Since 1 January 2026, every tonne of steel entering the EU carries a carbon price.
The proof of how clean that steel is still travels by email. CarbonPass turns it into a verified carbon passport that can't be counted twice.
+10% mark-up on top in 2026
fictional demo entity · EAF mill, 2026-07
−86% embedded emissions on the declaration. About €46,720 less in CBAM certificates for one month's output this year.
Double counting: impossible.
Enforced by the contract, not by a promise. 10,000 verified tonnes are minted once. Ship them to two importers and the batch is empty.
Clean steel shouldn't pay for dirty defaults.
Drop in a mill's invoices, let AI extract the numbers, sign as an accredited verifier, mint, ship, and try to sell the same tonnes twice. Live on the Sepolia testnet.
Fictional demo entities · public testnet · IEEE ClimateChain Hackathon 2026
Every number here is read from the contract.
Batches are minted by the demo flow on a public testnet, across all products (hot-rolled steel and its pig-iron precursor). Run it yourself, or open a passport.
A clean mill is priced like a dirty one, and its proof can be sold twice.
Unverified data costs more
Without verified actual emissions, importers must use EU default values plus a mark-up. A clean mill gets priced like a dirty one, so there's no reward for cutting emissions.
Double counting
Nothing stops the same verified low-carbon tonnes being promised to two buyers, a period certified twice, or one report reused across declarations.
Evidence travels by email
Importers can't tell if a file is the version the verifier approved, or if the verifier is accredited at all. SMEs can't afford consultants.
From an invoice to a burned certificate, in five signed steps.
- 01Producer
Evidence in, numbers out
Invoices and production logs are read by an AI model (Gemini). Every quantity is cited to its page and confirmed by a human.
AI - 02Producer
CBAM intensity, checked
A fixed calculator applies the CBAM method. Robust statistics flag values that don't match the plant's own history.
Calculation + checks - 03Verifier
Accredited sign-off
An on-chain-registered verifier signs with ECDSA and ML-DSA-65 (NIST FIPS 204). Only salted Merkle roots go on-chain.
Post-quantum signature - 04Producer → Importers
Tonnes that can't be sold twice
Verified tonnes are minted once (ERC-1155). Shipping more than exists reverts. Certified periods can't overlap.
Smart contract - 05Importer
Surrendered, never reused
When the CBAM declaration is filed, tonnes are burned. The public passport shows the trail and the € saved.
Burn on declaration
Because the core risk is a double-spend.
The AI suggests and explains; it never writes to the chain. The chain guarantees what humans signed, when, and that verified tonnes are conserved. It doesn't make a meter reading true, which is why an accredited verifier and anomaly checks sit in front of it.
Producer, verifier and importer sit in TR / IN / EU
No neutral database operator exists across borders
The core risk is the same verified tonnes claimed twice
That is the double-spend problem ledgers solve
Verifier sign-offs must be undeniable for years
Public, timestamped, post-quantum attestations
Plant data is commercially sensitive
Only salted commitments on-chain; selective disclosure
Run the whole border, end to end.
Prototype on a public testnet. Companies, installations and verifiers are fictional demo entities. Emission factors and default values are illustrative (see data/factors.json).