Key words to understand

Cobes Lechwe in the Okavango Delta, Botswana (18°45’ S, 22°45’ E) © Yann Arthus-Bertrand / Altitude

ADEME: Agence de l’Environnement et de la Maîtrise de l’Energie (French Environment and Energy Control Agency)

Carbon cycle: A series of exchanges in which carbon, an atom comprising part of the structure of living matter and present in the air in the form of carbon dioxide, contributes to vegetable and animal life before returning to the air and recommencing its journey.

Carbon Equivalent (eqC) – CO2 Equivalent (eqCO2) – t CO2e: Unit enabling comparability in terms of greenhouse effect production between the different greenhouse gases and CO2. This allows an overall assessment of the greenhouse effect caused by different types of emissions. 1 kg eqC = 0,27 kg eqCO2.

Carbon tax: Environmental tax on emissions of carbon dioxide, a greenhouse gas it is intended to limit with the aim of controlling global warming. This tax, rescinded in France in early 2010, is distinct from the carbon compensation mechanism.

Carbon sink: Reservoir of carbon whose size constantly increases, absorbing greenhouse gases. The main sinks are the ocean and vegetation. The processes producing greenhouse gases are called “sources”.

CDM (Clean Development Mechanism): cf. MDP

CER (Certified Emission Reduction) or CERU (Certified Emission Reduction Units): (Units of) certified emission reductions obtained after the validation and verification of CDM projects. CERs can be used to achieve reduction goals set by the Kyoto protocol or be traded on emissions markets.

CH4: Methane

Clean Development Mechanism (CDM): Mechanism established by the Kyoto Protocol enabling industrialised countries (Annex I) to fund projects producing a real reduction in emissions in developing countries and consequently to obtain Certified Emission Reductions credits (CERs). (Source: ADEME) Website:

Climate: Set of atmospheric and meteorological conditions specific to a region of the globe: mean weather conditions measured over a period of decades.

Climate change: Statistically significant variation in the mean state of the climate or of its variability persisting for an extended period. (Source: IPCC)

Climate Plan: Action programme developed by the French government in 2004 and intended to reduce greenhouse gas emissions in order to meet, and if possible exceed, the French objective defined by the Kyoto Protocol to stabilise emissions compared to 1990 over the period 2008–2012. (Source: ADEME)

CO2: Carbon dioxide

Ecodesign: A preventive approach characterised by considering the environment during a product’s design or improvement phase. The objective of this approach is to improve the ecological quality of the product, i.e. to reduce its negative impact on the environment throughout its lifecycle, while maintaining its quality in use. (Source: ADEME)

Emission factors (EF): An emission factor is defined as the average emission rate of a given GHG for a given source, relative to units of activity. (Source: UNFCCC)

Emission sources: main categories of emission sources in the Bilan Carbone® (Carbon Accounting) method, such as travel or downtime for example.

Energy efficiency: The rational use of energy resources, which consists of achieving a maximum reduction of energy used to provide a service.

Fossil fuels: Fuels produced from the fossilisation of organic material over millions of years (coal, oil and natural gas). When burned, they emit greenhouse gases, mainly carbon dioxide.

Greenhouse effect: A natural phenomenon essential to life on Earth. It enables the temperature in the lower atmosphere to remain at an average of 15°C. It is linked to the presence in the atmosphere of certain gases (carbon dioxide, methane, etc.) that trap the emissions from the Earth and return some of them towards the surface.

Greenhouse gases (GHG): Gaseous components in the atmosphere which absorb infrared radiation from the Earth and return part of it to the surface, helping to maintain the heat in the Earth’s atmosphere. The main GHGs of human origin are carbon dioxide (CO2), methane (CH4), tropospheric ozone (O3), fluorinated gases (HFC, PFC, SF6) and nitrous oxide (N2O). The emissions of different GHGs are often recorded in metric tons of carbon equivalent or CO2 (teqC or teqCO2). (Source: ADEME)

GWP: Global Warming Potential

HFC: Hydrofluorocarbons

Intergovernmental Panel on Climate Change (IPCC): The IPCC was created in 1988 by the World Meteorological Organization and the United Nations Environment Programme. It brings together 2,000 of the world’s most renowned climate and energy experts. It conducts studies of the scientific and technical literature available worldwide and publishes globally recognised evaluation reports as the most credible source of information on climate change. The work of the IPCC also responds to methodology questions and the specific requests made by subsidiary bodies to the Framework Convention. Its third evaluation report was published in 2001. Website:

Joint implementation: Mechanism established by the Kyoto Protocol under the terms of which a developed country can receive Certified Emission Reductions when it helps fund emission reduction projects in another developed country (including countries with transition economies). (Source: ADEME)

Kyoto Protocol: Protocol signed by around 180 countries in 1997 which came into force in 2005, aimed at combating climate change by international action to reduce the emissions of certain greenhouse gases responsible for global warming. Under the terms of the Protocol, 38 industrialised countries committed to lowering their greenhouse gas emissions between 2008 and 2012 by 5.2% compared to 1990. The Kyoto Protocol created three mechanisms to provide greater flexibility and reduce the costs caused by reducing emissions: the Clean Development Mechanism (CDM), emissions trading, and joint implementation. (Source: ADEME)

Meteorology: Scientific study of atmospheric phenomena: real-time weather conditions.

National Observatory on the Effects of Global Warming (Observatoire National sur les Effets du Réchauffement Climatique): French body created in 2001 with the aim of monitoring the issues related to an escalation of global warming, and in particular of adapting to its potential consequences in terms of climate, health and the economy. Website:

Ozone: Gas that is both essential for life on Earth and harmful to health and the environment. Situated in the stratosphere at an altitude of over 20 km, the good ozone protects life on Earth by filtering the harmful rays of the Sun (UV): this is the much talked about ozone layer. In the lower layers of air, on the other hand, this gas is produced by urban pollution, usually in sunny conditions. This ozone is harmful to humans and plant life, and is also a greenhouse gas. (Source: ADEME)

PDD: Project Design Document, document describing a project, required to qualify the project for a carbon label.

PFCs: Perfluorinated Hydrocarbons

Photosynthesis: Metabolic process of plants and some bacteria comprising, in the presence of light, the absorption and fixation of the carbon dioxide (CO2) from the air using chlorophyll and rejecting the oxygen (O2). (Source: ADEME)

PNLCC: Programme national de lutte contre le changement climatiqueNational programme to combat climate change : Action programme developed by the French government in 2000 and intended to reduce greenhouse gas emissions during the period 2000–2010. It was succeeded in 2004 by the Climate Plan. (Source: ADEME)

Project cycle: Represents the different stages of development of the projects funded by Carbon Action. In chronological order, Carbon Action preselects the projects submitted to it (Project Idea Note), visits the site, determines its participation after an in-depth analysis of the project (Project Design Document), signs a Framework Agreement with the partner and, during its implementation, makes annual checks of the actual reductions in emissions pertaining to the project, resulting in the issue of Verified Emissions Reductions (VERs).

Renewable Energy (REN): Energy produced by different natural processes (solar radiation, wind, wood, hydraulic, geothermal, etc.). Unlike the energy generated by fossil fuels, REN is inexhaustible and does not give off any greenhouse gases. (Source: ADEME)

SF6: Sulphur hexafluoride

t CO2e: see CO2 Equivalent (eqCO2)

Uncertainty: Gives the margin of error associated with a result and enables GHG emissions to be positioned in a range of values.

VER (Verified Emission Reduction): Verified reductions of GHG emissions obtained after validation and verification of voluntary projects. VERs are used in the context of voluntary initiatives carried out by natural or legal entities.