Method comparison

Ex-post dynamic crediting vs legacy ex-ante methods

Compare CH₄mber's physics-based 3-phase trajectory model with BCarbon production decline, control group additionality, and ex-post verification against legacy OOG/OCP and CarbonPath methodologies that front-load credits before emissions occur.

CH₄mber Dynamic (Ex-Post)

38,596 tCO₂e

Peaks year 5 (3,799 tCO₂e). Issued annually after verification. Includes control group + buffers.

OOG / OCP (Ex-Ante)

49,940 tCO₂e

70% year 0, 30% year 1—all credits issued upfront. No additionality adjustment or annual verification.

CarbonPath (Ex-Ante)

215,260 tCO₂e

Instant lump-sum over 50-year window. No reservoir physics, no government plugging discount, no verification.

Adjust assumptions

Manipulate parameters to see real-time impact across methodologies.

Dynamic ramp & decline

Control plug probability2.0%

Ramp to peak (years)6

Decline rate (% / year)6.5%

Uncertainty discount0.0%

Post-plug residual CH₄ (t/yr)0.000

Use multiplicative survival? (Compounds remaining control wells each year)

Global adjustments

GWP basisProject emissions (tCO₂e)

BCarbon inputs (optional)

Month	Production (MCF/day)

Methane fractionLarge leak probability

Restricted leak probability auto-adjusted to 90.0%

Large leak horizon (years)Restricted leak horizon (years)Crediting cap (years)Baseline cap (tCO₂e)

Total issued credits: 51,754 tCO₂e (+13,158 vs base case)

Peak issuance: Year 6 with 3,714 tCO₂e.

First issuance occurs in 0 (base: 0).

Key Differentiators

Why ex-post dynamic crediting is more accurate

3-phase physics-based trajectory model
Credits peak in year 5 at 3,799 tCO₂e following degradation (exponential increase) → peak (capped by production max) → depletion (exponential decline). Legacy methods assume constant emissions or arbitrary ramp patterns.
Ex-post annual verification vs ex-ante speculation
Dynamic issuance totals 11,345 tCO₂e less than legacy methods' 49,940 tCO₂e. Credits issued only after annual verification confirms actual reductions. OOG/OCP front-load 70% in year 0, 30% in year 1—before emissions occur. Ex-post eliminates over-crediting risk.
Control group additionality + graduated buffer pools
Control group survival function withholds 64-80% of baseline over 20 years to account for government plugging probability. Separate buffer pools (9-13%, declining over time) address residual risks: physical reversal, monitoring fraud, matching error, and catastrophic events. CarbonPath's 215,260 tCO₂e instant grant includes no additionality adjustment—82.1% overestimate.

Compare methodology trajectories

Methodology comparison

Compare total credits, peak issuance timing, and active years across different crediting methodologies.

Methodology comparison matrix

CH₄mber integrates BCarbon production decline analysis, 3-phase emission trajectory modeling, annual ex-post verification, control group additionality (withholds 64-80%), and graduated buffer pools (9-13%, declining over time). Legacy ex-ante methods issue credits upfront based on static assumptions, with no reservoir physics, no annual verification, and minimal or no additionality adjustments—leading to systematic over-crediting.

Methodology versions compared:

OCP (2025) | CarbonPath v1.3 | CH₄mber Dynamic v2.0 (WIP)

Note: ACR VM0037 v1.0 was made inactive May 9, 2025. Comparisons reflect its historical approach.

Note on OCP vs. OOG:

The Open Carbon Protocol (OCP) is a framework for developing crediting methodologies. The OCP-approved methodology for orphaned wells (2025) evolves from earlier OOG Framework specifications. They are related but not identical. Comparisons below reflect the current OCP approved methodology.

Icon	Aspect	OOG / OCP	CarbonPath	Dynamic methodology
CP	Crediting period	Fixed 20-year period issued ex-ante (70% year 0, 30% year 1).	Fixed 50-year period with 100% of credits granted at project start.	Annual, ex-post issuance that winds down once emissions become de minimis or peers are plugged.
BA	Baseline assumption	Models exponential decline from measured baseline using terminal decline rates (4.9–7.3% annually), without an explicit infrastructure degradation phase.	Models measured current leak rate held constant for entire 50-year horizon, without degradation or depletion phases.	Measures current fugitive rate, models ramp-to-peak and decline, and adjusts for survival probability.
AD	Additionality check	Treats plugging by states/third parties as zero-probability during crediting period.	No annual adjustment for peer plugging; additionality assumed at issuance.	Baseline reduced annually by observed control-group plugging to enforce additionality.
IT	Issuance timing	Credits largely front-loaded to finance plugging, regardless of future emissions trajectory.	Single lump-sum issuance in year 0 covering decades of assumed leakage.	Credits issued each monitoring year after verifying avoided emissions and updated parameters.
RM	Risk management	Relies on registry buffer pools; no project-specific permanence checks.	Registry buffer plus optional insurance; no annual holdback tied to plug integrity.	Holdbacks or insurance released after leak tests confirm plug integrity (12–18 months).
BP	Buffer pools	No methodology-specific buffer. Credits deposited into registry buffer pool (e.g., ACR) after issuance.	No methodology-specific buffer. Relies on registry buffer pool after credits issued.	Graduated ex-post buffer (13% → 11% over 20 years) withholds credits for physical reversal, monitoring fraud, control group error, and catastrophic risks. Buffers released at years 3, 5, 10, 20 as project performance validates.