6 days ago
Global fire seasons grow longer, threatening international collaboration
An increasing overlap of global fire seasons could challenge the ability for countries like Australia, the United States and Canada to help each other fight wildfires.
With firefighting aircraft and personnel historically shared between the two hemispheres, researchers are warning that a creeping closeness of fire weather is likely to put that under threat.
The warning comes as Australian firefighters help battle raging fires in Canada, which is experiencing one of the most severe wildfire seasons on record.
University of NSW climate scientist Doug Richardson said nations had long taken advantage of the "historically distinct" Northern and Southern Hemisphere fire seasons to lend each other a hand.
"It's been a really nice collaboration between Australia and the USA and Canada, for example, in how they fight fires and share resources, but unfortunately climate change is meaning that the fire seasons in both of those regions are getting longer and they're starting to bleed into each other a little bit now.
"That raises the question that perhaps these long-standing arrangements aren't going to be suitable moving forward."
Dr Richardson's research found that, since 1979, the degree of overlap between Australia's and North America's fire season weather increased by an average of one day per year.
"That doesn't sound like a lot … but when you accumulate that over several decades, this translates to nearly a month of extra overlap compared to what we were seeing in the 1980s and 1990s," he said.
As Australia leased firefighting aircraft from North America each year, Dr Richardson said that should prompt a review of the nation's resources.
"So far, thankfully, there haven't been too many problems with this, but it's something we're trying to raise awareness of that you should be thinking about whether we have to review these agreements."
Canada's wildfire season has started earlier than usual in recent years after hot, dry spring seasons.
Australian firefighters have been deployed to Canada in recent weeks to provide assistance, including from South Australia.
SA Country Fire Service executive director of operations Brenton Hastie said the Canadian fire situation had become increasingly problematic in recent years.
"Areas that have never been susceptible to fire before are now burning, and it's a bit of a global effort to support Canada and the USA as we saw last year dealing with these unprecedented fires," Mr Hastie said.
South Australia has already flagged it may enter its upcoming fire season early, after back-to-back years of drought.
"We had significant fires right up until five days before the start of winter this year in parts of SA," Mr Hastie said.
"That dryness makes more fuel available to burn, so when a fire does occur it can occur with a ferocity that is above what is expected in a normal year."
Mr Hastie said SA was in a lucky position to have sovereign capability with its firefighting aircraft, given the increasing overlap of global fire seasons.
"Some other jurisdictions do have contracts that rely on aircraft to come from the Northern Hemisphere," he said.
"For those states, it is increasingly problematic that the pinch point between the start of one season and the start of another is starting to overlap.
"Thankfully in SA that is not yet a problem for us."
