Fire Weather: On the Front Lines of a Burning World

by John Vaillant

Within hours, Fort McMurray was overtaken by a regional apocalypse that drove serial firestorms through the city from end to end—for days. Entire neighborhoods burned to their foundations beneath a towering pyrocumulus cloud typically found over erupting volcanoes.

Virtually unknown and, at the time, unseen by all but a handful of people, is the Chinchaga Fire of 1950, the largest fire ever recorded in North America. Igniting on the border of British Columbia and Alberta in June of that year, it burned eastward across northern Alberta for more than four months, impacting approximately 4 million acres, or 6,400 square miles, of forest (roughly, the combined area of Connecticut and Rhode Island, or three times the size of Prince Edward Island).

Like a plague of mice in a cheese cellar, this nano army raided the continent’s greatest petroleum reserve and left behind only wrappers and rinds. These unlikely predators, representing several different genera, are otherworldly creatures that nourish themselves on hydrocarbons, survive without oxygen, and off-gas methane (one of the only characteristics we share besides an appetite for crude oil). Small as they are, they appear to be the masters of a poorly understood domain known to geochemists as the “deep biosphere.”

Approaching this ancient oil with the diligence and discernment of a petroleum engineer, these tiny multitudes cherry-picked the simpler, “sweeter,” more marketable hydrocarbons, leaving behind the longer, more complex molecules laden with tarry asphaltenes, resins, salts, heavy metals, and complex sulphur compounds, among other unsavory impurities. Fifty million years on, with the low-hanging fruit largely gone, Alberta has inherited the dregs, and oil refiners don’t care for it any more than those intrepid microbes do.

Until relatively recently, great bergs of solid bitumen would appear spontaneously on the surface of the Dead Sea, where it would float due to the water’s exceptional buoyancy. This phenomenon occurred so predictably that, in ancient times, the Dead Sea was known as Asphalt Lake.

properties that it is hard to imagine it as pollution.[*4] Cyanobacteria’s prodigious oxygen production contaminated Earth’s atmosphere so thoroughly that most anaerobic creatures—the founding colonists of life on our planet—were gassed to death.

Reflecting on the moment later, he said, “It was almost as if, by talking about the fire, we were giving it oxygen.” Words possess spell-casting, shock-inducing power, even in this jaded age, and the English language has accounted for this: something that is “infandous” is a thing too horrible to be named or uttered. For a mayor or a fire chief, a fire running rampant through the city they are charged with protecting is infandous.

computer, the fire says, in effect, “Thanks, I’ll take it from here.” Instead of burning in spite of its environment—wet wood, cool temperatures, the dead, smothering air of an inversion—the environment becomes an ally attending to the fire’s every need: high temperatures, low humidity, dry fuel, and wind. Crossover is truly a crux in the day for fire and firefighter alike, and it is predictable almost to the

Disaster is, almost by definition, a kind of existential dissonance. For the individual, it is cognitive dissonance made manifest: a disruption to one’s personal and physical world order so profound that you don’t know where to file it, how to measure it, or even how to react—because you have no precedent, because it’s simply too big and violating to grasp.

This phenomenon of sudden and total combustion in an enclosed space is known and feared by municipal firefighters. They call it “flashover,” a reference to the flashing, or reflective nature of radiant heat, and it poses a lethal hazard for anyone inside a burning building. Because fire feeds on the gases released by heated fuel (as opposed to the fuel itself), a localized fire—like a burning sofa—will radiate heat that causes off-gassing in the fuels around it.

Known to meteorologists as a pyrocumulonimbus cloud, or pyroCb, these massive formations can be two hundred miles wide and reach into the stratosphere. A fully developed pyroCb, like the one shrouding Fort McMurray on May 3, is so huge and energetic that its behavior is influenced by the coriolis effect—the rotation of the earth.

fires caused by lightning can be ignited virtually anywhere within a fifty-mile radius of a pyroCb, where they are accompanied by all the hazards associated with electrical storms—tower strikes, power outages, and electrocution.

localized conflagration into a perpetual motion machine of destruction

In essence, the Lucretius Problem is rooted in the difficulty humans have imagining and assimilating things outside their own personal experience.

Flashover was now occurring on a massive scale; fire trucks and ambulances, blocked by craters, rubble, and liquefying streets, burst into flame spontaneously. As updrafts surpassed one hundred miles per hour, witnesses observed trees being torn from the ground and civilians being swept into the air, igniting like firebrands before disappearing into the annihilating vortex overhead. Down below, the flames coursing through the now-roofless and -windowless buildings mimicked the behavior of Japanese anagama “climbing” kilns, which are constructed in a series of ascending chambers through which rivers of fire race for hours on end, generating temperatures well over 2,000°F. According to an official with Hamburg’s Fire Protection Police, the only things that withstood the terrific heat were the steel safes built into the walls of banks.