13. Nuclear Holocaust
“One nuclear bomb can ruin your whole day.” It was true back in the late 1950s, and it’s just as true now. The world could end at any moment thanks to the countless nukes out there, just lying around. According to a 2010 Ploughshares Fund report, 22,000 active nuclear warheads are scattered around the globe. And that number doesn’t include smaller—and therefore more susceptible to theft—nuclear weapons like atomic artillery shells and bunker busters. In truth, we’re still exactly where we’ve been for the past 70 years: one international argument away from the end of the world.
12. Black Holes
Stars collapse on an almost daily basis. When a massive star collapses, it produces an immense gravitational pull along the way, drawing everything in its path—including light—toward its core, like a giant vacuum cleaner from which there’s no escape. While black holes sit at the center of most galaxies, including our own, the real danger comes from a discovery made in the year 2000. “We now have conclusive evidence,” physicist Michael Kaku told ABC News, “that there are wandering black holes—nomads, renegades—and right next to us in our own galaxy.” How long until one of these nomads bumps into the Earth? No one is sure, and it’s a big universe, but everyone agrees that it’s going to happen sooner or later.
Continue below for all the rest of the ways you will probably die.
What if the programming of billions of tiny self-replicating robots—nanobots in the technical parlance—suddenly went awry? And instead of doing the job for which they were built (like mopping up an oil spill), they started consuming all matter on Earth—while building more of themselves? In his 1986 book, Engines of Creation, nanotech pioneer Eric Drexler describes it this way: “Imagine such a replicator floating in a bottle of chemicals, making copies of itself… the first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four, and the eight build another eight. At the end of ten hours, there are not thirty-six new replicators, but over 68 billion. In less than a day, they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined.”
10. Gamma Rays
Gamma-ray bursts are high-energy beams of electromagnetic radiation shot out of a supernova, or exploding star. Researchers say a routine gamma-ray burst within 3,000 light years of the Earth would release more than enough radiation to completely cook our planet. Talk about global warming.
A strangelet—short for “strange nugget”—is a bit of “strange matter” that scientists are hunting for with particle accelerators. When strange matter encounters normal matter, it turns normal matter into strange matter. Now, normally, strange matter decays in microseconds and doesn’t cause much harm. But it’s theoretically possible for a chunk to stabilize. If that happens it would start turning all nearby matter into strange matter—and it wouldn’t stop. In an instant the “normal” Earth would be replaced by the “strange” Earth, which scientists strongly suspect would be inhospitable to all known life forms, including us.
Smallpox, plague, anthrax, tularemia, brucellosis, Q fever and your coworkers’ bad breath. These are just a handful of deadly pathogens that have already been made into bio-weapons. Any of these, especially with a little amount of genetic tinkering to make strains more virulent, would have the potential to end life as we know it. But that’s the devil we do know. Biologist Craig Venter, known for sequencing the human genome, recently created the world’s first synthetic life form. Pretty soon we’ll be genetically engineering bugs that no one has ever seen and to which no one has any natural-born immunity. If one of those suckers should get loose, it’ll make the bubonic plague seem like a case of the sniffles.
7. Mini Black Holes
That pesky Large Hadron Collider. It’s full of downsides—and none are more disturbing than the possibility of its creating mini black holes. Theoretically, Hawking’s radiation should dissolve these holes instantly, but no one knows for certain that Hawking’s radiation works on the micro scale. And if it doesn’t, that hole can start bouncing around the Earth, essentially dicing the planet into pieces. English astrophysicist Martin Rees said it’s a 1-in-50-million chance that it could happen. But what if he’s overestimated the odds—or we’re just unlucky?
Particle accelerators produce matter. They also produce antimatter. When matter and antimatter bump into each other, the result is total annihilation. While antimatter doesn’t normally float around our atmosphere, it can be manufactured in small amounts inside a particle accelerator—including the Large Hadron Collider in Geneva, Switzerland. Manufacture enough of it, release it into the atmosphere—purposely or accidentally—and, well, it’s goodnight and good luck for everyone.
Supervolcanoes are a bit like Mount Saint Helens on steroids. The explosion of such a giant volcano would pump enough ash and sulfuric acid into the atmosphere to blot out the sun and bring on a sequel to the ice age—and no, we don’t mean another one of those animated movies. Scientists calculate that 71,500 years ago, a Sumatran supervolcano exploded, plunging the Earth into a decade-long volcanic winter,” the effects of which reduced the total human population to less than 10,000 individuals. Worse, Sumatra’s is just one of six known supervolcanos. Another, the largest in the world, is at Yellowstone National Park. Unfortunately, scientists have discovered that Yellowstone’s erupts roughly once every 600,000 years, with the last explosion occurring 630,000 years ago—meaning we’re a little overdue.
4. Loss of Biodiversity
Currently, life on Earth is dying as never before. One quarter of all mammals now face extinction, while 90 percent of the large fish are already gone. If present trends continue, one-half of Earth’s animal species will have vanished within a hundred years. According to a warning issued by UN officials at the 2010 Convention on Biological Diversity, so dependent are humans on the services of plants and animals (for everything from pollination of food crops to protection against disease to cleaning our air and water) that unless this loss of biodiversity is halted, humans will likely join this list of extinctions.
3. Solar Flares
Solar flares are jets of plasma shooting out of the sun. In 1859, British astronomer Richard Carrington witnessed the greatest one on record: telegraph lines were electrified, shocking technicians, causing fires and shutting the entire system down. Nothing similar has happened since, but solar flares move in cycles and we’re due for stormy solar weather sometime circa 2012. This is not good news. A 2009 NASA-funded study by the National Academy of Sciences entitled Severe Space Weather Events said: “A contemporary repetition of the Carrington Event would cause… extensive social and economic disruptions.” How extensive? A solar flare coming upon today’s vast and interconnected power grid could cause massive outages, radio blackouts, satellite malfunctions, telecommunication-system meltdowns, a banking and financial-systems collapse, air-traffic control screens turned to fuzz—and on and on.
2. Near-Earth Objects
Ever since scientists figured out that it was the impact of an asteroid 10 kilometers wide that wiped out the dinosaurs, they’ve been hunting the skies for species-ending space rocks. An estimated 90 percent of these 3,200-foot-long big boys have been found, although none pose immediate danger. But we’ve barely begun drawing our map of the smaller rocks and therein lies the real problem. In 1908, an asteroid less than 40 meters wide exploded over Siberia, leveling forests for hundreds of square miles. If that had happened above New York, well, goodbye Gotham.
1. Alien Invasion
It’s a big universe and statistically (at least) we’re probably not alone in it. So what happens if visitors from outer space do show up? Well, they could come in peace or they could be here sport hunting or wanting our resources or carrying diseases to which we have no immunity—each of which could spell doom for the human race. And if these advanced invaders treat us anything like humans treat other cultures—well, the prognosis is decidely bad.