A carbon footprint is defined as the total emissions created by an individual, event, organization or product, expressed in tonnes of CO2 or CO2 equivalent per year.
It includes direct emissions, such as those resulting from the combustion of fossil fuels in the manufacturing, heating and transport processes, as well as the emissions needed to generate the electricity associated with the goods and services that are consumed. Moreover, the carbon footprint concept very often includes other greenhouse gases, such as methane, nitrous oxide or chlorofluorocarbons (CFCs).
There are several different tools for calculating the carbon footprints of individuals, companies and other organizations.
Generally, the methodologies used to calculate an organization’s carbon footprint include the Greenhouse Gas Protocol, from the World Resources Institute and the World Business Council for Sustainable Development, and ISO 14064, which specifically addresses greenhouse gas emissions.