Dear Jenny,

There is a lot of litter on our planet, but it hasn’t always been that way.

For most of human history, people made stuff out of things they found in nature. They might make tools out of rocks or sticks. These things break down and become part of the soil again.

It wasn’t until the invention of new materials, like plastic, that we started creating more litter. In fact, along with the rise of these new materials came the word “litterbug.”

That’s what I found out from my friend Erik Johnson. He’s a sociologist at Washington State University who is really curious about culture, the ways people interact and live together, and how that shapes a human being.

If you were eating a candy bar and the wind blew the wrapper out of your hand, you might chase after it and find a trash bin. But not everyone will make the same decision. They might let the wrapper blow away—or just toss it on the ground.

Humans make lots of different choices, including what they buy at the store. A lot of that stuff ends up being junk. It breaks or you don’t need it anymore, so it ends up being litter. It no longer has any value to you.

When your parents were growing up, you could actually return bottles and cans in exchange for money. Not surprisingly, places where you could get cash for your cans and bottles tended to have less litter.

Johnson said research has found that people will litter if they don’t have a garbage or recycle bin nearby. If they have a bin nearby, they are much less likely to litter.

He also said that people tend to litter in places where there is already litter. If litter is a normal sight and something that a lot of people do, other people will follow along and take a similar action.

One of the biggest sources of litter on our planet is cigarette butts. They are small, but they really add up. They can also add toxins like arsenic into the earth and water, which can poison places animals call home.

It’s also important not to toss apple cores, banana peels, or other food on the road or sidewalk. While fruit probably won’t cause any harm to the environment, they might attract a critter who doesn’t know a road can be dangerous.

Yes, it’s true that people litter. It’s much easier to litter than to take time and energy to find a proper bin for it. But it’s also true that a lot of people pick up litter. They also want to find ways to re-purpose our litter.

Some of my friends at WSU are looking at how to make fuel out of things like plastic bags, milk cartons, and water bottles. Maybe you can help us come up with an idea to prevent littering—or other ways to help keep our planet healthy and beautiful.

Dr. Universe