There was no name for the thing Tom Bates captured on video at the height of the notorious Australian bush fire season of 2002-2003. Prior to that sweltering afternoon, there was no such thing as “pyro-tornadogenesis,” because such a phenomenon—a tornado generated by a wildfire—was not known to occur on planet Earth. Wildfires in both hemispheres often whip up small twisters known as fire whirls, but as impressive as they are to behold, and as dangerous as they are to be near, they are relatively small and short-lived events—more like dust devils than full-blown cyclones. What Bates saw and filmed from a suburban rugby pitch just outside Canberra, in southeast Australia, was different. It occurred during a historic week of lightning-caused fires that killed 4 people, injured more than 400, and destroyed 500 homes west of Australia’s capital city.

On January 18, Bates and his neighbors in the Kambah neighborhood, about five miles southwest of downtown, were on high alert because local fires had advanced to within a mile and a half of their neighborhood. Looking northward that afternoon, toward the flames, Bates observed a large funnel cloud over Mount Arawang, one of several low, tree-covered peaks in the area that are laced with walking trails and surrounded by suburban homes.

Tornadoes are not unheard of in the region, but this one appeared to be rising up out of the fire itself, like an atmospheric Balrog. It was 4 in the afternoon, the ambient temperature was nearly 100 degrees Fahrenheit, and the air was so dark with smoke that it appeared to be nighttime. The year 2003 was before smartphones became widespread, but Bates had the presence of mind to get his video camera and record what would come to be a new kind of fire. “I’ve never in my life seen anything like it,” we hear Bates say as the funnel takes shape above the burning mountain. He struggles to describe what he is seeing, not because he lacks the words, but because no Earthling has ever witnessed what he is witnessing now: “Holy shit… Holy mackerel. It’s a big fireball. It’s gotta be rippin’ poor bastards’ houses up there.” Then, right before our eyes, Mount Arawang appears to detonate. The blinding flash, combined with the funnel cloud whirling above it, gives the impression of a nuclear blast. “Holy Jeezus,” Bates gasps. “This is bad news. It’s like a big fireball tornado.”

It is now clear that this monstrous thing, which Bates has just named, is headed directly toward him. Australians seem to have a gift for understatement, and, as the wind begins to hiss and roar through the camera mic, we hear Bates say, “This is rather frightening.” A moment later, tin roofing and other debris from the homes surrounding Mount Arawang begin clattering to earth all around him. Sticks and gravel are now flying in horizontal gusts. “I’m getting pelted with stuff. It’s stinging the daylights out of me,” he says, shortly before the video ends. “It’s just like being sandblasted.”

Mt Arawang Fire Tornado - 18th January, 2003

It was estimated later that, during the single blinding burst that caused Mount Arawang to briefly disappear, an area of roughly 300 acres ignited in less than a tenth of a second. Bates had managed to document the most dramatic instance of exterior flashover ever observed. The Canberra fire tornado of 2003 was rated an EF3 on the Enhanced Fujita Scale, with horizontal winds of 160 miles per hour, roughly equivalent to a Category 5 hurricane. As the first documented example of its kind, it was a milestone—another harbinger of 21st-century fire. But the Chisholm Fire, two years earlier in Alberta, Canada, had offered a preview. A funnel cloud was observed during that fire as well, and the resulting forest damage showed evidence of cyclonic action.

It took years of analysis for Australian fire experts to fully understand what Bates and his neighbors witnessed on that terrible January day. The term “pyro-tornadogenesis” did not enter the literature until nearly a decade after the event. A fire tornado, fire scientists would come to understand, is the delinquent offspring of a pyrocumulonimbus thunderstorm. While you can have a pyrocumulonimbus thunderstorm without a fire tornado, you cannot have a fire tornado without a pyrocumulonimbus. In this sense, a fire tornado is—so far—a wildfire’s most dramatic terrestrial expression. (There are other extraordinary things that wildfires can do now, but they take place in the upper atmosphere.) Both fire tornadoes and pyrocumulonimbus thunderstorms are generated by high-intensity wildfires burning in hilly terrain on exceptionally hot days that have been further energized by incoming high-pressure systems and, some believe, by massive infusions of superheated steam from rapidly burning forests. These events have the capacity to further amplify an already ferocious fire in shocking ways that human beings have no power to defend against.

Once this new, warmer, carbon dioxide-enriched atmosphere had proved itself capable of conjuring up a fire tornado, the question in 2003 was: Could it happen again? Australia is vast, drought-prone and, in places, heavily wooded, a combination that has generated the largest bush fires and the longest, most destructive fire seasons anywhere on Earth. It is fair to say that Australia rarely has a “good” fire season, but some are worse than others; the devastating fire season of 1973-1974 blackened an area the size of France and Spain combined (nearly half a million square miles). The Black Saturday Fires in 2009 were some of the worst ever. February was so hot and dry that year—even for southern Australia —that fire officials in the state of Victoria declared the weather forecast “uncharted territory.” “There are no weather records,” said an official on ABC television, “that show the kind of fire conditions [predicted] tomorrow.” The ambient temperature in Melbourne that day—February 7—was 116 degrees Fahrenheit, a record that broke the previous high (set in 2003) by 4 degrees. The searing heat was attended by gale-force winds; residents compared the experience of going outside to standing in front of a giant hair dryer.

Fire Weather: A True Story from a Hotter World

A stunning account of a colossal wildfire and a panoramic exploration of the rapidly changing relationship between fire and humankind

The Black Saturday Fires, concentrated in the hill country northeast of Melbourne, destroyed more than 2,000 homes and obliterated several small towns. One hundred and seventy-three people were killed. These fires, started variously by faulty power lines, lightning strikes and arsonists, were, as of that year, the most lethal and destructive bush fires in Australia’s dramatic fire history. While none of them generated a full-blown tornado, a fire service pilot estimated head fire heights at a hundred yards, and some victims perished in their cars, overtaken by flames even as they fled at highway speed. But there was another killing energy released by those fires that moved even faster—at the speed of light. So otherworldly were the fire conditions on Black Saturday that animals and people were killed by radiant heat alone, from hundreds of yards away, as if they had been felled by a death ray.

Afterward, a Royal Commission was ordered to investigate the disaster. One of the recommendations made was for a new fire danger category, because “Extreme” was deemed insufficient to express what had occurred on Black Saturday. The new, more dire classification is “Catastrophic,” or “Code Red.” In a document labeled “What you should do,” the Rural Fire Service for the state of New South Wales has shared a list of directives. The directive for “Catastrophic” fire could not be more stark: “For your survival, leaving early is the only option.”

And in 2013, Australia’s Bureau of Meteorology had to add two new colors (pink and purple) in order to accommodate new temperature extremes previously capped at roughly 122 degrees Fahrenheit.

This is not planet Earth as we found it. This is a new place—a fire planet we have made, with an atmosphere more conducive to combustion than at any time in the past 3 million years. Human activities—mainly the burning of fossil fuels like coal, oil, and gas—have pumped so much CO2 into the atmosphere that the planet has warmed by more than 1 degree Celsius since the late 1800s. The closest comparison we have to current levels of CO2 is the mid-Pliocene Warm Period. With the seas and continents close to their current configuration, the mid-Pliocene offers a useful analogue for our near future. At that time, our ancestors were still in Africa. Lucy (Australopithecus afarensis) was laying the groundwork for us in present-day Ethiopia, walking upright and experimenting with the crudest of stone tools. The Pliocene world was certainly habitable, but in a dramatically different way—not so much because of who lived in it, but because of the amount of atmospheric CO2. In Lucy’s day, CO2 levels were around 400 parts per million, commensurate with ours right now, but average temperatures were 2-3 degrees Celsius warmer, the current prediction for the end of the century. With far less year-round ice, global sea levels were about 80 meters higher than today. Currently, almost half of the human population lives in coastal areas.

In 2009, the year of the Black Saturday Fires, the Keeling Curve—a measure of atmospheric CO2 concentrationshit 390 parts per million, a 40 percent increase in atmospheric CO2 over preindustrial levels.

The Keeling Curve
This graph shows atmospheric CO2 concentrations as measured at Hawaii’s Mauna Loa since 1958. This essential piece of evidence, known as the Keeling Curve, helps demonstrate that human activities that have increased greenhouse gases in the atmosphere have led to global warming. Delorme / Data from Pieter Tans of NOAA / ESRL and Ralph Keeling of Scripps Institution of Oceanography / CC By-SA 4.0

By then, temperature records around the world were being broken on an annual basis as fire seasons lengthened along with the lists of damage done and fatalities caused. 2017 appeared to be a turning point. That year, atmospheric CO2 hit 405 parts per million, a 45 percent increase over preindustrial levels. It was not yet April before more than 2,000 square miles of grassland had burned across the Great Plains, from Kansas to Texas, killing thousands of cattle and at least seven people. That summer, wildfires spread across several countries in Europe, and Greenland experienced its first significant fire. More than 100 people were killed in Spain and Portugal alone when the first pyrocumulus clouds ever observed there supercharged seasonal wildfires into firestorms. That same year, New Zealand experienced unusually intense wildfires while Chile and British Columbia, two huge coastal territories in opposite hemispheres, suffered the worst fire seasons in their respective histories. California, too, had one of its worst ever, including what was, then, the most destructive fire in state history: the Tubbs Fire in Santa Rosa, a catastrophic blaze that destroyed 9,000 structures, killed 44 people and generated winds strong enough to flip cars.

And fires have continued to ravage the state. In 2018, the Northern Hemisphere experienced its first fire tornado in Redding, California. The Carr fire tornado, an EF3 firestorm with 165-mile-per-hour winds and peak temperatures of 2,700 degrees Fahrenheit, killed five people, tossed a Ford F-150 through the air, and tore hundred-foot-tall transmission towers off their concrete moorings. Veteran Cal Fire members had never seen anything like it.

Excerpted from Fire Weather: A True Story from a Hotter World by John Vaillant. Published June 6, 2023, by Alfred A. Knopf, an imprint of The Knopf Doubleday Publishing Group, a division of Penguin Random House LLC. Copyright © 2023 by John Vaillant.

Get the latest Science stories in your inbox.