The USA's space agency NASA has confirmed that human activity is responsible for a massive redistribution of freshwater across Earth. It said the redistribution is continuing as populations shift and demand for food increases. In particular, equatorial regions were drying, while tropical areas and higher latitudes were gaining water supplies. NASA warned that if this trend continued, many highly populated urban areas could struggle to find sufficient water in the future. NASA's claims are the result of a 14-year study into shifting locations and depleting resources of freshwater. It was part of a mission conducted between 2002-2016 called GRACE, which is an acronym for Gravity Recovery and Climate Experiment.

Researchers say that the shifting freshwater patterns are the result of human activity. Jay Famiglietti, a co-author of the research and the Senior Water Scientist at NASA's Jet Propulsion Laboratory, said: "The study shows that humans have really drastically altered the global water landscape in a very profound way." He warned that: "The human fingerprint is all over changing freshwater availability. We see it in large-scale overuse of groundwater. We see it as a driver of climate change." Professor Famiglietti said at least 40 per cent of the 34 hot areas examined in the research were drier than two decades ago because of human activity, especially excessive groundwater pumping for farming.