Driven by Meltwater and Rising Temperatures, the Global Water Cycle is Accelerating

Nature, 23 February 2022

Climate change, in part by causing an increase of meltwater flowing off ice sheets into the ocean, has intensified the “global water cycle” by roughly 7%. This has worsened droughts and extreme rainfall events across the world. The global water cycle involves the constant movement of freshwater between the clouds, land (including glaciers and ice sheets), and the ocean. Since 1970, two to four times more freshwater has moved from the equator to the poles than estimated by previous climate models. Rising global temperatures also shifts water away from dry subtropical areas. This shifting in the water cycle causes droughts to worsen in certain regions of the world, while intensifying storms and flooding in others. Sustained water cycle amplification will worsen the droughts afflicting the western half of the United States, exacerbate the unprecedented floods in Germany, and increase the severe rainfall already observed in cities such as Mumbai. Changes to the water cycle have cascading impacts on global infrastructure, agriculture, and biodiversity. Authors underscore the importance of reducing emissions and developing mitigation strategies to better adapt to these long-term effects on communities across the world.