Australian researchers warn that rainfall and flooding will intensify as climate change worsens. Their study, published on April 25 in the Geophysical Research Letters, cites that floods in some parts of Australia, especially in warmer areas like Darwin, will increase by 40 percent to 60 percent.

“As warming proceeds, storms are shrinking in space and in time,” explains University of New South Wales’ lead researcher Conrad Wasko. “They are becoming more concentrated over a smaller area, and the rainfall is coming down more plentifully and with more intensity over a shorter period of time. When the storm shrinks to that extent, you have a huge amount of rain coming down over a smaller area.”

An analysis from 1,300 rain gauges and 1,700 temperature stations across Australia reveals that atmospheric moisture is more concentrated close to the storm’s centre in warm storms than in cooler ones, consequently causing harsher peak rainfalls in these places. Australia is the ideal place to analyse global implications since the continent encompasses most of the globe’s climate conditions, except the Arctic or Antarctic.


Flash flooding in Perth, 2010. Credit: Wikimedia/Michael Spencer

“Look at the incidents of flooding in Mumbai or in Bangkok last year – you see urban streets full of water,” Wasko laments. “You see it now in Jakarta and Rome and many parts of Canada. That’s because the stormwater infrastructure cannot handle the rain, and part of the reason there’s more rain is the increase in global temperatures.”

The researchers point out that the stormwater infrastructures that have been used to manage rainfall patters are now inadequate. Rainwater has nowhere else to go, increasing flooding incidences.

The findings support a 2015 report in Nature Geoscience that showed storms are changing their temporal rainfall pattern. In other words, storms are getting shorter but more intense. Still, this is the first time to show that climate change is upsetting temporal patterns within the storms.