According to the GreenHouse Gas Protocol—the most widely used international tool for calculating and disclosing the inventory of atmospheric emissions—the carbon footprint is the amount of greenhouse gases (GHGs) emitted into the atmosphere by direct or indirect action of an individual, organization, event, or product (PIGA-SDA, 2016).
The carbon footprint is measured in tons of carbon dioxide (CO2) equivalent, i.e. in addition to carbon dioxide as a greenhouse gas, it includes other gases with the same potential. This is a reference value and a useful metric for comparing different GHG emissions (PIGA-SDA, 2016).
The identification and quantification of GHG emissions produced by public entities are performed in accordance with the following scopes, set in the GHG protocol: