Google has signed its largest carbon-removal contract to date with enhanced-rock-weathering (ERW) firm Terradot.

The deal will see Google purchase one million tons of near-term methane impact by 2030 and one million tons of carbon removal impact by 2040.

Terradot will deliver the removal credits from its megaton-scale climate project in Southern Brazil, which pairs methane avoidance in rice farming with permanent carbon dioxide removal (CDR). The project, conducted in partnership with Google, spans more than 200,000 hectares of rice farmland in Rio Grande do Sul.

As part of the project, Google is also providing an R&D grant to both Terradot and Stanford Doerr School’s Soil & Environmental Biogeochemistry Lab.

"For years, climate action has been framed as a choice: either move fast on the warming happening now or remove carbon permanently. Our project with Google eliminates that trade-off," said James Kanoff, CEO of Terradot. "We are pairing two proven technologies and deploying them together at a massive scale. With this new model, every tonne of removal meets the same rigorous standard, and delivers climate impact faster than ever."

ERW works by speeding up the natural process of carbon removal when rainwater interacts with silicate rocks. This is done by crushing tons of silicate rocks into a powder and spreading it onto farmland to accelerate rock dissolution rates. Subsequently, when it rains, the rocks react, generating alkalinity, which pulls CO2 out of the atmosphere and into water as a bicarbonate byproduct.

The deal is the company’s second with Google. In 2024, the firms signed a 200,000-ton removal deal, with credits expected to be delivered in the early 2030s.

"We built this agreement to be a template, not a one-off,” said Randy Spock, head of carbon removal at Google. “It's the largest carbon removal purchase Google has ever made, and by incorporating action on superpollutants, we realize that impact by 2030. We think it provides a replicable path to making a real dent in climate change in both the near and long term, and we’ve structured it so any buyer, supplier, or government can follow this same approach."

In addition to Google, Terradot has also signed a 12,000-ton removal agreement with Microsoft, and a $33 million agreement with the carbon buying consortium Frontier, which counts Alphabet and Meta as founding members. The Frontier deal will see its buyers secure the removal of 78,707 tons of CO2 between 2027 and 2030.

Earlier this year, the company acquired ERW competitor Eion. The acquisition will include all of the company's key assets, including its commitment to deliver 8,000 tons of carbon removal credits to Microsoft under a deal signed in 2024.