Most of us can agree that the human race has done a real number on planet earth; whether it’s the plastic we’ve put into the oceans, the urban sprawl that’s eaten up most of nature or the growing hole in the ozone layer, it doesn’t look as though we’ll be getting our security deposit back. But, to quote comedian George Carlin, “the planet isn’t going anywhere. WE are!”
So what would happen to the planet if humans were to suddenly disappear altogether? How long will it take the earth to recover from our time here? Here’s what experts think would happen, in approximate chronological order, if the human race disappeared overnight:
The lights will go out
Within just a few hours, most of the world will go dark should mankind cease to exist. Nuclear power systems will detect a drop in usage, automatically go into safety mode and stop emitting power. Fossil fuel plants will soon run out of fuel and stop working, wind turbines will eventually stop turning without maintenance and solar panels will be covered in dust.
However, hydroelectric plants like Niagara Falls or the Hoover Dam that rely only on the flow of water could continue to provide power for months or even years without human maintenance.
Subways and streets will flood
Underground tunnels and subway systems will likely begin to flood in just a matter of days. Many subterranean tunnels sit below water table levels and require pumps to keep groundwater out. With no electricity and no one around to operate the pumps, underground tunnels will soon begin to fill with water. The flooding will eventually find its way to the streets, turning many well-known avenues into temporary rivers.
Many animals will starve
Without humans around to care for them, millions of house pets, farm and zoo animals that are not accustomed to hunting down their own food will starve within a few weeks. Creatures such as rats, cockroaches and lice that depend on human activity for survival will also die out or even become extinct.
While other animals will thrive
While some animals will die without being fed, others will escape their now defunct electric enclosures and run amok. Stronger predators will hunt and kill weaker animals while domestic dogs and cats will start running in packs, picking off smaller and slower creatures. Within weeks, small dogs such as pugs or terriers whose survival instincts and features have been bred out by humans will have been killed off by larger creatures.
Raw sewage would flood the rivers
Sewage treatment plants obviously require power to operate. Without power, sewage would slowly back up and begin to flood, polluting the surrounding lakes and rivers. The sewage would likely poison a number of animals who’d managed to survive thus far.
Chemical plants will fail
Across the world, dangerous chemicals used for manufacturing are carefully stored and maintained. Many chemicals require electricity to remain stable and without power, dangerous liquids could be released as gases. Experts say that these chemicals could enter the earth’s atmosphere and cause a “mini chemical nuclear winter”.
Natural gas plants will cause fires
Much like chemical plants, natural gas plants require electricity to maintain dangerous substances. Without power, natural gas plants would begin to vent and the gas would eventually reach the fuel tanks of now ownerless vehicles, causing mass explosions and fires worldwide that would burn for days.
Nuclear plants will melt down
Although nuclear plants have stopped producing power, that doesn’t mean they would be harmless if not manned by humans.
About a month after a mass human exit, emergency generators would run out and the cooling pools used to control nuclear substances would evaporate, causing mass nuclear explosions far worse than Chernobyl or Fukushima. Pockets of dangerous radiation that could potentially remain for thousands of years would span the globe.
Satellites will fall from the sky
About a year into the world’s existence without humans, the night sky will begin to look very different as satellites begin to fall. Thousands of objects sent by man into orbit will slowly start to fall over the course of several years, appearing like shooting stars in the sky. Some of the furthest satellites could continue to orbit for decades before eventually falling back to earth.
Vegetation will revert back to its original form
Over the centuries, humans have managed to crossbreed and perfect fruits and vegetables to make them more plentiful, palatable and easier to grow. In just two short decades without human cultivation, vegetation will revert back to its original strains and some of your favorite healthy foods will be virtually unrecognizable in their wild forms.
Homes will crumble
After just a couple of winters without heat, pipes will begin to burst and homes will slowly start to deteriorate from the inside out. Most homes are built predominantly using timber and after about twenty or thirty years, the ones that haven’t already burned to the ground by mass fires caused by lightning strikes or other aforementioned disasters will begin to crumble and rot.