The Marshall Fire was a force of humans

Conditions crucial to the blaze’s ferocity were a direct outcome of climate change

January 13, 2022 8:12 am

Denver Fire Department crews battle flames in Boulder County on Dec. 30, 2021. (Denver Fire Department)

On the afternoon of the Marshall Fire, after its dreadful scale had started to sink in, Gov. Jared Polis appeared for his first press conference on the disaster.

It occurred “with no warning,” he said on Dec. 30. “This fire is frankly a force of nature.”


The misunderstanding that could permit the Colorado governor to say such things is a greater threat than any single blaze, even one that, like Marshall, devoured a thousand homes.

In the most immediate sense, the governor was referring to hurricane-force winds that propelled the fire through suburban neighborhoods. But the fire was indisputably a result of climate change, and scientists have long warned, explicitly, convincingly, methodically, of just this kind of event.

The Marshall Fire was not a force of nature. It was a force of humans.


“Climate change, by altering weather patterns, is likely to affect fire extent, frequency, and severity” in the area that includes Colorado, predicted a 2011 study co-authored by conservation scientist David Theobald of Colorado State University. 

The study noted the risk of wildfires that comes from heavy precipitation, which promotes the growth of vegetation such as grasses, followed by stretches of dryness, which turns the vegetation to fine fuels. It documented how the extent of wildfire burn areas had been unusually high in the years prior to the study, and it warned that “the median annual burned area over the period 2010–2070 may increase by between two and five times.” 

“This finding is particularly important because of the increasing numbers of people and structures moving into the wildland–urban interface,” the authors wrote.

That’s chilling to read in light of the Marshall Fire, which at just over 6,000 acres was relatively small in area but, in sweeping through a populated area bordering grasslands, exemplified the very threat the study foresaw.

Some of the conditions that made the fire so destructive were not on their own related to a warming planet. The expansion of neighborhoods on the Front Range is its own phenomenon. A low-pressure zone that developed just east of the mountains caused unusually high winds on the day of the fire.

A burned-out car sits in a Louisville neighborhood at W. Dillon Road and S. 88th Street that was flattened by the Marshall Fire, on Jan. 2, 2022. (Quentin Young/Colorado Newsline)

But other conditions crucial to the Marshall Fire’s ferocity were a direct outcome of climate change. The state for more than two decades has experienced a drought so severe and prolonged that scientists have begun to call it “aridification.” In the week of the fire, the entire state of Colorado was experiencing drought, and there was extreme drought in Boulder County. The intensity of drought in recent years is abnormal, and it’s further abnormal for such drought to occur in December.

Temperatures were extremely high leading up to the fire. “From June 1-Dec 29, the Front Range has been the warmest on record (by far), and among the driest,” tweeted state climatologist Russ Schumacher the evening of the fire.

The dry latter part of the year was preceded by heavy precipitation, producing abundant fine fuels. “We had a wet spring which meant lush grasses growing up, and then six months of among the driest and hottest weather we’ve ever had,” said CBS4 meteorologist Dave Aguilera.

Climate researchers have begun to use the phrase “climate-enabled and weather-driven” to refer to Marshall Fire-like events.

“‘Climate-enabled and weather-driven’ is actually a really good way to describe the response of quite a few physical hazards that are increasing due to #ClimateChange, and is in line with a great many scientific studies on extreme event attribution,” tweeted Boulder-based climate scientist Daniel Swain.

This was all predicted. It’s happening before our eyes. It will get worse. Human activity is to blame.

Among Colorado political leaders, Polis, as the governor, deserves the most scorn for every instance of climate neglect. But his Republican opponents too often engage in outright climate denial. “I believe the climate changes, I believe that it is more natural, I do not believe that it is man-made,” state Senate Minority Leader Chris Holbert said in June.

Anthropogenic climate change is the most critical issue facing humankind, and there is no close second. Survival of the species is potentially at risk, therefore no climate skeptic is qualified to hold office in state government. Members of the Legislature, which kicked off its 2022 session Wednesday, should elevate climate action to the top of every agenda.

But that’s not happening. Much of the discussion on both sides of the aisle prioritizes affordability, public safety and education this year.

House Speaker Alec Garnett’s opening day speech offered some hope.

“There is no doubt that the severity and the devastation of the Marshall fire were intensified by our changing climate,” he said in a prepared version of his opening-day address. “What began as a suburban grass fire that would have raised little concern a decade ago ended as a destructive inferno and a reminder that climate change is a clear and present danger.”

That’s a start. But the flame of such sentiments will flicker out without the heat of action.

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