Bushfires raging amid extreme heat in Australia sent choking smoke over neighborhoods this week, like this pool in Shoalhaven Heads, New South Wales.

Bushfires continue to rage in Australia this week, even as an area larger than West Virginia has been torched since the current round of blazes ignited last September.

It’s already one of Australia’s worst fire seasons on record and the deadly heat, wind, smoke, and flames show no signs of letting up through the week. Over the weekend, high winds spread massive smoke plumes, triggering storms and impeding firefighters.

The fires have now killed at least 24 people, torched more than 15.6 million acres, and destroyed more than 1,400 homes since September. The blazes turned skies orange and made breathing the air in Sydney as bad as smoking 37 cigarettes. The bushfires have also killed 480 million animals, environmental officials told the Times in the United Kingdom, including nearly one-third of the koalas in one of Australia’s most populated koala habitats, an area 240 miles north of Sydney.

Australia’s military deployed ships and aircraft to help rescue thousands of people trapped by fires in coastal tourist destinations. USA Today reports that over 100 firefighters from Canada and the US are heading to Australia to help beat back the fires.

The blazes ignited amid an unprecedented heat wave across much of Australia, closing out a hellish year of weather, the country’s hottest and driest on record. And the heat kept rising into the New Year.

Temperatures topped 105 degrees Fahrenheit in Sydney and triple-digit temperatures scorched much of the rest of the country last week. Over the weekend, Sydney experienced its highest temperature on record. So did Australia’s capital Canberra.

Cooler weather is arrived in parts of Australia’s southern coast, but severe heat is still baking regions further north.

Much of the severe heat was accompanied by brisk winds across much of Australia, worsening fire risks. Over the weekend, wind speeds gusted up to 80 mph, fanning flames and pushing heavy smoke over major cities.

Temperatures in southern parts of Australia have begun to cool off, but scorching temperatures remain on the horizon for regions further north. Meanwhile, Tropical Cyclone Blake, Australia’s first named storm of the year, is churning along the country’s northwestern coast.

It’s currently summer in Australia, and high temperatures, dry weather, and wildfires are not unusual this time of year. But the severity and continued persistence of these fiery conditions are alarming.

Writing in the Sydney Morning Herald, veterinarian Gundi Rhoades described the conditions for ranchers in Inverell, a town in NSW, in apocalyptic terms:

Most farmers in my district have not a blade of grass remaining on their properties. Topsoil has been blown away by the terrible, strong winds this spring and summer. We have experienced the hottest days that I can remember, and right now I can’t even open any windows because my eyes sting and lungs hurt from bushfire smoke. For days, I have watched as the bushland around us went up like a tinderbox. I just waited for the next day when my clinic would be flooded with evacuated dogs, cats, goats and horses in desperate need of water and food.

The extreme heat in Australia is not just a fluke. There were unique patterns in rain, temperature, and wind that converged to scorch the continent, factors that scientists were able to detect in advance. But Australia is also deep in the throes of the accelerating climate crisis, facing not just extreme heat but changes in rainfall patterns. These shifts in turn stand to worsen other problems like drought and wildfires. At the same time, the Australian government is struggling to limit its own contributions to climate change while appeasing its major greenhouse gas emitters, including its powerful coal mining industry.

Taken together, Australia serves as a microcosm of all the complicated ways that climate variables interact. Its weather this year also shows what other parts of the world may face as temperatures continue to rise. So let’s walk through the ingredients of Australia’s heat and wildfires, and how they will likely intensify in the future.

The warning signs of Australia’s current heat wave have been building up for years

Australia’s climate is notorious for its volatility, but this summer’s high temperatures — peaking at close to 120 degrees Fahrenheit in December — and subsequent fires have still been outliers.

The country itself spans a region from the tropics in the north to more temperate climates in the south, with deserts in the middle. It also sits between two major oceans and is buffeted by the shifting circulation patterns of both. So the weather over the continent can change drastically year to year and become hard to predict. Still, Sarah Perkins-Kirkpatrick, a senior lecturer at the Climate Change Research Centre at the University of New South Wales, Sydney, explained that there were warning signs that this year’s summer in Australia would get brutally hot.

One signal was that the Indian Ocean Dipole, the cycle of the temperature gradient between the eastern and western parts of the Indian Ocean, was in its positive phase this year. That led to much less rainfall over Australia as prevailing winds pushed moisture gathering above the Indian Ocean away from the continent in the spring.

Another alarm bell this year was the Southern Annular Mode. This describes the movement of the circular belt of wind around Antarctica as it shifts north or south. It’s in its negative phase right now, bringing dry conditions to Australia. This year, it also blended with a surge of heat in the stratosphere, channeling gobs of hot, dry air to southern Australia.

And while Australia’s annual monsoon rains in the northern part of the country packed a devastating wallop in February, causing dangerous flooding in the state of Queensland, they were also behind schedule. That allowed more heat to accumulate over the central part of the country this year.

“So there was lots going on in terms of natural climate variability for this season to be quite hot,” Perkins-Kirkpatrick wrote in an email.

At the same time, there were longer-term factors at work. One of them is that much of Australia is facing a severe drought, spurred by three winters in a row with very little precipitation.

“That’s never happened in the instrumental record,” Michael Roderick, a climate researcher at the Australian National University told the Sydney Morning Herald in November. “They’ve never really had two failed winters in a row.”

With drought conditions, there is less moisture evaporating in the heat, a phenomenon that usually has a cooling effect.

All the while, the climate is getting hotter. “Australia’s climate has warmed by just over 1° C since 1910, leading to an increase in the frequency of extreme heat events,” according to the Australian Bureau of Meteorology’s 2018 State of the Climate report. This has also led to more rainfall in northern Australia, but less in the southeast, where most Australians live.

The recent bushfires have sent smoke over iconic Australian landmarks like Bondi Beach.

Jenny Evans/Getty Images

These converging factors are why the temperatures in the country have been so stunningly hot. Australia broke a heat record on December 17, reaching a national average temperature of 105.6 degrees Fahrenheit. That record was broken the very next day, averaging 107.4.

“This in itself (the record being broken at the start of the season, being broken two days in a row, and by such a large margin) is phenomenal,” Perkins-Kirkpatrick said. “If the climate wasn’t changing, the chance of this happening is ridiculously low.”

Australia’s fire season is getting longer and more dangerous

The prolonged bout of surging temperatures this year has been an important element in the raging deadly infernos across Australia.

It’s important to note that wildfires are a natural part of the ecosystem in Australia. Many plants and other organisms even depend on regular blazes to germinate, cycle nutrients, and clear decay. However, the combination of rising heat and drier weather has turned vegetation into tinder, leaving trees, shrubs, and grass ready to ignite near some of the most densely populated parts of the country. “There has been a long-term increase in extreme fire weather, and in the length of the fire season, across large parts of Australia,” according to the 2018 State of the Climate report.

However, the links between fire risk and climate change are more complicated than the links between extreme heat and climate change. That isn’t to say humans aren’t contributing to the danger from fires. As in the United States, human-caused factors like building in fire-prone areas are contributing to the growing fire risk in Australia. Arson is also suspected as a cause of some of the recent fires.

Smoke from bushfires has degraded air quality in major Australian cities this month.

And as the climate changes, the underlying conditions for Australian bushfires will continue to amplify, namely heat and dryness. “Some cities in Australia will likely hit temperatures in the 50’s (Celsius) [more than 122 degrees Fahrenheit] by the end of the century,” Perkins-Kirkpatrick said.

As a result, scientists expect to see more extreme wildfires in Australia in the latter part of this century. That means history can no longer serve as a guide for cities coping with the heat or firefighters battling flames.

“Events that are unprecedented in a given region, such as the 2018 [fire] event, reveal that firefighting preparation and training cannot rely on previous events as guidance for the most dangerous conditions they can expect in the current and future climate in which large-scale fires occur more regularly,” researchers warned in a study published in December in the Bulletin of the American Meteorological Society looking back at the 2018 fires in Australia.

That’s why fire officials are growing anxious about the prospects of more extreme fires. A group of 23 fire chiefs requested a meeting with Prime Minister Scott Morrison in April to discuss the threat, a meeting that has yet to take place.

Australian cities are bracing for a hot and fiery future, but the national government is lagging

Cities like Sydney have started to recognize the risks posed by climate change, but are still struggling to adapt to the warming to come. “Extreme heat is our biggest risk,” according to the 2018 Resilient Sydney report from the city government. “But new homes are usually not constructed to provide maximum protection from heatwaves and there is less tree canopy cover to reduce surface temperatures.”

To deal with the rising heat, the city is working to deploy reflective surfaces and plant trees to add shade and to mitigate the urban heat island effect. Officials are also investing in making the power grid more reliable to prevent cascading infrastructure failures as thousands of air conditioners switch on and strain the electricity networks.

“When energy demand increases during a heat wave, electrical infrastructure is more likely to overload and fail, causing air conditioners to stop working and outages to communication networks, reducing the ability of people to seek help,” according to the report.

But Australia’s national government has been slower to respond to the risks posed by extreme heat, bush fires, and climate change. Australian Prime Minister Scott Morrison apologized last month for taking a vacation to Hawaii during the recent heatwave and bushfires. However, he brushed off calls to curb Australia’s reliance on coal.

“I am not going to write off the jobs of thousands of Australians by walking away from traditional industries,” he told Australia’s Channel Seven. In November, he proposed banning climate change protests because they would hurt the country’s mining industry.

Mourners pay respects at a memorial for Geoffrey Keaton and Andrew O’Dwyer, volunteer firefighters who died fighting bushfires in New South Wales this month.

Jenny Evans/Getty Images

Though Australia accounts for 1.3 percent of global emissions, it is currently the world’s largest exporter of coal. Delegates at the recent United Nations climate negotiations in Madrid, COP25, named Australia as one of the parties blocking progress toward settling the rules of the Paris climate agreement. Under the agreement, Australia committed to curbing its greenhouse gas emissions between 26 percent and 28 percent below 2005 levels by 2030. That target is not sufficient to meet the Paris target of limiting warming this century to less than 2 degrees Celsius.

Morrison defended Australia’s actions on climate change. “Australia is taking action on climate change,” he told Australia’s Nine News last week. “What we won’t do is engage in reckless, job-destroying and economy-crunching targets.” In 2014, Australia became the first country in the world to introduce and then repeal a national carbon tax.

Australian Environment Minister Angus Taylor also noted in The Australian on Tuesday that Australia is outperforming its peers on climate. “Since 2005, Australia’s emissions have fallen 12.9 per cent, even while building the biggest liquefied natural gas industry in the world,” he wrote. “Canada’s emissions have fallen just 2 per cent and New Zealand’s have risen 4 per cent.”

But many Australians aren’t convinced. In December, 20,000 Australians wearing breathing masks rallied in Sydney to protest their government’s limited actions on climate change.

And for Prime Minister Morrison, his lackadaisical response to the ongoing fires has become a liability and some people in the hardest hit regions hold him responsible in part for the destruction.

The hot, dry weather is likely to persist for the first part of January, but the Bureau of Meteorology now reports that phenomena like the Indian Ocean Dipole and the Southern Annular Mode are weakening, which likely means less searing heat in February. Forecasters, though, expect above-average temperatures throughout the country until April.