American Carbon Registry (ACR) is a nonprofit greenhouse gas crediting program and registry operated by Winrock International. Founded in 1996, it develops standards and methodologies for quantifying, monitoring, reporting, and verifying emissions reductions and removals in the voluntary carbon market. ACR provides an online registry system to list projects, track ownership, and retire credits, supporting transparency and environmental integrity.
ACR issues serialized carbon credits, known as Emission Reduction Tonnes (ERTs), after independent third-party verification against the ACR Standard. Its methodologies cover a broad range of sectors, including improved forest management and avoided conversion, agricultural practices (e.g., methane and nitrous oxide reductions), methane capture and destruction, industrial process improvements, biochar, and engineered solutions such as carbon capture and storage. ACR’s framework addresses additionality, permanence, leakage, and rigorous monitoring to ensure high-quality credits. The program is used by project developers and credit buyers globally and has been referenced by select compliance-linked and aviation programs alongside voluntary market use.