GHG quantification
General principles and requirements
RCCs shall be calculated for each credit issuance by subtracting the GHG emissions and removals of the project scenario from the emissions and removals of a baseline scenario, representing the product or practices that would have occurred without the implementation of the project. Quantification of GHG emissions for the baseline and project scenarios shall follow .
One RCC is issued per one tonne of CO equivalent avoided or removed by the project, compared to the baseline.
Project quantification of emissions and removals shall follow the instructions outlined in the relevant methodology. These quantifications shall adhere to the following principles:
Science-based: Use sound scientific methods, backed up by reputable sources.
Complete: Use a life-cycle approach, and a wide enough scope to encompass all GHG sources, sinks and reservoirs that are materially affected by the mitigation activity.
Transparent: Reproducible using the information provided in the project documentation and the methodologies. All necessary data and calculations shall be made publicly available to ensure transparency and allow for independent verification.
Accurate: Based on project-specific data as much as possible where relevant. The number of RCCs issued shall be as close as possible to the actual number of GHGs reduced/removed.
Conservative: Ensure that RCC issuance is not overestimated, and when faced with uncertainty, choose approaches that systematically underestimate GHG reductions/removals.
Project system boundary
The project system boundary shall include:
all processes under direct control of the project,
the key upstream and downstream processes,
indirect processes, such as activity shifting, identified in the leakage assessment, and
other processes that differ between the project and baseline, as a result of the project mitigation activity.
Due to the comparative measurement approach, processes that are identical in the project and baseline scenario may be excluded, since they will not affect the comparative results.
Processes to consider shall include but are not limited to raw material extraction, delivery of supplies, processing, manufacturing, distribution, use, retail, distribution, and waste treatment.
Processes with the lowest contributions to impacts, which each account for less than 1% of total impacts, may be excluded from the GHG quantification, up until the cumulative excluded processes exceed :
2% of total induced emissions for avoidance credit calculation and
2% of gross removals for removals credit calculation.
These processes shall be transparently identified and justified.
Methodologies may define the minimum processes to include in the project system boundary, and additional processes may be included where relevant for a given project. The project system boundary shall be transparently described in the project documentation and accompanying methodology.
Baseline system boundary
The baseline system boundary shall represent the processes and activities defined in the Baseline scope. Baselines shall be realistic, defensible, and conservative baseline estimations of emissions.
The baseline system boundary shall include the set of processes that are functionally equivalent to all products and services delivered in the project scenario.
The baseline system boundary shall be transparently described in the project documentation and accompanying methodology. Further details for defining the baseline are included in the Baseline scope section.
Input data
GHG quantification shall be based on verifiable primary data from project operations as much as possible. Project's primary data must be based on ongoing representative measurements, or recent conditions.
All secondary/background data (for example, emission factors, rates of recycling, composition of national electricity grid) shall be derived from traceable, transparent, unbiased, and reputable sources.
All assumptions and estimates shall be conservative, transparently presented and justified, in the methodology and/or in the project documentation
For geographic accuracy and consistency across projects, national-level background data should be prioritized. Local (region, state, city-scale) or global sources may be used if justified.
Methodologies shall define the project-specific input data needed, and any information that is set at the methodology level, such as common assumptions or background data.
Uncertainty assessment
All GHG quantifications and credit issuances shall include an uncertainty assessment, that:
evaluates the uncertainty of key elements of the GHG quantification,
manages uncertainties in a conservative manner, and
reports the uncertainties in publicly available documentation.
An uncertainty assessment must be conducted and documented at the methodology level for all aspects of GHG quantification set there. The findings from this assessment are then applied at the project level, where project-specific GHG quantification also undergoes an uncertainty assessment.
The overall project GHG quantification uncertainty is determined by qualitatively combining both the methodology-level and project-specific uncertainties for each identified source of uncertainty.
Evaluating uncertainty
The following GHG quantification elements shall be included in uncertainty assessments:
assumptions
selection of the baseline scenario
measurements
equations and models
estimates or secondary data used
Managing uncertainty
The degree of uncertainty shall inform the degree of conservativeness to take. Elements with higher uncertainty shall adopt a more conservative approach. The significance and sensitivity shall also be accounted for, where more significant and sensitive elements should be treated more conservatively.
Uncertainty shall be addressed by taking a conservative approach in at least one of the following ways:
Quantitative approach: where possible, a statistical approach (e.g. confidence intervals and standard deviations) should be used to quantify uncertainty, and to select conservative values.
Qualitative approach: where a quantitative approach is not possible, a qualitative approach based on informed judgement may be used to assess uncertainty and make a conservative choice.
Discount factor: after applying quantitative and qualitative approaches to manage uncertainty, any untreated sources of uncertainty shall be managed by applying a discount factor to the final GHG quantification. This represents a percent of credits that will not be issued in order to avoid overestimating GHG reductions and/or removals.
Discount factor
Methodologies shall establish a minimum discount factor for all projects certified under them. This factor shall reflect all unmanaged sources of uncertainty, their impact on quantification, and any conservative measures already applied to mitigate uncertainty. Complemented by a project-specific uncertainty assessment, a higher factor may be applied for any given project.
Discount factors shall be determined by qualitatively scoring the uncertainty of each source as none, low, medium, high or very high, after accounting for conservative approaches. The for outcome probability should be used for assessing the uncertainty of each element, as presented in the "Assigning uncertainty level" column of the table below.
By combining these individual uncertainty scores at both the project and methodology levels, an overall project uncertainty score is determined. This score can then be translated into a discount factor using the following criteria:
None
>99% of being accurate, it is virtually certain
—
Low
90-99% chance of the quantification element being accurate
3%
Medium
66-90% chance of being accurate
6%
High
50-66% chance of being accurate, more likely than not
9% or higher
Very high
<50% chance of being accurate
15%, ineligible
If the overall project uncertainty score is rated "Very high", and/or the project requires a >15% uncertainty discount factor, then the uncertainty is considered too high and the project is not eligible.
Global Warming Potentials
GHG emissions and reductions shall be calculated by default using the following IPCC Global Warming Potential values for a 100 year horizon (GWP100) according to . The GWPs for the main greenhouse gasses are summarized below, and the full list of GWPs can be found in the .
Alternative GWP100 values from other IPCC versions may be used by projects in order to comply with other accreditations (e.g. CRCF).
The source of GWP100 values shall be reported in the PDD.
CO2
1
CH4 fossil
29.8
CH4 biogenic
27
N2O
273
HFC-32
771
HFC-134a
1526
CFC-11
6226
PFC-14
7380
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