Rising temps could change landscape of Midwest

Algae blooms on Lake Superior, the disappearance of birch trees from Minnesota and more heat-related complications for human health are all likely without significant action to reduce greenhouse gas emissions and the warmer climate they are causing.

Those are among the conclusions of a new national report from the U.S. Global Change Research Project that is expected to help shape federal climate policy over the coming decade.

The Midwest, where Minnesota and other states saw their warmest year on record in 2012, could see average temperatures rise 4.9 degrees by mid-century, the report said. That's on top of the 3-degree rise in the past 30 years. It also cites links between continued warming and increased Midwest flooding.

"Minnesotans are already beginning to notice climate change. Really beginning to notice," said J. Drake Hamilton, science policy director of Fresh Energy, a group that advocates alternatives to fossil-based energy. "These will be unpleasant quality-of-life changes we're talking about."

University of Minnesota Extension climatologist Mark Seeley said the report was well-timed given recent election results.

"The change in political leadership allows for, shall we say, a fuller and open vetting of what climate change means to us," Seeley said. "I think we have people who are more willing to listen and engage on this topic," Seeley said.

The assessment could serve to bring about "a bipartisan agreement on a long-term energy vision for the country, and Minnesota," said Rolf Nordstrom, executive director of the Minneapolis-based Great Plains Institute. He was one of 240 authors of the U.S. Global Change Research Project report, most of whom were from government agencies and universities. The institute is a nonprofit agency that gets interested parties together to resolve energy controversies; it's currently working on issues surrounding the state's ethanol mandate.

The report is scheduled to go to Obama in March 2014, after a public comment period and administration policymakers sign off on its conclusions.

It includes assessments of impacts for eight U.S. regions. Among the potential impacts listed for the Midwest are:

• Longer growing seasons, which might be offset by impacts of heat waves, droughts and floods.

• A 90-mile northward shift of forest habitats, with maple, birch and spruce being replaced by oak.

• A decline in the region's ability to store carbon, with tree loss due to insect outbreaks and drought.

• A 7-degree rise in the water temperature of Lake Superior by 2050, with similar warming bringing invasive species and harming beaches and fish populations on all the Great Lakes.

Nationally, impacts would include costly damages from severe weather, sea level rise, impaired water quality and water supplies.

The report also notes, however, that the Midwest is in position to contribute to widespread reductions in greenhouse gas emissions by developing low-carbon or no-carbon energy sources such as wind, solar and biomass. Nordstrom noted that most Midwestern states, including Minnesota, have adopted goals for renewable energy. Minnesota's requires most utilities to produce 25 percent of their electricity by 2025.

"I think the Midwest is making genuine progress," he said.

A public comment period began Monday and runs through April 12. Readers can find the full report and comment at www.startribune.com/a1999.