Climate: the water cycle is accelerating and will produce more extreme weather phenomena

Climate change is causing the planetary water cycle to accelerate, altering the salinity of oceans, lakes and rivers. With each degree of warming gained, the risks of droughts and torrential rainfall are multiplied.

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[EN VIDÉO] The worrying warming of the oceans
In 2020, the oceans absorbed the equivalent of 20 sextillion joules. Not since 1955 has the temperature of the ocean been so high.

Satellite data reveals a worrying shift in the water cycle Earth’s global. The water cycle is the course that takes place naturally between the great water reservoirs of our planet. L’energy of Sun and the heat are at the origin of this course, by favoring the evaporation of water and its displacement in the atmosphere.

L’pure water becomes more and more fresh and salty water becomes more and more salty, this is the finding of a study by Spanish researchers from the Institute of Marine Sciences published in Nature. The forecasting models of climate had already considered this phenomenon, but not so quickly. As global temperatures risethe greater the evaporation from the surface of the oceans, which leaves surface waters saltier and adds additional moisture to the atmosphere.

More droughts or more floods depending on the region

This humidity will increase precipitation in certain regions of the world, and dilute the fresh water in rivers and lakes, making them even less salty. This development could also supercharge episodes of torrential rainfall. Wetlands will therefore be even wetter, with more intense and frequent rainfall leading to more flooding, and drylands will suffer even more from drought. A quarter of humanity already suffers from lack of water, and the prospect of droughts more frequent and stronger could lead to an unprecedented planetary crisis, according to the United Nations. In the polar regions, the climate change has already resulted in increased rainfall in the spring, melting the snow even faster.

The water cycle speeds up by 7% for each degree it increases

Climate change also results in general weakening from winds. These less strong winds allow the surface waters to warm up, without allowing the hot surface water to mix with the cooler water below: the surface waters evaporate and the salt therefore remains trapped on the upper level. The most recent climate prediction models estimate that for each degree of warming gained, the water cycle speeds up by 7%. Concretely, this means that wet areas will be 7% wetter, and dry areas will be 7% drier. Estimates that agree with the latest IPCC forecasts on the envisaged consequences of climate change: if humanity manages to limit the rise in temperatures to 2°C compared to pre-industrial levels (knowing that we are already at 1.2°C), the extreme weather phenomena will be 14 times stronger anyway compared to what they were at the beginning of the industrial revolution.

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