Patz, who is also affiliated with UW-Madison's Nelson Institute for Environmental Studies' Center for Sustainability and the Global Environment, conducted the study with Stephen Vavrus, a climatologist and director of the UW-Madison Center for Climatic Research, also part of the Nelson Institute.
Changes in regional weather patterns and, in particular, an increase in the number and intensity of severe rainfall events are predicted to accompany global warming. Climatologists have already cataloged a decades-long trend toward more tempestuous weather, says Vavrus.
"We have seen an uptick in the incidence of severe precipitation events in the last couple of years, but this has been a trend for decades," says Vavrus, noting an increased frequency of both major storms and total precipitation in the late 20th century. "And we are expecting climate (in the Great Lakes region) to change significantly in the future, so we'll very likely see an increase in these extreme precipitation events."
Climate change, scientists know, will prompt extremes of the hydrologic cycle, causing intensified precipitation as well as drought. Using the best available computer climate models, the Wisconsin researchers found that southern Wisconsin is likely to experience a 10 to 40 percent increase in the strength of extremely heavy precipitation events, leading to greater potential for flooding and the waterborne diseases that accompany the high discharge of sewage into Lake Michigan.
Previously, Patz led a U.S. Environmental Protection Agency-funded study linking outbreaks of waterborne disease in the U.S. to extreme rainfall. That study, published in 2001, showed that two-thirds of waterborne disease outbreaks between 1948 and 1994 were correlated with heavy rainfall.
The new study, say Patz and Vavrus, points to a need to strengthen pubic health infrastructure and improve aging urban drinking water and sewage systems, an
|Contact: Jonathan Patz|
University of Wisconsin-Madison