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ACR StatsThe American Carbon Registry (ACR) provides a robust and secure electronic registry system for Members to transparently register offset projects as well as transfer and retire serialized project-based verified emission reductions (VERs), branded as Emission Reduction Tons (“ERTs”).

The contracting of ERTs for purchase or retirement takes place directly between buyer and seller through over-the-counter (OTC) transactions outside of the Registry system. After a sale takes place, the counter-parties record the transfer of ownership or retirement of ERTs within the Registry.

Voluntary and California Compliance Markets

ACR registers voluntary carbon market projects that meet the ACR Standards.

In addition, ACR is an Air Resources Board (ARB) approved Offset Project Registry (OPR) for the California compliance market and is now accepting offset project listing and registration for projects developed under ARB compliance and early action protocols. For more information on OPRs, the compliance offset protocols and compliance offset project listing process, see our California Compliance Offset Projects page.

Public Registry Reports

Click on the links below to view public registry reports on projects, issuance, retirement as well as buffer account balance and serial number search. Reports are sortable by column heading and can be searched, printed and/or downloaded as CSV or PDF file.


This report shows all projects submitted to the Registry which have been at a minimum certified by ACR and includes information on project type, status, geographic location as well as links to download project documentation.

Issued ERTs

This report details information about all the ERTs issued in the Registry. Information provided includes project name and type, location, quantity of ERTs issued, issuance date, serial numbers and links to download project documentation.

Retired ERTs

This report details information on all ERTs that have been retired in the Registry. Information provided includes project name and type, location, quantity of ERTs retired, retirement date, serial numbers, retirement reason and name of transferee/honoree.

Buffer Pool Account Balance

This report shows the volume of ERTs held in the buffer account to protect against forest carbon project reversals.

ERT Serial Number Search

This report allows a search for information on ERTs by serial number

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