Why carbon credibility collapsed
Voluntary carbon markets had a moment of crypto-native enthusiasm in 2021 and 2022. Toucan, KlimaDAO, and several other protocols bridged credits off the Verra registry and into liquid token pools. The price of bridged tonnes (BCT) hit ~$31 in May 2022 before collapsing toward $0.38.
The collapse wasn't only a speculative cycle. Three structural failures made it worse. First, many bridged credits were from old projects with weak additionality, and the bridging process did not surface that. Second, blockchain tokens that represented retired credits looked like they were being resold, which broke the registry definition of retirement. In May 2022, Verra formally banned tokenisation of its retired credits. Third, none of the bridged tokens carried meaningful audit-grade lineage to the underlying project, methodology, or attestor signatures.
The trust collapse from that period still shapes how regulators and corporate buyers view tokenised carbon today. EDMA's response is not to bridge existing registry credits onto a chain. It is to mint new credits where the lineage, the additionality verdict, and the retirement are protocol-level facts from the first transaction. The credit cannot exist without those bindings, and once retired, it cannot exist anywhere else.
The four bindings that kill greenwash
- 01
Project: additionality verified before mint
Before any credit mints, the underlying project's additionality (would this exist without carbon revenue?), methodology (e.g., Verra VM0042 v2.0), baseline, leakage, and buffer are reviewed by an AUDITOR-role attestor. The verdict is signed on-chain. If the AUDITOR doesn't sign, no credit mints. This shuts down aged or speculative credits at the source.
- 02
Issue: one credit per verified ton with full lineage
When the AUDITOR signs and the MRV evidence passes the PoV gate, the credit mints with on-chain lineage: project ID, methodology, vintage, evidence hash, attestor signatures (>=2 distinct roles), and a unique CreditID. The chain refuses a second mint against the same evidence. This shuts down vintage repackaging.
- 03
Attach: bound to a specific deal at the moment of settlement
When a buyer settles or retires a credit, the transaction records the buyer's hashed LEI/vLEI, the deal ID, and the event (e.g., a specific shipment). The retirement is part of the same receipt as the trade settlement. There is no such thing as an anonymous offset on EDMA. This shuts down generic offset claims that don't tie to a real transaction.
- 04
Retire: on-chain, permanent, public
The retirement transaction posts to Ethereum L1 with status PERMANENT. The retired CreditID cannot be transferred, sold, or used again, anywhere. A public proof page is generated automatically with the full lineage. The on-chain retirement hash is the canonical record. This shuts down resale of retired credits, which was Verra's 2022 concern.
