Facial tissues are the one piece of trash I see on the trail the most (by far), but I also see an occasional orange peel or apple core. I know where hikers who toss these aside are coming from — since they are food items, the idea is that either an animal will get it, or mother nature will.

The problem is that often neither of those are true. If an animal does not eat your leftovers (which is much less likely than you think), then it is going to be there for quite a while. But don’t just take my word for it.

In an article published in Popular Science, Alisha McDarris writes that “…food scraps like orange and banana peels can take up to two years [emphasis added] to break down in the wild, meaning they’re going to be sitting alongside the trail or in a ditch by the road for a lot longer than you might think.”

The essential problem is that the great outdoors is not like a compost pile. A compost pile is a situation that is supremely optimized to enhance the breakdown of organic matter. This is a very different environment, as it turns out, then simply beside a trail. “The conditions present in a compost pile or facility—like a microbe-rich environment, heat, and the frequent turning of materials,” writes McDarris, “are required to break down food waste so quickly. Those conditions don’t exist in nature.”

And it gets worse, as McDarris lays out:

The food itself can also make animals sick and even kill them. Most of what people leave outdoors—peels, cores, and trail mix, to name a few—is almost never food that’s part of animals’ normal diet. Often, they can’t decipher the difference between actual food and scented items like chapstick, potato chip bags, and snack bar wrappers, which can be fatal.

https://www.popsci.com/story/diy/what-happens-food-trash-outdoors/

So yeah, the cardinal rule of trails remains: If you pack it in, pack it out. Thank you very much, from the person who has to pick up the shit you leave behind.