CO2equivalents

CO2 equivalents, often abbreviated as CO2e or CO2eq, is a unit of measurement used to express the amount of greenhouse gas emissions in terms of the global warming potential of one mole of carbon dioxide. Greenhouse gases, such as methane (CH4) and nitrous oxide (N2O), have different capacities to trap heat in the atmosphere over a given period. CO2e provides a standardized way to compare the climate impact of these various gases.

To calculate CO2e, the warming potential of each greenhouse gas is multiplied by its specific global warming potential (GWP) value. The GWP is a relative measure of how much heat a greenhouse gas traps over a specified time horizon, usually 100 years, compared to carbon dioxide. For instance, methane has a higher GWP than carbon dioxide, meaning that a ton of methane emissions contributes more to warming than a ton of CO2 emissions over 100 years.

Therefore, a quantity of emissions from a gas other than CO2 is converted into its equivalent amount of CO2 that would have the same warming effect. This conversion allows for a single, aggregated metric to represent the total climate impact of a mixture of greenhouse gases. CO2e is widely used in climate change reporting, carbon footprint calculations, and in setting emissions reduction targets.