John Wick, co-founder of the Marin Carbon Project in California, oversees a five hundred forty acre ranch.

To learn how to better care for his land, Wick asked a team of scientists to conduct soil tests and stumbled upon a discovery:

Wick: “We found that there was ten-year-old carbon deep in the soil system on sites that had wet dairy manure applied to them.”

The team wondered if compost would work like the manure, so they applied half an inch to Wick’s land in 2008. One year later, they found that each hectare had pulled about a ton of carbon from the air and stored it in the soil. Not only that, the grass had grown better, and the soil retained more water — benefiting the ranch. Amazingly, the land has continued to store carbon without applying any more compost.


Wick: “We’re on our sixth year now, and every year, we’re measuring an increase of carbon coming into the system on its own.”

Scientists estimate that if compost were applied to just five percent of California’s rangeland, it would offset the state’s emissions from agriculture and forestry for one year.

Wick: “This actually has tremendous, exciting implications. We could actually influence the climate through agriculture in a good way.”

Reporting credit: ChavoBart Digital Media.

More Resources
Marin Carbon Project
California ranchers tackle the climate crisis one pasture at a time
A sprinkle of compost helps rangeland lock up carbon

Diana Madson contributed regularly to Yale Climate Connections from 2014 to 2021. She enjoys exploring U.S.-based stories about unexpected and innovative solutions to climate change. In addition to her...