal fear" that Sun Belt states would use their growing political clout to grab Great Lakes water.
But the wildlife federation report says climate change is an equally serious threat. The proposed compact wouldn't do anything to prevent it, but would give state governments the legal and policy tools they need to deal with the effects, said Noah Hall, a Wayne State University law professor who helped craft the report.
"We have known for many years that existing laws are inadequate to protect the Great Lakes from diversions and overuse," Hall said. "Now we know that climate change is certain to put additional stress and pressure on the Great Lakes."
While not breaking any new scientific ground, the report summarizes previous findings from studies of the possible effects of climate change in the region.
During the century beginning in the late 1800s, temperatures in the Great Lakes region rose nearly twice as much as the average increase for the entire nation, the report says. As the trend continues, evaporation rates could jump enough to more than offset any precipitation increases.
Water levels on the Great Lakes -- particularly Superior, Michigan and Huron -- have been in decline for much of the past decade.
But not everyone agrees that global warming is to blame. Some scientists contend short-term weather conditions and historical ebb-and-flow patterns might be at least partly responsible.
It's also too early to say whether climate trends that began in the late 1990s will continue, said Cynthia Sellinger, deputy director of NOAA's Great Lakes Environmental Research Laboratory in Ann Arbor.
"If it does continue in this direction, then absolutely it would be prudent to take precautions for protecting our water quantity such as (ratifying) the compact," Sellinger said.