Climate change and fires’ ‘unequivocal link’
Leading Australian scientists say there was an "unequivocal" link between last summer's catastrophic bushfire season and climate change.
Speaking at Wednesday's Senate inquiry into the 2019-2020 bushfire season, Bureau of Meteorology (BOM) chief executive officer Dr Andrew Johnson said "there's no doubt" the planet was warming.
"There's no doubt the causes of that warming have significant human footprint. That's well established and scientific evidence is unequivocal," he said.
He said average temperatures had risen 1.4C since the turn of the century while parts of the country had experienced a rapid decline in rainfall.
"How that (global warming) translates to a severe weather event is a broad field, (but) there are certain dimensions of the warming planet and what we're experiencing today that's becoming clear," he said.
In January Prime Minister Scott Morrison and his Energy and Emissions Reduction Minister Angus Taylor suggested the country did not need to cut emissions more aggressively in a bid to stem global warming despite a three-year drought and raging fires.
Australia contributes about 1.3 per cent of the world's carbon emissions but remains one of the largest carbon emitters per capita.
Dr Johnson said a rise in global emissions was driving up temperatures, which was likely to increase the risk of bushfires.
"Bushfires are starting earlier and ending later. There's a climate signal in that," he told the panel.
"How that plays out in the future will very much depend on how humanity responds."
He said the bureau had provided extensive advice to government about the link between climate change, bushfires and emissions.
"We've been very clear and consistent in our advice to government across all three levels for many years," Dr Johnson said.
"That advice is freely available to the general community.
Noting the BOM's submission, Queensland Senator Murray Watt said it had provided more than 100 briefings about the bushfire risk to federal and state governments in the months leading up to what would be the most catastrophic bushfire season on record.
That included briefings about the risk associated with areas that were the hardest hit.
Dr Johnson said the bureau provided "extensive briefings to all levels of government leading into the summer", spanning from daily updates to forward briefings.
Committee chair Senator Tim Ayres questioned several of the country's most well-regarded scientists and scientific bodies about one of the nation's most "catastrophic events".
Professor Mark Howden, of the Climate Change Institute at the Australian National University, said drought, high temperatures, low humidity and strong winds all contributed to the development of extreme bushfires.
This is on top of the lowest rainfall and highest temperatures experienced on record.
"There's a long and strong link to reduced humidity due to climate change which is projected to get worse in the future," Prof Howden said.
"Each of these four major drivers will get worse … and the risks associated with climate change are growing."
Professor John Sharples, of UNSW's School of Science, echoed those comments, saying "what drives bushfires will increase due to global warming".
"It's hard to put an exact number on whether that will double or triple," he said.
Prof Howden argued that Australia, along with the rest of the world, must reduce greenhouses gases.
"The question is whether we can extend that action (from the Paris Agreement)," he said.
Although, this summer could look a little different.
Dr Karl Braganza, the BOM's head of climate change, said there was a potential for a La Niña event - the cooling of the Pacific Ocean - to occur this year.
He explained this could increase the risk of tropical cyclones and flooding.
"We would have to increase provisions for those things," he told the inquiry.
"All going well, (it) would mean more rain and reduce the risk of bushfires this summer. Having said that we haven't seen the rain we expected to fall in the recent months.
"We are watching conditions as they unfold."
He said the bureau would now focus on its long-range forecasts.
"There's still some very parched areas of the country so the next few months is crucial," Dr Braganza said.
The inquiry continues.
Originally published as Climate change and fires' 'unequivocal link'