Voluntary standards and programs are used by companies and institutions on a purely voluntary basis. The motivation for reporting GHG emissions and purchasing carbon offsets varies and includes corporate public relations and code of ethics, a desire to go beyond what is mandated in terms of emission reductions, and to prepare for expected compliance action, e.g. the introduction of a cap-and-trade system. Because of its voluntary nature, the voluntary market for carbon offsets is much smaller than the compliance market. For an introduction on the mandatory and voluntary carbon markets, go here.
The distinction between protocols, programs and and standards can be confusing, since the terms are often loosely defined, for example several of offset programs call themselves “standards” (e.g. Voluntary Carbon Standard). For an explanation of the terms, go here.
Voluntary Offset Standards:
Organization for Standardization (ISO) standard 14064.
World Business Council for Sustainable Development/ World Resources Institute (WBCSD/WRI) Greenhouse Gas Protocol for Project Accounting
Voluntary Offset Programs:
American Carbon Registry
Climate Action Reserve
Climate, Community & Biodiversity Standards
EPA Climate Leaders
Green-e Climate Protocol for Renewable Energy
Green-e Climate Program
Social Carbon Methodology
Verified Carbon Standard