CLEVELAND - The newest update to a Lake Erie management plan predicts global warming will lead to a steep drop in water levels over the next 64 years, a change that could cause the lake's surface area to shrink by up to 15 percent.The drop could undo years of shoreline abuse by allowing water to resume the natural coastal circulation that has become blocked by structures, experts said.Updated annually, the plan is required by the Great Lakes Water Quality Agreement between the United States and Canada. It is developed by the U.S. Environmental Protection Agency, Environment Canada and state and...