Glossary entry

Carbon Dioxide Equivalent (CO2e or CO2eq)


Option 1

Carbon Dioxide Equivalent (CO2e or CO2eq) means the standard metric measure used by [the UN’s Intergovernmental Panel on Climate Change (IPCC)] [in industry] [for vehicles] to compare the emissions from various Greenhouse Gases (GHGs) on the basis of their global warming potential over a specified timescale in order to express a Carbon Footprint that consists of different GHGs as a single number.

Option 2

Carbon Dioxide Equivalent (CO2e or CO2eq) means a unit of measurement that is used to standardise the climate effects of various Greenhouse Gases.

Drafting notes

The various Greenhouse Gases (GHGs) do not contribute to the greenhouse effect to the same extent and they remain in the atmosphere for different periods of time. In order to make the effects of different GHGs comparable, the Intergovernmental Panel on Climate Change (IPCC) of the United Nations has defined the Global Warming Potential (GWP) for each GHG. This index expresses the warming effect of a certain amount of a GHG over a set period of time (usually 100 years) in comparison to carbon dioxide (CO₂). For example, methane’s effect on the climate is 28 times more severe than CO₂, but it doesn’t stay in the atmosphere as long.


Used in the definition of Carbon Footprint, Carbon Budget, Carbon Reporting and Declared Carbon Capacity (of Woodland). Very wide application, being a useful metric.  Could be used in any document where you would otherwise refer simply to carbon or GHGs, for example supply chain clauses, national climate laws, project finance documents (e.g. loan, guarantee and recourse agreements, engineering, procurement and construction contracts), policy documents.

Used in Zain’s Clause [Mutual Sustainability Rights], Callum & Theo’s Clause [Climate Standard Transaction Terms] and Tristan’s Clause [Construction Materials: Procurement].