Helsinki-based carbon market infrastructure provider Puro.earth announced that Frontier, an advance market commitment to purchase $1.8 billion in permanent carbon removal, has formally approved its Enhanced Rock Weathering (ERW) 2025 methodology. This endorsement allows Frontier suppliers to utilize the updated framework to certify ERW credits for existing procurement commitments. The approval marks the second major methodology from Puro.earth to be accepted by Frontier, following the 2024 validation of its Geologically Stored Carbon framework, and builds upon Frontier’s 2025 designation of Puro.earth as a Leading Credit Issuer.

The decision addresses the ongoing challenge of establishing rigorous, accountable, and scientifically verifiable delivery standards across emerging engineered carbon dioxide removal (CDR) pathways. As the engineered CDR market attempts to transition into an institutional-grade asset class, verifying net carbon reductions faces persistent hurdles related to measurement uncertainty, carbon loss accounting, and unrefined sampling frameworks. Without a standardized, highly reliable quantification protocol that satisfies demanding procurement standards, institutional buyers face verification risks, while suppliers struggle to monetize high-quality CDR assets with full market confidence.

To overcome these accounting barriers, Puro.earth collaborated with experts from academia, industry, and the non-profit sector to develop its updated ERW 2025 methodology. The solution institutes stringent quantification requirements, specifically forcing suppliers to combine two independent measurement methods to achieve higher structural reliability. Furthermore, the updated protocol introduces clearer sampling mandates, refined accounting frameworks for tracking potential carbon losses, and a specialized framework to quantify and manage measurement uncertainty during the carbon storage cycle.

The validation of this methodology integrates ERW projects into the broader infrastructure of the engineered CDR market. By meeting Frontier’s rigorous procurement standards, Puro.earth expands its verified marketplace, which has already facilitated over 100 engineered CDR projects and issued more than 1.5 million CO₂ Removal Certificates (CORCs). Backed by Nasdaq’s majority ownership and eligibility under the Integrity Council for the Voluntary Carbon Market (ICVCM), the approved standard provides a scalable blueprint for verifying durable, long-term carbon storage of 100 to over 1,000 years.