A hard rain to fall in Australia with climate change

A hard rain to fall in Australia with climate change
Extreme precipitation is projected to increase almost everywhere in Australia from tropical regions in the north to mid-latitudes in the south. Credit: Shutterstock

Dorothy Mackellar's classic view of Australia as a country of droughts and flooding rains is likely to get a further boost with just a 2°C rise in global warming, new research suggests.

New findings from the ARC Centre of Excellence for Climate System Science, published today in Nature Climate Change, have pointed to strong increases in rainfall during events in Australia as a result of . The results also resolved some important discrepancies in previous published estimates of how Australian rainfall is affected by .

This paper reveals that with just a rise of 2°C in global average temperatures, Australia will see a 11.3-30% intensification in rainfall from extreme precipitation events. This will occur even as some areas may become increasingly drought prone.

"There is no chance that rainfall in Australia will remain the same as the climate warms," said an author of the paper UNSW Professor Steve Sherwood.

"The only way that this intensification of falls at the lower end of the scale is if the continent becomes drier overall. The long and the short of it is that with 2°C of global warming Australia is stuck with either more aridity, much heavier extreme rains, or some combination of the two," said Sherwood, from UNSW's Climate Change Research Centre.

The researchers used the NSW and ACT Regional Climate Model (NARClim) project to tease out the future changes because of its high regional detail, and ensemble of 12 models.

They looked at the heaviest 1% of rainfall events experienced in Australia across all seasons with a particular focus on precipitation in the very different climates of Darwin, Sydney and Melbourne.

The researchers found average humidity was a key component determining how rapidly extreme rainfall events intensified as global temperature increased.

Greater average humidity led to a sharper increase in the intense rainfall events. But even in areas where average humidity and rainfall was lower, suggesting increasing aridity, the most extreme rainfall events still saw an 11.3% increase in total rainfall with 2°C of global warming.

"Extreme precipitation is projected to increase almost everywhere in Australia from tropical regions in the north to mid-latitudes in the south and from dry deserts in the centre to wet places along the coast," said PhD student and lead author Jiawei Bao.

"Rising air temperature is the primary reason for this change. Australia's infrastructure will need to be prepared to adapt to these more extreme rainfall events even if we act to moderate the global temperature rise to within 2°C."

The paper also went beyond the 2°C international Paris Agreement target, looking at what would happen with a 4°C rise in , which is a likely outcome based on current increases in the rate of carbon emissions. It produced a projected increase in rainfall for extreme events of 22-60%.

"Current policies worldwide are nowhere near enough to actually meet the Paris targets, so it is likely we face even greater changes unless policies are strengthened," Sherwood said.

"Australia cannot use past observations alone to develop rainfall infrastructure. This research tells us we need to be prepared to adapt to a world of far more intense extremes, if we can."


Explore further

Global warming increases rain in world's driest areas

More information: Jiawei Bao et al. Future increases in extreme precipitation exceed observed scaling rates, Nature Climate Change (2017). DOI: 10.1038/nclimate3201
Journal information: Nature Climate Change

Citation: A hard rain to fall in Australia with climate change (2017, January 17) retrieved 26 June 2019 from https://phys.org/news/2017-01-hard-fall-australia-climate.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
21 shares

Feedback to editors

User comments

Jan 25, 2017
This is good news!. Water is a scarce commodity in most of Australia.

Jan 25, 2017
Can you say ALTERNATIVE FACTS.
Well, the AGW Cult, with their Pathological "science", have taken it even further into the realms of Alternative LIES. Sad.
LOL.

Jan 25, 2017
This is good news!. Water is a scarce commodity in most of Australia.


Can you say ALTERNATIVE FACTS.


You aren't really aware how much damage floods/hard rain cause in Australia, are you?

To make it simple for you so you can wrap your one brain cell around this:
A bit more rain averaged over the year: good
A lot more rain in a short period of time: bad (flood damage, destroyed crops)

What we have here is the latter.

Got it?

Jan 25, 2017
You aren't really aware how much damage ......

You aren't really aware how much damage a tard like you can cause, are you?
Of course not, you're a tard. Fortunately that damage is to yourself.

The dry era of the 1920s and 1930s may well have been the driest period in Australia over the past four centuries.

https://en.wikipe...ustralia

Mar 15, 2017
The weakening jet streams will eliminate the desert latitudes. Deserts like the Sahara, Australian, and Arabian will experience more rainfall as storms will be allowed to track over them.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more