What data granularity should a carbon ledger store to ensure auditability and re

Capture data at the lowest practical activity-event level with complete metadata. For each record: activity value and unit (e.g., liters diesel, kWh, tonne-km), time stamp (period granularity aligned to factor validity), facility/asset, supplier or contract, and source document reference (invoice, meter, BOL). Record the emission factor identifier (publisher, dataset, version, geography, year), calculation formula, and scope/category mapping. Include data quality scoring (e.g., primary vs modeled; temporal/geographic/technological representativeness), uncertainty estimate, and reviewer/approval status to support QA/QC. Storing raw activity data enables recalculation when factors are updated or methods change (e.g., Scope 2 market-based). This approach aligns with GHG Protocol’s principles of relevance, completeness, consistency, transparency, and accuracy, and facilitates ISO-conformant inventories. It also supports product-level allocations and regulatory disclosures without re-collecting data. Key Takeaway: Store event-level activity data plus factor/version metadata to enable recalculation, traceability, and audit-ready reporting.