Carbon footprint is the amount of carbon dioxide produced by a person, activity, or system. It is measured in units such as kilograms or tons of CO₂. Carbon footprints are calculated using data about energy use and consumption.

Driving a car, using electricity, or flying in an airplane all contribute to carbon emissions. A household, a company, or even a country can have a carbon footprint. Calculations may include fuel use, electricity consumption, and production of goods.

Carbon footprints are used in climate studies. They are tracked by scientists, organizations, and governments using environmental data.