Lithos, a Seattle agtech startup that makes use of basalt rocks to assist farmers take away carbon, lands $6.3M

Lithos, a Seattle startup applying carbon capture technology in an agricultural setting, announced Thursday that it raised a $6.29 million seed funding round.

Lithos provides a permanent carbon removal strategy by spreading the dust of crushed basalt rock on croplands. When the rain falls, the basalt reacts with the water and carbon dioxide in the air, turning it into dissolved bicarbonate. The “enhanced rock weathering” process also releases nutrients to the soil, benefiting crop production.

The startup uses software to custom-deploy the basalt rock based on variables such as soil chemistry and crop nutrition. The software also measures carbon removal volume.

Lithos sells carbon removal credits to corporations and provides a share of the sales with the farmers where the product was applied.

Carbon removal is seen by most as a necessary solution for fighting climate change. The current market value for carbon credits is $1 billion, according to McKinsey research, and it’s expected to increase to at least $30 billion by the end of this decade.

Lithos launched in March and is live across more than 1,000 acres. It is the largest supplier of credits to Frontier, a $1 billion advance market commitment led by Stripe, Alphabet, Shopify, Meta, and McKinsey.

Lithos co-founder and CEO Mary Yap previously worked with two San Francisco startups that were acquired — including social payments company Tilt, acquired by Airbnb — and holds a bachelor’s degree in earth and planetary sciences and geology from Yale. Yap’s family are generational farmers in Taiwan.

“We don’t just capture carbon,” Yap said in a statement. “Lithos’ approach is directly valuable to farmers, increasing crop yields and replacing the expensive status quo – agricultural lime – with basalt dust, derived from rock that is safe from heavy metals.”

Co-founder Dr. Noah Planavsky is an associate professor of Earth & Planetary Sciences at Yale and co-founder Dr. Chris Reinhard is an associate professor of Earth & Atmospheric Sciences at Georgia Tech. The professors co-invented technology used by Lithos, including an approach for precising verifying the amount of carbon removal in soil.

The seed round investment was led by Union Square Ventures and Greylock Partners with participation from Bain Capital Ventures, climate funds Carbon Removal Partners and the Carbon Drawdown Initiative, as well as agriculture funds Fall Line Capital and Cavallo Ventures.

Lithos represents the first climate investment for Greylock Partners and Bain Capital Ventures.