Why Are More Than Half of the World's Large Lakes Drying Up?

53% have shrunk since 1990, say scientists. Altogether, they are losing 22 gigatonnes of water every year. That’s 17 times the volume of Lake Mead, the largest reservoir in the US. Researchers from the University of Virginia studied 2,000 of the world’s largest lakes. They found that climate change is the biggest culprit.