Half of world's largest lakes are drying up: study
STORY: More than half of the world's large lakes are drying up
From the Caspian Sea to South America's Lake Titicaca
scientists assessed almost 2,000 large lakes using satellite measurements and climate models
They found a cumulative water-loss rate of around 24 billion tons over nearly three decades
That's about 17 times the volume of Lake Mead, the United States' largest reservoir
The study found that 56% of the decline was driven by climate warming and human consumption
It has intensified concerns about water for agriculture, hydropower and human consumption
