CLEVELAND -
Scientists at the Great Lakes Environmental Research Laboratory say there has been more than a 30 per cent ice decline on the lakes since the 1970s.
The drop attributed to global climate change leaves the largest system of freshwater lakes on Earth open to evaporation that can lead to lower lake levels.
Ice also protects the shoreline from erosion and protects underwater fish eggs.
Scientists who have studied the lakes at the lab in Ann Arbor, Michigan, say the waters also are influenced by natural cycles that counter global warming.
Researcher Jia Wang says natural variability is at least as large a factor as global warming.
He says regional climate patterns and global climate change are competing over the Great Lakes.
