Emissions inventory
A structured account of greenhouse gas sources and quantities within a stated boundary and period.
Example
An annual corporate inventory provides a basis for tracking operational and value-chain changes.
The catch
Inventory completeness and calculation choices should be disclosed.
In more depth
Emissions inventory, explained.
An emissions inventory starts with boundary choices that can change the total before a single meter is read. The GHG Protocol lets a company consolidate by equity share or by control, so a joint venture can appear in full, in part or not at all. Next comes the choice of scopes, then activity data, then the emission factor for each source.
Countries keep their own versions. A national emissions inventory follows IPCC guidelines and counts emissions within a territory, which differs from a company's view across its value chain. Treat any inventory as a set of estimates with uneven confidence, since fuel use is usually well measured while methane from landfills and pipelines is far less certain.