Understanding Carbon Offsets
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American Carbon Registry

Type of Standard and Context

The American Carbon Registry (ACR) was founded in 1996 as the GHG Registry, the first private voluntary GHG registry in the USA, by the environmental non-profit organization Environmental Resources Trust (ERT). In 2007, ERT and its registry became part of Winrock International, a non-profit based in the USA. The registry was re-branded as American Carbon Registry (ACR) in 2008. In 2012, ACR was accepted as an approved Offset Project Registry by the California Air Resources Board within the California cap-and-trade compliance offset market. The American Carbon Registry Standard outlines the eligibility requirements for registration of project-based carbon offsets and includes requirements for methodology approval, project validation and verification, and other procedural requirements and information on the general use of the American Carbon Registry. This external link provides a summary of changes made between versions, and public comment and responses.

Standard Authority and Administrative Bodies

Direct oversight of ACR is provided by the Winrock International Management and Executive Teams, as well as the Winrock International Board of Directors. Technical decisions are made by sector-specific Technical Committees (e.g., agriculture forestry and other land use – AFOLU) who review new methodologies and tools, advise the selection of scientific peer reviewers, and advise ACR on the need to update standards and commission new methodologies or tools.

ACR’s methods are developed by ACR staff with assistance and support from Winrock International. methods undergo public comment and external scientific peer review. Methodologies are developed internally by Winrock staff or can be developed by third parties and brought to ACR for approval. All approved methodologies have undergone public comment and blind scientific peer review.

ACR approved Validation and Verification Bodies (VVBs) must meet the competency requirements laid out in ISO 14065 and ISO14066 and be IAF member-accredited in the relevant project sector. VVBs may be chosen from a list on ACRs website.

Regional Scope

ACR registers project-based carbon offsets from around the globe, although some sectors and methodologies within the ACR Program prescribe regional applicability limitations.

Recognition of Other Standards/ Linkage with Other Trading Systems

ACR methodologies and protocols are all based on International Standards Organization (ISO) 14064. ACR allows project developers to use methodologies and tools for GHG measurement from the CDM to the extent that they comply with the ACR’s published standards. Projects may be transferred between ACR and another registry provided all unsold, non-transferred, and non-retired offset credits are canceled. ACR acts as one of the compliance market registries for the California cap-and-trade regulatory system.