Dear Recyclebank: Why is composting my food scraps better than putting them in the trash, if they’ll just decompose in the landfill anyway? –Hanna M.
Dear Hanna: Unlike plastic or glass, food waste decomposes quickly, so it’s natural to wonder what harm it does in the landfill. The problem lies in the way the food waste and other organic matter decomposes: Because much of it is buried under other trash in the landfill, it’s doesn’t get the oxygen needed to decompose naturally. Instead, it decomposes without oxygen, which means methane gas is generated — one of the most potent greenhouse gases.
One study estimates that around 8 percent of the total greenhouse gases around the world are caused by food waste.
So here’s where composting comes in: Aerobic composting (in other words, decomposition in conditions where air is circulating) “does not emit methane, which makes it a better alternative than sending organic materials to landfills,” says Kat Nigro, head of marketing and engagement for CompostNow, a composting service that collects organic waste from homes, restaurants, and businesses. Instead, the process off-gasses carbon dioxide, which, although a greenhouse gas, is significantly less potent than methane.
One advantage of using a commercial service, such as CompostNow, is that they can compost things that home composting systems can’t handle, such as meat and bones, dairy products, and even greasy pizza boxes. “Commercial facilities are able to compost meat and dairy because their piles reach a temperature of 160˚F, which is the necessary temperature to kill off any pathogens that might be present,” explains Nigro. “Backyard systems can rarely get to this temperature, so composting meat and dairy in backyard systems isn’t recommended.” It takes around 60 to 90 days for food scraps to turn into compost in a commercial facility. In a home system it can take a little longer.
Of course, there’s another major benefit to composting: “Landfilling organic matter is a waste of the nutrients present in those materials,” says Nigro. “Composting eliminates methane emissions from organics rotting in a landfill, and more than that, it adds the necessary nutrients back into our soils to improve soil health and strengthen local food systems.” CompostNow estimates its members have collectively diverted more than 9 million pounds of waste from the landfills since 2011, producing around 3 million pounds of nutrient-rich compost. And that’s just one company in one small region of the US. Imagine how much waste we could divert if everyone composted!
So, if you think about it, compost is the ultimate form of upcycling: Turning food scraps (which would otherwise take up space in a landfill and create methane) into a versatile material with applications in gardening, farming, carbon sequestration, erosion control, and more!