Expert Voices

If humans went extinct, what would the Earth look like one year later?

A cloudy burning orange sky hangs above a desert wasteland with the towering ruins of a modern city decaying on the horizon.
Artist's depiction of a post-apocalyptic world. (Image credit: f9photos , Shutterstock)
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Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to In this entry, Essie, age 11, of Michigan asks: "If humans went extinct, what would the Earth look like one year later?"

Have you ever wondered what the world would be like if everyone suddenly disappeared? 

What would happen to all our stuff? What would happen to our houses, our schools, our neighborhoods, our cities? Who would feed the dog? Who would cut the grass? Although it’s a common theme in movies, TV shows and books, the end of humanity is still a strange thing to think about.

But as an associate professor of urban design – that is, someone who helps towns and cities plan what their communities will look like – it’s sometimes my job to think about prospects like this.

Related: Sun blasts out powerful X-class solar flare causing radio blackouts on Earth (video)

So much silence

If humans just disappeared from the world, and you could come back to Earth to see what had happened one year later, the first thing you’d notice wouldn’t be with your eyes. 

It would be with your ears. 

The world would be quiet. And you would realize how much noise people make. Our buildings are noisy. Our cars are noisy. Our sky is noisy. All of that noise would stop.

You’d notice the weather. After a year without people, the sky would be bluer, the air clearer. The wind and the rain would scrub clean the surface of the Earth; all the smog and dust that humans make would be gone.

It wouldn’t be long before wild animals visited our once well-trodden cities. (Image credit: Getty Images)

Home sweet home

Imagine that first year, when your house would sit unbothered by anyone. 

Go inside your house – and hope you’re not thirsty, because no water would be in your faucets. Water systems require constant pumping. If no one’s at the public water supply to manage the machines that pump water, then there’s no water.

But the water that was in the pipes when everyone disappeared would still be there when the first winter came – so on the first cold snap, the frigid air would freeze the water in the pipes and burst them. 

There would be no electricity. Power plants would stop working because no one would monitor them and maintain a supply of fuel. So your house would be dark, with no lights, TV, phones or computers. 

Your house would be dusty. Actually, there’s dust in the air all the time, but we don’t notice it because our air conditioning systems and heaters blow air around. And as you move through the rooms in your house, you keep dust on the move too. But once all that stops, the air inside your house would be still and the dust would settle all over.

The grass in your yard would grow – and grow and grow until it got so long and floppy it would stop growing. New weeds would appear, and they would be everywhere. 

Lots of plants that you’ve never seen before would take root in your yard. Every time a tree drops a seed, a little sapling might grow. No one would be there to pull it out or cut it down. 

You’d notice a lot more bugs buzzing around. Remember, people tend to do everything they can to get rid of bugs. They spray the air and the ground with bug spray. They remove bug habitat. They put screens on the windows. And if that doesn’t work, they swat them. 

Without people doing all these things, the bugs would come back. They would have free rein of the world again.

Given enough time, roads would start to crumble. (Image credit: Armastas/iStock via Getty Images Plus)

On the street where you live

In your neighborhood, critters would wander around, looking and wondering

First the little ones: mice, groundhogs, raccoons, skunks, foxes and beavers. That last one might surprise you, but North America was once rich with beavers

Bigger animals would come later – deer, coyotes and the occasional bear. Not in the first year, maybe, but eventually.

With no electric lights, the rhythm of the natural world would return. The only light would be from the Sun, the Moon and the stars. The night critters would feel good they got their dark sky back.

Fires would happen frequently. Lightning might strike a tree or a field and set brush on fire, or hit the houses and buildings. Without people to put them out, those fires would keeping going until they burned themselves out.

Around your city

After just one year, the concrete stuff – roads, highways, bridges and buildings – would look about the same. 

Come back, say, a decade later, and cracks in them would have appeared, with little plants wiggling up through them. This happens because the Earth is constantly moving. With this motion comes pressure, and with this pressure come cracks. Eventually, the roads would crack so much they would look like broken glass, and even trees would grow through them.

Bridges with metal legs would slowly rust. The beams and bolts that hold the bridges up would rust too. But the big concrete bridges, and the interstate highways, also concrete, would last for centuries.

The dams and levees that people have built on the rivers and streams of the world would erode. Farms would fall back to nature. The plants we eat would begin to disappear. Not much corn or potatoes or tomatoes anymore. 

Farm animals would be easy prey for bears, coyotes, wolves and panthers. And pets? The cats would go feral – that is, they would become wild, though many would be preyed upon by larger animals. Most dogs wouldn’t survive, either.

Like ancient Rome

In a thousand years, the world you remember would still be vaguely recognizable. Some things would remain; it would depend on the materials they were made of, the climate they’re in, and just plain luck. An apartment building here, a movie theater there, or a crumbling shopping mall would stand as monuments to a lost civilization. The Roman Empire collapsed more than 1,500 years ago, yet you can see some remnants even today.

If nothing else, humans’ suddenly vanishing from the world would reveal something about the way we treated the Earth. It would also show us that the world we have today can’t survive without us and that we can’t survive if we don’t care for it. To keep it working, civilization – like anything else – requires constant upkeep.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The views expressed are those of the author and do not necessarily reflect the views of the publisher.

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Carlton Basmajian
Associate Professor of Community and Regional Planning, Urban Design, Iowa State University

Dr. Carlton Basmajian is an Associate Profess of Community and Regional Planning and Urban Design at Iowa State University, where he studies the history of urban and regional planning in the United States. He holds a bachelors degree from the University of Chicago, a masters degree from the Georgia Institute of Technology and earned his Ph.D. at the University of Michigan in 2008. 

  • Andyross
    History Channel had a special, then series, all about it titled "Life After People". The special went through in time as things degraded. The series focused on certain aspects, and used real-life examples when possible. Looks to be available with History Channel cable/satellite service link. Not sure if it's is on History Vault.
  • Unclear Engineer
    Of course, if humans went extinct by the processes that we know of, instead of just quietly vanishing, there would be damage to the Earth that would take extensive time to repair. Nuclear winter, asteroid impact, climate change extreme enough to make the world actually unliveable for humans, would all have major effects on the restorative capabilities of the natural ecosystems.

    On the other hand, a truly "renewable" human infrastructure might look reasonably intact after a year. Solar powered electrical systems run by computers, water supplied from local cisterns, located in a region that does not freeze in winter, might continue to provide services after a year. Sure, these things eventually require maintenance. But, there are places where people can live without much infrastructure (e.g., Amazon rain forest), and also places where human infrastructure is essential to human habitation (densely populated cities in regions that freeze).

    Which brings up a point about whom to blame for CO2 emissions. Comparisons of per capita emissions by region are not that useful for a couple of reasons. First, the amount of energy needed per capita depends on the local climate. Second, the energy expended to produce the goods and infrastructure for one location might actually be expended in other locations. For instance, China makes a lot of the goods used in the U.S., Canada and Europe, and most of the technological goods used in Africa come from outside Africa.

    Also, it is useful to realize that a lot of the people in the low per capita CO2 emission regions are simply not affluent enough to live the lifestyles of people in the higher CO2 emission regions, but they aspire to those life styles, so efforts to create "equity" among the regions are, in effect, efforts to create more CO2 emissions on the behalf of those in the "less developed countries".

    To me, the bottom line is that humans need to learn to control our population densities by voluntarily controlling our own reproduction rates, so as not to have them controlled by wars, famines and pandemics.
  • Phillip Huggan
    If plants go we might get aeolian Earth. A solar flare in a 1B yrs, Milankovitch ice ball Earth in 2.5B, about that for rats to hunt in packs. If we were going to voluntarily control our population, AIDS and overcrowding would've done it already. I see us stopping AGW easily enough. It is an issue of bringing up as much area and nations on Earth to future 1st world standards. We will be curing cancers and heart disease. Pollutants will soon be a main killer, Incinerators leave their junk 5 km away. You wouldn't want to live near there. I'm looking at how much better it is to dry clay using ethane than cement or plastics. Several entire fields of the economy can be replaced with less polluting varieties.
    Space is a positive forcing here. We can get ready for a space economy where the principles with sustainability intersect. Triton has natural gas and nitrogen. Some Ammonia based hydrogen is maybe better than coal including the space application. You might subsidize potential space uses of natural gas for a while. The asteroids are cold vacuum materials at risk of impact. Saturn is even colder and more remote. Neptune has cosmic ray irradiation. With re-entry shields in space we can eventually phase out the worst mining on Earth.
    To answer the question, the book hinged alot on whether nuclear employees got a 10 second chance to scram their reactors.
  • Phillip Huggan
    Weizman's book was one of the last ones I read before being Techno-specifically engineering. He wasn't sure if oil tanks rust or get hit with lightning. One year there is maybe nuclear pollution, is chemical pollution, and I think they had animals wrong, dying in colder cities. To be honest, I don't think we can go extinct. Some of us are made to wipe out Earth-based civilization in 500 years (before AI is made). But a solution has been found. And that solution includes forcing people to go to Sirius and to stop watching TV. Any behaviour management that has already wiped out free will or prevented mind-control by evil actors has already happened in 1998. The baseball players can't do triple plays anymore but the dauphins are clearly on another ship...the military and private King's Tutors were also supposed to be able to blog space PM is okay going for the human project even though the devil time machined his religion on permanently, it promotes space. An example, a space music song is "Watch your step". Because some 500 yrs-ers got control of public transport in the USA in the 1980s, hicks didn't fund publicly space much. Both attempted extinction. Instead, space is forced and a dead devil is allowed to steal my bus fare and run late and early just for me. Extinction doesn't happen, my feet get sore and employment is harder. The driver had a kid get on for free and then told me "we aren't there for you in space". The ancients made the evil AI's beatable by our version of their creator or his hacker buddy. You guys ignore me and all that happens is technology of the ancient's AI makes you preserve yourselves still.
  • Phillip Huggan
    Another astronaut song is "Headwheel". An instrumental about quantum effects of the brain: your study areas become a headwheel. And there is nothing extinction there. No one knows what an AI with time outputs if the headwheel leaves the universe. Apparently a place without aging that is a galaxy of good stars and blueprints to make my ex. Either way I still think I have to reverse engineer their tech to turn the TM into Sphere and make people without headwheels by Artificial Womb in the meantime.
  • Phillip Huggan
    100 headwheels eventually or war extinction. Green energy sources can be used to sub in lesser polluting substances. Wave enrgy will be made by 3d printing an ocean bulwark from limestone or titanium. Solar and wind can provide 2nd world life especially w/ batter batteries. And hydropower making lesser polluting but normally more GHG intensive substances. Part of why I dropped out is Gr. 10 couldn't figure you can sub in greener electricity to factories. Japan's ammonia investment uses equipment that almost goes to asteroid temps. A freebie for a moon rocket soon is I'll want palladium at Honest Trading a LY away for space air filters. Earth will get a version eventually of directional filter and I might offer radioactive Ag asteroid hard to snatch through the badlands. So space makes our air cleaner and how much pollution it takes to get to space is a deeper accounting.
  • Phillip Huggan
    Those aoelian worlds would benefit from trees. A flare 10M yrs ago from Procyon may have approached 2M km at closest and carried the 1000C asteroid to 0.5 LY away now. 5% Ag in ponds and 2.8% a Sargasso Sea you'll probably split near an iron asteroid 1 LY away and then raid it as it tanks 0.01c towards Sirius. I'll bring back 1000 colonists and there are 3 nodes of civilization. There might only be clay and silica fired around Sirius. These are extinction events only if civilization is localized and stuck at our tech level. Consider Earth still the hub as travel is twice as slow and dangerous between her neighbours and some past object travelling outwards left radioactive debris from the neighbour system towards Earth along the way. It seems like viable space countries have been laid out it is more a question of whether to catch Arcturus's wave's last 30000 yrs of moisture and its 2nd best nearby star. For pollution I have oil going to Triton fuels as well as DLC and anything needing tools to handle at UHV or <= asteroid temps. I'm not sure how many cohorts of astronauts using space seafoods it takes to live longer and teach Earth a better diet. Older people surely learn how not to go extinct.
  • Phillip Huggan
    I've figured what it is, another paper pledged the same 70 IQ reasoning, that base load electricity never changes: the VASIMR guy, Drexler, Obama...weren't supposed to get free credit for environmentalism. Until a person is 120 IQ, they don't have economic logic. It looks like you need alot of binders for wave power. The dirty generation nations are stuck making low polluting low GHG emitting stuff or stuff that gets your IQ 120-150. I'll bring 75 to short of Procyon. Make AW engineers. They will escort the ladies back to Triton as 2 to 4 people with unmanned loot a shuttle mission away tanking back, I'll pick up 1000 colonists needing to grow Procyon 10x each trip. It is dangerous the 1st two trips back and forth. One of the USA CRN guys wasn't allowed to pursue the bio-nano route to avoid WMDs and Regan shuffled things around; Japan had a breeder reactor guy learn coal emissions instead...we have almost a degree to give and green concrete, utility batteries and a cheap wave power foundation win no AGW.
  • Atlan0001
    Sixty-five million years ago there was an almost intelligent, complex, almost human-like dinosaur developing from the carnivorous and scavenger class dinosaurs. Sixty-five million years later, we are here, not to be custodians of the Earth but to take, to expand, life out into the universe at large.

    If we implode, if we go extinct in the 1,000 years Hawking gives us if we don't do the job we were made to do, and if life has enough time before all of it goes extinct, it will develop an even more brutally less caring of poor Earth species to get the job done for it. What does life in general on Earth probably think, if it can think, of the environmentalists and their environmentalism? Idiots and idiocy!!!! It wasn't why all the eggs were put into one species basket that could look outside the box, think outside the box! One apex of the pyramid! It has no need whatsoever of any custodian species. What it has need of is a carrier species to carry it out into the outland frontier universe for its continued expansion of life, survival of life from a dead certain extinction on a single rock, and a generally emerging energizing prosperity of life in its birth out of the womb of the Earth!

    If Mankind can't or won't do the job it was made for, Nature, given more time, will bring into being a species that will do the only job it is intended to do (all else being nothing more than reward), the only job it is really good at, and damn environmentalism, full speed ahead.

    What would Earth look like one year after humans went extinct? Another space looking and spatially minded species on the way up to fill the void between Earth life and its continuing mass extinction ending expansion (in Noah's Ark-like Space Colonies) out of Earth and into the universe.
  • Phillip Huggan
    I outpaced the tech level of environmentalism for 12 yrs. It has caught up to me with air filters and trading CaO for CaCO4 and reactive extrusion binders are lower footprint. We have in situ flaries eventually. An 80km Ag one is white silver w/ orange scorching poking an inch to metre out of the pond in regular geometric shape pieces. Its sunset is one millionth Earth's ocean's brilliance. 6 metals are mixed in at least 1%. Is dusty. A 500km by 10km orbital panel of Ag focused on a 40C world's surface could cool a city below 0C permitting Jetson's condos. Another star may have had a flary (10M km closest flare approach) w/ hull quality clay (eroded like metal) hard to cut w/ an island of sapphire (big enough for raccoons if on Earth but not deer) deep. Another flary was Mercury but a flare passed through it and is now an asteroid whose samples would appear to be different elements if it were flipped as the interface mix is 10M x stronger than is my planned cosmic ray metallurgy to be learned in NY. One flary has a city of 1% iron oxide (deep). With space neuroimaging and in situ alot of the sci-fi storyline risks go away but big Earth gets a tech level centuries behind soon.