Using measurements from Earth-observing satellites, NASA scientists have found that humans have dramatically altered the location of water around the world. “The team of researchers analyzed 14 years of data from NASA’s twin GRACE satellites and studied regions that have seen large increases or decreases in the total amount of freshwater, including water in lakes and rivers and water stored in underground aquifers, soil, snow and ice,” reports The Desert Sun. From the report: The scientists examined precipitation trends and other data to determine the most likely causes of these huge losses and gains of water around the world. Their findings in a new study reveal that of the 34 “hotspots” of water change in places from California to China, the trends in about two-thirds of those areas may be linked to climate change or human activities, such as excessive groundwater pumping in farming regions. In eight of the 34 regions, the researchers said the trends reflect “possible” or “probable” impacts of climate change, including losses of ice sheets in Greenland and Antarctica, precipitation increases in the high latitudes of Eurasia and North America, the retreat of Alaska’s glaciers and melting ice fields in Patagonia.
They ascribed changes in 12 regions to natural variability, including a progression from a dry period to a wet period in the northern Great Plains, a drought in eastern Brazil and wetter periods in the Amazon and tropical West Africa. In 14 of the areas — more than 40 percent of the hotspots — the scientists associated the water shifts partially or largely with human activity. That included groundwater depletion combined with drought in Southern California and the southern High Plains from Kansas to the Texas Panhandle, as well as in the northern Middle East, northern Africa, southern Russia, Ukraine and Kazakhstan. The first-of-its-kind study has been published in the journal Nature.
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