Global water cycle extremely erratic; massive glacial loss worldwide: WMO report

HT had reported on August 27 that the once-stable Southwest Monsoon in India is undergoing rapid change due to increasing atmospheric moisture.

The global water cycle is becoming increasingly erratic and extreme, exposing people to both deluge and drought with cascading impacts on economies and societies, the World Meteorological Organization (WMO) warned in its ‘State of Global Water Resources’ report released on Thursday.

The Rhone Glacier, with some insulating foam covering a small part to prevent it from melting next to its glacial lake, formed by the melting of the glacier due to global warming. (AFP File Photo)

The report found that in 2024, only about one-third of global river basins recorded “normal” conditions. The remainder were either above or below normal, marking the sixth consecutive year of imbalance in river discharge.

In India, 385 people lost their lives due to extreme rainfall on July 30 in Kerala, which triggered devastating landslides. Major river basins such as the Godavari, Krishna, Ganges, and parts of the upstream Indus registered above-normal discharge conditions, the report noted.

HT had reported on August 27 that the once-stable Southwest Monsoon in India is undergoing rapid change due to increasing atmospheric moisture. This year’s disasters in Himachal Pradesh, Uttarakhand, and Jammu and Kashmir have provided a glimpse of what lies ahead.

Scientific studies in recent years have shown that while monsoon circulation is weakening, global warming is intensifying moisture levels, leading to more extreme rainfall events and longer dry spells during the monsoon season. Experts warn that farmers, authorities, and the public at large remain unprepared for these shifts.

Record mass loss was observed in Scandinavia, Svalbard, and North Asia, while regions such as the Canadian Arctic and Greenland’s periphery recorded more moderate losses. WMO warned that many small-glacier regions have already reached or are close to reaching “peak water” — the point at which annual glacier runoff hits its maximum and then begins to decline due to glacier shrinkage.

Meanwhile, severe drought gripped the Amazon Basin, large parts of South America, and southern Africa in 2024. In contrast, wetter-than-normal conditions prevailed across central, western, and eastern Africa, parts of Asia, and central Europe. WMO attributed these shifts mainly to 2024 being the hottest year on record, combined with an El Niño event that disrupted major river basins.

Between 2019 and 2024, only about one-third of the world’s river catchment areas had normal discharge conditions compared to the 1991–2020 average. This means two-thirds faced either excess or deficit flows — a clear sign of the increasingly erratic hydrological cycle.

WMO reported below-normal discharge across several key basins, including the Amazon, São Francisco, Paraná, and Orinoco in South America, and the Zambezi, Limpopo, Okavango, and Orange basins in southern Africa. Extensive flooding struck West African basins such as Senegal, Niger, Lake Chad, and Volta. Meanwhile, above-normal discharge was reported across Central Europe and parts of Asia, swelling the Danube, the Ganga, Godavari, and Indus rivers.

“Water sustains our societies, powers our economies and anchors our ecosystems. Yet, the world’s water resources are under growing pressure and, at the same time, more extreme water-related hazards are having an increasing impact on lives and livelihoods,” WMO secretary-general Celeste Saulo said.

“Reliable, science-based information is more important than ever before because we cannot manage what we do not measure,” she added.