Rising water temperatures on Lake Superior are leading to stronger winds, which will impact everything from currents to pollution on the world’s largest lake, according to researchers at the University of Wisconsin-Madison. Since 1985, surface water temperatures (as measured by lake buoys) have gone up 1.2 degrees per decade, about 15 per cent faster than the air above the lake and twice as fast as temperatures rising over nearby land. Part of this is due to melting ice: “There is less ice on Lake Superior during the winter, and consequently the water absorbs more heat,” says atmospheric and oceanic sciences professor Ankur Desai. In the study, researchers spent over 20 years following Superior’s water and wind system. They witnessed currents increasing nearly 10 per cent per decade, largely based on changes in the wind. Lake Superior is an anchor for the Great Lakes, which hold one-fifth of the world’s fresh surface water, but the impact of these rising temperatures is still not well understood.