What if Humanity Suddenly Vanished from the Earth?
Could our bustling cities, once alive with activity, end up as huge, abandoned places? What would become of our planet a hundred, a thousand, or even ten thousand years in the future? Humans have dominated the Earth for over 7,000 years. Since the rise of agricultural civilizations, our species has colonized every continent on Earth. We’ve adapted to extreme environments, constructed elaborate settlements, and harvested innumerable resources. With a population of 7.8 billion and counting, humanity has evolved from simple primates into a global force.
We’ve shaped the Earth’s topography. We’ve cut down forests and manipulated the Earth’s ecosystems, disrupting food chains, eradicating species, and in many ways toppling the laws of nature. In fact, the rise of humanity, thousands of years ago, started the first geological epoch dictated not by the evolution of the natural world but by a single, globally dominant species. What if, in the blink of an eye, humanity ceased to exist?
Imagine a mass extinction event annihilated every human being on the planet—all 7.8 billion of us. If humanity suddenly disappeared, what would happen next? After the sudden extinction of our species, the world becomes unnervingly quiet. Without planes, trains, and automobiles—the noisy workhorses of humanity—the Earth breathes a sigh of relief; but it doesn’t take long for the remnants of humankind to wreak havoc on the world.
Without us to keep an eye on them, 443 nuclear reactors in 30 countries could start to overheat dangerously. Thankfully, most modern nuclear power plants are built to power down automatically if they’re not being managed, which helps prevent disasters like the Chernobyl meltdown in 1986. It’s unlikely any of our reactors will explode, but each power plant will irradiate the atmosphere for thousands of years—damaging ecosystems, eradicating wildlife, and gradually poisoning our planet.
Like nuclear reactors, precautionary systems prevent our factories, wellheads, and drilling rigs from bursting into flames; but those systems may fail, sparking industrial fires, releasing pillars of black smoke, and further polluting the atmosphere with greenhouse gases. In the beginning, the ocean absorbs some of the pressure. For decades, the ocean has diminished global CO2 emissions, absorbing excess carbon dioxide from the atmosphere. Between 1994 and 2007, the ocean absorbed around 31% of anthropogenic carbon dioxide, but even the ocean has its limits.
Eventually, an overabundance of carbon dioxide will acidify the ocean, killing marine life and crippling vital ecosystems. As the ocean slowly acidifies and industrial plants poison the Earth, every drizzle and thunderstorm inundates our largest cities with torrents of natural run-off. Subway networks, no longer drained by underground pumps, fill with millions of gallons of rainwater. Violent floods rush through subway tunnels, sweeping away train cars and erupting from stations and stairwells in the once crowded streets of London, Manhattan, and Beijing.
Within decades of our extinction, human infrastructure crumbles. Cities fall to their knees as water erodes support structures hidden underground. Overpasses and bridges collapse into piles of rubble. High-rises and homes sink into the ground. Around the world, our urban spaces give way… and Mother Nature reclaims the Earth. Tropical rainforests, like the Amazon and the Congo, gradually bury the remnants of humanity under a dense layer of green. Tropical vegetation creeps into every window and doorway, and diverse wildlife, like birds, monkeys, and rodents, fill the void humanity left behind.
In frozen deserts and snowy taigas, buildings and roadways break down under the wind and extreme cold of successive winters. In regions with heavy snowfall, like Canada, Scandinavia, and Northern Asia, entire towns disappear into the icy tundra, entombing human structures in mountains of white snow. As nature slowly reclaims human settlements, new ecosystems develop in our absence. A changing hierarchy of animals survives and even flourishes in the relics of humanity.
Wild dogs and cats, no longer sheltered by humans, become apex predators in urban and suburban spaces. Other city-dwellers, like raccoons, mice, and bats, thrive in abandoned buildings, where they feed on humanity’s trash and organic waste. But few animals boom in our absence like the world’s insects. Without humans, insect species feed freely on farmlands, no longer threatened by pesticides. The insect population, which has steadily declined over the last few decades, surges to new heights, launching an ecological domino effect.
Rising populations of insect species attract hungry insectivores, like birds and reptiles, who entice larger carnivores and apex predators. Many insect species are also prolific pollinators, stimulating the reproduction of angiosperms or flowering plants. The disappearance of humanity and the absence of artificial toxins may rejuvenate entire ecosystems, stimulating a burst of biodiversity around the world. Pesticides may fade, but not every toxic remnant of humanity disappears.
Mounds of non-biodegradable waste, which humans abandoned in dumps and landfills, will remain piled high for a thousand years at least. High levels of greenhouse gases, like methane and CO2, will persist for several millennia, long after humans have disappeared. Global warming, the product of heavy deforestation and the burning of fossil fuels, continues to radicalize the Earth’s climate, melting the polar ice caps and raising temperatures around the world.
Once our buildings decay and our infrastructure crumbles, will garbage and chemical pollution be the only remnants of our species? Think about the cradles of civilization, like the Sumerians or the Ancient Egyptians. Their stone wonders stood tall a few thousand years ago, but only a small amount of physical evidence remains. If our species vanished tomorrow, no one would maintain or preserve the relics we leave behind. They would be destroyed by Mother Nature and overrun with wildlife. Eventually, human achievement might disappear into the analogues of history—a history no other species learns or remembers.
Millions of years in the future, long after humanity’s sudden extinction, it’s possible another highly intelligent species evolves on Earth. This species might research the planet’s history.