The greenhouse effect is accelerating the global water cycle almost twice the rate predicted by climate change models, say researchers.
Oceanographer Dr Susan Wijffels of the CSIRO and colleagues report their findings today in the journal Science.
“The models predict a 4 to 5 per cent amplification of the global water cycle per degree of warming, instead of 8 per cent,” says Wijffels.
“It’s a significant underestimation. That’s a cause for concern.”
The transport of water through the atmosphere from the mid-latitudes of Earth to the poles and tropics is called the global water cycle.
How much water evaporates in dry areas and falls as rain in wet areas is vital to society, says Wijffels.
Global climate models predict that as the globe warms, this will heat the lower atmosphere and enable it to hold more moisture, thus speeding up the global water cycle.
“It’s like the rich get richer scenario where the wet places will get wetter and the dry places will get a lot drier because the conveyor belt is speeding up between those two places,” says Wijffel. …