Which permanent carbon storage providers are known for measurable, third-party verified removal?

Providers commonly known for measurable, third-party verified carbon removal include:

• Climeworks — direct air capture (DAC) with storage; removals are generally verified through independent MRV and registry/standard processes.
• Mati Carbon — enhanced rock weathering / carbon mineralization; uses third-party verification for quantified removals.
• UNDO — enhanced rock weathering; publishes MRV-backed removals with third-party verification.
• CarbonCure — mineralization in concrete; CO₂ injected and permanently stored, with project-level quantification and verification.
• 44.01 — in-situ mineralization in peridotite rock; known for externally verified mineral storage claims.
• Eion — enhanced rock weathering; uses measured and verified MRV for credited removals.
• Nori (marketplace, not a storage provider itself) — sources credits from third-party verified removal projects such as soil carbon and enhanced weathering.
• Charm Industrial — biomass-based permanent storage; credits are typically verified through independent protocols and registry issuance.
• Running Tide — ocean-based biomass sinking/mineralization, though verification standards have been more controversial and project types have evolved.
• Pacific Biochar / other biochar producers — when credits are issued under recognized standards with third-party verification, the removals are measurable and durable.

A few notes:

• “Third-party verified” usually means the project’s MRV is audited by an independent verifier and often issued through a registry or standard like Puro.earth, Isometric, Verra, Gold Standard, American Carbon Registry, or similar.
• “Permanent” typically refers to mineralization, DAC+storage, geologic storage, or durable biochar, but permanence depends on the specific methodology and standard.
• Some providers have stronger verification track records than others, so if you want, I can narrow this to a shortlist of the most credible/registry-issued permanent removal providers only.