PCS MD 011 Methodology Development Standard_v1.0

Document Control

Document identification

• Document code: PCS-MD-011

• Title: Methodology Development Standard

• Scope: Defines the rules and procedures for developing, reviewing, approving, revising, and retiring PCS methodologies, including required structure, conservativeness, uncertainty treatment, data rules, transparency requirements, and versioning/sunset procedures.

• Outcome: Establishes the binding governance and quality bar for methodologies used under PCS.

Version history and change log

Table DC-1. Revision history

Version	Date	Status	Summary of changes	Prepared by	Approved by
v1.0	TBD	Draft	Initial release for review	PCS Secretariat	TBD

Superseded versions

No superseded versions for v1.0.

Governance note on versioning and archiving

Only the latest approved version of this Standard shall be used. Superseded versions shall be archived and retained for traceability and audit purposes, consistent with PCS governance rules.

Chapter 1 – Introduction

1.1 Purpose

1. The PCS Methodology Development Standard establishes the rules and procedures governing how methodologies are designed, evaluated, and applied within the Planetary Carbon Standard (PCS). The Standard ensures that every methodology used under PCS produces mitigation outcomes that are real, quantifiable, additional, conservative, and verifiable. It creates a uniform framework for determining baselines, demonstrating additionality, quantifying emission reductions or removals, and monitoring project performance. By defining these principles, PCS ensures that methodologies operate consistently across technologies, geographies, and project types.

1.2 Role of Methodologies in PCS

1. Methodologies are the foundation of environmental integrity within PCS. Each methodology provides a standardized approach for identifying eligible activities, determining the baseline scenario, setting monitoring parameters, identifying leakage, and calculating mitigation outcomes. Without such standardization, quantification would become inconsistent and unverifiable. This Standard therefore ensures that methodologies reflect scientific good practice, use credible data sources, and remain transparent to all users.

1.3 Alignment With Global Frameworks

1. The PCS methodology framework aligns with the scientific and regulatory expectations established under international climate agreements and recognized technical bodies. This includes the methodological logic of the IPCC Guidelines for National Greenhouse Gas Inventories, the quantification rules and guidance developed under UNFCCC Article 6 and the Clean Development Mechanism, the quality criteria articulated by the Integrity Council for the Voluntary Carbon Market, and the verification and accounting principles embedded in ISO 14064 standards. This alignment ensures that PCS methodologies maintain global credibility, comparability, and acceptance across markets.

1.4 Foundation Principles for Methodology Development

1. The development of any PCS methodology is guided by a set of fundamental principles. These principles ensure that methodologies serve the broader goals of environmental integrity and program consistency rather than the interests of any specific project or sector. They include the need for methodological transparency, scientific rigor, conservativeness, practical applicability, consistency with PCS standards, and feasibility of monitoring.

2. Assumptions must be disclosed clearly, data sources must be traceable, and methodological steps must be replicable by independent actors.

3. The overarching objective is that methodologies err on the side of underestimating, rather than overstating, mitigation outcomes.

4. To capture these principles concisely, Table 1-A summarizes the criteria that inform methodology formulation and review.

Table 1-A: Core Principles Underpinning PCS Methodology Development

Principle	Definition
Environmental integrity	Mitigation outcomes must reflect real and measurable GHG reductions or removals.
Conservativeness	Assumptions and default values must avoid overstating project benefits.
Transparency	All methodological elements must be documented and open to scrutiny.
Consistency	Methods must align with PCS rules and recognized scientific guidance.
Practical feasibility	Monitoring and data requirements must be achievable in practice.
Robustness	Methods must remain valid across different contexts and through time.
Additionality	Emission reductions must be beyond business-as-usual and legal requirements.

1.5 Scope of Application

1. This Standard applies to all methodologies developed for use under PCS. It governs methodologies prepared by the PCS Secretariat, by external organizations seeking PCS approval, by project developers proposing new methodological approaches, and by sector-specific working groups convened by PCS.

2. It also applies to revisions, updates, and superseding versions of existing methodologies.

3. The Standard complements, and does not replace, other PCS requirements such as the Project Standard, Validation & Verification Standard, and the PCS Digital Monitoring guidelines, all of which influence how methodologies are applied in practice.

1.6 Governance of Methodology Development

1. Methodology development and approval follow a structured governance process overseen by the PCS Methodology Panel, a technical advisory group supported by independent experts, sector specialists, and the PCS Secretariat. The governance system ensures that methodologies undergo rigorous technical review, public consultation where appropriate, and a transparent approval process.

2. Final approval rests with the PCS Secretariat, which evaluates whether the methodology meets PCS environmental integrity requirements and aligns with the broader program architecture, including registry processes and digital MRV protocols.

1.7 Versioning, Revision, and Sunset Procedures

1. PCS methodologies evolve over time as science, technology, and policy advance. This Standard establishes the procedures for initiating and reviewing methodological updates, assigning new version numbers, and retiring outdated methods.

2. Revisions may be minor (clarifications), moderate (adjustments that do not change crediting outcomes materially), or major (fundamental modifications).

3. PCS may apply transition periods, allowing projects to continue using an earlier version for a defined timeframe, unless the earlier version is found to compromise environmental integrity.

4. Sunset clauses may be applied where methodologies become obsolete or materially inconsistent with scientific understanding.

1.8 Integration With Digital Monitoring and the PCS Registry

1. PCS methodologies operate in a digital environment supported by tamper-evident data systems and a blockchain-anchored registry. Consequently, methodologies must specify digital monitoring expectations where applicable, reference standardized data structures, and describe how parameters interact with PCS registry versioning and audit trails. This ensures transparency, improves replicability, and strengthens verification procedures.

1.9 Transparency and Public Access

1. All approved PCS methodologies, including their version history, are published in the PCS Methodology Library.

2. Publication includes all formulas, applicability conditions, parameter tables, monitoring requirements, and revision notes.

3. This level of transparency enables independent scrutiny, facilitates consistent implementation, and supports stakeholder confidence in the PCS system.

1.10 Summary

1. This introductory chapter defines the purpose, scope, and foundational principles of the PCS Methodology Development Standard.

2. The chapters that follow outline the detailed requirements that methodologies must meet, including baseline setting, additionality demonstration, quantification rules, monitoring criteria, and uncertainty treatment.

3. These provisions collectively ensure that PCS methodologies deliver consistent and scientifically credible results across all sectors.

Chapter 2 – Purpose

2.1 Purpose

1. The purpose of the PCS Methodology Development Standard is to provide a coherent and authoritative framework governing how methodologies are created, revised, and applied within the Planetary Carbon Standard.

2. Methodologies determine the entire technical foundation of crediting under PCS: they specify how emissions are quantified, how baselines are constructed, how additionality is demonstrated, and how monitoring must be conducted.

3. This Standard therefore ensures that every methodology used under PCS is scientifically robust, conservatively designed, transparent in structure, and applicable across a wide range of project contexts without compromising environmental integrity.

4. By establishing clear development rules, PCS provides a consistent approach that allows methodology developers, project proponents, Validation & Verification Bodies, and market participants to understand how emission reductions and removals should be calculated.

5. A unified framework also reduces methodological ambiguity and minimizes the risk of inconsistent quantification across projects operating under the same sector or technology.

2.2 Ensuring Environmental Integrity Across Sectors

1. Mitigation activities vary widely in scope, scale, and technological maturity. This Standard ensures that methodologies for each sector—whether energy, industrial processes, land use, removals, waste, or distributed household technologies—conform to the same integrity principles. The aim is not uniformity for its own sake, but uniformity of rigor.

2. Regardless of the sector, each methodology must deliver mitigation outcomes that are real, additional, conservative, and verifiable.

3. PCS recognizes that the credibility of the carbon market depends on the accuracy and consistency of the methodologies that underpin credit issuance. As such, the Standard provides detailed direction on how methodologies must treat baseline emissions, leakage, uncertainty, project boundaries, monitoring parameters, and data sources.

2.3 Facilitating Transparent and Replicable Climate Accounting

1. A central purpose of this Standard is to ensure that PCS methodologies are transparent and can be applied consistently by independent actors.

2. Methodologies must be designed so that qualified practitioners and Validation & Verification Bodies can replicate calculations without ambiguity. Clear formulas, transparent assumptions, structured data requirements, and documented parameter sources are therefore essential features of methodology development.

3. Transparency also supports public trust. Because PCS methodologies are published in full through the PCS Registry, the development rules must ensure that methodologies withstand scrutiny from technical experts, host country authorities, civil society, and market participants.

2.4 Supporting Alignment With International Climate Architecture

1. This Standard serves to harmonize PCS methodologies with broader international climate frameworks. In doing so, it ensures that emission reductions quantified under PCS remain consistent with the expectations of:

• UNFCCC Article 6 guidance,

• IPCC scientific methods,

• ICVCM Core Carbon Principles,

• and ISO GHG accounting standards.

1. The purpose is not duplication but alignment. By reflecting international expectations within PCS methodologies, the Standard ensures high levels of interoperability and acceptance across regulatory, compliance, and voluntary carbon markets.

2.5 Providing a Structured Basis for Methodology Review and Approval

1. The Standard provides a clear basis for how methodologies should be developed, submitted, reviewed, and approved. It outlines the elements a methodology must contain, the logic it must follow, and the scientific thresholds it must meet. This reduces uncertainty for methodology developers and ensures that all proposals are evaluated consistently and objectively.

2. The Standard also defines how revisions to existing methodologies must be assessed, how sunset provisions apply, and how transition rules operate when methodological changes influence credit issuance.

2.6 Ensuring Practicality and Feasibility

1. Another purpose of the Standard is to ensure that methodological requirements remain implementable within real project settings.

2. Methodologies written without regard for practical feasibility risk imposing excessive monitoring burdens, limiting adoption, or forcing reliance on unattainable data sources. By requiring methodological feasibility—including reasonable monitoring obligations, achievable data collection pathways, and clear applicability conditions—PCS ensures that methodologies maintain both integrity and usability.

2.7 Integration With PCS Digital Architecture

1. The Standard ensures that methodologies can interact seamlessly with PCS’s digital monitoring ecosystem, including automated data capture, digital MRV, parameter versioning, and blockchain-backed audit trails. This ensures that methodologies are future-proof and designed to benefit from technological advancements that improve accountability and reduce verification burdens. Methodologies must therefore specify parameters in ways that are compatible with digital data structures and automated validation where possible.

2.8 Protecting Host Party Interests and Regulatory Coherence

1. Host Parties rely on methodology integrity to ensure accurate accounting, avoid double claiming, and maintain alignment with national climate commitments. The Standard supports these interests by ensuring methodologies include clear treatment of host country policies, grid emission factors, land-use classifications, and national regulations relevant to baseline development. This strengthens the credibility of mitigation outcomes and supports integration with national reporting frameworks.

2.9 Summary

1. The purpose of the PCS Methodology Development Standard is to provide a coherent and authoritative foundation for all methodology-related processes within PCS. It ensures methodological rigor, scientific credibility, transparency, and practicality across sectors. It aligns PCS with international climate frameworks while supporting digital MRV systems and facilitating consistent quantification of climate outcomes. The following chapters build on this purpose by specifying the detailed requirements for constructing and applying methodologies under the Planetary Carbon Standard.

Chapter 3 – Entry Into Force

3.1 Effective Date

1. This Standard enters into force on the date of its official publication by the PCS Secretariat. From that date onward, all methodologies newly developed, submitted, or revised for use under the Planetary Carbon Standard must comply fully with the provisions set out in this Standard.

2. The entry into force ensures that all subsequent methodological work adheres to the same principles of transparency, scientific rigor, and environmental integrity that define the PCS framework.

3.2 Applicability to New and Existing Methodologies

1. Upon its entry into force, this Standard applies to:

• all new methodologies proposed for approval under PCS,

• all revisions to existing PCS methodologies,

• any modular tools, sectoral modules, or supplementary methodological guidance integrated into PCS.

1. Existing methodologies remain valid to the extent that they do not conflict with the requirements of this Standard.

2. Where conflicts exist, methodologies must be revised to achieve compliance within a transition period defined by the PCS Secretariat.

3.3 Transition Provisions

1. PCS recognizes that methodology revisions and transitions must be managed carefully to maintain predictability for Project Proponents while also ensuring environmental integrity.

2. Accordingly, the PCS Secretariat may establish transition provisions that allow existing methodologies to remain usable for a defined period after the entry into force of this Standard. These provisions may vary depending on:

• the degree of inconsistency between the methodology and the Standard,

• the impact on crediting outcomes,

• the urgency of correcting methodological deficiencies,

• the sector and jurisdiction in which projects operate.

1. Transition provisions will be communicated publicly through official PCS notices.

3.4 Obligations During the Transition Period

1. During any transition period, projects may continue to apply the previous version of a methodology if allowed by the PCS Secretariat, provided that the methodology does not compromise environmental integrity. Where the PCS Secretariat determines that immediate alignment is necessary, a shorter or no transition period may be applied.

2. All methodologies undergoing revision must be updated to comply with this Standard before the end of the transition period.

3. Failure to transition within the defined period may result in suspension of the affected methodology for new project registration.

3.5 Superseding Previous Provisions

1. With the entry into force of this Standard, any prior guidance or rules governing methodology development within PCS are superseded to the extent that they conflict with or duplicate the provisions of this Standard.

2. The PCS Secretariat may issue clarifications or technical notes to support consistency during implementation, but such documents must remain subordinate to this Standard.

3.6 Amendments and Future Updates

1. The PCS Secretariat retains the authority to amend or update this Standard in response to evolving scientific understanding, international regulatory developments, digital MRV advancements, or emerging sectoral needs.

2. Any amendment will follow a structured review process, including expert consultation and, where appropriate, public comment.

3. Updated versions will clearly indicate the effective date and any relevant transition arrangements.

3.7 Legal Standing Within the PCS Framework

1. This Standard holds authoritative status within the PCS rulebook and forms part of the mandatory requirements applicable to all Project Proponents, methodology developers, Validation & Verification Bodies, and other PCS stakeholders.

2. Compliance with this Standard is a prerequisite for methodology approval and for use of the methodology in project registration and crediting under PCS.

3.8 Summary

1. This chapter sets forth the legal and procedural basis by which the PCS Methodology Development Standard enters into force. It defines the applicability of the Standard, establishes transition provisions to support orderly implementation, and clarifies its authority within the broader PCS framework.

2. All subsequent methodological development must adhere to these provisions to ensure consistent and credible quantification of emission reductions and removals.

Chapter 4 – Methodology Development Requirements

4.1 Purpose

1. This chapter defines the technical elements that every methodology under the Planetary Carbon Standard must contain. These elements ensure that emission reductions and removals calculated under PCS are accurate, additional, conservative, and verifiable. They also establish a standard structure so that methodologies across sectors maintain consistency while allowing flexibility for technology-specific approaches.

2. A PCS methodology must include, at minimum, clear applicability criteria, a well-justified baseline scenario, a transparent additionality test, conservative calculation frameworks, robust monitoring procedures, and a coherent treatment of leakage and uncertainty.

4.2 Sectoral Scopes Under PCS

1. PCS uses a set of sectoral scopes to organize methodologies. These scopes allow the methodology to specify which types of activities fall within or outside its domain and ensure internal consistency across the program.

2. The PCS sectoral scope structure is presented below.

Table 4-A: PCS Sectoral Scopes

PCS Scope	Description
PCS-01	Energy industries (renewable and non-renewable)
PCS-02	Manufacturing and industrial processes
PCS-03	Chemical processes and fugitive emissions
PCS-04	Transport
PCS-05	Waste and circular economy
PCS-06	Agriculture (non-land use)
PCS-07	AFOLU / Nature-Based Solutions
PCS-08	Carbon dioxide removal (engineered removals)
PCS-09	Household and distributed technologies
PCS-10	Digital and technological innovations

1. A methodology must indicate its primary sectoral scope(s) and justify its categorization when activities cross multiple scopes.

4.3 Applicability Conditions

1. Every methodology must clearly define the conditions under which it may be applied. Applicability conditions ensure that methodologies are only used where technically appropriate and scientifically justified.

2. Applicability conditions typically address:

• project technologies and practices that the methodology covers,

• geographic or environmental conditions necessary for correct application,

• minimum data requirements and exclusions,

• any restrictions linked to policy or market conditions,

• compatibility with PCS safeguards and risk classification.

1. Applicability conditions must be phrased in objective terms that can be evaluated by the VVB and must be consistent with the methodology's baseline approach and monitoring requirements.

4.4 Project Boundary

1. The methodology must define the spatial, operational, and emission boundaries relevant to the project.

2. Boundaries must be comprehensive enough to include all significant sources and sinks of greenhouse gases affected by the activity. Project boundaries include:

• the physical area where project technologies operate,

• upstream and downstream sources of emissions where relevant,

• all GHG sources, sinks, and reservoirs required by IPCC classification,

• leakage pathways,

• carbon pools for land-based activities.

1. To support clarity, the methodology should include a summarized boundary table.

Table 4-B: Example Boundary Table Structure

Category	Baseline Scenario	Project Scenario
Direct emissions	Included / Excluded	Included / Excluded
Indirect emissions	Included / Excluded	Included / Excluded
Carbon pools (AFOLU)	Included / Excluded	Included / Excluded
Upstream / downstream effects	Included / Excluded	Included / Excluded

The table is illustrative; methodologies must develop content appropriate to their sector.

4.5 Baseline Scenario Determination

1. The baseline scenario is the most important determinant of crediting integrity. Every methodology must define how the baseline scenario is identified, justified, and quantified.

2. The baseline must represent realistic conditions that would occur in the absence of the project and must not create crediting opportunities where no real improvement takes place. Baseline approaches may include:

• historical performance methods,

• emissions intensity benchmarks,

• modelled scenarios using conservative assumptions,

• common practice analyses,

• performance standard approaches,

• technology-specific baselines (e.g., grid factors, fuel consumption).

1. The methodology must define:

• the time period used for baseline data,

• adjustment rules for anomalies or abnormal events,

• the minimum data quality requirements,

• conditions under which baselines may be updated or fixed.

1. Where Host Party regulatory frameworks already require specific activities, these must be reflected in the baseline, preventing crediting for activities that are legally mandated.

4.6 Demonstration of Additionality

1. Additionality ensures that emission reductions are not business-as-usual. Every methodology must provide a structured approach to demonstrating additionality that is transparent, replicable, and aligned with international norms.

2. PCS accepts three families of additionality approaches:

• Regulatory Surplus — ensuring the activity is not required by law.

• Investment or Financial Additionality — demonstrating that the project requires carbon revenue to proceed.

• Barrier or Common Practice Analysis — demonstrating that similar activities are not widespread or that barriers exist.

1. The methodology must define which tests are required and how they are applied, including:

• relevant benchmarks or thresholds,

• required financial parameters,

• data sources,

• treatment of incentives or subsidies,

• documentation expectations.

1. If using a positive list, the methodology must clearly justify the criteria for automatic additionality and show alignment with the evidence base.

4.7 Quantification of Emission Reductions and Removals

1. The methodology must provide formulas, parameters, and data sources to calculate emission reductions or removals. This includes:

• baseline emissions,

• project emissions,

• leakage emissions,

• net emission reductions.

1. Formulas must be fully transparent. All parameters must be described clearly, including units, data sources, default values, acceptable ranges, and required justification for deviations.

2. Where relevant, the methodology must specify:

• sampling requirements,

• use of measurement equipment,

• frequency of measurement,

• data aggregation rules.

1. Quantification methods must be conservative and must avoid overstating reductions.

4.8 Leakage Assessment

1. Leakage refers to increases in emissions outside the project boundary caused by the project. Every methodology must include rules for identifying, assessing, and quantifying leakage. Leakage may include:

• market leakage (shift in supply or demand),

• activity-shifting leakage (migration of emissions to nearby areas),

• upstream or downstream leakage,

• leakage across carbon pools in AFOLU projects.

1. Methodologies must quantify leakage where feasible, or require a conservative deduction where quantification is not practical.

4.9 Monitoring Methodology

1. Monitoring provisions must describe how data will be collected, stored, and verified. Monitoring must be realistic yet rigorous, ensuring that the mitigation outcomes can be replicated during verification.

2. Monitoring frameworks must specify:

• parameters to be monitored,

• measurement frequency,

• acceptable instruments and calibration rules,

• roles and responsibilities,

• requirements for digital monitoring (where applicable),

• evidence required during verification.

1. A monitoring summary table is generally required.

4.10 Remaining Lifetime of Baseline Equipment

1. Where crediting depends on the retirement of existing equipment or practices, the methodology must include:

• clear rules for determining the remaining useful lifetime,

• data sources for equipment age and condition,

• conservative assumptions and minimum lifetimes where data are uncertain.

1. This prevents crediting for activities that would have occurred naturally within the same timeframe.

4.11 Global Warming Potentials (GWPs)

1. All PCS methodologies must use the GWPs from the latest IPCC Assessment Report approved for use by PCS. Methodologies must state:

• the GWP values used,

• the source report and year,

• the treatment of gases with uncertain GWPs.

1. Updates to GWP values must follow PCS versioning and transition rules.

4.12 Treatment of Uncertainty and Conservativeness

1. Every methodology must address uncertainty explicitly. Uncertainty considerations may affect:

• measurement data,

• sampling approaches,

• model assumptions,

• emission factors,

• leakage calculations.

1. The methodology must apply conservative adjustments or deduction factors where uncertainty may lead to overstated reductions.

Table 4-C: Uncertainty Treatment Logic (Illustrative)

Type of Uncertainty	Required Treatment
Measurement uncertainty	Apply conservative factor or confidence interval deduction
Model uncertainty	Apply conservative parameter or scenario settings
Sampling error	Use statistically justified sample sizes with confidence/precision criteria
Default factors	Use recognized international sources and conservative values

4.13 Use of External Tools and Guidance

1. PCS allows methodologies to reference recognized external tools, such as:

• IPCC default factors,

• UNFCCC methodological tools,

• ISO-based calculation frameworks.

1. Where external tools are used, the methodology must provide:

• justification for the tool’s relevance,

• version control and update rules,

• any required modifications under PCS.

4.14 Summary

1. This chapter sets out the core structural and technical requirements that all PCS methodologies must satisfy. By defining clear rules for boundaries, baselines, additionality, quantification, monitoring, and uncertainty, the PCS methodology framework ensures consistency, scientific rigor, and environmental integrity across all project types.

Chapter 5 – PCS Data Management Rules For Methodologies

5.1 Purpose

1. This chapter establishes the rules governing data generation, handling, quality control, and documentation within PCS methodologies. Because methodologies define the parameters that must be measured or monitored, they must also specify how such data must be managed to ensure consistency, reliability, and traceability. These requirements ensure that emission reductions and removals quantified under PCS are based on verifiable and tamper‐resistant information, and support the use of the PCS Registry and digital MRV systems.

5.2 Integration With PCS Digital MRV Architecture

1. All data requirements specified in methodologies must be compatible with PCS’s digital monitoring ecosystem. This ecosystem includes:

• digital data capture,

• version-controlled parameter storage,

• tamper-evident audit trails anchored by distributed ledger technology,

• automated validation checks,

• standardized data schemas for monitored parameters,

• integration with the PCS Registry.

1. Methodologies must therefore define parameters and data structures in a way that aligns with PCS’s digital framework and allows seamless ingestion, verification, and storage of monitoring records.

5.3 Hierarchy of Data Sources

1. Methodologies must establish a hierarchy of acceptable data sources for key parameters. This hierarchy ensures consistency, prioritizes higher-quality data, and provides clarity to project developers and VVBs when multiple data sources exist.

2. The PCS hierarchy of data sources is summarized in Table 5-A.

Table 5-A: PCS Data Source Hierarchy

Level	Preferred Data Source	Description
Level 1	Direct measurement	Primary data gathered from calibrated instruments or sensors.
Level 2	Project-specific monitored data	Field measurements, surveys, or sampling conducted under the methodology.
Level 3	Host Party official data	National statistics, regulatory datasets, government-published emission factors.
Level 4	International default values	IPCC default factors, UNFCCC tools, ISO standards.
Level 5	Conservative assumptions	PCS-approved conservative proxies used only when higher-tier data are not available.

1. Methodologies must clearly indicate which tier applies to each parameter, and must require higher-tier data where feasible.

5.4 Data Quality Assurance and Quality Control (QA/QC)

1. Methodologies must outline minimum QA/QC requirements to ensure data integrity. QA/QC measures may include calibration of instruments, validation of data entry processes, review of sampling procedures, assessment of data completeness, and detection of anomalies or inconsistencies. These requirements must reflect the level of risk associated with the parameter and the potential influence of errors on crediting outcomes.

2. Although methodologies may specify additional sector-specific measures, all must require that data management procedures be documented and auditable during verification.

5.5 Traceability and Auditability

1. PCS requires that all data used for baseline determination, additionality assessment, monitoring, and quantification be fully traceable. Methodologies must therefore specify the types of evidence required for each monitored parameter and describe how traceability is maintained.

2. Traceability includes the ability to identify:

• the source of each data point,

• the date and location of data collection,

• the responsible individual or system,

• the calibration state of instruments used,

• any transformations or adjustments applied to the data.

1. The PCS Registry maintains digital audit trails, but methodologies must define the underlying data requirements that feed into these systems.

5.6 Use of Digital Monitoring Technologies

1. Where digital monitoring is feasible—such as through IoT sensors, smart meters, remote sensing, or geospatial monitoring—methodologies must incorporate provisions supporting their use. Digital monitoring may improve data accuracy, reduce verification costs, and enhance transparency.

2. The methodology must specify:

• acceptable digital monitoring devices or systems,

• minimum accuracy thresholds,

• calibration or maintenance requirements,

• handling of sensor failure or data gaps,

• validation rules for digital data streams.

These requirements ensure compatibility with the digital MRV principles established under PCS program rules.

5.7 Version Control and Parameter Updates

1. Methodologies must specify how parameters that change over time—such as emission factors, grid intensities, or regulatory values—are updated.

2. Updates must follow structured version control principles so that projects can replicate historic calculations. Every parameter must be categorized as:

• fixed for the duration of the crediting period,

• rolling (updated at predefined intervals), or

• dynamic (updated whenever new official data becomes available).

1. Methodologies must clearly describe how project proponents incorporate updated parameters into Monitoring Reports and how such updates affect issuance.

5.8 Handling Data Gaps and Missing Information

1. Methodologies must define how data gaps are treated to ensure that lack of data does not lead to inflated crediting. Where data are missing, methodologies must require:

• conservative substitution values,

• supplemental measurements or surveys, or

• deductions applied directly to the emission reduction calculation.

1. Data gaps must always be documented, justified, and disclosed in Monitoring Reports.

5.9 Sampling Requirements

1. Where methodologies permit sampling, they must define:

• the sampling frame,

• sample size requirements,

• confidence and precision thresholds (typically 90% confidence with ±10% precision unless otherwise justified),

• stratification rules where population heterogeneity affects results,

• periodicity of sampling.

1. Sampling rules must reflect ISO and UNFCCC good practice principles and be sufficiently rigorous to prevent biased results.

5.10 Data Transparency and Replicability

1. Methodologies must require that data used for quantification be transparent and replicable. Replicability means that a VVB should be able to reproduce calculations independently using the documented formulas, parameters, and monitoring records. This requirement reinforces the need for methodologies to provide:

• clear formulas,

• transparent parameter tables,

• unambiguous variable definitions,

• detailed notes regarding data sources.

1. PCS will not approve methodologies that rely on opaque calculations or proprietary algorithms that cannot be independently reproduced.

5.11 Data Retention Requirements

1. Methodologies must specify that all project-level data—including raw data, processed datasets, monitoring records, calibration certificates, sampling logs, photographs, geospatial files, and digital monitoring outputs—be retained for the entire crediting period and for at least seven years after project completion. Retention rules support verification, audits, and long-term transparency obligations.

5.12 Integration With PCS Registry Evidence Requirements

1. All data management rules must be compatible with evidence submission and validation processes in the PCS Registry. This includes:

• ensuring parameters can be linked to registry fields,

• ensuring version histories can be cross-referenced,

• enabling automated validation checks,

• ensuring data formats support digital integrity protocols (e.g., hashing, anchoring, provenance tracking).

1. Methodologies must describe how data will be presented in Monitoring Reports to align with Registry structures.

5.13 Summary

1. This chapter defines the data management rules that methodologies must incorporate to ensure reliability, traceability, and digital compatibility. By establishing a hierarchy of data sources, strict QA/QC expectations, provisions for digital monitoring, and rigorous transparency requirements, PCS ensures that all methodologies deliver consistent, credible, and verifiable mitigation outcomes.