Understanding Carbon Offsets

Registries & Enforcement


Enforcement systems assure that contracts clearly identify ownership of carbon credit and define who bears the risk in case of project failure. Carbon offset registries track crediting projects and issue offset credits for each unit of avoided emission or enhanced removal that is verified and certified. Registries are vital in creating a credible, fungible carbon credit commodity. Registries record the ownership of credits. A serial number is assigned to each verified carbon credit. When a credit is sold, the serial number for the credit is transferred from the account of the seller to an account for the buyer. If the buyer “uses” the credit by claiming the avoided emissions or enhanced removals against their own emissions, the registry retires the serial number so that the credit cannot be resold. In this manner, registries reduce the risk of double counting (that is, to have multiple stakeholders take credit for the same credit.) Registration and enforcement systems must include:

  • A registry with publicly available information to uniquely identify crediting projects.
  • Serial numbers for each carbon credit generated by each project.
  • A system to transparently track ownership of carbon credits which makes it possible to trace each credit back to the project from which it originated.
  • A system to easily check on the status of a carbon credit (i.e., whether a credit has been retired).
  • Contractual or legal standards that clearly identify the original “owner” of carbon credits.
  • Contractual or legal standards that spell out who bears the risk in case of project failure or partial project failure (e.g., who is responsible for replacing the credits that should have been produced by the failed project).

Voluntary Market Registries

There are several registries in the voluntary carbon credit market, which have been developed by governments, independent non-profits, and the private sector. The following voluntary registries are currently operating: