Researchers from Nasa have used satellite data to identify areas where freshwater reserves have increased or decreased. The study found that in 14 regions, the changes were likely due to human factors (e.g. groundwater pumping), and in 8 areas, the changes were caused mainly by climate (e.g. drought or ice-sheet melting). Freshwater availability decreased in several areas including northern India, north-east China, the Caspian and Aral Seas and some of the Middle East.
Freshwater availability is changing worldwide. Here we quantify 34 trends in terrestrial water storage observed by the Gravity Recovery and Climate Experiment (GRACE) satellites during 2002–2016 and categorize their drivers as natural interannual variability, unsustainable groundwater consumption, climate change or combinations thereof. Several of these trends had been lacking thorough investigation and attribution, including massive changes in northwestern China and the Okavango Delta. Others are consistent with climate model predictions. This observation-based assessment of how the world’s water landscape is responding to human impacts and climate variations provides a blueprint for evaluating and predicting emerging threats to water and food security.
Rodell, M., Famiglietti, J.S., Wiese, D.N., Reager, J.T., Beaudoing, H.K., Landerer, F.W. and Lo, M.H., 2018. Emerging trends in global freshwater availability. Nature, p.1.
Find the full study here. See also media coverage in the Financial Times here or in the Guardian here. See also the Foodsource resource How do the climate and environment directly affect the conditions required for food production?
26 May 2018
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