WASHINGTON (dpa-AFX) - An international team of scientists using observations from NASA-German satellites found evidence that Earth's total amount of freshwater dropped abruptly a decade ago, and has remained low ever since. Reporting in Surveys in Geophysics, the researchers suggested the shift could indicate Earth's continents have entered a persistently drier phase.
From 2015 through 2023, satellite measurements showed that the average amount of freshwater stored on land, which includes liquid surface water like lakes and rivers, plus water in aquifers underground - was 290 cubic miles lower than the average levels from 2002 through 2014. 'That's two and a half times the volume of Lake Erie lost,' said Matthew Rodell, one of the study authors and a hydrologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
During times of drought, along with the modern expansion of irrigated agriculture, farms and cities must rely more heavily on groundwater, which can lead to a cycle of declining underground water supplies: freshwater supplies become depleted, rain and snow fail to replenish them, and more groundwater is pumped. The reduction in available water puts a strain on farmers and communities, potentially leading to famine, conflicts, poverty, and an increased risk of disease when people turn to contaminated water sources, according to a UN report on water stress published this year.
The team of researchers identified this abrupt, global decrease in freshwater using observations from the Gravity Recovery and Climate Experiment (GRACE) satellites, operated by the German Aerospace Center, German Research Centre for Geosciences, and NASA. GRACE satellites measure fluctuations in Earth's gravity on monthly scales that reveal changes in the mass of water on and under the ground.
The decline in global freshwater reported in the study began with a massive drought in northern and central Brazil, and was followed shortly by a series of major droughts in Australasia, South America, North America, Europe, and Africa. Rodell and team report that 13 of the world's 30 most intense droughts observed by GRACE occurred since January 2015. Rodell and colleagues suspect that global warming might be contributing to the enduring freshwater depletion.
Copyright(c) 2024 RTTNews.com. All Rights Reserved
Copyright RTT News/dpa-AFX
© 2024 AFX News
