Another issue the Anishinabe never had to deal with

Something seems amiss with mighty Superior, the deepest and coldest of the Great Lakes, which together hold nearly 20 percent of the world's fresh surface water.Superior's surface area is roughly the same as South Carolina's, the biggest of any freshwater lake on Earth. It's deep enough to hold all the other Great Lakes plus three additional Lake Eries. Yet over the past year, its level has ebbed to the lowest point in eight decades and will set a record this fall if, as expected, it dips three more inches.Its average temperature has surged 4.5 degrees Fahrenheit since 1979, significantly above the 2.7-degree rise in the region's air temperature during the same period. That's no small deal for a freshwater sea that was created from glacial melt as the Ice Age ended and remains chilly in all seasons.A weather buoy on the western side recently recorded an "amazing" 75 degrees, "as warm a surface temperature as we've ever seen in this lake," says Jay Austin, assistant professor at the University of Minnesota at Duluth's Large Lakes Observatory.Water levels also have receded on the other Great Lakes since the late 1990s. But the suddenness and severity of Superior's changes worry many in the region; it has plunged more than a foot in the past year. Shorelines are dozens of yards wider than usual, giving sunbathers wider beaches but also exposing mucky bottomlands and rotting vegetation.