A new global study has revealed a worrying trend Earth’s continents are steadily losing freshwater, putting nearly 6 billion people at risk and reshaping the future of water security.
The research, published in Science Advances, shows that around 75% of the world’s population lives in countries where freshwater reserves have been declining continuously since 2002. Scientists describe this long-term pattern as Continental Drying, a phenomenon where water stored on land is gradually decreasing.
This includes water found in rivers, lakes, soil, glaciers, and underground aquifers. The findings are based on data collected from NASA’s GRACE satellite mission and its successor GRACE Follow-On mission, which measure subtle changes in Earth’s gravity to detect water loss or gain across regions.
Scientists analysed data spanning more than two decades, from 2002 to 2024, and found that the drying trend is widespread and persistent not just a temporary fluctuation caused by seasonal changes.
One of the most striking discoveries is the emergence of large “mega drying” regions, especially across the Northern Hemisphere. These include areas in northern Canada and Russia, parts of Europe, and a vast stretch extending from North Africa through the Middle East into Central and East Asia. Another major drying belt covers parts of the southwestern United States, Mexico, and Central America.
Researchers identified groundwater depletion as the biggest contributor to freshwater loss. About 68% of the decline in non-glacial regions is linked to excessive extraction of underground water for agriculture, industry, and urban use. Critical reserves like the Central Valley Aquifer and the Arabian Aquifer System are being drained faster than they can naturally recharge.
This loss is particularly alarming because groundwater acts as a safety buffer during droughts. Once depleted, it can take centuries or even longer to recover.
The study also highlights a surprising link between land drying and rising sea levels. As freshwater moves from land into the oceans, it contributes directly to sea level rise. Scientists estimate that continental water loss is adding nearly 1 millimetre per year to global sea levels more than the contribution from individual ice sheets like Greenland or Antarctica in some cases.
Experts warn that this trend is not just an environmental issue but a growing human crisis. In several regions, the loss of stored water is equivalent to about 10% of their renewable water supply, significantly weakening their ability to cope with droughts.
However, researchers emphasize that part of the problem is still within human control. Since groundwater depletion is largely driven by overuse, better water management policies such as regulating extraction, improving irrigation efficiency, and recharging aquifers could help slow the crisis.
The findings underline a critical shift in the global water cycle. While melting glaciers and rising seas have dominated climate discussions, the silent loss of freshwater on land is emerging as an equally serious threat.
As scientists warn, the way countries manage water today will determine whether future generations face chronic shortages or a more sustainable and secure water future.