Climate targets, transition & carbon claims · Working
Marginal abatement cost
Also called: MAC
ELI5
The cost of reducing one additional unit of emissions.
Used in conversation
“State the boundary and evidence behind marginal abatement cost before publishing the claim.”
Pitch context
You will see “Marginal abatement cost” in sustainability reports, impact decks, climate plans and assurance materials when the discussion reaches climate targets, transition & carbon claims.
Why it matters: In climate targets, transition & carbon claims, the reporting boundary, method, period and evidence can materially change the claim.
Caution
State the reporting boundary, method, period and evidence; standards, regulation and assurance requirements vary.
Connected terms
- Material adverse changeThe search label “MAC” can route to both entries.
- Minimum annual commitmentThe search label “MAC” can route to both entries.
Sources & evidence · 3
Direct term-level sources and supporting source families.
- International Organization for Standardization — ISO Net Zero Guidelines and related workDirect source · institutional · checked 2026-08-16
- GHG Protocol — Standards and GuidanceDirect source · institutional · checked 2026-08-16
- IFRS Foundation / International Sustainability Standards Board — IFRS S1 and IFRS S2 Sustainability Disclosure StandardsDirect source · primary · checked 2026-08-16