CarbSet Glossary
Alphabetised definitions of the core terms used across CarbSet, from the AAA to D grade scale and the five quality dimensions to registries, eligibility flags, vintages, and retirement.
How to use this glossary
Terms are listed alphabetically. Where a term relates to quality scoring, remember the platform's honesty position.
All quality assessments on CarbSet are currently provisional. This means scores have not yet been independently verified by an external assessor. A Provisional badge is shown wherever a grade appears.
A
AAA to D grade scale: CarbSet's financial-grade quality rating, aligned with the conventions used by specialist carbon raters. AAA is the highest quality and D is the lowest. The full ladder runs AAA, AA, A, BBB, BB, B, CCC, and D. The grade is derived from a composite score across five dimensions.
Additionality: One of the five quality dimensions. It asks whether the emission reduction would have happened anyway without the credit revenue. If a project would have gone ahead regardless, its credits are not additional and the climate benefit is weak.
Article 6: The mechanism in the Paris Agreement that allows one country to transfer a mitigation outcome to another and have it counted towards a national climate target. It requires host-country authorisation and a corresponding adjustment to prevent double counting.
C
Claim suitability: CarbSet's guidance on the strongest defensible use for a credit. One of five values: corporate_net_zero, internal_carbon_price, voluntary_offset, compliance_adjacent, or not_recommended.
Co-benefits: One of the five quality dimensions. It captures positive effects beyond carbon, such as biodiversity protection, clean water, gender equity, community jobs, and education.
CORSIA: The Carbon Offsetting and Reduction Scheme for International Aviation. A compliance scheme under which airlines offset emissions from international flights using eligible credits, usually tied to a defined vintage period.
G
Gold Standard: A carbon credit registry known for its emphasis on sustainable development and community co-benefits alongside verified carbon reductions.
Grade: See AAA to D grade scale.
I
ICVCM: The Integrity Council for the Voluntary Carbon Market. It publishes the Core Carbon Principles (CCP), a benchmark that marks high-integrity credits.
ITMO: Internationally Transferred Mitigation Outcome. A mitigation outcome transferred between countries under Article 6. It needs host-country authorisation and a corresponding adjustment.
IVU: Impact Value Unit. A future cross-category unit of account intended to let carbon, plastic, water, and other impact types be compared on a common scale. It is not active in Phase 1.
M
Measurement: One of the five quality dimensions. It assesses how accurately the project quantifies its emission reductions or removals, including the rigour of its monitoring data.
P
Permanence: One of the five quality dimensions. It asks how durable the climate benefit is and how likely it is to be reversed, for example by a forest fire releasing stored carbon.
Provisional: The current state of every quality assessment on CarbSet. A provisional assessment has been drafted internally but not yet confirmed by a qualified external assessor. A Provisional badge appears wherever such a grade is shown.
R
REDD+: Reducing Emissions from Deforestation and forest Degradation, plus the sustainable management and enhancement of forest carbon stocks. A major project category focused on keeping forests standing.
Registry: An independent body that sets methodologies, reviews projects, issues credits with unique serial numbers, and records retirements. Gold Standard and Verra are the registries listed on CarbSet.
Retirement: The permanent cancellation of a credit on its registry so it can never be used again. Retirement is what converts ownership into a valid offset claim.
V
Verification: One of the five quality dimensions. It reflects the strength and independence of the third-party review that confirmed the project's claims.
Verified: A status describing an assessment that a qualified external assessor has confirmed with supporting evidence. No CarbSet assessment holds this status in Phase 1; all are provisional.
Verra: A carbon credit registry that operates the Verified Carbon Standard (VCS), the largest voluntary programme by issued volume.
Vintage: The calendar year in which a credit's emission reduction or removal actually occurred. It is distinct from the year of purchase.
VCM: Voluntary Carbon Market. The market in which organisations and individuals buy credits by choice, rather than to meet a legal compliance obligation.