On Sept. 13, during an unrelenting downpour, Chicago chose to prevent urban flooding by opening and releasing runoff containing raw sewage into Lake Michigan. About a month later, a University of Wisconsin study published in the American Journal of Preventive Medicine predicted an increase of 50 to 120 percent in such releases into the lake by the end of the century.
“One of the strongest indicators from climate models is more intense rains,” said co-author Stephen Vavrus, director of the university’s Center for Climatic Research. “They don’t agree on everything, but they do agree on that. A warmer atmosphere holds more moisture, so as we get more moisture in the air, when we do have a storm situation, you get more total rainfall.”