The concept of “footprint” is relatively recent and due to differing opinions on what this term refers to, things may get confusing for a non-expert audience. Terms like “carbon footprint”, “energy footprint” or “environmental footprint” are often used without a clear understanding of their respective meaning.

“Footprints” methodologies belong to the family of the environmental assessment methods based on Life Cycle Thinking (LCT) i.e. an approach that takes into consideration the spectrum of resource flows and environmental interventions associated with a product, service, or organization from a supply chain perspective, including all phases from raw material acquisition through processing, distribution, use, and end-of-life processes. Hence footprints methodologies are all LCA-based (Life Cycle Assessment) approaches.

An environmental footprint, unlike a carbon or energy footprint, is a multi-indicator measure of products/services/organisations impacts (see the definitions provided in the following sections).

Environmental/carbon/energy footprints can be applied to:

• - Products and services (Product Environmental Footprint – PEF, Product Carbon Footprint - PCF),
• - Organizations (Organization Environmental Footprint – OEF)
• - Even regions or countries.

Useful links:

• - European Commissions - Single Market for Green Products Initiative
• - Joint Research Centre of the European Commission – European Platform on Life Cycle Assessment
• - UNEP / SETAC – Life Cycle Initiative
• Carbon Footprint of Nations

A Life Cycle Assessment (LCA) is an environmental evaluation approach that considers the entire life cycle of a product or service, from raw material acquisition through processing, distribution, use, and end-of-life processes. LCA is a multi-criteria approach i.e. it takes into account several environmental issues. Through such a perspective, environmental burden shifting between life cycle stages or individual processes can be identified and avoided. A similar approach is undertaken for LCA of organisations or projects.

The ISO 14044:2006 standard specifies requirements and provides guidelines for life cycle assessment (LCA).

An environmental footprint is the assessment of the potential environmental impacts of a defined product/service, organization or territory, within a specific spatial and temporal boundary. Environmental footprints are Life Cycle Assessment approaches which means that they take into consideration the whole life cycle of the studied system, i.e. all the steps from the raw material extraction through processing, distribution, use and end-of-life.

Environmental footprints are multi-criteria methodologies i.e. not only focusing on one environmental issue such as climate change or energy consumption, but covering several environmental impacts such as:

• - Mineral/fossil resources depletion,
• - Water consumption,
• - Ozone depletion,
• - Eutrophication
• - Acidification
• - Etc.

A carbon footprint is a type of environmental footprint focusing on a single environmental issue: climate change.

In certain cases, it can be relevant to focus on a specific environmental impact category instead of looking at various impact categories (even if it is still recommended to consider several environmental impacts to avoid burden shifting): relevant impact categories are different for different sectors or product categories. For example, climate change (GHG emissions) is very important for energy-intensive sectors, whilst they are not as important for example for cosmetics– where it would be more the water use and toxicity aspects that define environmental performance.

A carbon footprint is a measure of the total amount of potential greenhouse gases (GHG) emissions to the atmosphere of a defined product/service, organization or territory considering all relevant sources within a specific spatial and temporal boundary. This is calculated in most methodologies as carbon dioxide equivalent (CO2e).

Just as carbon footprint, energy footprints are environmental footprints focusing on a single environmental issue, the energy consumption. Hence an energy footprint is the assessment of the energy consumption related to a defined product, organization or territory, within a specific spatial and temporal boundary. This is calculated in most methodologies from a life cycle perspective.

Usually, several types of energy sources can be distinguished according the nature of the energy source and its renewability e.g. non-renewable energy sources (fossil, nuclear), renewable energy sources (solar, wind, geothermal, water). There are several indicator definitions used to quantify energy footprint. Some of them consider all types of energy

Solar radiation is re-emitted by the Earth’s surface in the form of infrared radiation, which is itself partially absorbed by various chemical species in the atmosphere: this is called the "greenhouse effect." The radiation balance determines the average temperature of the planet and the presence of greenhouse substances allows the temperature to be compatible with life on Earth (without this, the temperature would be about -15 ° C).

However, human activities generate long life greenhouse gas (GHG) emissions such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and halocarbons (a group of gases which includes fluorine, chlorine or bromine), resulting in an increased radiative forcing that causes an enhancement of the greenhouse effect.

In conjunction with natural forces, it contributes to global climate changes: rising temperatures on the surface of the Earth and oceans, changes in precipitation, rising sea levels ... The influence of greenhouse gases on the changes of the Earth’s climate system varies according to the radiative properties of these gases and their lifetime in the atmosphere.

Greenhouse gases (GHGs) are gaseous substances able to trap heat in the atmosphere. The “enhanced” greenhouse effect, which is responsible for climate change, is caused by human activities emitting GHGs in the atmosphere such as: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6). Please note that water vapour, although the largest contributor to the natural greenhouse effect, is not directly affected by human activity and is not included. (source: based on Kyoto Protocol website)

A methodology offers the theoretical support for understanding which method or "best practices" can be applied to a specific need, and guidance on how to implement the method in order to evaluate the environmental footprint (such as carbon or energy footprint) related to a specific product or organisation.

Methodologies may be used for monitoring, assessing, and analysing many possible aspects of a business, in order to help organisations and public entities to become more carbon or energy efficient and, therefore, reduce costs and ultimately their environmental impact. Within the ICT sector, there are several methodologies which aim to assessing the carbon footprint and energy efficiency of ICT goods, services, and organisations.

Methodologies are generally described in general and/or technical guidelines which can be subject to a specific standard developed either by an official Standards Development Organization (SDO) or through voluntary initiatives by a consortium of various private/public stakeholders.

Go to the Methodologies page to learn more about them.

ICTFOOTPRINT.eu provides information on methodologies specific to the ICT sector and related with environmental footprint implementation, with a particular focus on carbon footprint and energy footprint.

Additional methodologies may be applied to calculate performance indicators, for instance in terms of energy consumption.

Go to the Methodologies page to learn more about them.