Understanding Carbon Offsets
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Protocols & Standards

The distinction between protocols, programs, standards, and registries can be confusing since the terms are loosely defined. For example, several offset programs call themselves “standards” (e.g., Verified Carbon StandardGold Standard) and “registries” (e.g., American Carbon Registry) though these are offset programs that have the same basic functions and components. We suggest you use these general definitions:

Offset Project Protocol / Methodology

Project Protocols / Methodologies cover GHG accounting rules and program requirements for monitoring, reporting, verification, and certification. In other words, they outline the rules and procedures to determine project eligibility, additionality, and baseline and project emissions for a particular project type. The terms “protocol” and “methodology” are often used interchangeably. Offset Programs either have their own protocols/methodologies for a set of project types or approve the use of protocols developed by another offset program.

Offset Programs

There are three core components of a carbon offset program:

  1. Eligibility definitions and rules for the design and early implementation phase of a project. They can include additionality and baseline methodologies, definitions of accepted project types, and procedures for validating project activities.
  2. Monitoring, reporting, verification, and certification rules ensure that offset projects perform as they were predicted to during project design. Certification rules are used to confirm the actual GHG reductions that can enter the market once the project is implemented.
  3. Registration and enforcement systems clarify ownership, enable trading of credits, track credit retirement, and ensure that credits are not double counted through sale to multiple buyers. These systems must include a registry with publicly available information to uniquely identify offset projects and a system to transparently track ownership and ownership transfers of credits.

Offset Registries

An offset registry is a system for reporting and tracking offset project information including project status, project documents, credits generated, ownership, sale, and retirement. Offset Programs must utilize a registry.


Standards can include protocols/methodologies and guidance documents. These standards provide guidance and/or specifications on GHG quantification, monitoring, reporting. Stand-alone standards typically do not have an associated regulatory body that registers projects and also do not typically have registration and enforcement systems to track and ensure legal ownership of offset credits (e.g., ISO 14064-2). In other words, standards do not have registration and enforcement systems. The use of a standard alone is therefore not sufficient to guarantee the quality of offset credits. Many offset programs have their own standards, as part of their program, that outline requirements and guidance for offset projects using their system.