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Carbon Offset Standards, Methodologies and Protocols

The American Carbon Registry (ACR) registers voluntary carbon market projects that meet the ACR Standards, as described below. In addition, ACR has been approved by the California Air Resources Board (ARB) as an Offset Project Registry (OPR) for the California compliance market.

California Compliance Offset Protocols

To be eligible for compliance in the California cap-and-trade system, offset projects will be required to use ARB-approved compliance or early action offset protocols, to be verified by ARB-approved verification bodies, and to register on an ARB-approved Offset Project Registry (OPR) or Early Action Offset Program, such as American Carbon Registry. For more information on the California compliance offset program, see our California Compliance Offset Projects page.

American Carbon Registry Standards and Methodologies

The American Carbon Registry (ACR) publishes standards, methodologies, protocols and tools for greenhouse gas (GHG) accounting, which are all based on International Standards Organization (ISO) 14064 and sound scientific practice. ACR only registers project-based carbon offset tons that are real, additional, permanent and independently verified.

ACR process for development and approval of standards and methodologies is led by a qualified technical team. Approval includes a public comment period and a scientific peer review process, a rigorous technical review by experts in the relevant field(s). This combination of approaches ensures that our published standards and methodologies are the highest quality.

The Winrock and ACR team that leads the development of standards and methodologies includes internationally recognized leaders in the forestry, agriculture and clean energy sectors and is widely recognized for its deep expertise in carbon accounting. Team members have co-authored carbon project protocols for the Clean Development Mechanism (CDM), U.S. Environmental Protection Agency (EPA), U.S. Department of Energy (DOE), the U.S. Department of Agriculture (USDA), the USDA Forest Service, the California Energy Commission (CEC), the World Bank, the International Tropical Timber Organization and United Nations organizations.

ACR Standards

Standard Version Status

American Carbon Registry Standard

Forest Carbon Project Standard

ACR Nested REDD+ Standard

3.0

2.1

1.0

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ACR Approved Methodologies

Methodology Version Status

Conversion of High-Bleed Pneumatic Controllers in Oil and Natural Gas Systems

Improved Forest Management (IFM) on U.S. Timberlands

N2O Emission Reductions through Changes in Fertilizer Management

Afforestation and Reforestation of Degraded Lands

REDD - Avoiding Planned Deforestation

Switch from non-renewable biomass for thermal applications

100-year Improved Forest Management (IFM) on U.S. Timberlands

Improved Forest Management (IFM) on Non-Federal U.S. Forestlands

REDD Methodology Modules

N2O Emission Reductions through Reduced Use of Fertilizer on Agricultural Crops

Emission Reductions through Truck Stop Electrification

Restoration of Degraded Deltaic Wetlands of the Mississippi Delta

Emission Reductions in Rice Management Systems

Emission Reductions in Rice Management Systems - Mid-South Module

Avoided Conversion of Grasslands & Shrublands to Crop Production


Grazing Land and Livestock Management

Carbon Capture and Storage (CCS) in Oil and Gas Reservoirs

Energy Efficiency Measures in Thermal Applications of Non-Renewable Biomass

Low GHG emitting safe drinking water production systems

Reduction in Emissions from the Recycling of Transformer Oil

Reduced Carbon Intensity in Fed Cattle

Improved Vehicle Fleet Efficiency

Emissions Reductions from Biochar Projects

EPA Climate Leaders Landfill Gas Offset Methodology

Emissions Reductions from Compost Additions to Grazed Grasslands

California Deltaic and Coastal Wetland Restoration

1.1

1.0

2.0

1.1

1.0

2.0

1.0

1.0

1.0

1.0

1.1

1.0

1.0

1.0

1.0

1.0

1.0

1.1

1.0

1.0

1.0

2.0

1.0

1.3

1.0

1.0

Published

Published

Published

Published

Published

Published

Published

Published

Published

Published

Published

Published

Published

Published

Published

Public comment period closed

Public comment period closed

Published

Published

Published

Public comment period closed

Published

Public comment period closed

Published

Public comment period open

In Development



New Methodologies

The American Carbon Registry promotes innovation to bring new offsets types to market. Project developers are welcome to submit new offset methodologies and methodology modifications for evaluation. New methodologies and methodology modifications are approved for use through ACR's public comment and scientific peer review process. Upon approval, ACR will publish the methodology for future use.

Other Accepted Methodologies

American Carbon Registry (ACR) generally accepts methodologies and tools approved for use by the Clean Development Mechanism (CDM). However, project proponents wishing to use a CDM methodology should first consult ACR for a review to include applicability as well as clarifications and/or conditions for its use for registration on ACR.

ACR may also elect to approve environmentally robust methodologies from other programs to the extent that they have been through a public stakeholder process and comply with ACR’s Standards.

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