Global warming will likely drain more water from the Great Lakes and pose added pollution threats to the region's vulnerable ecosystem, environmental groups said in a report issued on Wednesday.
Climate change could further reduce scant ice cover observed in recent winters, increasing evaporation rates and dropping water levels in the five lakes that collectively make up 20 percent of the world's surface fresh water.
Last year, Lake Superior water levels receded to their lowest in 77 years before rebounding, and the report by the Healing Our Waters-Great Lakes Coalition predicted global warming could lower lake levels by up to 3 feet (1 meter) over the next century.
