It took me years to start composting at home. There’s a program in Los Angeles, where I live, that sells compost bins to residents at cost, but in order to get one you have to attend a short class that always seemed to fall on a day I had to work or had other plans. Sure, I could have built something myself—a few wooden palettes tied together can do the trick—but I had a toddler, a job, etc., etc. Finally, I just started piling food scraps and yard waste in a narrow space between the fence and the wall of a small office that sits in the corner of our backyard. Now, setting aside peels and tops and roots and skins is part of my cooking habits—my two-year-old daughter will even say of an orange peel, “This is compost.”
“Putting your food waste in the compost bin can really help reduce methane emissions from landfills, so it’s an easy thing to do that can have a big impact,” Sally Brown, who authored the paper, told the UW news service.
Composting promotes aerobic decomposition, which generates less methane than burying food waste in a landfill, an anaerobic, or airless, environment. It’s no wonder some farmers use anaerobic digesters to decompose waste and capture the methane to power their farms—there’s simply more of it when food is broken down without air than with it.
Yard waste pickup programs are more commonly offered by city sanitation services. But the UW study found that the reduction in methane emissions achieved by composting food waste did not vary based on geography and climate. Grass clippings, however, decomposed at very different rates depending on location, making it more difficult to qualify the difference in emissions.
There are still greenhouse-gas emissions associated with composting, and it is not a solution to America’s food waste problem in and of itself. More than 40 percent of the food produced in the U.S. ends up getting trashed every year, and diverting all of it from landfills to compost bins would represent only marginal progress. Instead, limiting food waste—which President Obama wants to cut in half by 2030—has to first involve consuming more of that scrapped food, which may be thrown away from reasons that range from aesthetics to economics. If we’re only composting the inedible bits, the emissions will be negligible.
There are now municipal composting programs in Seattle, the surrounding Kings County area, and San Francisco, as well as state programs in Vermont and Massachusetts. But despite increased interest from individuals and governments alike, a full 95 percent of food scraps generated in the U.S. end up in landfills.