In a recent “first-of-its-kind” study led by NASA, scientists found major changes to freshwater availability — changes that could impact water shortages over the course of the century. For the study, published this week in Nature, scientists drew on 14 years of satellite observations combined with data on human activity to track freshwater trends in 34 regions worldwide. And, according to hydrologist Jay Famiglietti, “What we are witnessing is major hydrologic change.”
Specifically, wet areas around the globe are getting wetter, and dry areas are getting drier. This is bad news for the dry areas, most of them between the tropics and the high latitudes. Several of these hotspots, such as the Middle East, California and Australia, are complicating the issue by depleting their reserves of groundwater. While the study did not find a clear connection between the changing freshwater patterns and climate change, it is unlikely that the situation in these areas will improve without significant government action.
Humans playing a huge role in changing freshwater availability via climate change, water management and changing extremes. Freshwater security is more tenuous than we thought. Out now in @Nature https://t.co/KxnC9eQts4 pic.twitter.com/h8Gab3dHrb
— Jay Famiglietti (@JayFamiglietti) May 16, 2018
There are multiple factors behind the trends, including climate change, natural cycles and human water management. Lead author Matt Rodell of NASA’s Goddard Space Flight Center said, “A key goal was to distinguish shifts in terrestrial water storage caused by natural variability — wet periods and dry periods associated with El Niño and La Niña, for example — from trends related to climate change or human impacts, like pumping groundwater out of an aquifer faster than it is replenished.”
Famiglietti said, “The pattern of wet-getting-wetter, dry-getting-drier during the rest of the 21st century is predicted by the Intergovernmental Panel on Climate Change models, but we’ll need a much longer data set to be able to definitively say whether climate change is responsible for the emergence of any similar pattern in the GRACE data.” The study states that government policies that encourage water conservation could help avoid increased water shortages.
Via The Guardian