Carbon footprint
A carbon footprint is the sum of greenhouse gas emissions and removals attributable to a defined subject within a stated boundary and period, expressed as carbon dioxide equivalent. The subject may be an organization, product, service, event, activity, or other specified system.
In simple terms
Calculating a footprint begins by defining what is included, such as organizational operations or a product’s life cycle. Activity data are linked with emission factors, gases are converted using global warming potential values, and the results are combined in carbon dioxide equivalent. Organizational footprints may include Scope 1, Scope 2, and relevant Scope 3 emissions. Results are comparable only when boundaries, methods, periods, and data quality are sufficiently aligned.
Why it matters
A carbon footprint makes emissions sources visible and provides a baseline for reduction targets, procurement choices, product redesign, and progress tracking. Its usefulness depends on transparent boundaries and methods. A narrow footprint can omit important value-chain emissions, while an unexplained total can conceal uncertainty, removals, or differences in the factors used.
Example
For example, a manufacturer can calculate a product footprint from raw-material production, transport, factory energy, use, and end-of-life treatment. It records the life-cycle boundary, data sources, assumptions, and carbon dioxide equivalent method so later design options can be compared on a consistent basis.
How it differs
Carbon dioxide equivalent
A carbon footprint is a quantified result for a defined subject and boundary; carbon dioxide equivalent is the common unit used to express that result.
Material footprint
A carbon footprint measures greenhouse gas emissions and removals in carbon dioxide equivalent; a material footprint measures the quantity of raw materials associated with consumption or production.