CSIRO warns Central Australia primed for big bushfires after heavy rainfall and La Nina event

Central Australia will be primed to burn for months on end in the aftermath of a wetter La Nina season and worsening climate change-induced bushfires, according to new research.

CENTRAL Australian rangelands will be primed to burn for months on end in the aftermath of a wetter La Nina season and worsening climate change-induced bushfires, according to new research from Australia’s national science agency.

The research by CSIRO combines analysis of previous fire sites with eight drivers of fire activity including climate, fuel accumulation, ignition and management.

While Australian forests tend to burn when systems are in drought, Central Australia – with its vast rangelands – is likely to see far greater levels of burning after a season with high rainfall.

“Good rains, like we’ve been having in the last few months, produce a lot of grass growth, and sooner or later that’s likely to burn,” said co-author and CSIRO rangeland ecologist Garry Cook.

“Across Central Australia, the system is much more driven by rainfall for most of the time – if there’s sufficient fuel there, the conditions would support a fire.”

Mr Cook said the La Nina event this year, coupled with Alice Springs’ wettest November on record, would go a long way towards increasing the fire load in the region.

A 2017 Alice Springs fired threatened trees in the Todd River bed. Picture: SABINE HAIDER

“That water is going to go down the rivers, into big flood out areas, down the Finke, and across all the country running off the MacDonnell Ranges, producing a lot of grass growth.

“Eventually, the rains will stop and that grass will dry out and potentially become fuel for fires, and it’s something the people in Central Australia need to be ready for.”

CSIRO ecologist Garry Cook shows a smoke spread simulation.

Following Central Australia’s wettest ‘dry’ season on record in 2010/11, which was also a La Nina event, fire tore through tens of millions of hectares of Central Australian rangelands the following season over the space of several months.

“By the following spring and summer, hot, dry weather, some lightning storms or something like that happens, and the system gets put alight.”

Published in Nature Communications, the new research found climate was the overwhelming factor driving fire activity, and the frequency of forest megafires are likely to continue under future projected climate change.

NT Fire and Rescue Service Acting District Officer Stephen Hunter said preventative measures would be undertaken for next bushfire season. “We can anticipate higher fuel loads compared to previous years and as such preventative and measure planning is undertaken in conjunction with other agencies, departments and local councils,” he said.