A type of environmental footprint. Carbon footprint is the number of greenhouse gasses (usually expressed as carbon dioxide equivalent, i.e. CO2e) that an entity, organization, event, service, site, or unit emits into the atmosphere. The carbon footprint results from, among others, burning fossil fuels and acquiring materials (logging, peat extraction).
An accurate carbon footprint calculation involves a complex process of observing all events connected to the creation and lifetime of a product or service. The carbon footprint is calculated "from the cradle to the grave", including all emissions from the extraction of materials, from the use of the product, and from its disposal at the end of its life cycle.