A carbon footprint refers to the total amount of greenhouse gases emitted into the atmosphere by an individual, organization, or country. These emissions include carbon dioxide (CO₂) as well as other greenhouse gases like methane (CH₄) and nitrous oxide (N₂O). The measurement is usually expressed in tons of emissions per unit of comparison. It encompasses both direct emissions, such as those from fossil fuel combustion, and indirect emissions associated with the production of electricity consumed by goods and services. (Wiedmann, T., & Minx, J. 2007)