SYDNEY, Australia — More than 70 fires burned across Australia’s east coast on Tuesday, 40 of them out of control, as officials warned that catastrophic conditions would worsen through the afternoon and evening, with intensifying winds blowing flames toward larger cities and towns.
More than 100,000 homes are at risk over the coming days as a combination of drought, heat and blustery winds bears down on New South Wales, the country’s most populated state.
“The conditions are expected to get worse,” Shane Fitzsimmons, the Rural Fire Service commissioner, said on Tuesday afternoon in Sydney. “There’s still a way to go before they reach the potential of the forecast.”
“Complacency kills,” he added. “We cannot afford to be complacent.”
The fires, which began burning in earnest over the weekend, have caused four deaths and destroyed more than 150 properties, with a handful more added every few hours.
Maps from fire officials showing the areas likely to burn showed blazes potentially doubling in size over the next 24 hours, with Coffs Harbour, a coastal city of 70,000 people, looking especially vulnerable, along with Sydney’s outer suburbs.
And as an especially hot day wore on, with temperatures far above seasonal norms, the fires also continued to set off emotional arguments about climate change.
A day after the deputy prime minister, Michael McCormack, said that only leftist “lunatics” were linking the blazes to climate change, mayors from the areas already burning demanded that lawmakers pay attention to common-sense science and public outrage.
“They need to get out and have a real look at what’s happening to this country,” said Claire Pontin, the deputy mayor of the MidCoast Council.
Carol Sparks, the mayor of Glen Innes, where two people died over the weekend, said: “It is not a political thing — it is a scientific fact that we are going through climate change. I think that Michael McCormack needs to read the science.”
Schools close and firefighters get air support.
Across the region, the day began with preparations for the increased fire risk.
More than 600 schools and education centers across New South Wales, and a number in neighboring Queensland, canceled classes Tuesday. Several other schools evacuated students Tuesday as the threat of fire approached.
Commissioner Fitzsimmons said there were around 100 aircraft ready to help the roughly 1,500 firefighters already posted at blazes across New South Wales. The equipment includes Australian Defense Force helicopters that will fly night missions over Sydney and the wider area to help firefighter movement and possible civilian rescues. Some larger planes have come from California under a sharing deal that’s been in place since 2001.
In Sydney’s suburbs near the Blue Mountains, where a devastating fire destroyed hundreds of homes and left two people dead in 2013, residents reported packing their cars with clothes, water and essentials in case they needed to flee. Farther north, where fires continued to rage, evacuation centers have been filling up with residents fleeing to safety.
Conditions were expected to ease somewhat on Wednesday in New South Wales, with temperatures cooling and winds slowing, but the fire threat was expected to remain for several days.
Drier-than-normal conditions set the stage for danger.
An omen for the current fire season came in September, when a historic lodge in a rain forest burned nearly to the ground.
The areas where fires were raging as of Tuesday morning, north of Sydney near Port Macquarie and the Queensland border, have been suffering from a lengthy drought.
But scientists note that moisture levels of live trees and shrubs around Sydney are also at record lows — even lower than the levels during the Black Christmas fires of 2001, which destroyed more than 500 buildings on the edge of Sydney and burned for three weeks.
Given the drier-than-normal conditions, there is fuel both on the ground, with dry leaves, and in the branches of trees that are dying or dead. And if something ignites, high winds threaten to carry the flames far and wide.
On Tuesday, the federal Bureau of Meteorology reported that winds were already starting to reach 70 kilometers per hour, or 43 miles per hour, with gusts in excess of 90 km/h (56 m.p.h).
“It’s not just out in the bush, because many people in cities are right on that edge,” said Lesley Hughes, a biology professor at Macquarie University who works with the Climate Council of Australia. “Everybody loves to live in the bush and around the bush — it’s becoming an increasingly dangerous place.”
Debate rages as government officials deny link to climate change.
Despite several months of mass protests drawing attention to the Australian public’s concerns about climate change, the country’s deputy prime minister on Monday dismissed questions about its role in the fires.
In an interview with ABC Radio National, the official, Michael McCormack, said it “galls” him when people raise climate change in relation to bush fires. He said global warming was a concern of “raving inner-city lunatics.”
Scientists, firefighters and mayors immediately responded. Many pointed out the clear connections between climate change and the extended and more intense fire seasons in Australia, California and other places around the world.
“Fires are burning in places and at intensities never before experienced,” Greg Mullins, a former fire and rescue commissioner in New South Wales, wrote in an op-ed article for The Sydney Morning Herald, citing rain forests in northern New South Wales, tropical areas of Queensland and the “formerly wet old-growth forests” of Tasmania.
He also said that thunderstorms caused by fires — known as “pyro-convective” events — were rare in the past but were now happening regularly.
Joëlle Gergis, a climate scientist and writer from the Australian National University, said it was clear that “there’s a human fingerprint on the temperature increases since 1950 — all the weather patterns are occurring in a planet that is warming and warming because of human activity.”
By dismissing the role of climate change, she said, the government was choosing immediate disaster response over long-term needs.
“We’re really missing the opportunity to prepare for future life in Australia,” Dr. Gergis said.
“It’s going to be a lot warmer, and we’re going to see a lot of prevalence of extreme fire conditions,” she added. “The further we kick the can down the road and avoid these conversations, we’re really missing the opportunity to get the Australian public ready for what is upon us.”
Jamie Tarabay, Isabella Kwai and Sasha Gattermayr contributed reporting.