A firefighter at the Bobcat Fire in Monrovia, California on September 15.

A firefighter at the Bobcat Fire in Monrovia, California on September 15. RINGO CHIU/AFP via Getty Images


The Age of Megafires: The World Hits a Climate Tipping Point

From Siberia to Australia to the western U.S., massive fires have consumed millions of acres this year and spawned fire-generated tornados and other phenomena rarely seen before. Scientists say the world has entered a perilous new era that will demand better ways of fighting wildfires.

In the late 1980s, three massive wildfires burned in China, Canada, and the United States — fires that in hindsight were a harbinger of the huge, climate change-driven conflagrations now destroying millions of acres in the western U.S.

In the spring and summer of 1987, one of the largest wildfires ever recorded — the Black Dragon Fire — spread in hot, dry conditions from northeastern China into the taiga of the Russian Far East. Entire towns were wiped out in Heilongjiang province as walls of flames more than 100 feet high, driven by 60 mile-per-hour winds, ripped through everything in their path. More than 18 million acres burned, mainly in Siberia, and at least 220 people died.

Two years later, excessive heat and drought fed more than 1,100 wildfires in Manitoba, eventually burning 8 million acres.

But it was the 1988 wildfires in Yellowstone National Park, which began with a series of lightning storms, that captivated the world’s attention. Fire managers initially allowed the fires to burn as they had done a number of times since 1972 when the National Park Service embraced the “let-burn” policy. But as the summer evolved into the hottest and driest in 110 years, the conflagrations quickly spun out of control, consuming 800,000 acres — more than a third of the park — and overwhelming all efforts to suppress them.

“The winds came again and again and the worst-case scenario happened almost weekly,” said Richard Rothermel, then a researcher at the Northern Forest Fire Laboratory. “It was an amazing season. Nobody had seen this combination of weather and fires before.”

Rising temperatures and worsening droughts mean that the world has entered an era of increasingly catastrophic wildfires.

In the three decades since those fires, hotter, drier weather has only increased the scale, intensity, and frequency of destructive wildfires worldwide. The buzz among wildfire scientists these days revolves around the rising number of “firsts” that have occurred in the last 15 to 20 years, from massive fires spawning tornadoes and fire-generated thunderstorms, to a growing number of fires in the Arctic (including Greenland), and unprecedented wildfires burning in Australia, Europe, and Southeast Asia.

In the 1980s, when wildfire scientist Mike Flannigan was conducting a study of a possible link between global warming and the dramatic increase in wildfires, he was on the fence. The uncertainty didn’t last long. He and a colleague in the Canadian Forest Service predicted much of what we are seeing now. Flannigan, however, is still shocked by the magnitude of what is happening this year, with more than 5 million acres burning this summer in California, Oregon, and Washington, and vast bushfires in Australia in 2019 and 2020.

“Unprecedented and devastating bushfires in Australia this past fire season burned over 45 million acres,” said Flannigan, director of the newly created Canadian Wildfire Strategic Network. “Arctic fires are releasing record amounts of greenhouse gases. We expected these increases in fire activity, but they are happening faster than anticipated.”

Indeed, just as global warming has propelled the Arctic Ocean past a tipping point that is expected to lead to a largely ice-free Arctic in summer in the coming decades, wildfire scientists say that rising global temperatures and worsening droughts mean that the world has entered a new era of megafires. Scientists say that wildfires are behaving in unprecedented ways and that the traditional methods of fighting them are proving inadequate to this new reality.

A neighborhood in Talent, Oregon destroyed by wildfire on September 13.

A neighborhood in Talent, Oregon destroyed by wildfire on September 13. David Ryder/Getty Images

The evidence of a new, climate-driven era of colossal wildfires has been building for a decade or two since Flannigan and others made those early predictions. This year’s fires in the western U.S. underscore this new reality. Prior to 2003, huge fires were rare in California. But 17 of the 20 largest fires in the state’s history have occurred since then. The largest fire ever seen in California is happening this summer, as are the third and fourth largest.

The situation is similar in Oregon, where fires have burned more than 1 million acres in recent weeks, erupting in places where they rarely burn and overwhelming firefighters whose tools and strategies are no longer sufficient to deal with the new wildfire paradigm.

Such firsts have become commonplace this century. The idea that a fire could spawn a tornado, as one did in Canberra, Australia in 2003, was so implausible that it took several years to convince the scientific community that it was not just a big fire whirl, but a category F-2 tornado. Many more fire tornadoes have occurred since then, including a major Category F-3 tornado that the Carr fire in California spawned in 2018. This year, for the first time, the National Weather Service issued a fire tornado warning for California.

Fires aren’t supposed to burn on the frozen tundra because it is too cold and wet. But in 2007 the Anaktuvuk fire consumed 270,000 acres of tundra on the North Slope of Alaska for nearly three months. Tundra fires a hundredth of that size were previously unheard-of. As remarkable as Anaktuvuk fire seemed at the time, fire has since burned the tundra along Greenland’s ice cap in 2017 and 2019.

Graphs showing wildfire frequency, severity, and firefighting costs in the United States from 1985 to 2017.

Graphs showing wildfire frequency, severity, and firefighting costs in the United States from 1985 to 2017. Courtesy of the Union of Concerned Scientists

Lightning triggers fires, even as far north as Alaska. But no one dreamed that a thunderstorm could shoot out 65,000 lightning strikes and ignite more than 270 fires as one did in Alaska in 2015. More than five million acres burned that year.

Humans are by far the main cause of fire in California. But it was 12,000 lightning strikes that caused the huge blazes this summer, with lightning triggering 585 fires across the state. Southern California’s most destructive fires used to come in the fall, when the hot, dry Santa Ana winds blew in. In recent years, however, summer wildfires have become more common, as UCLA scientist Alex Hall predicted, leaving the state now facing two damaging fire seasons, created in part by the growing number of lightning strikes.

Like so many aspects of the burgeoning number of wildfires, the increase in lightning is connected to climate change. Lighting increases by about 12 percent for every 1 degree Celsius temperature increase. Simple mathematics, and many studies, suggest that there will be much more lightning in some places as temperatures rise by another 2 or 3 degrees C this century in wildlands that are already severely stressed by drought, disease, and insects such as the mountain pine beetle.

Thunderstorms created by the energy of intense fires, known as pyroCbs, have occurred in the past. But they were once rare and few people suspected that they could shoot out lightning that would trigger blazes 20 miles from the fire’s front, as one did in the Alberta tar sands region in 2016. Five pyroCbs erupted in 2017 in the forests of British Columbia and Washington within the space of just five hours — the mother of all pyroCb events, according to David Peterson a meteorologist with the U.S. Naval Defense Lab. No one expected anything to rival that until this year’s fires in Australia generated at least 18 pyroCbs.

The list of “firsts” just keeps on growing, with record breaking fires in Portugal in 2003, when nearly 6 percent of the country burned; in Siberia, which has broken records for area burned in 2010, 2012, 2015, 2019, and 2020; in South Korea in 2019 when the military was called in; and even in Hawaii, where the need to evacuate people was never considered seriously a decade ago as it was last year in Maui.

The new fire era means that the old ways of fighting wildfires will no longer suffice.

What’s less clear is what the future “firsts” will look like when the number of fires is expected to double and possibly triple this century in places where tens of millions of people live in or along wildlands.

Wildfire scientists agree that the planet will experience more pyroCbs and fire tornadoes, and more large, destructive fires burning in places where fire has not been a frequent visitor.

Many experts no longer think that Scandinavia and the east coast of North America will be spared because it is expected to be wetter there in the future. Sweden needed outside help to deal with record fires in 2018. The Pinelands of New Jersey may get a lot rain, but 10 days of blue skies, high temperatures, and gusty winds can nevertheless create prime fire conditions. People who live in the Pinelands know this all too well based on the region’s prolific fire history.

The new fire era the world is now entering means that the old ways of fighting wildfires will no longer suffice to suppress blazes that are growing more numerous, burning hotter, and consuming ever-larger areas of homes and woodlands. More money is certainly needed to put more firefighters on the ground and in the air. Thinning forests and grasslands and burning them lightly may well be part of the answer. But firefighters also need new and improved tools such as unmanned aircraft for surveillance, fire risk maps, real time warnings, smoke projections from active wildfires, and computer models that predict where fires might start.

A firefighting crew in Yucaipa, California on September 5.

A firefighting crew in Yucaipa, California on September 5. AP Photo/Ringo H.W. Chiu

“As fires grow larger and become more intense, fire management will be even more challenging,” said Flannigan of the Canadian Wildfire Strategic Network. “Traditional fire management and suppression may be reaching their limit in terms of effectiveness.”

Today, eight regional fire compacts cover almost all of the U.S. and Canada, with states and provinces sending firefighters and equipment to other jurisdictions experiencing major wildfires. But the events of this and recent summers have shown that in a world of multiple, massive wildfires even regional compacts are insufficient. Fires that have burned in British Columbia and other Canadian provinces required the assistance of firefighters from Mexico, South Africa, and Australia. Australian and Mexican firefighters have answered California and Oregon’s pleas for help this year.

We are now in a situation where even international cooperation — nations sharing wildfire suppression resources — is not enough. This is not the “new normal,” as California Governor Gavin Newsom and others have described it. There is nothing “normal” about the new fire paradigm that is setting in. Decision-makers and the public continue to believe that if agencies put enough water bombers in the air and men and women on the ground, fires can be suppressed before they cause widespread destruction. But the best that firefighters can do when a megafire burns in hot, dry, windy conditions is to slow it down or steer it in another direction.

Several decades ago, a government policy of letting fires burn out naturally — which was initially followed in the 1988 Yellowstone Park fire — seemed like a good idea. Since then, “letting it burn” has posed far greater risks. And as population and development increases, it has become increasingly difficult to allow fire to burn because there are now too many people living and working in places that are vulnerable to fire. Witness the evacuations of tens of thousands of people in California, Oregon, and Washington this summer.

In an era in which global warming is now a major cause of the worsening wildfire landscape, this summer’s events have starkly demonstrated that business as usual is no longer viable.

Correction, September 24, 2020: An earlier version of this article incorrectly stated that more than 3 million acres of the Arctic had burned this year. That figure was actually for California.