Yes, they’ll decompose, but not as fast as you think.
There’s no trash can in sight, so you throw the peel of the banana you’ve just eaten on the ground to get rid of it. It’s fine, you think to yourself, it’ll decompose anyway. The many discarded banana peels and apple cores you’ve seen walking down the street throughout the years seems to only confirm your theory.
But is there really any truth to this? Or is it one of those myths like “lightning never strikes the same place twice” that we’ve all just gone along with?
For the answer, we tapped Rhonda Sherman, an extension solid waste specialist at North Carolina State University’s Department of Horticultural Science and the author of Backyard Composting of Yard, Garden, and Food Discards, to find out.
Throwing “natural” foods like banana peels and apple cores on the ground isn’t bad for the planet because they’ll just decompose anyway.
It’s not really about if banana peels and similar foods decompose—there’s no question that they do—but rather how long the process takes. Most people, Sherman says, are wrong about how quickly they’ll decompose.
Before we go any further, let’s take a look at the decomposition process. The first thing that happens after you toss your peel is that microorganisms start breaking it down by secreting enzymes that cause the decomposition, Sherman says. But because microorganisms don’t have mouths or teeth, this doesn’t happen quickly.
“Broccoli stalks, watermelon rinds, banana peels—these are tough for us to even eat, never mind the microorganisms,” she says. “These all take a long time [to decompose] because they’re so thick and tough and resistant to breaking down.”
Next, insects get attracted and begin aiding in the process. Sherman says that unlike microorganisms, insects have mouths and the ability to tear things apart, so they work with the microorganisms to help decompose the waste.
And while weather does play a role—things decompose more quickly in tropics than, say, a desert—when all is said and done, food waste can take years to decompose, not just a few weeks like many people may think.
If your banana peel is just laying on the ground for two years, it’s not good for the environment. Plain and simple.
“Basically, litter begets litter,” Sherman says. “So if people see litter, then they’ll do it, too. Then, there’s so much litter on the ground that it will eventually look like a dump.”
The trash won’t just look like a dump—it will probably end up at a dump, too. And according to Sherman, landfills are designed to keep oxygen out, and so methane—a gas made up of carbon and hydrogen—is created. Methane, Sherman says, is a greenhouse gas that’s 34 times more potent than carbon dioxide.
And according to the Environmental Defense Fund, “if methane leaks into the air before being used … it absorbs the sun’s heat, warming the atmosphere.” Landfills are the third biggest human contributor to methane, Sherman says.
If you finish a piece of fruit, wait to discard it in the nearest trash can. Or, better yet, compost it.
“Composting is better [for the environment] and so easy,” she says.
All you have to do is get a compost bin for your backyard, fill it up about halfway with dead leaves, and start collecting your food waste. Sherman keeps a plastic shoebox or two in her freezer to collect any fruit or vegetable residue, and when the shoeboxes become full, she makes a hole in the leaves outside in the compost bin, tosses the frozen waste in, and covers it with the leaves.
“If a banana peel or apple core is in a compost bin, it’s an aerobic environment with oxygen, and a tiny amount of carbon dioxide is produced,” Sherman says.
And according to the University Corporation for Atmospheric Research’s Center for Science Education, carbon dioxide promotes photosynthesis, in which plants and some microbes create food. “Photosynthetic organisms combine [carbon dioxide] and water to produce carbohydrates (such as sugars) and emit oxygen as a by-product.”
Food waste will decompose much more quickly when composted—a couple of weeks versus a couple of years if it were just left on the ground.
This article was written by Daniella Zickl and published by Popular Mechanics on 13/09/2019