QET-CCS: Registry-Grade Carbon Storage Certificates for Residual Neutralization

For corporate sustainability programs in hard-to-abate sectors — cement, steel, aviation, chemicals, refining — for SBTi pathway holders approaching their long-term target year, for ESG teams structuring the residual-emissions budget, and for CCS project developers monetizing verified storage attributes, QET-CCS is the registry-grade environmental-attribute certificate engineered for the neutralization step of a credible net-zero pathway. Each token represents 1 tonne of CO₂ captured and durably stored in geologic formations, with the verified storage-pathway and permanence attributes that survive ISO 14064-3 reasonable-assurance review and the disclosure cycles a 2026+ corporate program now operates under. This page is the buyer's view of the product — what it is, who it's for, how it fits the abatement-first pathway, and what makes it defensible in the assurance environment that's hardening every year.

QET-CCS, in one paragraph. QET-CCS is Greentruth's tokenized carbon storage certificate — each token represents 1 tonne of CO₂ captured and durably stored in qualifying geologic formations, with verified storage pathway and permanence attributes anchored under ISO 14064-3 reasonable-assurance verification on the EarnDLT blockchain registry (Hedera Hashgraph). Engineered for the residual-neutralization step of a SBTi Corporate Net-Zero Standard pathway — the ≤10% of baseline emissions that cannot be eliminated through reduction or abatement at the long-term target year. Single-mint enforcement at the registry layer (one tonne of stored CO₂ produces exactly one token); irrevocable on-chain retirement; framework-aligned exports for GHG Protocol Land Sector & Removals Guidance, CSRD ESRS E1, IFRS S2, SB 253, TCR.

For the QET-CCS methodology in detail

For the net-zero pathway context

If you arrived from a Core Concept methodology read, the methodology sibling explains exactly how the product works mechanically. This page is the buyer-side view of why it exists, what procurement problem it solves, and how a corporate residual-neutralization budget actually consumes it.

Three properties define the product for a buyer:

• One tonne, durably stored, audit-defensible. Each token represents 1 tonne of CO₂ captured and stored in qualifying geologic formations (saline aquifers, depleted oil and gas reservoirs, basalt and ultramafic formations with mineral trapping). The storage pathway is verified, the permanence attributes are documented, and the verifier's ISO 14064-3 reasonable-assurance opinion sits on-chain alongside the certificate.
• Built for the residual, not the abatement substitute. The instrument is structured around the neutralization role in the mitigation hierarchy. It is not a way to avoid operational decarbonization; it is the certificate that closes the residual ≤10% at the long-term target year of a SBTi Corporate Net-Zero Standard pathway. This positioning matters because the major frameworks now explicitly disallow substituting cheap neutralization for the abatement that should have happened upstream.
• Procurement-ready as a registry-grade EAC. Acquisition, transfer, and retirement run through the same EarnDLT registry every other QET class does, with the same Machine-Ready API surface, the same framework-aligned exports at retirement, and the same buyer wallet and disclosure-cycle integration. Your team doesn't operate a parallel CCS-only workflow; the carbon storage certificate surfaces in the unified cross-token Marketplace inventory.

For the marketplace lifecycle context

For the carbon dioxide removal Core Concept

For corporate sustainability programs

For SBTi alignment in full

The integrity argument is the sequence. A company that has actually executed Phases 1–3 and reaches a real residual at the target year, then closes that residual with verified geologic-storage retirements, has a defensible net-zero claim. A company that skips operational abatement and substitutes neutralization upstream of residuals does not — and increasingly cannot — defend that claim under SBTi CNZS, GHG Protocol guidance, or CSRD ESRS E1 disclosure review.

The product is built to support the correct role in that sequence. It is not positioned, sold, or documented as an offset substitute for the abatement that should have happened.

SBTi Corporate Net-Zero Standard

GHG Protocol Land Sector and Removals Guidance

For corporate buyers and the verifiers and auditors who eventually review their retirements, the integrity of a QET-CCS retirement record depends on three structural properties operating together.

• ISO 14064-3 reasonable-assurance verification. Every mint requires an unmodified verification opinion under ISO 14064-3:2019 at reasonable-assurance level — the higher of the two assurance levels in the standard. The verifier must be accredited to ISO 14065:2020 by an acceptable accreditation body (ANAB, UKAS, DAkkS, INMETRO, or another International Accreditation Forum signatory), with sector-specific scope covering geologic storage and CCS measurement, monitoring, and verification (MMV). Limited assurance is not sufficient for issuance; reasonable assurance is the operative bar.
• Single-mint enforcement at the registry layer. One tonne of stored CO₂ produces exactly one token. The Hedera-anchored registry structurally rejects any attempt to issue a second token for the same physical tonne — double-counting prevention operating at the infrastructure level, not the policy level. Migration in or out requires permanent cancellation in the prior registry first.
• Irrevocable on-chain retirement. When a buyer retires the certificate against a neutralization claim, the closing event is irrevocable. The Hedera state machine writes the token's status to RETIRED and rejects any subsequent attempt to un-retire, re-trade, or re-use it. The retirement record is permanent, queryable on the registry, and traceable back through every transfer to the original mint and the verifier's reasonable-assurance opinion.

How ISO 14064-3 underpins the platform

How double counting is structurally prevented

What's on each certificate, beyond the basic one-tonne attribution, is what makes the instrument defensible against the kind of CCS scrutiny that has hardened across the major frameworks. The storage-pathway and permanence attributes recorded immutably on the token:

• Storage formation type. Saline aquifer, depleted oil and gas reservoir, basalt or ultramafic mineralization site, with formation depth and seal characterization where applicable.
• Storage operator and project identifier. The legal entity operating the geologic storage facility, the regulatory permit reference (US Class VI under SDWA, EU Storage Directive permit, or analogous national permit), and the site's MMV program cadence.
• Storage timestamp and reporting period. The date range during which the tonne was captured and stored, with the verifier's opinion covering that reporting period.
• Permanence framework reference. The permanence framework the operator commits to (long-duration MMV, post-injection site care, financial assurance for liability transfer where applicable), with explicit pointers to the permit's permanence obligations.
• Verifier of record. The accredited ISO 14065:2020 verifier whose reasonable-assurance opinion underwrote the mint — lead verifier credentials, opinion date, and materiality threshold.

For corporate buyers, the retirement record carries the documentation an auditor would otherwise assemble by hand — storage permit, MMV reports, verifier opinion, permanence framework — into a single machine-readable artifact that flows directly into the disclosure cycle.

IEA CCUS hub

For the retirement step in detail

A retirement does not produce one disclosure output — it produces the framework-aligned exports the buyer's program needs across every reporting regime simultaneously. The same retirement event populates the relevant lines in:

• SBTi Corporate Net-Zero Standard (CNZS V1.3; V2.0 in consultation). The framework expects residual neutralization at the long-term target year to be backed by high-integrity CDR. Retirement records carry the methodology, verification, and permanence attributes the framework anticipates, with the V2.0 trajectory designed to be additive rather than disruptive.
• GHG Protocol Land Sector & Removals Guidance (LS&R). The Protocol's CDR treatment under LS&R requires structured documentation of the removal pathway, the storage durability assessment, and the verification chain. Retirements produce the LS&R-aligned export directly.
• CSRD ESRS E1. The EU corporate disclosure standard for climate change requires structured transition-plan disclosure including residual treatment. A retirement populates the ESRS E1 payload with the underlying methodology and verifier opinion.
• IFRS S2 climate-related disclosures. The standard's assurance trajectory expects reasonable-assurance documentation for material climate disclosures. ISO 14064-3 reasonable-assurance verification underlying the closing event satisfies that bar.
• California SB 253 and TCR. Both regimes accept QET-backed disclosures, with the retirement record serving as supporting evidence at the elevated assurance tiers their phased schedules require.

A single retirement produces framework-aligned outputs across all of these at the same transaction. The buyer runs one workflow with framework-specific exports flowing into the relevant ESG software (Watershed, Persefoni, Sweep, Workiva, or in-house GHG accounting) via webhook through the Machine-Ready API.

For cross-framework alignment in detail

For the Machine-Ready API surface

The regulatory environment for CCS has matured substantially. Three regimes shape the documentation landscape.

• US 45Q tax credit framework. The federal 45Q credit (as amended through the IRA and subsequent guidance) provides per-tonne credits for secure geologic storage, with values varying by capture source and storage class. Class VI wells under the Safe Drinking Water Act regulate dedicated geologic-storage injection; Class II wells govern enhanced oil recovery (EOR) storage with distinct permanence considerations. Mints anchored to Class VI projects align cleanly to dedicated-storage 45Q claims; qualifying Class II EOR mints carry the appropriate framework metadata.
• EU CCUS Strategy and Net-Zero Industry Act provisions. The EU's CCUS Strategy, paired with the Net-Zero Industry Act and the EU Storage Directive, sets operational requirements for geologic storage in member states and establishes injection-capacity targets. Operators serving EU industrial offtakers produce documentation satisfying both the EU Storage Directive permit conditions and customer-side CSRD ESRS E1 disclosure expectations.
• ISO 27914 and analogous geologic-storage standards. ISO 27914 (the international standard for geologic CO₂ storage) and analogous national standards provide the technical framework operators design MMV programs against. Reasonable-assurance verification incorporates ISO 27914-aligned site characterization, monitoring, and risk-assessment expectations where applicable.

A single QET-CCS retirement produces documentation aligned to the regulatory regime the underlying storage actually operates under, with the regime metadata recorded on the token at mint so downstream consumers can reason about framework provenance directly.

The cross-token integration is what lets a corporate program run a single procurement workflow across the full mitigation hierarchy — Phase 2 reduction, Phase 3 abatement, Phase 4 neutralization — without operating parallel verification stacks, registries, or disclosure cycles. Every retirement, regardless of token class, produces the same framework-aligned exports and flows through the same Machine-Ready API.

For the foundational platform context