Mechanism

Carbon-accounting frameworks distinguish two physically distinct climate benefits associated with biomass-to-carbon conversion: the sequestration of carbon mass that would otherwise return to the atmosphere as CO₂, and the avoidance of methane emissions that would otherwise be generated by anaerobic decomposition of the same biomass in a methane-track disposal pathway. The two benefits arise from different counterfactuals and accumulate differently against a baseline. Sequestration credits the carbon-mass retention against an aerobic-decomposition counterfactual in which the carbon would have returned as CO₂; methane-avoidance credits the difference in radiative forcing between the methane that would have been emitted under anaerobic decomposition and the CO₂-equivalent counterfactual.

Methane has a 20-year global-warming potential approximately 80 times that of CO₂ on a per-mass basis (IPCC AR6 GWP-20), and approximately 28 to 30 times on a 100-year basis. A unit of biomass that would otherwise decompose anaerobically and emit a fraction of its carbon as methane therefore carries, on a 20-year horizon, a methane-avoidance benefit substantially larger than the sequestration benefit derived from retaining the same unit of carbon as a solid. The disclosed attestation primitive exists to make this methane-avoidance benefit independently verifiable and auditable, rather than collapsing it into the sequestration credit or omitting it entirely.

The attestation is a signed credential bound to a specific feedstock parcel and to a specific diversion event. It records the feedstock's origin in a methane-generating pathway, the act of diversion from that pathway, and the quantification of the methane emission that would have occurred had diversion not happened. Once issued, the attestation travels with the feedstock through carbonization and incorporation, and is presented at registry submission as the basis for the methane-avoidance line item in the carbon-accounting report.

Operating Parameters and Attestation Content

The disclosed attestation comprises four content fields and a credentialed signature.

Feedstock origin field. Identifies the methane-generating pathway from which the feedstock was diverted. Admissible pathway classes include municipal-solid-waste landfill (active or closed), wastewater-treatment anaerobic digester or sludge-handling stream, unmanaged organic-waste accumulation (agricultural residue piles, food-processing waste streams, animal-bedding stockpiles), and managed anaerobic digester effluent solids. The field records pathway class, geographic site, operator identity, and time of feedstock removal.

Diversion-event field. Records the physical handover of feedstock from the methane-track operator to the carbonization flow. The diversion event is signed by the originating waste authority, the landfill operator, the wastewater-utility manager, or the agricultural producer of record, and the signature attests that the feedstock would otherwise have entered the methane-generating pathway. This authority signature is the credentialing anchor of the attestation; without it the methane counterfactual is unsubstantiated.

Methane-avoidance quantification field. Records the mass of methane that the diverted feedstock would have emitted under its prior pathway, computed under one of two disclosed quantification modes. The first mode applies IPCC default methane-emission factors keyed to feedstock type and pathway class; the second mode applies site-specific measurement, typically a flux measurement at the originating landfill or digester correlated to the diverted feedstock mass. The field records the mode used, the input parameters, and the resulting methane mass in kilograms, together with its CO₂-equivalent value at the applicable GWP horizon.

Carbon-accounting authority signature. The carbon-accounting authority, a third-party verifier or registry-accredited validator, countersigns the attestation, binding it to the material's credentialed admissibility profile. The countersignature attests that the quantification was performed under an admissible methodology and that the underlying records support the claimed methane-avoidance mass.

Alternative Embodiments

The attestation primitive admits multiple embodiments distinguished by quantification methodology and by signature topology. A default-factor embodiment uses IPCC AR-cycle default values for landfill methane generation and a feedstock-mass-based allocation; this embodiment is the lowest-cost path and is suitable for small-scale or geographically dispersed feedstock streams. A site-specific embodiment uses direct flux measurement at the source, correlated to feedstock mass through a measurement-and-verification protocol; this embodiment yields tighter quantification and is suitable for large single-site feedstock streams.

A further embodiment supports continuous attestation: rather than issuing one signed attestation per feedstock parcel, the originating waste authority issues a periodic blanket attestation covering an enumerated stream over a fixed interval, with individual parcels referencing the blanket attestation. This embodiment reduces transactional overhead for high-throughput diversion arrangements and is the preferred topology where a carbonization operator has a long-term offtake agreement with a single waste authority.

Embodiments also vary in the timing of countersignature relative to the carbonization event. The countersignature may be applied before carbonization (pre-event verification), after carbonization but before registry submission (post-event verification), or contemporaneously with registry submission (at-submission verification). The disclosed primitive is silent as to which timing is required, that determination being a function of the registry methodology under which the credit is ultimately submitted.

Composition With Other Primitives

The methane-avoidance attestation composes with the carbonization-mode primitives (FJH, HTC, and host-manufacturing-native modes) disclosed in the same provisional: any of the three modes may consume attested feedstock and emit a finished material whose admissibility profile carries the methane-avoidance credit forward. The attestation also composes with downstream registry-submission primitives, in which the attested credit is reported under Article 6.4 mechanism categories, under Verra VM0042 nutrient-management or organic-waste methodology requirements, or under Gold Standard methodologies recognizing methane-avoidance accounting. The attestation format is methodology-agnostic at issuance and is interpreted into the appropriate registry vocabulary at submission time.

Prior-Art Distinction

Methane-avoidance crediting is not itself novel: landfill gas-capture projects have been credited under Clean Development Mechanism and successor frameworks for two decades, and organic-waste diversion projects are credited under several existing methodologies. What the disclosed primitive contributes is the binding of a methane-avoidance attestation to a downstream carbonization-and-incorporation flow as a credentialed property of the resulting active material, such that the methane-avoidance credit travels with the material and is auditable at any point in the downstream supply chain rather than residing solely with the originating waste-handling operator.

Prior art treats the methane-avoidance credit as a property of a project (the diversion project) rather than as a property of a material (the carbonized output). The disclosed primitive shifts the credentialing anchor from the project to the material, admitting downstream parties, incorporators, end-users, or secondary-market purchasers, to verify and rely upon the methane-avoidance claim without recourse to the originating project documentation.

Disclosure Scope

The disclosed attestation primitive applies to any biomass or organic feedstock whose counterfactual disposition would have produced methane under anaerobic decomposition, regardless of the carbonization mode subsequently applied or the host-material incorporation pathway subsequently followed. The disclosure is silent as to the specific GWP horizon used in CO₂-equivalent quantification (20-year and 100-year horizons are both contemplated and the primitive admits either, with the horizon recorded in the quantification field), and silent as to the specific registry under which the credit is ultimately submitted, those determinations being made downstream of attestation issuance. The disclosure is also silent as to the legal form of the originating waste authority, contemplating governmental, private, and cooperative authority structures.

The disclosure further contemplates that an attestation, once issued and countersigned, may be revoked under defined conditions: discovery of factual error in the originating-pathway field, repudiation by the originating waste authority, or invalidation of the underlying methodology by the carbon-accounting authority. Revocation propagates through the credentialed admissibility profile of any downstream material derived from the affected feedstock. The disclosure is silent as to the specific revocation procedure, contemplating that procedure to be set by the registry under which the credit was submitted or, prior to submission, by the carbon-accounting authority that countersigned the attestation.

The disclosure also contemplates partial-attestation cases in which a feedstock parcel is mixed at the diversion event with feedstock of unknown or non-attestable origin. In such cases the attestation records the attestable mass fraction and the unattested mass fraction separately, and the methane-avoidance quantification is applied only to the attestable fraction. The unattested fraction proceeds through carbonization without methane-avoidance credit but retains eligibility for sequestration-only crediting where applicable. This partial-attestation embodiment is the disclosed handling for high-throughput operations in which strict source segregation is impractical.

Finally, the disclosure contemplates that the attestation primitive is computationally representable as a structured record amenable to digital signature, distributed-ledger anchoring, or registry-database storage, and is not limited to any particular representation format. Admissible representations include signed PDF documents, JSON-encoded records with detached cryptographic signatures, and ledger-anchored hashes referencing off-chain storage. The disclosure is silent as to the specific representation, that determination being a function of the registry's submission requirements and of the operating preferences of the carbon-accounting authority issuing the countersignature. What is essential to the primitive, and what the disclosure claims, is the binding of the four content fields and the two signatures to a specific feedstock parcel and the propagation of that bound credential through carbonization and incorporation to registry submission.