The United Nations reported on October 7 that climate change is making the water cycle increasingly unpredictable, with floods and droughts becoming more severe.
Last year was the driest for rivers worldwide in over 30 years, glaciers lost the largest volume of ice in half a century, and numerous floods occurred, according to the World Meteorological Organization (WMO) of the United Nations. “We are receiving warning signals in the form of extreme rainfall, increasing floods, and droughts causing significant damage to lives, ecosystems, and economies,” said WMO Secretary-General Celeste Saulo.
The Rhone Glacier in the Swiss Alps, September 30. (Photo: Fabrice Coffrini/AFP).
Saulo indicated that the warming of the Earth’s atmosphere is causing the water cycle to become “more erratic and unpredictable.” Last year was the hottest on record, with high temperatures and widespread dry conditions leading to prolonged droughts.
These extreme events are influenced partly by natural climate conditions, including the La Niña and El Niño phenomena, but are increasingly affected by human-induced climate change. “A warmer atmosphere holds more moisture, conducive to heavy rainfall. Faster evaporation and drier land exacerbate the drought problem,” Saulo noted.
Whether too much or too little water, many countries are facing increasingly difficult situations. Last year, Africa was the continent most severely impacted in terms of casualties. In Libya, two dams collapsed due to heavy flooding in September 2023, resulting in over 11,000 deaths and affecting 22% of the population, according to WMO.
Currently, 3.6 billion people lack sufficient freshwater at least once a month, according to the United Nations. This number is expected to rise to over 5 billion by 2050. Over the past three years, more than 50% of river basins have experienced drier than normal conditions. Meanwhile, inflows into lakes have fallen below normal levels in many parts of the world over the past five years.
Rising temperatures mean glaciers are melting at unprecedented rates, losing over 600 billion tons of water, the worst in 50 years of observation, according to preliminary data from September 2022 to August 2023. “Glaciers and ice melting threaten the long-term water security of millions of people. But we have yet to take the urgent actions needed,” Saulo remarked.
In addition to reducing greenhouse gas emissions that cause global warming, WMO emphasizes the need for better monitoring of freshwater resources worldwide so that early warning systems can minimize damage to humans and wildlife.
Stefan Uhlenbrook, director of WMO’s hydrology, water, and ice department, warned that returning to a more natural and balanced water cycle is very challenging. “The only thing we can do is stabilize the climate, an enormous challenge,” he stated.
