According to a new report published in Nature journal, led by Australian researchers, climate change has intensified the global water cycle by up to 7.4 per cent – compared with previous modelling estimates of two to four per cent. The water cycle describes the movement of water on Earth – it evaporates, rises into the atmosphere, cools and condenses into rain or snow and falls again to the surface. The report released to the public said that the hotter temperatures are speeding up the constant cycle of freshwater between the clouds, the land and the ocean, leading to more extreme weather conditions with the world's wetter areas becoming even more soaked and the dry regions becoming even more parched.
“When we learn about the water cycle, traditionally we think of it as some unchanging process which is constantly filling and refilling our dams, our lakes, and our water sources, but the numbers paint a picture of the larger changes happening in the global water cycle,” said Dr Taimoor Sohail, the study’s lead author and Mathematician at the University of New South Wales.
Last August, the Intergovernmental Panel on Climate Change’s sixth assessment report concluded that climate change will cause long-term changes to the water cycle, resulting in stronger and more frequent droughts and extreme rainfall events. Sohail said the volume of extra freshwater that had already been pushed to the poles as a result of an intensifying water cycle was far greater than previous climate models suggest.
Scientists estimate the volume of extra freshwater that shifted from warmer regions between 1970 and 2014 is between 46,000 and 77,000 cubic kms. “We’re seeing higher water cycle intensification than we were expecting, and that means we need to move even more quickly towards a path of net zero emissions,” he said.