Lithos Carbon

Lithos Carbon was founded in March 2022 in Seattle by CEO Mary Yap alongside two academic co-founders, Dr. Noah Planavsky (Yale University, Earth & Planetary Sciences) and Dr. Christopher Reinhard (Georgia Institute of Technology, Earth & Atmospheric Sciences). Planavsky and Reinhard had spent years researching enhanced rock weathering (ERW) — spreading crushed basalt on cropland to accelerate a natural mineral-weathering reaction that draws down atmospheric CO2 and stores it as dissolved bicarbonate, eventually reaching the ocean as stable carbonate over geological timescales. Yap, a Yale-trained geologist with a family farming background in Taiwan and prior operating experience at consumer startups (including Tilt, acquired by Airbnb), set out to commercialize the science while directly benefiting farmers through improved soil pH, nutrient replenishment, higher yields and a new carbon-credit revenue stream that could replace costly agricultural lime.

The company emerged from stealth in mid-2022 and announced a $6.29 million seed round on October 20, 2022, co-led by Union Square Ventures and Greylock, with participation from Bain Capital Ventures, Carbon Removal Partners, Carbon Drawdown Initiative, Fall Line Capital and Cavallo Ventures. Lithos differentiated itself scientifically with a novel, Yale-developed soil-sampling and high-precision elemental measurement technique for quantifying CO2 removal (rather than relying solely on indirect bicarbonate flux modeling), paired with machine-learning models to target basalt application for maximum carbon capture and crop yield.

Lithos scaled quickly through corporate carbon-removal offtake deals. In December 2023, Frontier (the advance market commitment backed by Stripe, Alphabet, Shopify, McKinsey and others, later joined by JPMorgan Chase, Autodesk, H&M Group, Workday and additional buyers via Watershed) signed a $57.1 million agreement — the world's first enhanced-weathering offtake and, at the time, the largest ERW purchase ever — for 154,240 tons of CO2 removal between 2024 and 2028. Around the same period, Climeworks (2023) committed to purchasing 3.5 million tons of Lithos carbon removal credits over more than a decade, among the largest ERW offtakes in the industry. Microsoft became a customer in 2024, signing a multi-year research and removal agreement. Lithos also partnered with Puro.earth (announced March 2025) to certify its credits and, in December 2025, delivered 5,160 registry-certified tons of carbon removal in a single issuance — roughly seven times larger than any prior ERW credit delivery and enough, per industry coverage, to make Lithos the largest ERW developer by issued credits at that point. In March 2026, Lithos and Climeworks announced a deeper partnership to bring verified ERW credits to market.

Business model

B2B carbon removal supplier: Lithos coordinates basalt feedstock sourcing, delivery and application on partner farms (often free or subsidized for farmers), uses its ML/MRV platform to measure resulting CO2 removal, and sells the resulting verified carbon removal credits to corporate buyers and carbon-credit marketplaces/offtakers.

Sale of verified enhanced-rock-weathering carbon removal credits to corporations and carbon-credit purchasing coalitions (e.g., Frontier, Climeworks, Microsoft) under offtake/purchase agreements; farmers receive basalt application and soil benefits generally at no direct cost in exchange for participating in the carbon program.