Climate change is rapidly warming lakes around the world, threatening freshwater supplies and ecosystems, according to a new NASA and National Science Foundation-funded study of more than half of the world's freshwater supply.Using more than 25 years of satellite temperature data and ground measurements of 235 lakes on six continents, this study — the largest of its kind — found lakes are warming an average of 0.61 degrees Fahrenheit (0.34 degrees Celsius) each decade. The scientists say this is greater than the warming rate of either the ocean or the atmosphere, and it can have profound effects.The research, published in Geophysical Research Letters, was announced Wednesday at the American Geophysical Union meeting in San Francisco.