Sustainability Language

Carbon Markets & Offsetting

American Carbon Registry (ACR)

A US-based non-profit carbon crediting programme, founded in 1996 as the world's first private voluntary greenhouse gas registry, operating in both voluntary and compliance markets.

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Definition

A carbon crediting programme and registry operated by the non-profit Winrock International. ACR approves methodologies, oversees registration and independent verification of emission reduction and removal projects, and records issuance, transfer and retirement of serialised carbon credits. Founded in 1996, it describes itself as the first private voluntary GHG registry in the world.

References

American Carbon Registry

Mission; role (methodologies, verification oversight, registry functions); founded 1996 as first private voluntary GHG registry; compliance and voluntary market operation.

Winrock International

Non-profit enterprise of Winrock; sectors covered (forestry and land use, energy, industrial); science-based methodologies.

Climate Decode

ERT heritage; governance model; ICVCM CCP labelling; relationship to ART under Winrock.

Overview

What it means

ACR grew out of Winrock's Environmental Resources Trust registry (also 1996) and is one of the longest-running offset programmes, alongside peers such as Verra, Gold Standard and the Climate Action Reserve. Its credits have been used in voluntary markets and in compliance contexts such as California's cap-and-trade programme and international aviation offsetting (CORSIA).

How it is used

Project developers register projects under ACR methodologies; credits are issued after third-party verification and retired by buyers making climate claims. ACR has emphasised "integrity-era" positioning, including early adoption of ICVCM Core Carbon Principles labelling for eligible credits.

Why it matters

Registries are the plumbing of carbon markets: their rules determine what counts as a tonne reduced or removed. ACR's age and non-profit governance make it a reference point in debates about offset quality, double counting and market integrity.

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