Climate change: NZ faces 40% jump in city fires under ‘worst case’ warming scenario

New Zealand could be facing 40% more urban fires by 2100 under a “worst case” global warming scenario, show new projections. Photo / Brett Phibbs.

• Scientists studied fires and air temperatures from more than 2800 cities in 20 countries, covering over 20% of the world’s population.
• New Zealand had the strongest link between fires and warming, and would see over 40% more city fires by 2100 with unmitigated warming of over 4C.
• Globally, the researchers estimate this would lead to a third of a million more fire deaths and over a million more injuries from 2020 to 2100.

New Zealand could be facing 40% more urban fires by 2100 under a “worst case” global warming scenario, new projections show, prompting fresh warnings against development in risky areas.

In a just-published major study, a China-led team of researchers analysed data from more than 2800 cities in 20 countries to explore how some types of fires were likely to change as the planet heats.

In all, they projected an 11.6% jump in vehicle fires and a 22.2% increase in outdoor fires this century, under the UN’s SSP5-8.5 emissions scenario.

Going by that extreme but currently unlikely scenario — involving about 4C of temperature rise by century’s end — the world could also see about 335,000 fire-related deaths and 1.1 million injuries between 2020 and 2100.

The researchers found this could be halved if global temperature rise was kept to 1.5C, although that was something climate scientists also now widely consider unlikely.

Amid the data, New Zealand showed the strongest link between warming and fire risk, with 40% more city blazes under the UN’s SSP5-8.5 scenario of several degrees of temperature rise.

That outsized risk — strongly influenced by smaller-scale urban and outdoor fires that escalated with rising temperatures — wasn’t surprising to John Tookey, a professor of construction at AUT University.

Being a cooler, moist environment with many trees meant New Zealand faced a greater shift in danger as drier, warmer conditions created more dry timber and slash.

Tookey, who was not part of the study, also pointed out New Zealand appeared as the country with the biggest drop in building fires in the future, as Kiwis began to live a more indoor life.

The paper also did not signal any surge in fire deaths here, but Tookey noted the projections couldn’t capture complex factors, such as migration to towns and cities, which could influence future risk.

“Auckland, in particular, is going to see huge growth of up to 400,000 additional people before the end of the century,” he said.

“What effects will this have on water pressure and availability for firefighting? We already see significant numbers of non-fatal fire related incidents for various reasons.”

But the new findings — coming soon after Los Angeles’ devastating wildfires — nonetheless highlighted areas where New Zealand could take steps to ready itself for future fires, he said.

That could include stronger fire breaks and buffer zones between forests and homes, more firefighting resources, tightening the fire permits system and requiring fire extinguishers in vehicles.

Professor Bruce Glavovic, of Massey University’s School of People, Environment and Planning, similarly raised a need to understand which of our communities faced bigger risks — and how they could be addressed.

“We must stop new development in fire-prone areas — especially at the wildland-urban interface.”

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.

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