Continents are experiencing unprecedented freshwater loss since 2002. A recent study highlights four 'mega-drying' zones in the northern hemisphere.
Illustration image Pixabay
The 'mega-drying' refers to an accelerated and widespread loss of freshwater reserves across large continental areas. This phenomenon, observed since 2002, is primarily due to human activity and climate change.
Satellite observations reveal an alarming trend: freshwater reserves are decreasing at an accelerated rate. This situation results from climate change, overexploitation of groundwater, and extreme droughts. Researchers emphasize the major impact on water security and agriculture.
The study, published in
Science Advances, shows that 75% of the world's population lives in water-deficit countries. Data from GRACE and GRACE-FO missions, covering more than two decades, provide a clear picture of hydrological trends.
This figure illustrates long-term trends in terrestrial water storage, averaged by country (2/2003-4/2024).
Credit: Arizona State University and US-German GRACE and GRACE-FO missions. Researchers identified a tipping point around 2014-2015, marked by extreme climate events. Since then, dry regions have been expanding primarily in the northern hemisphere, reversing a historical trend. This previously unreported oscillation is worsening conditions in already vulnerable areas.
The consequences of this continental drying are multiple: threats to biodiversity, food insecurity, and social instability. Adaptation to these changes is crucial for future generations.