The water cycle is becoming increasingly irregular and extreme, with fluctuations ranging from intense precipitation to periods of drought. The alert comes from a new report by the World Meteorological Organization (WMO) that highlights the cascading effects that both excess and scarcity of water have on economies and society.
The latest report on the state of global water resources indicates that in 2024 only about one third of the planet’s river basins presented “normal” conditions. In the rest, the recorded values were above or below normal, reflecting a clear imbalance for the sixth consecutive year.
Last year saw, for the third consecutive year, a widespread loss of glacial mass in all regions.
Many regions of small glaciers have already reached or are about to exceed the so-called peak water, that is, the point at which a glacier reaches its maximum annual runoff rate, after which it decreases as a result of the glacier’s retreat.
Extremes
The Amazon basin and other parts of South America, as well as southern Africa, were affected by episodes of severe drought in 2024, while in central, western, and eastern Africa, and in parts of Asia and central Europe, wetter than normal conditions were recorded, as detailed in the report.
“Water is indispensable for our societies, drives our economies, and sustains our ecosystems. However, global water resources are under increasing pressure, and water-related hazards—increasingly frequent and devastating—have a growing effect on our lives and livelihoods,” said Celeste Saulo, Secretary-General of the WMO.
“It is more important than ever to have reliable and scientifically based information, because you cannot manage what you do not measure. In this sense, the WMO report on the state of global water resources in 2024 responds to the Organization’s commitment to provide such knowledge,” added the Argentine.
The annual report on the state of global water resources is part of a set of WMO publications intended to provide information and guidance to decision-makers. It provides an authoritative assessment of the availability of global freshwater resources, including river flows, reservoirs, lakes, groundwater, soil moisture, snow, and ice.
It is prepared using data contributed by WMO Members, as well as information from global hydrological modeling systems and satellite observations provided by a wide range of partners.
This report highlights the urgent need to improve monitoring and data sharing.
“It is essential to continue investing and strengthening collaboration on data sharing to address monitoring gaps.
Without data, we run the risk of acting blindly,” commented Saulo.
It is estimated that some 3.6 billion people lack adequate access to water for at least one month per year—a figure that is expected to rise to over 5 billion by 2050, according to UN-Water data—and the world is still far from achieving Sustainable Development Goal 6 on clean water and sanitation.
Key Data
Above-average precipitation was observed in central and western Africa, the Lake Victoria basin in Africa, as well as in Kazakhstan and southern Russia, central Europe, Pakistan and northern India, southern Iran, and northeastern China.
River flows were well below normal in key river basins, such as the Amazon, São Francisco, Paraná, and Orinoco in South America, and the Zambezi, Limpopo, Okavango, and Orange in southern Africa.
Flooding was recorded in large areas of West Africa, particularly in the Senegal, Niger, and Volta river basins, and Lake Chad. In central Europe and parts of Asia, river flow was above normal, and some of the most important basins, such as the Danube, Ganges, Godavari, and Indus, experienced flood events.
In virtually all of the 75 major lakes worldwide analyzed, temperatures reached above or well above normal in July, affecting their water quality.
Trends in reservoir inflow, groundwater, soil moisture, and evapotranspiration highlighted regional contrasts: while recharge was observed in wetter areas, for example in parts of Europe and India, deficits persisted in some parts of Africa, America, and Australia.
Excessive groundwater extraction remains a problem in some areas, as it reduces future water availability for communities and ecosystems and increases pressure on global water resources. Only 38% of wells (from a sample of 37,406 wells in 47 countries that provided groundwater data) showed normal levels; the rest recorded either excessive abundance or water scarcity.
Glaciers. In 2024, widespread ice loss was recorded for the third consecutive year across all glacier regions. A total of 450 Gt was lost, equivalent to a huge block of ice 7 km high, 7 km wide, and 7 km deep, or a volume of water sufficient to fill 180 million Olympic-sized swimming pools.
Such a quantity of meltwater contributes to a global sea level rise of about 1.2 millimeters in just one year, posing an increased risk of flooding for hundreds of millions of people living in coastal areas.
Unprecedented mass loss was recorded in the glaciers of Scandinavia, Svalbard, and northern Asia, while other regions, such as the Canadian Arctic and the periphery of Greenland, experienced more moderate losses.
In the Colombian glaciers, located within the tropical region, mass loss reached 5% in 2024.
Europe suffered its most extensive floods since 2013, and one third of the river networks recorded flows that exceeded the “high” flood threshold.
In Asia and the Pacific, unprecedented tropical cyclones and rainfall claimed the lives of more than 1000 people.
Brazil experienced multiple extreme events simultaneously: while catastrophic floods occurred in the south of the country, causing 183 deaths, the Amazon basin continued to be ravaged by the 2023 drought, which affected 59% of the national territory.
How it is made
The report on the state of global water resources contains contributions from a wide network of hydrology experts, including National Meteorological and Hydrological Services, World Data Centres, members of the global hydrological modelling community and supporting organizations such as the United States National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), the German Research Centre for Geosciences (GFZ), the World Glacier Monitoring Service (WGMS), the Global Runoff Data Centre (GRDC) and the International Groundwater Resources Assessment Centre (IGRAC).
This report aims to improve the accessibility and availability of observational data (through improvements in both monitoring and data sharing), further integrate relevant variables into the report, and encourage country participation in order to better understand and report on the dynamics of the water cycle.
Future reports are expected to include even more observational data, supported by initiatives such as the WMO Global Water Status and Outlook System (HydroSOS), the WMO Hydrological Observing System (WHOS) and collaboration with world data centres.
Cover image: Christel on Pixabay
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climate changeCeleste Saulo Secretary-General of the World Meteorological Organizationglacier meltingwater cycle reportfloodsWorld Meteorological Organizationdroughts
