The NASA satellite imagery, analyzing 14 years of data, found global freshwater sources dwindling at a staggering pace
Researchers from the National Aeronautics and Space Administration (NASA) analyzed 14 years of data from the Twin Gravity Recovery and Climate Experiment (GRACE) satellites and found significant decreases in groundwater and freshwater sources globally. The researchers found that two-thirds of the 34 hot spots from California to China may be linked to climate change and human activities such as groundwater extracting. Published in the journal Nature, this study is the first to combine direct satellite measurements to assess shifts in freshwater everywhere on the planet and analyze the causes.
“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,” said Jay Famiglietti, senior water scientist at NASA’s Jet Propulsion Laboratory. “The study shows that humans have really drastically altered the global water landscape in a very profound way.”
According to the findings, eight of the investigated regions showed trends related to climate change, including loss of ice sheets in Greenland and Antarctica; precipitation increases in northern Eurasia and North America; retreat of Alaska’s glaciers; and melting ice fields in Patagonia. To put the staggering losses in perspective, Southern California loses the groundwater equivalent of the volume of Lake Mead every 15 years due to drought and farming, Famiglietti said.
“Water scarcity is getting much severer and we need to consider better water management practices in many intensively irrigated regions,” said Yoshihide Wada, a water scientist at the International Institute of Applied Systems Analysis. “In these regions, human impacts are expected to put much bigger pressure on freshwater resources than climate change.”
Continuing in the research, another group of twin satellites, called GRACE Follow-On, will launch May 22 into orbit from California.