The End of the World

THE END OF THE WORLD

Writing about science can open one up to a universe of opportunities. For example, I regularly get invites to talk about everything from astronomy to zombies. In 2012, I was one of the speakers at Doomsday Live! a radio show and live-audience theater event organized by the SETI (Search for Extraterrestrial Intelligence) Institute. It was a slick production, hosted by the Computer Science Museum in Mountain View, California. The topics seemed thrilling enough to me: asteroid strikes, viral plagues, rebellious computers, environmental chaos, irrational doomsday predictions, and more. But it might easily have been a disaster about disasters. I wasn’t sure how people would react. Fortunately, it turned out to be one great apocalyptic spectacle. The live audience was one of the warmest and most enthusiastic I have ever spoken to. At times, I felt like I was at a Super Bowl bash or maybe one of those Tony Robbins seminars. Yeah, there is just something about the end of the world that picks up a party. But I should have expected it because this is nothing new.

Apocalyptic fears and fantasies have intrigued, excited, burdened, and haunted humankind for millennia. I would not be surprised if Homo erectus bands often paused between hunting and gathering to worry about the end of the world, too. Maybe caves were the first doomsday bunkers and cavemen the first doomsday preppers. What is certain is that we have a strong and enduring interest in a final day of reckoning that borders on obsession. Just note the steady flow of films, books, and television shows with apocalyptic themes in pop culture today. Numerous religions, past and present, were built on a foundation of end-of-the-world threats and promises of escape. Science has done its part too by providing several charming, evidence-based doomsday scenarios for us to contemplate at bedtime. I understand the appeal. Horrible as global death and destruction may be, there is also a certain attraction to it for some people who think the idea of hitting the reset button might not be so bad. No more rent or mortgage payments to worry about. No lame job to show up for anymore.

The end of the world, human extinction, and the collapse of civilization are all interesting subjects for the skeptic because the world really could “end” and take us with it. It’s not an entirely crazy topic. For example, gamma rays, a nearby supernova, and solar flares are no joke. They are real phenomena, though their effects depend on the event and should be assessed separately. Asteroid impacts have happened before, and large impacts can devastate life on Earth. The estimate cited here is that approximately a million objects in our solar system could pose a direct threat one day. The timing and severity of a future impact are separate questions; a long-term hazard does not establish an imminent catastrophe.

Supervolcanoes are thousands of times more powerful than the regular volcanoes we are familiar with. These gigantic monsters are rare, but they have erupted in the past and will erupt again. Toba in Sumatra erupted 74,000 years ago. One proposed explanation of a human population bottleneck links it to that eruption: material thrown into the atmosphere could have darkened and chilled the world, with the population perhaps falling to as few as two thousand people. It is unlikely but plausible that a virus could evolve or be engineered to kill us all one day. Writing after the Cold War, I regarded nuclear war as probably the greatest threat to civilization, despite the decline in public concern. The danger I had in mind was the United States and Russia possessing thousands of nuclear weapons that could be launched by order or by accident.

My favorite end-time scenario, by far, is human extinction via a massive “methane burp” from the seafloor. Yes, believe it or not, the gaseous residue of hundreds of millions of years of microbial activity beneath the bottom of the ocean might be unleashed in one colossal fart that kills us all by abruptly altering the atmosphere and climate we depend on. Critics less forgiving than me might feel it would be poetic justice, a fitting end for the species responsible for two world wars and too many boy bands.

Don’t panic and run screaming into the streets just yet, however. Even these frightening, evidence-based scenarios probably wouldn’t cause our extinction because we may develop the means to predict, avoid, eliminate, or lessen their impact. This is why it is vital for us to continue exploring and discovering. Some of the answers we find today may save us tomorrow. There is also strength in numbers. Even a population of more than seven billion, spread across much of the planet, presents a formidable obstacle to complete extinction. Our large population, combined with our creative intelligence, makes us a very tough species to kill off. A 2009 University of Colorado study supports my view on this, concluding that we are “unlikely to become extinct without a combination of difficult, severe, and catastrophic events.” The researchers said that it was hard to come up with plausible scenarios capable of killing everybody. But this doesn’t mean that the world isn’t doomed. In fact, it almost surely is.

In four or five billion years, our star will die like all stars eventually do. But the Sun won’t go quietly. It will behave like an angry man dying, punching and flailing at anyone near. After all the life-giving support it provided for billions of years, the Sun’s final act will include frying the Earth and boiling away all its water. But there is still plenty of room for hope. Four billion years is a long time. It is unlikely, if not impossible, that we would be close to anything resembling what we think of as human today, if we still exist. Maybe by then our descendants will be living comfortably on a safer planet far away or on an artificial world they built. Maybe they will have become so technologically advanced that they can control the Sun or somehow protect the Earth from its fury. But even if we can dodge the Sun’s wrath, we might not be able to escape ultimate doomsday. One astronomical projection described here puts the end of the era of shining stars at about 100 trillion years. Still we might escape by jumping to another universe or circling back in time. Then again, maybe humanity—along with all our accomplishments, creations, and memories—will be erased from the cosmos forever. Time will tell.

Evidence-based predictions of possible doomsday scenarios, while fascinating and well worth concern where appropriate, just are not a big problem for very many people. If one thinks critically and carefully about such ideas, and assesses the danger like a good scientist might, then there’s not much to lose sleep over. Yes, we need to improve our early-detection abilities for near-Earth objects that may threaten us. We also need to be ready to respond effectively when they do. Yes, we should do more to discourage and prevent people and nations from weaponizing viruses and bacteria. We also might want to reduce nuclear arsenals to only enough firepower needed to destroy civilization, say, once or twice and no more.

The key to dealing with this subject sensibly is, of course, science and skepticism. When irrational thinking creeps in, apocalyptic thoughts not only become silly, but also can turn dangerous. There are many examples of irrational believers doing terrible things in the name of doomsday. To my knowledge, however, there are no suicidal groups based solely on a scientific reading of the Sun’s expiration date. There are no apocalyptic religions centered on what geologists say about supervolcanoes. I doubt anyone has quit his job and sold his house in anticipation of the big methane burp or the rise of artificial intelligence. No, the science of doomsday, while important, is just not a popular source of self-destructive behavior. It is belief in unscientific doomsday claims that consistently causes the trouble.

Far back in time, during the first days of civilization or even earlier perhaps, some man or woman told anyone who would listen that the world was about to end in some spectacular way that would kill everybody. And people bought it. So began a weird and steady freak show of human behavior. For generation after generation, in society after society, hundreds of millions of people have believed in countless doomsday claims. They always come with excessive drama and are delivered with unwavering confidence. But good evidence and logical arguments are never part of the presentation, which probably explains why the failure rate of these predictions is 100 percent to date. Why does this diseased thinking keep infecting us? I’m not sure, but I do know that skepticism is the cure.

It’s impossible to know accurate numbers, but there is no doubt that throughout history many millions of people have suffered and/or died as a direct result of belief in irrational, never-going-to-happen doomsday declarations. Does our fascination with death somehow derail our ability to recognize and reject stories that are clearly made up? Maybe all or most of us come with a built-in doomsday fetish that makes this weird seduction inevitable. Maybe our fondness for patterns leads us to imagine a near and specific end to the human story, just for the sake of completing the picture or closing the loop.

The good news is that you never have to fall for these stories. All you need to do is think like a scientist, and the madness bounces right off. Skeptics are the last people on Earth who will burn up nervous energy, throw away money, join a kooky organization, kill themselves, or harm anyone else in anticipation of a doomsday prediction that no one is able to back up with good evidence. We know that it makes sense to assume that there will be a tomorrow. Skeptical thinking has defied doomsday and saved the world many times before and can again. All we have to do is think, and those scary predictions wither and die.