Climate chaos: WMO warns of an erratic water cycle

Many small-glacier regions have already reached or are about to pass the so-called peak water point when a glacier's melting reaches its maximum annual runoff, after which this decreases due to glacier shrinkage.

Mumbai: The water cycle has become increasingly erratic and extreme swinging between deluge and drought, according to a World Meteorological Organization (WMO) based on a comprehensive analysis of 2024. 

The State of Global Water Resources report of the Geneva headquartered WMO says only about one-third of the global river basins had “normal” conditions, while the  rest were either above or below normal the sixth consecutive year of clear imbalance. 

Besides, 2024 was the third straight year with widespread glacier loss across all regions. 

The Amazon Basin and other parts of South America, as well as southern Africa were gripped by severe drought in 2024, whilst there were wetter than normal conditions in central, western and eastern Africa, parts of Asia and Central Europe, it says.  

“Water sustains our societies, powers our economies and anchors our ecosystems. And 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,” said WMO Secretary-General Celeste Saulo, in a press statement on Thursday. 

An estimated 3.6 billion people face inadequate access to water at least a month per year and this is expected to increase to more than 5 billion by 2050, according to UN Water, and the world falling far short of Sustainable Development Goal 6 on water and sanitation.

“Water is one of the first frontlines where the climate crisis becomes visible whether through devastating floods or persistent droughts. The science is clear, unless we rapidly cut fossil fuel emissions, these extremes will intensify, threatening ecosystems, agriculture, and human health. Reducing our dependence on coal, oil, and gas is the only way to stabilize water resources for future generations.” Dr Davide Faranda, Directeur de recherche CNRS, IPSL, France, said reacting to the WMO report. 

The year 2024 was the hottest year on record and began with an El Niño event which impacted major river basins. It contributed to droughts in northern South America and the Amazon Basin and southern Africa. It was wetter-than-average in Central and western Africa, the Lake Victoria basin in Africa, Kazakhstan and Southern Russia, Central Europe, Pakistan and Northern India, Southern Iran, and North-Eastern China.

In the past six years only about one-third of the global river catchment area had normal discharge conditions compared to the 1991-2020 average. This means that two thirds have too much or too little water reflecting the increasingly erratic hydrological cycle.

There was much below-normal discharge across key river basins including the Amazon, São Francisco, Paraná, and Orinoco in South America, and the Zambezi, Limpopo, Okavango, Orange basins in southern Africa. Extensive flooding occurred in West African basins in Senegal, Niger, Lake Chad, Volta). There was above normal river discharge across Central Europe and parts of Asia, swelling major basins including the Danube, Ganges, Godavari, and Indus.

Nearly all out of selected 75 main lakes across the globe saw above or much above normal temperatures in July, affecting water quality.