World's Largest Lake Drying Up

Lake Superior, the greatest Great Lake and the world's largest freshwater reservoir, is at its lowest point in 81 years. Other Great Lakes are down too, but none as dramatically as Superior. The culprit could be, you guessed it, global warming. For a quick look at how global warming might affect the world's top 5 largest lakes, click here. The average temperature of the lake has gone up 4.5 degrees since 1979. Warmer water evaporates faster, holds less ice in the winter. Add to that drought and warmer air temperatures -- which contribute to evaporation -- and you have a recipe for declining water level. The low lake, besides causing sometimes dramatic views of the shoreline for locals, has some real effects. Both cargo and recreational boat traffic is restricted, hydroelectric power plants have reduced output, and the ecology of the lake's near shore environment is altered to the detriment of some wild species. If theories about global warming being behind the drop in lake water prove correct, these changes could just be a taste of what's to come, according to a story in the June 14 USA Today. Related Story Global Warming's Effect On Top 5 Lakes