What would the Earth look like a year from now if humans were to disappear?

Curious Kids is a series for kids of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.

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

What would happen to all our belongings? What would happen to our homes, our schools, our neighborhoods, our cities? Who would feed the dog? Who would mow the lawn? Despite being 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—someone who helps towns and cities plan what their communities will look like—it’s sometimes my job to think about such possibilities.

Too much silence

If humans suddenly disappeared from the face of the Earth and you were able to return a year later and see what had happened, the first thing you would notice wouldn’t be your eyes.

It happens with your ears.

The world would be quiet. And you would notice how much noise people make. Our buildings are noisy. Our cars are noisy. Our skies are noisy. All that noise would stop.

You would notice the weather. After a year without humans, the sky would be bluer, the air clearer. The wind and rain would cleanse the Earth’s surface; all the smog and dust that humans had made would be gone.

home Sweet Home

Imagine your first year standing at home undisturbed by anyone.

Go into your house and hope you’re not thirsty because there’s no water in your taps. Water systems require constant pumping. If there’s no one to operate the machines that pump water in the public water supply, 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 with the first cold snap, the freezing weather would freeze the water in the pipes and burst them.

There would be no electricity. Power plants would stop working because no one would be watching them to keep the fuel supply up. So your house would be dark, with no lights, no television, no telephone, no computers.

Your house would be dusty. In fact, there is always dust in the air, but we don’t notice it because our air conditioning systems and heaters are blowing air around. And as you move through the rooms in your house, you keep the dust moving. But when all that stops, the air inside your house becomes stagnant, and dust settles everywhere.

The grass in your yard would grow – and grow – and grow – until it got so long and limp that it would stop growing. New weeds would come up, and they would be everywhere.

Many plants you’ve never seen before can take root in your garden. Every time a tree drops a seed, a small sapling can grow. There would be no one to pull it out or cut it down.

You’ll notice a lot more bugs buzzing around. Remember, people do everything they can to get rid of bugs. They spray the air and ground with insecticide. They clean up bug habitats. They put screens on the windows. And if that doesn’t work, they squash them.

If humans hadn’t done all these things, the insects would have come back. They would have had free rein on Earth again.

On the street you live

In your neighborhood, animals would be wandering around, staring and wondering.

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

Larger animals would come later—deer, coyotes, and occasionally bears. Maybe not the first year, but eventually.

Without electric lights, the rhythm of the natural world would return. The only light came from the Sun, Moon, and stars. Night creatures felt good about having the dark sky back.

Fires occurred frequently. Lightning might strike a tree or a field and ignite brush or strike houses and buildings. Without people to extinguish them, these fires would burn themselves out.

Around your city

After just one year, concrete structures (roads, highways, bridges, and buildings) would look pretty much the same.

Let’s say you go back ten years later and cracks would have appeared and little plants would be wiggling through them. This is because the Earth is constantly moving. With that movement comes pressure, and with that pressure comes cracks. Eventually the roads would crack so much they would look like broken glass, and even trees would grow through them.

Metal piers would slowly rust. The beams and bolts that held them up would rust too. But the great concrete bridges and the interstate highways, also made of concrete, would last for centuries.

The dams and levees that humans have built on the world’s rivers and streams are eroding. Farms are returning to nature. The plants we eat begin to disappear. There aren’t many corn, potatoes or tomatoes left.

Livestock would be easy prey for bears, coyotes, wolves, and panthers. But what about domesticated animals? Cats would become feral—that is, wild—but many would be preyed upon by larger animals. Most dogs wouldn’t survive either.

Like Ancient Rome

A thousand years from now, 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 were in, and just plain luck. An apartment building here, a movie theater there, or a collapsed shopping mall would stand as monuments to a lost civilization. The Roman Empire collapsed more than 1,500 years ago, but you can still see some of its remnants today.

If nothing else, the sudden disappearance of humans from the face of the earth will reveal something about the way we treat the Earth. It will also show that the world we have today cannot survive without us, and that we cannot survive if we do not value it. Civilization, like everything else, needs constant maintenance to keep it running.

Hello, curious kids! Have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age, and city.

And since curiosity has no age limit – adults, let us know what you’re curious about. We won’t be able to answer every question, but we’ll do our best.

This article is republished from The Conversation, a nonprofit, independent news organization that brings you facts and trusted analysis to help you understand our complex world. By Carlton Basmajian Iowa State University

Read more:

Carlton Basmajian does not work for, consult, own shares in, or receive funding from any company or organization that would benefit from this article, and has disclosed no affiliations beyond his academic appointment.