Lightning strikes near a tall, cylindrical rock formation.
Lightning strikes near Devil's Tower National Monument in Wyoming. Devil's Tower is surrounded by the red rocks of the Permian period. (Mike Hollingshead / Corbis / Getty)

Burning Fossil Fuels Almost Ended All Life on Earth

A road trip through the geological ruins of our planet's worst mass extinction.

“Who you with?”

“I’m a science journalist,” I said, jolted from my reverie on the shoulder of I-68 in Maryland, where a crowd of geologists had gathered on a field trip to poke at some rocks revealed by the highway department’s dynamite. The rocks, slate gray and studded with pebbles from a punishing ice age, spoke to a mysterious global die-off at the end of the Devonian period, hundreds of millions of years ago.

“I’m researching a book on mass extinctions,” I said.

“Cool, I work on the end-Permian boundary in Wyoming.”

My ears perked up. He was talking about a line in the rocks that recorded the greatest catastrophe the Earth has endured in its entire history.

“I didn’t really realize there was a—”

“Let’s go out there. Want to go out next week?”

This was my introduction to Jonathan Knapp, a PhD candidate at West Virginia University. The surprisingly bold introductory exchange, I would later learn, was not atypical for Knapp, for whom there are no half measures. A week later I was in his passenger seat on a road trip across the country to Wyoming to see the worst thing that’s ever happened in person: the end-Permian mass extinction.

Imagine you took a random spin in a time machine and ended up in the Permian. Now imagine the time machine breaks down. You slam your fists on the dashboard and a digital red “251.9 MYA” dimly flickers and dies. The view out the cockpit window reveals red sand dunes and little else. From what you remember of your geology training you know that 252 million years ago is just about the worst thing you could possibly read on your display.

You kick the door open and—holy hell is it hot. You scarcely believe your breath. As you reach for the latch to slam it shut you’re startled by a thundering roar coming from the other side of the dunes. Curious, you step out into the primeval landscape. There’s no life, save a wilting weed here or there, where the dunes give way to barren soils, cracked and crusted with salt. The sandblasted husk of some odd creature sprawls across the wastes, its fangs bared.

A sole mayfly buzzes in and out of your sight—its presence in this desolate wilderness is comforting. Scrambling over the red sand, and gasping for air, you follow the distant roar. You notice that, though the sun is out, there’s a funereal gloom to the day. As you crest the dunes you see why. A strange ocean spreads out before you, hosting the largest waves you’ve ever seen. They’re eerily backlit and slosh a sickly purple and green. Through the haze, and over the roiling ocean, a sublime darkness organizes on the horizon.

You walk down to the shoreline and take a few steps into the lapping waters, drawn toward the enveloping gloom. The seawater is almost painfully hot. There’s nothing alive under the waves. There doesn’t seem to be anything alive anywhere really. You squint and marvel at the growing terror on the horizon. You’ve seen billowing thunderclouds before, but this panoramic tempest seems to tower into eternity. Wild hot winds begin to whip in all directions. You find it difficult to breathe. Slowly baking, you know should head back to the temporary safety of the ship, but you linger here all alone on the dimming coast, transfixed by the blossoming apocalypse just over the Earth’s curve. A putrid odor begins to ride in on the swirling winds and, as you finally turn back in a panic, you pass out. Before long, this doomsday storm makes landfall, and what meager life clings to this country is stamped out for millions of years.

This is one vision of what it might have been like to visit the world as it ended a quarter billion years ago during the end-Permian mass extinction—the worst moment in the planet’s entire history. The nightmare was sketched for me by the head of geosciences at Pennsylvania State University, Lee Kump, whose “horror movie” speculation was that there might have turbocharged “hypercanes” of almost unbelievable intensity assaulting the supercontinent Pangaea—the result of runaway global warming. These mega-storms might have had 500-mph winds, filled with poisonous hydrogen sulfide sucked out of a rotting ocean that topped 100 degrees Fahrenheit.

Admittedly, this is mostly Kump’s speculation, but we do know that something apocalyptic was unfolding then, when the Earth suffered a catastrophe that nearly sterilized the planet. Once magnificent coral reefs, built of strange Paleozoic creatures, and hosting a party of tentacles, trilobites and technicolor fish, were turned into piles of bacterial slime, as oxygen-starved and rapidly acidifying seas spread out onto the shelves, killing almost everything in the ocean. The planet’s forests all but disappeared for almost 10 million years. With Earth’s vegetation destroyed, rivers stopped meandering in narrow channels, instead spilling forth in wide, sloppily braiding torrents. Even insects suffered a mass extinction, their only such misfortune across all of natural history. Meanwhile an odd menagerie of misfit proto-mammalian offshoots—some rhinolike and lumbering, others lupine and athletic—seem to have been nearly wiped out. Fungus spread across the Earth.

The cause of all this misery—a growing consensus of paleontologists and geologists believe—was burning fossil fuels. Though acid rain and a ravaged ozone layer likely played a role as well, geochemical signals in the layers of ancient rock that capture the global die-off suggest a carbon dioxide-driven global warming catastrophe—one so profound it would dwarf even the extraterrestrial disaster that cut short the dinosaurs’ reign almost 200 million years later.

Near the top of the supercontinent Pangaea in what is now Siberia, a gigantic plume of magma—enough to cover the lower 48 states a kilometer deep—was burbling through one of the most coal-rich regions in the world and covering millions of square miles of Pangaean countryside in basalt lava. As the molten rock ponded underground, seeping sideways into the crust, it incinerated not only untold seams of coal laid down by ancient forests in the hundred million years before, but huge deposits of oil and natural gas as well. The ignited oil and gas exploded at the surface, leaving behind half-mile craters. The volcanoes injected as much as 40,000 gigatons of carbon into the atmosphere. This unthinkable volcanism, and the greenhouse gases it liberated, account for the extreme global warming and ocean acidification seen in the rocks spanning the dreaded Permian-Triassic boundary. It’s even been called The Great Dying. Carbon dioxide, it seems, nearly killed the planet.

I was picked up at Midway Airport in Chicago in a forest-green Jeep Wrangler. Knapp, an oil geologist, had plastered a geological time scale to the center console, and the trunk was filled to the roof with rocks, camping equipment and two luxuriant, wool-lined, full-length farwa coats he had picked up in Saudi Arabia. The farwas, he said, would protect us from the brutal mid-continental Wyoming November cold.

If having a good conversation partner is the key to a successful road trip, Knapp should be inducted into the road-trip hall of fame. Not only has he accumulated an endless supply of good stories in his young but colorful life aboard oil rigs—from the Gulf of Mexico to North Dakota to Nigeria (“people would go up to the pipeline and make holes in it in and fill their Zodiac boats with crude oil”)—but he can illuminate the featureless stretches of middle America with the revelatory light of geology.

Western Kansas is crushingly boring to drive across, but a little less so when you realize its flatness belies a former life at the bottom of the Cretaceous Interior Seaway, an inland ocean filled with 50-foot-long killer mosasaurs. Knapp can convincingly hold forth on virtually anything you point at—which is exactly what I did as we drove through the long, drawing board-flat monotony of the heartland.

“Natural gas compression station,” he said, as I pointed to an anonymous facility in the distance.

“Natural gas pipeline transfer station,” he said, when I indicated another.

And another.

“Unconventional well pad,” he said. “It probably goes down a mile and then goes over two miles.”

In the hubbub of a New York City or San Francisco one gets the intoxicating sense that the city streets and skyscrapers are where the business of the country is conducted—that that’s where the action is. But driving around the heartland with an oil geologist you realize these glitzy coastal diversions are a facade. The unassuming, diffuse infrastructure of flyover land is, in fact, the country’s circulatory system: unmarked metal boxes on the side of the highway, inscrutable pipes and polished valves behind fences at the edge of the prairie. This is the inconspicuous hardware that delivers the glowing screens and cheap meat of modernity.

The road trip reminded me that the coasts are separated by a sea, just as they were a hundred million of years ago, but this one is made of corn and soy rather than seawater. These amber waves of grain are fed by fertilizers synthesized from fossil fuels. The artificial bounty is then transformed into the millions of cows crowded on the vast, sweeping feedlots of western Kansas and eastern Colorado that we passed along a 150-mile stretch of road that smelled like shit, even with the windows rolled up. In some of these roadside tableaus the entire modern life cycle was in view, with oil pumpjacks bobbing up and down in the middle of the vast cattle multitudes, whose farts account for a more than a quarter of US methane emissions. Knapp noted that the road we were driving on was made of asphaltene, the heaviest component of crude oil. Food, livestock, electricity, pharmaceuticals, roads, plastics—it’s fossil fuels all the way down.

“ExxonMobil is a chemical company,” says Knapp. “That’s what we forget.”

Those who rail against the corporate sins of companies like Exxon tend not to appreciate the extent to which their existence, as well as the entire upside-down ecosystem of modernity, depends on it. And now that we have 7 billion people, most of whom sprang from this artificial surfeit of geological energy, it will be far harder to put that genie back in the bottle than most imagine. But the failure to do so will mean the end of the world as we know it. Knapp’s familiarity with burning hydrocarbons and coal wasn’t incidental to his study of the worst mass extinction in Earth’s history. It was the kill mechanism.

“Need petroleum?” Knapp asked me, offering chapstick.

No industry is more responsible for our knowledge of the ancient Earth than fossil fuel companies, which have funded much of the world’s geology research for over a century. It makes their calculated and coordinated misdirection on the topic of climate change all the more jarring. At a recent geology conference, sponsors like Hess and Exxon were prominently thanked for their generosity, while climate change activists and academics like Naomi Oreskes and James Hansen were invited to take center stage as honorees and keynote speakers. The energy industry is schizophrenic: at its best, staffed with brilliant geochemists who understand the carbon cycle better than anyone on Earth and, at its worst, recklessly following economic incentives into a civilization-threatening tailspin.

Knapp provided an insider’s perspective on the industry: he champions natural gas as a “bridge fuel” to a zero-carbon economy (certainly a debatable strategy at this late stage in the world’s carbon budget crisis) and is the part-owner of a drill rig in Michigan, but insists that if we burn all our coal, an end-Permian catastrophe isn’t out of the question.

Near Lawrence, Kansas, at the gateway to the prairie, Knapp swerved off the highway and pulled over next to an unremarkable road cut. He invited me to look closer. There were fossil seashells everywhere and, in some of the layers, ancient plant roots dug down into the fossilized muck. He pointed toward an oval knob sticking out of the ancient strata.

“Lungfish burrow,” he said. “This was normal. This was life. There was everything here. The world was happy.”

This was before the Permian.

After driving for three more hours into south-central Kansas on the border with Oklahoma, the prairie fell away and the landscape suddenly took on an alien aspect. Everything went rusty red, and the unending flatness gave way to ragged crimson hills and buttes. Shimmering seams of salt and gypsum crystals from dried up seas slumped out of the hillsides like shattered glass. There were no more shells, no more lungfish burrows, no fossils, nothing. It didn’t look like any version of Kansas I had ever pictured, or really much like any place I’d ever seen, for that matter. Once again Knapp swerved onto to the shoulder.

“Permian?” I asked.

Knapp nodded as he stepped out of the car and pulled a thicket of tumbleweed out of a gully. He invited me to crawl under a barbed-wire fence to take a closer look at the rocks. I grumbled that I wasn’t eager to be shot for trespassing.

“Trespassing is a vital skill for geologists,” he retorted.

These were the Gyp Hills near the border of Oklahoma in central Kansas. The unusually hilly terrain (for Kansas) is a product of the enormous Permian salt layers that had dissolved underground, giving the region its strange topography. Some of the hills had crosses on them (memorials for the Permian, I liked to imagine).

This was no country for Kansas farmland. Here the earth was literally salted, from dried-up Permian seas. Some of these dissolved Permian salt layers have formed caverns underground, which are used to store reservoirs of fossil fuel.

Earlier in the trip we’d dropped by the University of Kansas core lab in Lawrence, Kansas, an Indiana Jones-style warehouse of ancient wonders: cylinders of rock drilled out from the far corners of the state. Knapp pulled out a famous core from the same rocks as those we’d seen in the Gyp Hills, a core that had been drilled a half-century ago by Amoco in search of oil. The rock alternated between Martian-looking dusty reds to huge sections of pure salt. In 2013 Knapp’s advisor at West Virginia, Kathleen Benison (then at the University of Kansas) found that lake water trapped in the salt reached literally otherworldly temperatures on the day that it was sealed away in these rocks, as high as 163.4 degrees Fahrenheit.

“These are the most extreme conditions in all of Earth’s history that we have a record of,” says Knapp. Even stranger, this was happening on an Earth that, not long before, had had ice on its poles. “It’s a different planet.”

Unsurprisingly, there’s no life in these ghastly rocks (even most plant life checks out at temperatures not much more than 40 degrees Celsius), making them exceedingly difficult to date.

“There’s absolutely nothing to date in any of these rocks because everything’s dead,” says Knapp. “But what we can say is that this is definitely Permian.”

The rocks most likely predate the greatest mass extinction of all time, possibly by millions of years. They may be indicative of a world that was stumbling toward its date with Armageddon, its supercontinental configuration making life on Earth increasingly unpleasant. The period is punctuated with mysterious minor extinctions, like one that might have taken out sail-backed proto-mammals—creatures like science museum star Dimetrodon, whose bones are mostly known from neighboring Oklahoma and Texas. As the Permian planet limped to its finale plants and animals would continue to thrive elsewhere and, to the south, coral reefs in Texas would blossom as well, leaving behind the Guadalupe Mountains and a trillion of dollars of oil—but here in Kansas it was hell. Rocks similar to the Gyp Hills extend all the way to North Dakota, indicating that this wasn’t some quirk of local geography like Death Valley.

“This isn’t local,” says Knapp. “This is all of central Pangaea.”

Southern Methodist University geologist Neil Tabor has dubbed these vast lethal expanses that took over the middle of the planet in the Permian the “wastelands of tropical Pangea.”

To Knapp the Kansan rocks indicated that much of the world was already getting quite weird in the run-up to the greatest mass extinction ever. One speculation, borne out by modeling, is that supercontinents promote giant arid interiors that shut down the processes of rock weathering—the planet’s most effective way of drawing down excess carbon dioxide over geological time spans. As a result, the Permian planet might have been less effective at regulating its temperature.

“So what I like to talk about is ‘the Great Weirding’ and not just the Great Dying because the Great Dying seems to have been a relatively quick event at the very end. But if you just talk about the Great Dying you’re missing all of this other crazy stuff that led up to it,” he said. “The Earth was getting really weird in the Permian. So we’re getting these huge lakes with these negative pHs, which is really weird, we don’t know why that happened. Another thing is that the whole world turned red. Everything got red. You walk around today and you’re like, ‘Hey, there’s a red bed, I bet it’s Permian or Triassic.’ The planet started looking like Mars. So that’s really weird. We don’t know why it turned red. Then you have a supercontinent, which is weird in the first place. Plate tectonics has to be acting strangely when you have all the continents together. Eventually it rifts apart and we go back into normal plate tectonics mode, but during the Permian-Triassic everything’s jammed together. So there has to be something strange going on. And then at the end, the Earth opens up and there’s all these volcanoes. But we’re not talking about normal volcanoes, we’re talking about weird volcanoes.”

As we continued north on Route 287, over the Colorado-Wyoming border, the trappings of society fell away and the sun set again over the pale grasslands. Driving through Carbon County, Wyoming, the unending darkness of the barren plains was pierced by a glittering Oz on the prairie. This was Sinclair, Wyoming, (named after the oil company) and an enormous, illuminated refinery twinkled like a lonely Manhattan, ceaselessly digesting carbon from the ancient seafloor day and night.

“If we understood why things got so crazy in the Permian I would be a lot more comfortable,” Knapp said, breaking the silence. To some geologists, the extraordinary nature of the end-Permian catastrophe represents a level of environmental chaos so extreme that humanity could never hope to emulate it. But Knapp wasn’t so sure.

“I see [a few] possibilities. The first is that things just really got that crazy. Shit happened. The second is that we just really don’t understand positive feedback loops yet. That’s the scary option. The third is that you can’t do it without a supercontinent. We need to be studying these time periods when carbon dioxide caused problems, because right now we don’t understand them at all. It should be a national priority to study the Permian to figure out what the hell happened.”

The next morning we set out from Rawlins, Wyoming, for the extinction boundary. But we couldn’t look at the prototypical rock section, first described in the 1960s.

“It’s on a ranch and they won't let you access it anymore,” Knapp said, eyes blearily searching the horizon, pulling from a cup of cheap coffee. “They say it's a liability thing but I think it's because they don't like geology and global warming and think the Earth's 6,000 years old. That's been the most challenging part of my work. I can't get access to any of the outcrops because they’re all on ranches.”

The end-Permian rocks of Wyoming can be seen from space, or (more easily) from Google Maps. They appear as strange little shocks of crimson peeking out from under the faded tans of the prairie. In the northeast corner of the state they fleck the periphery of Devil’s Tower. But there aren’t many people studying these rocks. When Knapp returns to the same outcrop in central Wyoming every few years he finds his rock hammer on the same rock he left it on.

We drove over a ridge that looked out over an empty basin and pulled off the road and into a small canyon of red rocks. At the top of the canyon the rocks gave up their Martian hue at long last, and were etched with the geological traces of tranquil lakes and river channels and even dinosaur footprints. Up in those rocks the Earth was finally recovering, and the reptiles of the Earth’s most storied age—the Mesozoic—were making their tentative claims to a world that they would come to rule for more than 100 million years. But down here along the dusty trail was the end of the Permian, and the planet was still fighting for its life. In the huge stacks of red rock Knapp saw an alternating hellscape of sheet floods and red desert soils, and even some piles of bacterial slime that festered in grotesque ephemeral lakes.

“One thing I don’t see anywhere here is roots,” he said. “At the top of that rock over there in the Triassic, we start to see tons of roots. It’s the same depositional environment as here. But here everything’s dead.”

Here, at the end of my pilgrimage, I picked off a rock from this end-Permian wall and turned it over in my hand. As this pebble was forged, 90% of life on Earth was going extinct, even at the poles. Faraway in northern Pangaea volcanoes burning through fossil fuels were ruining the planet for everyone, driving global warming and ocean chemistry changes that nearly rid the planet of complex life.

We still had one final sightseeing adventure in Wyoming, a four-hour detour. We were off to see an open-pit coal mine. And not just any open-pit coal mine, the largest surface coal mine in North America. Though there aren’t many landmarks to lead you through eastern Wyoming—save prairie grass—the colossal open-pit coal mines of the Powder River Basin are easy to find.

“We’ve just got to follow the train tracks,” Knapp said. We kept the tracks to our left and kept pace with a ceaseless parade of empty train cars rolling headlong toward the Powder River Basin to be refreshed with coal. The train tracks they glided along were immaculately well-maintained, and why shouldn’t they be? Their precious cargo was the lifeblood of civilization. The empty train cars were returning from the nodes of civilization, like spent red blood cells, to this giant, unyielding pump of geological energy in the prairie. The train cars heading out of the basin, freshly topped off with jet black mounds of fossil jungles from the Paleocene. They were shuttled along the infrastructural aorta before branching into capillaries where they’d deliver their carbon to far off power plants to be metabolized near cities, by metropolitan mitochondria. The trains pulled in and out of the Powder River Basin all day and all night, every day, every year without interruption.

Finally, after taking some wrong dirt roads and being rebuffed by surly coal mine security workers—and even scarier signs (“ORANGE CLOUD POSSIBLE AVOID CONTACT”)—we found an overlook into the manmade chasms. As you’ve probably heard about large industrial mining operations, encountering their inhuman scale in person is stupefying. It’s the biggest thing you’ve ever seen happen. The walls of these manmade canyons were shaded mostly in dull grays and browns, but hundreds of feet down at the very bottom was a 25-foot-tall stripe of pure black that wrapped around the entire pit. Here a tiny earthmover came face-to-face with the planet’s history and dug in. It pulled out forests from 60 million years ago, when atmospheric carbon dioxide was much higher and Wyoming was a lush swampy Eden haunted by crocodiles. The little toy trucks shuffled this trapped sunlight, stored in the earth, up the sides of the pit wall to be delivered to the far corners of the world and burned.

After visiting ancient fossil reefs and lifeless rock exposures, this might have been my best view of what was happening at the end of the Permian. As far as we can tell, we’re shooting carbon dioxide up into the atmosphere ten times faster than the ancient volcanoes of Russia did during the end-Permian mass extinction, an episode that almost ended the project of complex life on Earth. Our planet is once again at a crossroads, and the tangled path to redemption is still very much open. But we now find ourselves falling towards the first steps down an older, much darker road.

“What we’re doing is the equivalent of that supervolcano going through Siberia,” Knapp said, overlooking the pit. “By stripping out all of the coal from everywhere it exists on Earth and burning it. And we’re doing it really, really fast. So we have an analog in Earth’s history. And it’s fucking scary.”

Related Video