Soaring temperatures may bring rising seas, disrupted agriculture, vast migrations, and the inundation of coastal cities around the world—and there are a lot of coastal cities around the world. Still, I live three hundred metres above sea level in a region that may well benefit from global warming (the risks of invasion, famine, war, mass extinction, and the complete collapse of civilization aside). What would really throw wooden shoes into Canada’s proverbial gears is cooling. Only a mere 12,000 years ago, the place where I live was just emerging from an ice sheet a mile thick. You may think Canadians hate shovelling snow now… wait until there’s nearly two kilometres of the stuff. Straight up.
So, if we wanted to cool down the Earth, how would we go about it? One way is to screw with the atmosphere (or distribution of the continents) so that either less light reaches the ground or proportionately more heat escapes out into space. The real world offers some fairly dramatic examples of what’s achievable here: the Azolla Event, for example, may have drawn down the amount of CO2 in the atmosphere by 80%, transforming the world from a tropical greenhouse into its current icebox state. Our ancestors had it easy: the Great Unconformity (in which a considerable amount of crustal material is apparently missing) has been explained as the side effect of the glaciers of “snowball Earth” scraping or eroding away a staggering amount of material.
A number of SF authors have imagined scenarios in which the earth cools down dramatically. Here are five that I liked …
Precisely what happened to the climate in Poul Anderson’s The Winter of the World is unclear; it’s set far enough in the future that Mars is green (presumably a hat tip to now outmoded models of Martian climate), so it’s possible that Earth is simply the victim of natural processes. Still, references in the novel suggest that the first phase of the cooling that ended our civilization involved a large number of extreme heating events provided courtesy of our pal, the nuclear bomb. (Presumably using them made sense at the time?) Millennia later, humanity is well on its way towards recovering what was lost under the ice—not least of all, epic imperialism. While the political machinations are familiar from history, time and isolation have given rise to something entirely novel in the far north.
The cause of the cooling in John Christopher’s The World in Winter (The Long Winter in the US) is quite straightforward: the Sun dims ever so slightly. Hard cheese for the people of Great Britain, which as we know has had its indigenous human population wiped out by encroaching glaciers a half dozen or so times in the last million years. A bunch of privileged Brits head for Africa, which is less affected by the cooling. Much to the consternation of the refugees, they find that African nations only recently freed from their colonial conquerors do not welcome them with open arms…much like the real-world reactions of wealthy nations shutting out victims of climate change, war, and social disruption.
There’s nothing wrong with the Sun in Housuke Nojiri’s Usurper of the Sun. The problem begins with Mercury, which alien mechanisms are busy converting into a ring around the Sun. Why the aliens think this is a good idea isn’t immediately clear. What is clear is that the ring material blocks enough of the sunlight to cause abrupt global cooling on Earth. The episodic novel focuses on attempts to mitigate the effect of the Ring and better understand the enigmatic beings who created it.
Fred Hoyle’s The Black Cloud is in no sense enigmatic. As soon as the entity becomes aware that Earth is inhabited by intelligent beings, it’s happy to communicate with them. Unfortunately for a considerable fraction of the human race, the Cloud only belatedly notices humanity—that is, after the vast alien (large enough to eclipse the Sun while feeding) has wreaked havoc on the planet’s climate. Its attempts to befriend us have…mixed results.
Fritz Leiber embraces the old saying “No sun, no problem!” Runaway warming has been vanquished forever thanks to the timely intervention of a passing dark star that flicked Earth out into deepest space. Many stories focus on the immediate efforts to survive. “A Pail of Air” touches on the question of why, given the circumstances, humanity should even try to survive.
“So I asked myself then,” he said, “what’s the use of going on? What’s the use of dragging it out for a few years? Why prolong a doomed existence of hard work and cold and loneliness? The human race is done. The Earth is done. Why not give up, I asked myself—and all of a sudden I got the answer.”
“Life’s always been a business of working hard and fighting the cold,” Pa was saying. “The earth’s always been a lonely place, millions of miles from the next planet. And no matter how long the human race might have lived, the end would have come some night. Those things don’t matter. What matters is that life is good. It has a lovely texture, like some rich cloth or fur, or the petals of flowers—you’ve seen pictures of those, but I can’t describe how they feel—or the fire’s glow. It makes everything else worthwhile. And that’s as true for the last man as the first.”
[…] “So right then and there,” Pa went on, […] “I told myself that I was going on as if we had all eternity ahead of us. I’d have children and teach them all I could. I’d get them to read books. I’d plan for the future, try to enlarge and seal the Nest. I’d do what I could to keep everything beautiful and growing. I’d keep alive my feeling of wonder even at the cold and the dark and the distant stars.”
And really, isn’t that the way we should deal with all setbacks? Do what we can to survive, while keeping our sensawunda?
In the words of Wikipedia editor TexasAndroid, prolific book reviewer and perennial Darwin Award nomineeJames Davis Nicoll is of “questionable notability.” His work has appeared in Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews and Young People Read Old SFF (where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis). He is surprisingly flammable.