See how much you don't know about energy use and energy sources with this quiz from National Geographic.
Learn about the energy challenges we face in the future by calculating your carbon footprint, taking quizzes, and more.
Calculate your carbon footprint from the energy you use, including car travel, air travel, home energy, and renewable energy.
Freshwater Hero - Zeb Hogan
See photos of freshwater mammals, such as manatees, hippos, otters, and more, in this photo gallery from National Geographic.
Learn all you wanted to know about Chinese paddlefish with pictures, videos, photos, facts, and news from National Geographic.
Water Footprint Calculator
Meet the Freshwater Heroes at National Geographic
Natural Disasters --Tornado Pictures -- National Geographic
See photos of waterscapes (the Colorado River, Jordan Pond, Nile River, and more) in this photo gallery from National Geographic.