In a move the polar bears have been pushing for years, the Detroit Zoo is going green. Sourcing power from three newly built DTE wind farms, the zoo plans to run on 100 percent renewable energy by the end of 2020. DTE and the zoo estimate the move will offset 7,425 metric tons of carbon dioxide. It's not the first time the zoo has made major moves toward sustainability. It already had removed plastic bags, water bottles, straws and lids from concessions. MORE ►Viewing animals at Detroit Zoo reduced stress, study shows |