The World Meteorological Organization (WMO) reported that most of the globe was drier than normal in 2021, with “cascading effects on economies, ecosystems and our daily lives”.
According to the UN agency’s first report on the world’s water resources, unusually dry areas included the Rio de la Plata region of South America, where persistent drought has affected the region since 2019.
In Africa, large rivers such as the Niger, Volta, Nile and Congo had below average water flow in 2021. The same trend was observed in rivers in parts of Russia, the Western Siberia and Central Asia.
In contrast, river flows were above normal in some North American basins, northern Amazonia and South Africa, as well as in the Amur River Basin in China and northern India. ‘India.
According to the WMO, 3.6 billion people do not have access to water for at least one month a year and this figure is expected to rise to more than five billion by 2050.
Climate crisis
For Petteri Taalas, Secretary-General of WMO, “The impacts of climate change are often felt through water – more intense and frequent droughts, more extreme floods, more erratic seasonal rainfall and accelerated melting of glaciers – with cascading effects on economies, ecosystems and all aspects of our daily life
” And yethe added, understanding of changes in the distribution, quantity and quality of freshwater resources is insufficient”.
The State of the World’s Water Resources report “aims to fill this knowledge gap and provide a concise overview of water availability in different parts of the world”, the WMO SG further said, noting that “this will inform climate change adaptation and mitigation investments as well as the UN campaign to provide universal access over the next five years to early warnings of hazards such as floods and droughts.”
The majority of water-related natural disasters
Between 2001 and 2018, 74% of all natural disasters were water-related, according to UN-Water.
The recent United Nations Climate Change Conference, COP27, in Egypt urged governments to further integrate water into adaptation efforts, the first time water was referenced in a COP outcome document. in recognition of its critical importance, noted the WMO.
The first edition of the report examines river flow – the volume of water flowing through a river bed at any given time – and also assesses terrestrial water storage – in other words, all water above and below the earth’s surface and the cryosphere (frozen water).
The report highlights a fundamental problem: the lack of accessible verified hydrological data.
The WMO data policy aims to accelerate the availability and sharing of hydrological data, including river flows and information on transboundary river basins.
Apart from variations in river flow, overall terrestrial water storage was rated as below normal on the West Coast of the United States, central South America and Patagonia, North Africa and Madagascar, Central Asia and the Middle East, Pakistan and North India. It was higher than normal in central Africa, northern South America – particularly in the Amazon basin – and northern China.
In this sense, the WMO has warned that “Overall, the negative trends are stronger than the positive ones”with several emerging hotspots including Patagonia, the headwaters of the Ganges and Indus, as well as the southwestern United States.
Cryosphere
The cryosphere – consisting of glaciers, snow cover, ice caps and, where present, permafrost – is the largest natural reservoir of fresh water in the world.
WMO notes in this regard that “changes in the water resources of the cryosphere affect food security, human health, the integrity and maintenance of ecosystems, and lead to significant impacts on economic and social development“, sometimes causing river flooding and flash flooding due to overflows from glacial lakes.
With rising temperatures, the annual runoff from glaciers generally increases at first, until a crucial point, often referred to as “peak water”, is reached, at which point the runoff decreases.
According to the WMO, long-term projections of glacier runoff and the timing of peak water are key elements for long-term adaptation decisions.