When done at a large scale, composting can make a dent in emissions. San Francisco, which established mandatory city-wide composting in 2009, has been able to divert 80 percent of its waste from landfills every year, more than 2.5 million tons overall.
One estimate from the Natural Resources Defense Council finds that San Francisco’s composting laws reduced the equivalent of 90,000 metric tons of carbon dioxide every year, the same number of emissions as about 20,000 passenger vehicles.
In addition to reducing landfill emissions, compost makes soil healthier. When layered on top of soil in a garden or on a farm, the organic matter found in compost improves unhealthy soils. It also helps bind soil particles together and holds more water. Better soil helps support plant growth, which can help sequester carbon from the atmosphere. Stronger, nutrient-rich soil also reduces the need for fertilizer and pesticides, which are pollutants themselves and are often produced with destructive mining practices and a high carbon footprint.
In fact, the only downside to composting may be the “ick factor.” On that point, Sherman says not to worry.
“It’s not stinky, it’s not gross. And once a week I go to my backyard compost bin. It takes me three minutes to compost. I just really try to encourage people. I try to tell people it’s so easy to do.”