January 19, 2013
Report Analyzes Impact Of Climate Change On Great Lakes, US Midwest
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redOrbit Staff & Wire Reports - Your Universe Online
Because of global warming, heat waves will become harsher and intense rainstorms will become more common in the US Midwest over the next couple of decades, claims a new report released by the federal government last week.
The Midwest chapter of the over 1,100 page National Climate Assessment also revealed that the region would be subject to degrading air and water quality, an increased frequency of flooding, and potential public health risks, the University of Michigan announced on Friday.
Three researchers from the Ann Arbor-based institution were the lead convening authors of chapters in the report, which was compiled by a team of more than 240 scientists and analyzed “the key impacts of climate change on every region in the country and analyzes its likely effects on human health, water, energy, transportation, agriculture, forests, ecosystems and biodiversity,” the university said.
Those three staff members were aquatic ecologist Donald Scavia, who was a lead convening author of the Midwest chapter; Dan Brown of the School of Natural Resources and Environment (SNRE), who was a lead convening author of the chapter on changes in land use and land cover; and Rosina Bierbaum of SNRE and the School of Public Health, who was a lead convening author of the chapter on climate change adaptation.
The National Climate Assessment asserts that the American way of life is already being affected by climate change in many different ways, and that the situation is only expected to worsen in the years ahead. That is echoed in the Midwest chapter of the report, which predicts more frequent and stronger heat waves, increased threats to the Great Lakes, and possible damage to agriculture, transportation, and infrastructure.
“In agriculture, longer growing seasons and rising carbon dioxide levels are likely to increase the yields of some Midwest crops over the next few decades, according to the report, though those gains will be increasingly offset by the more frequent occurrence of heat waves, droughts and flood,” officials from the university explained.
“In the long term, combined stresses associated with climate change are expected to decrease agricultural productivity in the Midwest,” they added. “The composition of the region's forests is expected to change as rising temperatures drive habitats for many tree species northward. Many iconic tree species such as paper birch, quaking aspen, balsam fir and black spruce are projected to shift out of the United States into Canada.”
Additionally, global warming is expected to worsen existing problems in the Great Lakes, the researchers said. Among those issues are changes in the range and distribution of fish species, some of which are commercially important; an increase in the number of invasive species in the waters of the lakes; and a decline in beach health couples with an increase in the frequency of potentially harmful algae blooms.
“The rate of warming in the Midwest has accelerated over the past few decades, according to the report. Between 1900 and 2010, the average Midwest air temperature increased by more than 1 degree Fahrenheit,” the researchers explained. “However, between 1950 and 2010, the average temperature increased twice as quickly, and between 1980 and 2010 it increased three times as quickly.”
“The warming has been more rapid at night and during the winter. The trends are consistent with the projected effects of increased concentrations of heat-trapping greenhouse gases, such as carbon dioxide released by the burning of fossil fuels,” they added. “Projections for the end of the century in the Midwest are about 5.6 degrees for the low-emissions scenario and 8.5 degrees for the high-emissions scenario, according to the report.”
The draft National Climate Assessment report is available here.