World's water cycle becoming more unpredictable, UN warns

The United Nations has issued a warning that the Earth's water cycle is becoming increasingly unpredictable, with an unprecedented El Nino expected to exacerbate the long-term trend of erratic weather patterns. In a recent report, the World Meteorological Organization (WMO) stated that 2025 was among the three driest years for rivers in the past 35 years.

Additionally, glaciers worldwide have been shrinking at an alarming rate, with 2025 marking the fourth consecutive year of significant ice loss. This trend has led to a decline in the overall freshwater storage, which includes groundwater, lakes, rivers, soil moisture, vegetation, and ice and snow reserves.

The WMO's secretary-general, Celeste Saulo, expressed particular concern over the depletion of slow reserves such as groundwater and glaciers, which traditionally act as a buffer against droughts and water crises. She warned that the planet is now spending its reserves, depleting the "savings account" that once protected against water shortages.

The report also revealed that nearly two-thirds of monitored wells worldwide showed conditions outside the historical norm in 2025, with groundwater levels declining in multiple regions.

The report further highlighted the increasing frequency of water-related disasters, including droughts and floods, which are becoming more common due to the unpredictable nature of the water cycle. The upcoming El Nino, one of the strongest on record, is expected to further increase the risk of drought in some areas and flooding in others.

Saulo emphasized the importance of sharing data, standards, and early warnings across borders, as weather respects no borders and a river basin is fed by water upstream in another country.