Frequently asked questions

A carbon credit is a certificate representing one tonne of CO2 equivalent that a project avoided or removed, checked by an independent auditor and recorded in a registry. It should be retired once it is used for a claim so that nobody can count it again.

One carbon credit equals one tonne of carbon dioxide equivalent (1 tCO2e) under all the major standards, including Verra, Gold Standard and India's CCTS. Other gases such as methane are converted into CO2 equivalent using IPCC global warming potential values.

Credits are earned only by a registered project that follows an approved methodology, passes independent validation and verification, and then has credits issued by a programme such as Verra, Gold Standard or India's CCTS. This takes time, money and monitoring, and income is never guaranteed, so treat any promise of easy earnings with caution.

Avoidance credits pay for emissions that were prevented, such as methane captured at a landfill, while removal credits pay for CO2 taken out of the air and stored, such as in new forests or underground. Removals are usually seen as more relevant for balancing residual emissions in net zero plans.

Additionality means the emission cut or removal would not have happened without the money from selling carbon credits. If a project would have gone ahead anyway, its credits do not represent any extra climate benefit.

Retiring a credit means cancelling it permanently in the registry when it is used for a claim, so it cannot be sold or counted again. Always ask for the registry retirement record with the serial numbers and the name of the organisation it was retired for.

A CCP label shows that a credit meets the Core Carbon Principles of the Integrity Council for the Voluntary Carbon Market (ICVCM). It requires both an approved crediting programme and an approved credit category or methodology, and the list of approvals changes over time.

Carbon credits are not a scam in themselves, but their quality varies a lot and some projects have been criticised for issuing more credits than their real impact. Check the standard, methodology, additionality, permanence and retirement record, and use credits only alongside real emission cuts.