What is a GHG inventory?
A greenhouse gas (GHG) inventory is an organisation's dated emissions record. The GHG Protocol glossary defines it as a quantified list of emissions and sources. Chapter 9 requires the reporting period, organisational and operational boundaries, separate Scope 1 and Scope 2 totals, methods and exclusions. Requests may call it a corporate carbon footprint, organisational carbon footprint, carbon inventory or Treibhausgasbilanz. It is not a product footprint or an unexplained total: each tonne must trace to a source, calculation and document.
Why does a GHG inventory matter to you?
CDP's 2026 full corporate Questions 7.6 and 7.7 ask for gross global Scope 1 and Scope 2 emissions in metric tonnes CO2e. Question 7.8 asks you to account for gross global Scope 3 emissions and explain any exclusions. The 7.9 question series asks for the verification or assurance status of reported emissions.
EcoVadis update 32.4 says evidence for Energy & GHG KPI reporting must cover at least 95% of operations. Update 32.2 says site-level coverage is measured by employees or sites, not turnover. Update 32.9 replaced one undifferentiated Scope 2 metric with separate location-based and market-based metrics on 7 May 2026.
For Australian entities within the reporting thresholds, AASB S2 paragraph 29(a) requires absolute gross Scope 1, Scope 2 and Scope 3 emissions. It also requires the measurement approach, inputs and emission factors. A total without its boundary and method cannot answer these checks.
How does a GHG inventory work?
Keep four linked parts. A boundary note names the entities, sites, reporting dates, Scope 3 categories and whether the inventory uses ownership share, financial control or operational control. A source register, the line-by-line calculation table, gives each line an entity, site, scope or category, activity value, unit, factor, geography, factor year, result and evidence reference. A totals sheet adds those lines by scope without subtracting carbon credits from gross emissions. A method note records estimates, exclusions, conversions, review checks and prior-year changes.
Reconcile every total to the source register, check all boundary-listed sites and months, and label location-based and market-based Scope 2 separately. Save the dated factor file, invoices, meter exports, fuel logs, refrigerant service records, travel reports, waste records and reviewer sign-off with the calculation version.
What mistakes should you avoid?
- Sending one emissions total without the reporting period, boundary, scope split, method or exclusions.
- Calling a product footprint or project estimate the company's GHG inventory.
- Subtracting offsets or carbon credits from gross Scope 1 and Scope 2 totals instead of reporting them separately.
- Keeping a factor value without its unit, geography, year, publisher and source file, so the calculation cannot be repeated.
Is a GHG inventory the same as carbon accounting?
No. Carbon accounting is the process used to define boundaries, collect data, choose factors and calculate emissions. The GHG inventory is the dated output of that process: the source register, calculation lines, totals, method note and supporting files.
What do you send when a customer asks for a GHG inventory?
Send the boundary and period note, separate Scope 1, Scope 2 and relevant Scope 3 totals in metric tonnes CO2e, the calculation workbook, factor register, method and exclusions note, and the requested assurance statement. Share source documents only through the customer's approved channel.
Does a GHG inventory have to include Scope 3?
The GHG Protocol Corporate Standard requires a conforming public report to include at least Scope 1 and Scope 2. A customer, CDP Question 7.8 or AASB S2 paragraph 29(a) can also require Scope 3. Record all 15 categories as calculated, not relevant, not yet calculated or excluded, with the reason for each decision.