An annual emissions inventory should explain which entities and activities were included and where the numbers came from. Confirm boundary, year, and purpose before collecting energy, procurement, and operating records.
When to begin
Organizations establishing a baseline, responding to customers, preparing disclosure, or setting reduction targets can first map existing bills and data owners. Acquisitions, site changes, or method revisions also call for a comparability review across years.
Identify what source records mean
Refrigerant purchases do not necessarily equal leakage during the year, and travel expenses do not directly represent travel activity. Record period, unit, entity, and site for each input. Reconcile stock, activity, and calculation method to avoid omissions and double counting.
Boundaries and scopes
The GHG Protocol Corporate Standard supports organizational inventories; use the Scope 2 Guidance and Scope 3 Standard for purchased energy and value-chain emissions. Set organizational boundaries using equity share or control; control may be financial or operational. Apply the selected approach consistently.
Scope 1 covers direct emissions from owned or controlled sources. Scope 2 covers indirect emissions from purchased electricity, steam, heat, and cooling. Other upstream and downstream activities are assessed across the 15 Scope 3 categories. Assess leased and outsourced activities in light of the relevant control relationship.
Where the Scope 2 Guidance dual-reporting requirements apply, report both location-based and market-based results and assess contractual instruments against quality criteria. Retain activity data, emission factors, GWP version, estimates, and limitations. Carbon-credit information does not directly reduce the inventory total.
Suggested inventory stages
- Confirm purpose, organizational boundary, year, and base-year policy; list sites and activities.
- Assign inputs to the teams that hold the records and verify period, unit, and coverage.
- Document methods, factors, and exclusions; review significant sources and data quality.
- Prepare results, explain changes, index evidence, and arrange review, updates, and assurance readiness.
Information and possible outputs
Prepare entity and site lists, control relationships, energy, refrigerant, procurement, logistics, travel, and other activity records. Possible outputs include a boundary statement, emissions inventory, calculation workbook, data-quality notes, and improvement register. Independent assurance is separate from advisory work.
Effort depends on sites, years, Scope 3 categories, and supplier data. A preliminary estimate using secondary data may locate hotspots before collection effort is focused on significant sources. Data preparation, calculations, platform use, and external assurance should be scoped separately.