The carbon footprint describes the climate load caused by a specific configurable entity. The carbon footprint can be calculated, for example, for a company, municipality, investment, product, or service.

The climate load is caused by the release of greenhouse gases such as carbon dioxide (CO2), methane (CO4), and nitrous oxide (N2O) into the atmosphere. The carbon footprint is expressed in terms of carbon dioxide equivalents, considering the different global warming effects of different greenhouse gases.

When determining the carbon footprint, all direct and indirect emissions during a life cycle associated with a specific entity need to be taken into account. For example, in the case of a company or municipality, the carbon footprint can be determined per selected unit of time, such as a year.

The carbon footprint is expressed in terms of mass, either in tonnes, kilograms, or grams.

The emission factor describes the amount of emissions generated with the quantity of product or service produced. Emission factors are used to determine the carbon footprint.

Emission factors can be of many types. They may describe the use phase or life-cycle emissions, include only carbon dioxide emissions or all greenhouse gas emissions in CO2 equivalents, and may sometimes be average values or represent a specific period of time. For example, the emission factor for electricity generation is often expressed in g CO2/kWh and the emission factor for food in kg CO2eq./kg.

The emission factor of a product or service is often referred to as the carbon footprint. To be precise, this is only the case when the emission factor describes the amount of life cycle greenhouse gas emissions in terms of carbon dioxide equivalents.

The carbon handprint describes the positive climate impacts of a particular solution throughout its life cycle. A positive carbon handprint arises from the fact that using the solution provided reduces the carbon footprint of someone else (usually the customer). On the other hand, reducing the carbon footprint of one's own operations does not increase the carbon handprint.

The carbon handprint of the same product or service may be different depending on the situation, for example, in different markets. Therefore the carbon handprint is always determined in relation to the selected baseline.

VTT and LUT University have developed a carbon handprint calculation methodology and published a guide. According to the guide, a positive carbon handprint can be achieved, for example, by improving material or energy efficiency, replacing non-renewable materials or energy with renewables, extending product lifetime, reducing waste and reducing losses, or capturing and storing carbon dioxide. The carbon handprint can be used, for example, to communicate the climate benefits of a product or service to customers or other stakeholders.

Greenhouse gases absorb the thermal energy released from the earth and cause global warming. The atmosphere contains natural greenhouse gases such as water vapor (H2O), carbon dioxide (CO2), and methane (CH4). Human activities, such as burning fossil fuels and industrial processes, also release carbon dioxide and other greenhouse gases into the atmosphere.

The carbon dioxide equivalent describes the combined global warming potential of different greenhouse gas emissions.

Different greenhouse gases have different global warming potentials (GWPs). The Intergovernmental Panel on Climate Change (IPCC) publishes GWP indices for greenhouse gases in its assessment reports.

The GWPs of other greenhouse gases are proportional to the global warming potential of carbon dioxide, set at 1. For example, the global warming potential of methane relative to carbon dioxide over 100 years is 28.

A carbon-neutral company, product, or service does not burden the climate. In practice, this means that the carbon footprint of a given entity has first been determined and reduced by usable means. Emissions that cannot be reduced by own measures are offset by participating in emission reduction projects elsewhere or purchasing emission reduction units from the market. When offsetting emissions, it is essential to ensure that the realization of emission reductions is reliably verified.