From KQED Science, find out how San Francisco’s 600 tons of compostable waste can be transformed into a dark, nutrient-rich material that will not only feed plants to improve the quality of what we eat and drink, but that also has the potential to offset America’s carbon emissions by over 20%. Above, agronomist Bob Shaffer takes us Inside the Compost Cycle.

Food scraps, mostly compostable, are over 30% of everyone’s garbage, and could instead help turn poor dirt into nutrient-rich soil where you live. If you’re interested in learning how to compost, check out these excellent links:

Watch more videos about sustainability, including the Moser Lamp, shaggy lawnmowers, Pierre’s high school greenhouse, Brooklyn’s Eagle Street Rooftop Farm, and how to use a paper towel.