What is Carbon Footprint?

Carbon footprint (or footprint greenhouse gases) represents an estimate of the total amount of greenhouse gases that an activity, product, company or country emits into the atmosphere. The common unit of measurement is the CO₂ equivalent (CO₂e) per unit of comparison, for example tons of CO₂e per year, kilograms of CO₂e for protein production, kilometers driven, or a piece of clothing. The carbon footprint of a product includes emissions during the entire life cycle of the product – from production to consumption to disposal.

Similarly, an organization's carbon footprint includes both direct and indirect emissions that the organization causes. The Greenhouse Gas Protocol classifies these emissions into three categories: scopes 1, 2 and 3. There are several methodologies and online tools for calculating the carbon footprint, which are adapted to different entities such as countries, organizations, products or individuals. For example, a product's carbon footprint can help consumers consider environmental aspects when making a purchase decision.

The carbon footprint helps distinguish between economic activities with a high and low impact on the climate, which is crucial for the creation of strategies to reduce emissions.

Emissions of carbon dioxide equivalent (CO₂e) per unit of comparison is a common way of expressing the carbon footprint. It includes greenhouse gases such as CO₂, methane, nitrous oxide and other gases, and assesses emissions from various economic activities, events, organizations and services. However, in some definitions, only CO₂ emissions are taken into account, which can lead to an incomplete picture.

Different methods of carbon footprint calculation may vary by entity. It is common practice for organizations to use the Greenhouse Gas Protocol, which covers three ranges of emissions:
– **Scope 1:** Direct emissions.
– **Scope 2 and 3:** Indirect emissions. Scope 3 includes indirect emissions from sources that the organization does not own or control.

It is common for countries to use consumption-based emissions accounting to calculate their carbon footprint for a given year. This method uses input-output analysis supported by supercomputers to analyze global supply chains. Countries usually prepare national greenhouse gas inventories for the UNFCCC, which focus only on emissions within the country (territorial accounting).

Consumption-based accounting is more comprehensive as it also includes emissions from imports and the total carbon footprint, including scope 3 emissions. Comprehensive carbon footprint reporting enables a better understanding of overall demand for emissions and where consumption of goods and services is greatest. This type of reporting also includes international transport and provides a more detailed picture of climate footprints.

Overall understanding and measuring the carbon footprint helps identify areas for improvement and effective emission reduction, which is key to combating climate change and creating more sustainable solutions.