The annual report of the World Meteorological Organization (WMO) highlights the poor state of global water resources. The climate crisis is making the water cycle more erratic, and thus more unpredictable
Water is the ‘wake-up call for climate change.’ In 2023, it sounded repeatedly. Warning signs have come from extreme rains, floods, and droughts that have crippled ecosystems and economies, costing many lives. ‘And yet we are not taking the urgent measures needed,’ laments Celeste Saulo, Secretary-General of the World Meteorological Organization, who presented the latest WMO report on the state of the global water crisis yesterday.
The main messages of the WMO report on the state of global water resources are three:
In 2023, global rivers recorded their lowest flows in 33 years, since the beginning of systematic data collection.
Glaciers have suffered the greatest volume loss in the last fifty years.
Climate change is making the global hydrological cycle more erratic.
‘The result of rising temperatures is the acceleration of the hydrological cycle. It has also become more irregular and unpredictable, and we are facing increasing problems of too much or too little water. A warmer atmosphere holds more moisture, leading to heavy rainfall. Faster evaporation and soil drying worsen drought conditions,‘ Saulo adds.
‘Yet, far too little is still known about the true state of the world’s freshwater resources. We cannot manage what we do not measure,’ explains the Secretary-General of the WMO, who continues the fight to create a global early warning system based on timely and accurate data, even from regions that are currently less monitored.
Global Water Crisis: The State of Rivers in 2023
Last year, global rivers hit a new negative record regarding flow. Like in 2022 and 2021, over 50% of global river basins recorded negative flow deviations. Conversely, fewer rivers exhibited flow conditions above the historical average.
The global water crisis has affected rivers on every continent. The basins of the Mississippi and the Amazon recorded unprecedented low water levels. The Horn of Africa, which had experienced five consecutive very dry rainy seasons, was hit by floods. The Ganges, Brahmaputra, and Mekong recorded below-normal conditions across almost their entire basins.
Aquifers: Extreme Situations
Too much water or too little, with no middle ground. This was also the situation that characterized global aquifers in 2023. In South Africa, most wells showed above-normal aquifer levels due to above-average rainfall, as did those in India, Ireland, Australia, and Israel.
A notable depletion of aquifer availability was observed in parts of North America and Europe due to prolonged drought. Not all of this is solely related to the climate crisis: in Chile and Jordan, aquifer levels were below normal, but long-term declines were due to excessive human withdrawals rather than climatic factors.
The Agony of Glaciers Continues
The WMO report adds another data point to the long agony of global glaciers: in 2023, 600 billion tons of water were lost due to glacier melting. This is the worst result in 50 years of observations. Extreme melting situations occurred in the western North America and the European Alps, where Swiss glaciers lost about 10% of their remaining volume in the last two years.
Snow cover in the Northern Hemisphere in May 2023 (at the end of the accumulation season) was the 8th lowest ever recorded from 1967 to 2023. This is a consequence of the low snow water equivalent levels recorded in March, which refers to the volume of water stored in the snowpack
Read here the WMO report on the state of global water resources
