Data, Technology & Verification Systems
Activity data
A quantitative measure of an activity that results in greenhouse gas emissions — such as fuel burned or kilometres travelled — which is multiplied by an emission factor to calculate emissions.
Definition
A quantitative measure of a level of activity that results in greenhouse gas emissions, expressed in physical units such as litres of fuel, kilowatt-hours of electricity, kilograms of material or tonne-kilometres of freight. Activity data are multiplied by emission factors to estimate emissions, forming the basis of most greenhouse gas inventories under the GHG Protocol.
References
Emission factors relate emissions to activity performed; activity data (distance travelled, fuel combusted) as the basis for calculation; scope definitions.
Activity-based vs spend-based methods; activity data as default for Scopes 1–2; hybrid approaches for Scope 3.
GHG Protocol Scope 3 data hierarchy (supplier-specific, hybrid, average-data, spend-based); regulatory direction of travel.
Overview
What it means
The GHG Protocol's Scope 3 Standard ranks data types by accuracy: supplier-specific (primary) data, hybrid, average-data and spend-based estimates.
"Activity-based" calculation — physical activity data multiplied by matching emission factors — is the default for Scope 1 and 2 and the preferred approach for material Scope 3 categories; spend-based estimation is a lower-accuracy fallback used where activity data are unavailable.
How it is used
Companies collect activity data from utility bills, fuel records, procurement systems and suppliers, then apply factors from sources such as the US EPA, UK DESNZ or the IPCC Emission Factor Database. Assurance providers test activity data quality, and regulations such as the EU carbon border adjustment mechanism increasingly require activity-based rather than spend-based figures.
Why it matters
Emissions figures are only as credible as the activity data beneath them. The shift from spend-based estimates to activity-based data is the main lever for improving inventory accuracy, auditability and the ability to track real-world reductions.
Review
Public comments appear only after editor acceptance. Draft comments stay in the review queue.
Reviewers choose the definition or an overview paragraph, leave a comment or replacement, and attach evidence or a source link.
Editors compare reviewer cards side by side. AI may help find agreement, conflicts, unsupported claims and possible source issues.
Only an editor-accepted synthesis changes the public page. Reviewer identities are shown only with consent and an editorial decision to attribute them.
Submitted reviews stay private until an editor decides whether to accept and attribute them.
Contribute to this entry
Help improve this definition
Your contribution is private while it is checked. Nothing changes on this page unless an editor accepts it.
Loading verified endorsements… Endorsements are not votes and never determine publication.
Endorse this definition
Endorse the exact version shown here. This is not a vote, and publication remains an editorial decision.
Review board
Comment on a specific line. Each reviewer stays separate until an editor accepts a merged draft.
Each person comments on the definition or overview in their own draft card, with role, evidence and suggested wording kept together.
AI can compare comments against the current text, flag conflicting claims, surface missing evidence and identify where reviewers agree.
An editor merges compatible suggestions into a draft change, checks sources, records disagreements and decides what can be published.