Additionality
Would the emissions reductions have happened anyway? Additionality is the test that separates real climate impact from business-as-usual repackaged as carbon credits.
A project is additional if the emissions reductions or removals it claims would not have occurred without revenue from carbon credits. This includes financial additionality (the project needs carbon finance to be viable), regulatory additionality (it goes beyond what law requires), and common-practice additionality (it is not already standard in the region).
Non-additional credits are the single biggest reputational risk in the voluntary carbon market. Buying them means paying for reductions that would have happened anyway — funding marketing, not climate.
Regulators (CORSIA, EU CSRD, SBTi) increasingly require buyers to demonstrate additionality, not just registry listing.
Financial test
Investment analysis or benchmark analysis showing the project's IRR is below industry hurdle without carbon revenue.
Barrier analysis
Documented technological, institutional or capacity barriers the project overcomes that comparable activities do not.
Regulatory surplus
The activity is not mandated by enforced law in the host jurisdiction at the time of registration.
Common-practice test
Penetration of similar technologies in the region; we down-score projects above ~20% market share.
- VCS VT0001 — Tool for the Demonstration and Assessment of AdditionalityVerra's flagship additionality tool, applied across most VCS methodologies.
- CDM Tool 01 / Tool 02The original UN CDM additionality and barrier tools, still referenced by many standards.
- Gold Standard Additionality Guidelines v2.2Combines financial, barrier and common-practice tests with mandatory stakeholder evidence.
- Article 6.4 SBM-DRThe Paris Article 6.4 Supervisory Body's draft additionality requirements for the new UN mechanism.
- Project economics are positive without carbon revenue (high IRR baseline).
- Activity is already mandated by national or sub-national regulation.
- Technology has >20% market penetration in the host region.
- Crediting baseline assumes practices the developer was already doing.
- Retroactive crediting for actions taken before project registration.