Humans’ global water footprint is up to 18 percent greater than previous estimates, researchers from Sweden report in a new study.
An analysis of water and climate data from 1901 to 2008 from 100 large water basins around the world revealed more water loss to the atmosphere and less water runoff compared with conclusions from earlier studies. The researchers link both water impacts to human activities. Water management techniques such as irrigation and damming rivers to create reservoirs, rather than climate conditions or geographic location, better explain the findings, they say.
On a global scale, the new results suggest that humans use about 10,700 cubic kilometers of water per year, more than all the water in Lakes Michigan, Huron, Ontario and Erie combined. That’s about 18 percent more than a 2012 estimate for current water use. The level is increasingly unsustainable, the scientists report December 4 in Science.