Understanding Additionality in Carbon Crediting
Additionality asks whether the credited outcome depends on the incentive created by the carbon-crediting mechanism.
Additionality addresses a counterfactual question: would the emission reduction or removal have occurred without the carbon-crediting incentive?
Because the alternative future cannot be directly observed, methodologies use evidence and tests. Depending on the program and activity, these may consider regulation, common practice, barriers, investment conditions or specific performance thresholds.
A claim about causation
Additionality is not the same as environmental benefit. An activity can be beneficial and still be non-additional if it would have happened anyway. It is also not established simply because an activity is uncommon or expensive.
The relevant test and evidence depend on the methodology. Readers should avoid treating one approach as universal, and should check the applicable version of the official rules.
Additionality remains challenging because circumstances change. Policies, technology costs and common practice can evolve over a crediting period. Methodological design must consider when assumptions are set and how they are reassessed.