SF Startup Uses Crushed Rock to Remove Carbon from Air

Scientists have spent decades chasing complex technologies to fight climate change, but a new Stanford spinoff is betting on something surprisingly simple: crushed rocks.

Terradot, a San Francisco startup, is taking a natural carbon removal process that normally takes millennia and supercharging it to work in just years. The secret is pulverized rock spread across farmland like a fine powder.

"We take rocks that naturally remove carbon over really, really long time periods, and we crush them up to create a powder and spread them on farmland to make them remove carbon in years instead of millennia," explained James Kanoff, a Stanford graduate and Terradot co-founder.

The method, called enhanced rock weathering, works like this: storms and moisture naturally dissolve certain rocks over thousands of years, triggering chemical reactions that bind with carbon dioxide. That carbon eventually gets carried into soil, water systems, and the ocean.

Terradot simply speeds up the timeline. The rock powder sprinkles over soil like a thin layer, gets mixed in by farmers during normal cultivation, and starts pulling carbon from the air right away.

Stanford researcher Scott Fendorf, who co-founded the company, says the approach fits seamlessly into existing farming operations. "Think of it as just a fine little powder that gets sprinkled over the top of the soil," he said. The bonus? In many cases, it can actually improve crop yields.

The Ripple Effect

Tech giants are paying attention. Google and Microsoft are backing Terradot's large-scale test in Brazil's farming region, where the company is precisely measuring how much carbon dioxide the rock powder can actually capture.

The startup has also deployed the technology in the southeastern United States. To scale up efficiently, they're focusing on areas near quarries or other rock sources to cut transportation costs.

The team knows they're just getting started. "We need to deliver billions of tons of carbon removal in order to actually help stabilize Earth's climate," Kanoff said. "When I think about where we are right now versus where we need to go, I feel like we're still basically just at the beginning."

What started as academic research is now becoming a practical tool farmers can use while growing food, turning agricultural land into a massive carbon sink without disrupting production or requiring new infrastructure.

Sometimes the best solutions aren't the flashiest ones.