Composting will prevent tons of material from going to the landfill, create healthy soil for our local farms and help us fight global warming.

Today at the Farmer’s Market in front of San Francisco’s iconic Ferry Building I am signing the nation’s first mandatory composting law. It’s the most comprehensive recycling and composting legislation in the country and the first to require residents and businesses to compost food scraps.

A number of years ago, San Francisco set a lofty green goal—we wanted to divert 75 percent of our resources from the landfill by 2010 and achieve zero waste by 2020. At the time, many people thought our targets were overly ambitious. However, San Francisco is poised to meet these goals. We are currently keeping 72 percent of recyclable material out of our landfill.

We recently conducted a waste-stream analysis and discovered that about two thirds of the garbage people throw away—half a million tons each year—could have been recycled or turned to compost. If we were able to capture everything, we’d be recycling 90 percen —preventing additional waste material from going to the landfill, and creating hundreds of green-collar jobs.

San Francisco already converts over 400 tons of food scraps and other compostable discards into high-grade organic compost every day. It’s so nutrient-rich that the final product is almost jet black in color. It’s snapped up by farms and vineyards across the Bay Area, we can barely keep up with the demand. By requiring all residents and businesses to compost, we’ll increase the amount of “black gold” available for sustainable regional agriculture and improve our environment.

When food scraps break down in an oxygen-starved landfill it creates large quantities of methane gas, a greenhouse gas 72 times more potent than carbon dioxide when measured over a 20 year period. It also creates acids that can leach toxins from the landfill.

Composting food scraps produces little to no methane because there is sufficient oxygen in the process. And using the resulting compost reduces greenhouse gases by returning carbon to the soil, increasing plant growth, and reducing emissions associated with chemical fertilizers, pesticides and irrigation. Recent studies show that farming one acre of land using conventional industrial methods releases 3,700 pounds of carbon into the atmosphere each year. Farmed sustainably, with compost and cover crops, that same acre will put 12,000 pounds of carbon back into the earth.

I believe that composting will become second nature for Americans, just like sorting bottles and paper. It will take time, but I believe mandatory composting will spread across the country—improving the air we breathe and reducing our need for landfills.

Greenopolis offers ideas to compost in style: Check out this related story.

Share