Associated Press: Ice cover on the Great Lakes has declined more than 30 percent since the 1970s, leaving the world’s largest system of freshwater lakes open to evaporation and lower water levels, according to scientists associated with the National Oceanic and Atmospheric Administration. They’re concerned about how the milder winter freeze may affect the environment. But they’re also trying to come to terms with a contradiction — the same climate factors that might keep lake ice from freezing might …