tCO₂e (Tonne of CO₂ Equivalent)
The standard unit of the carbon market: one metric tonne of carbon dioxide, or the amount of another greenhouse gas with an equivalent warming effect. One carbon credit represents one tCO₂e.
Why the tCO₂e unit matters for carbon credit buyers
Every price, volume, and target in the market is expressed in tCO₂e, which is what makes different project types comparable at all. Non-CO₂ gases are converted using global warming potential factors, which is how a small volume of methane or nitrous oxide can generate a large number of credits. Those factors depend on which IPCC assessment report a methodology references and over what time horizon, so credits from different vintages are not always calculated on identical assumptions. A simple check before comparing quotes: confirm the price is per tCO₂e rather than per bundle, per hectare, or per project.
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