The last mayor of Portland, Oregon, stood on a hill, bundled against a cold June breeze. Her name was Wilhelmina Nansen, and she was watching the first day of the demolition of her city. In the distance, the Cascades blocked the horizon with a mass of snow and ice, punctuated by the jagged spire of Mount Hood. Closer to hand, a fleet of bulldozers puffed smoke into air that hadn’t seen such pollution in centuries.
The smoke was for show, staged for the hovering holocams and their not-so-stalwart operators, safely ensconced in Tri-V studios somewhere in the New Temperate Zone of Brazil or Zaire. Those people didn’t have to wear parkas in June and weren’t about to risk chilblains witnessing in person a story they could more comfortably cover from a distance.
The smoke had been the mayor’s idea, and as she watched the giant bulldozers belch it, she was proud of her inspiration — as long as the wind didn’t shift. Those fumes would be toxic to anything that breathed, but if the wind stayed from the southwest, there was nothing downwind that mattered. Nothing but polar bears and Arctic hares, and there were plenty of polar bears. What really mattered wasn’t the smoke; it was the carbon dioxide going up with it, as the bulldozers chewed their way through tidy rows of plastic houses.
Not that they were actually bulldozers. They were automated incinerators that existed only to destroy, powering themselves from their intensely hot fires as they searched out houses, roads, factories and abandoned landfills to burn — anything that held a rich store of carbon. Technically, they were called Save the Carbon Units (Mobile), or SCUMs for short. The name was a poke in the eye to the acronym-happy vocabularies of the people who’d got her city into this trouble so many generations before. She was proud of that, too, though she doubted anyone else caught the irony.
For weeks to come, the bulldozers — for so Mayor Nansen couldn’t help but think of them — would continue to work in what had once been a high-class residential area, braving the very snout of the glacier to free as much carbon as possible before it disappeared under the ice. But starting tomorrow, there would be no smoke. There was no sense poisoning the planet if this project proved successful enough to be launched elsewhere on a larger scale.
The entire concept was her idea, one she’d pushed at both science conferences and mayoral conferences for more than a decade. Finally, exasperated, she’d persuaded the city council to raid the street-repair budget to fund this demonstration. “In ten years, there won’t be any streets,” she’d argued. “Let’s give the world something to remember us by.”
To her surprise, the council agreed. At the time, Portland still had 75,000 residents, and funds were available. Today, she’d have been begging for a grant from a federal government so afraid of making another mistake that it no longer had the will to do anything.
Read more science fiction from Nature Futures
Read more science fiction from Nature Futures
The demise of her city had started innocently enough centuries ago with the discovery that otherwise-unrecyclable plastics could be moulded into park benches. At the time, there being only a limited need for park benches, that was mostly a curiosity. Then Hurricane Xanthe blew salt water nearly as far up the Mississippi as Memphis, Tennessee. Climate-change deniers were caught selling off beachside vacation homes. A powerful senator built a giant berm around his own coastal residence. He claimed it was a privacy screen, but a staffer leaked tapes of him haranguing the construction company about the need to move fast, before “the next Xanthe” washed his entire estate off the map. Even the most conservative voters were forced to admit global warming was real.
Reducing emissions was the first priority, but that was followed by finding ways to remove carbon dioxide from the air and sequester it from ever returning. There was talk of creating chemical factories to do this, but nature had long had its own process. The only problem was that biomass eventually rotted, releasing its captured carbon back into the air. That, however, could be prevented, and soon everything from pulp timber to straw, corn stalks and lawn clippings were being converted into plastic building materials that could never decay. Not park benches, but lumber, pavement, roofing and anything else anyone could imagine.
It took decades, but it worked. Global warming stopped, then reversed. Sea levels dropped and politicians returned to their grandparents’ seaside estates. Bioplastics became the norm for pretty much all types of construction.
Nobody thought about the possibility of overshoot until the glaciers started to advance. Even then, they were slow to realize the cause, let alone take steps to deal with it: a perfect mirror of how their ancestors had been slow to react to global warming before Hurricane Xanthe.
Mayor Nansen remembered, as a child, watching Anchorage go under the ice. Soon it was Juneau’s turn, then Seattle’s, while in the heartland, ice sheets forming in Manitoba and Labrador spread south with enough momentum to frighten the residents of Ohio and even Kentucky. Nansen herself wasn’t afraid of cold — her ancestors came from Greenland and Baffin Island and she liked to believe antifreeze was in her blood. But when the University of Washington closed down and Portland State became the West Coast’s northernmost institution of higher education, she returned to school for a master’s degree in glaciology.
Undergraduate minors in history and sociology had already made her a believer in the pendulum theory of human progress. Overshoot, undershoot; overshoot, undershoot. That was the normal state of human affairs. It was hardwired into the human psyche not to react until the pendulum had moved so far out of equilibrium that everyone recognized the looming crisis … and then pushed it too far the other way. Her studies also convinced her that politics, not academia, was the route to salvation, so she devoted herself to moving up the ladder as fast as possible before the place she’d chosen to call home became nothing but a sheet of ice.
She was also a fan of old movies. One day, at a film festival, she watched in awe as a nineteenth-century steam locomotive — already an anachronism at the time it was filmed — curdled the air with a plume of black smoke. What if all of that soot were actually carbon dioxide? she’d wondered, and the SCUM project had been born.
Now, one of her brainchildren extruded a backhoe and began to dig, as its carbon sensors detected a subterranean source of the all-important element. Moments later it unearthed the first in a succession of ebony boxes.
She gasped as the machine plucked coffins out of the earth and fed them into its maw, as easily as a farmer might hoe potatoes. Then she grunted. “Voice note,” she said, activating her new, all-metal, guaranteed-no-plastic personal recorder. “From now on, all funerals should be by cremation.”
After all, every bit of carbon made a difference.
Until the pendulum swung too far and her great-to-the-nth grandchildren had to repeat the cycle all over again.