Frontier, the advance market coalition backed by Stripe, Google, and JPMorgan Chase, has approved Puro.earth's updated 2025 Enhanced Rock Weathering (ERW) methodology. This means suppliers can now use the Puro.earth framework to certify ERW carbon removal credits as part of Frontier's purchase commitments. It is the second Puro.earth methodology to get Frontier's nod, following the Geologically Stored Carbon methodology approved in 2024. The 2025 ERW methodology requires suppliers to combine two independent measurement methods for more accurate quantification. It also includes clearer sampling rules, better accounting for CO2 losses, and a framework for handling measurement uncertainty. Puro.earth developed the update with input from academic and industry experts to tighten the rigor around verifying that rock weathering actually removed carbon from the atmosphere. Frontier's $1.8 billion advance market commitment runs from 2022 to 2040 and aims to buy permanent carbon removal. This approval signals that the ERW methodology meets Frontier's procurement standards. For the broader carbon removal market, it provides a clearer pathway for ERW projects to sell credits to major corporate buyers, which could help scale the technology.
