Some of the Great Lakes' treasured national parks are showing ill effects of climate change that are likely to worsen in coming decades, from shoreline erosion to decline of certain wildlife and plant species, a former park system administrator said Wednesday. Without changes in public policies and personal habits that pump greenhouse gases into the atmosphere, the parks could lose qualities that attract visitors and support unique ecosystems, Stephen Saunders, former deputy assistant secretary of the Interior Department, said in a report released by two advocacy groups. "Human disruption of the climate is the greatest threat ever to America's national...