Here's what would happen if ALL humans completely disappeared
It’s 9:41 A.M. You’ve just woken up and brewed yourself a cup of coffee. Outside your window you see the normal bustle of cars honking at a busy intersection, people waiting in clumps to cross the street, either mouthing conversations you can’t hear or scrolling through their cell phones. You look up at the sky and see airplanes flying high, weaving in and out of dark clouds. The clock strikes 9:42 A.M. and all of a sudden, for reasons unknown, you and everyone else in the world vanish completely. Without a warning and without leaving a trace.
The clock strikes 9:43. Your dog is barking feverishly, sniffing at the puddle of spilled coffee and broken glass that is shattered all over the spot of the floor that you stood on just a few seconds ago. The only remaining evidence that you stood there only milliseconds before. The streets outside are now littered with terrible traffic accidents and electrical fires caused by the collision of newly abandoned cars. Those planes that were flying through the clouds will stay airborne for a few more hours until their fuel runs out and gravity pulls them back down to Earth, where they crash in fiery explosions.
There is no one left to call for help, no police sirens in the distance. Just smoke, sparks and flames until eventually, total silence. This is what would happen to our natural world if human beings disappeared suddenly, without leaving a trace. All 7.9 billion of us.
Throughout the first day of our absence, all of the fossil fuel power plants around the world would shut down in rapid succession without humans around to re-fuel them with coal or oil. These shutdowns would lead to electrical blackouts across the globe, causing our world to rapidly go dark, grid-by-grid. If you were to look at Earth from space at the end of the second day without humans, the only city that would still have electricity would be Las Vegas due to it being powered by the Hoover Dam.
Sometime around the 36-hour mark without power, New York City’s entire subway system would completely flood due to the loss of manual laborers who pump around 13 million gallons or 49 million liters of water out of it every single day. Within the first three days of your absence, various insects would have begun infiltrating your home, making their way to whatever food was left out on the counter or table. At the same time, your dog would be on the same mission and would start munching on whatever scraps they can find, scrambling to survive without you around to feed and take care of it.
Over the next week or two, the insects in your home would be followed by small animals like mice, rats, squirrels and chipmunks that would enter by chewing through the walls and foundation. Domesticated pets will have either found a way to escape their abandoned homes or will have starved to death inside, depending on the capability of the animal and the circumstances of the space they were left in. But even for the dogs and cats who are successful in escaping, their struggle has only just begun. On their own now in the wild for the first time, these pets would not only have to compete with all the other newly freed dogs and cats out there, but also more experienced predators like wolves, coyotes, bears, eagles and snakes.
To make matters even more complicated, the global power outage would disable electrical fences at zoos around the world, allowing even larger and more exotic animals to break out and roam free. Imagine, if you will, lions prowling around supermarkets, or monkeys climbing on playgrounds. Surprisingly enough, house cats are predicted to have a better shot at survival as a species than dogs in the absence of humans, because dogs have been domesticated and selectively bred by humans for thousands of years longer than cats have.
Furthermore, when left to fend for themselves, dogs form hierarchical pacts which can lead them to hunt and kill their own, whereas cats are solitary hunters who avoid preying on their own as a means of preserving the species. On approximately the tenth day without humans, the planet and everything that is left inhabiting it will be forced to overcome a major environmental problem. All around the world, humans have built 440 nuclear power plants. Inside them are diesel generators which, unless carefully stored in cool water tanks, will heat up to 1,000 degrees Fahrenheit and explode.
The moment the power goes out on the first or second day without us, a ticking time bomb for these power plants is initiated. The generators will begin heating up their tanks, causing the water to boil before evaporating completely. This would lead to the generators igniting, causing all 440 nuclear power plants to begin a chain reaction of explosions, subjecting the world to the worst nuclear disaster in human history. Or should I say, human and post-human history. In total, these explosions would unleash about 500 times as much radiation as was released on Hiroshima with the atomic bomb. Radioactive smoke would fill the air, coating every plant and tree it touches with a metallic, black film. Over half of the world’s insect and rodent population would be killed off instantly.
Heavier animals would cope better with the radiation, as their organs are more insulated. Smaller animals who have found ways to sustain themselves indoors, either in supermarkets, homes or other buildings, would also be better protected. Within the first month or two without humans, almost all farm-raised dairy cows, chickens and sheep would have either starved to death or been killed off by predators. Within the next three to six months of your absence, water would begin to seep in through the cracks of your home that were created by the insects and small animals. This water would erode the walls, floors and ceiling even further. The unchecked water damage would rot the wooden beams supporting the roof, while mold continued to coat everything under it. Homes made of wood would be entirely infested with termites by this point.
At the one-year mark, hundreds of thousands of fires left to burn unhindered would have destroyed entire cities. In winter climates, the cold would have brought with it the freezing and bursting of water pipes in houses and buildings. Smaller dogs are predicted to be long gone by this point, wiped out by stronger and smarter dogs who have instinctually hunted them. Some of which may have even begun mating with wolves.
After one year without us, Las Vegas would finally go completely dark. This would be the result of the Hoover Dam shutting down due to the infiltration of a small breed of freshwater mussel called the quagga that, without humans to keep them at bay, would eventually clog the pipelines that are feeding cooling water to the dam’s generators. Who would've thought that the entire city of Las Vegas could be conquered by animals less than an inch in length? Without water running through the Hoover Dam, the Colorado River would also eventually run dry.
Over the past century, our cars pumped out approximately seven billion tons of carbon dioxide into the air every year. But now with us gone, the air is clearing up like it never had the chance to before. Plants and trees will begin sucking up the remaining Co2 we left behind for them, a process that will continue for the next 100,000 years.
Two years after our disappearance, our once-manicured lawns have completely overgrown into fields. Concrete sidewalks are now filled with greenery that has pushed its way through the cracks. The ice rink at the Rockefeller Center in New York City is now a garden.
After 10 years without humans, forest fires will have destroyed coastal cities like Los Angeles. After two decades, the paint on the White House will have faded to gray and l cities such as Amsterdam, London and Chicago will be completely flooded.
After 30 years, the 6542 satellites we have positioned in space will become visible in the night sky, soaring above the Earth like shooting stars before gravity finally pulls them to the ground where they’ll crash and burn once their batteries are all dead.
Half a century after our disappearance and the only remotely human sounds that’ll be left on Earth would be emanating from formerly domesticated parrots that would still retain traces of human speech.
Seventy-five years and the 1.2 billion abandoned automobiles we left behind would be nothing more than withered-down, skeletal heaps of their former selves.
A full century after we’re gone and underground running water would corrode the metal structures that hold up city streets, causing the vegetation-covered roads to cave in on themselves and turn into rivers. Like a gothic ghost town version of Venice. Insect populations are predicted to have fully recovered from the nuclear power plant explosions by this point and be thriving thanks to the absence of man-made pesticides. This jump in the insect population would trigger an increase of all the animals that feed on them. This pattern of population growth would reverberate all the way up the food chain, causing the entire animal kingdom to boom over the next century.
At around three hundred years without humans, the steel rivets which hold bridges together would have rotted and degraded so much that they’d begin to collapse one-by-one. The Eiffel Tower would fall, along with the Statue of Liberty and all the skyscrapers in the world. Once the buildings made of metal and glass are gone, only the ones made of brick and mortar would remain. But even those would have become weakened by the continual water damage and lack of maintenance. The last remaining man-made structures would be the Great Wall of China, the pyramids of Giza, and Mount Rushmore, all of which could remain in-tact for several thousand years after our disappearance.
One hundred million years after humans disappeared, the sole remaining evidence of human life on Earth would be shards of plastic and Mount Rushmore. If any new species of sentient life were to form at any point around this time, these artifacts would be all they have to piece together who humans even were.
When we talk about the greatest threats to human civilization we tend to think of man-made constructs like foreign governments, nuclear weapons and artificial intelligence. But rarely do we ever consider the power that seemingly harmless things such as water, climate and plant life possess against this rather fragile reality we’ve collectively built. And so, at first, thinking about how swiftly Mother Nature would reclaim her Earth after we’re gone can feel kind of depressing. But at the same time, thinking about how powerful this planet really is, even despite the tremendous amount of environmental damage we’ve caused, can be oddly reassuring, maybe even liberating.
Wherever you are right now, I urge you to look out your window. This time, instead of thinking about the intersection and the honking cars, focus on the shrubs and greenery planted along the sidewalk. Instead of looking at the people waiting to cross the street, think about the ground they’re standing on and all the layers of nature that have been buried underneath that concrete. When you look up at the sky, instead of focusing on the planes flying high, think about the clouds they soar amongst.
Realize that this planet we call Earth is so vast and that human life and all that we’ve created is really just one small part of it. Remember that if we suddenly vanish, we would miss Earth far more than she would miss us.