Voluntary markets for emissions reductions that are not compliant with the Kyoto protocol, for sale to corporations and individuals who want to offset their emissions for non-regulatory purposes. Emissions offsets in this latter category are verified by independent verifiers, but are not certified by a regulatory authority for use as a compliance instrument, and are commonly referred to as Verified Emission Reductions (VER's).

Voluntary markets for emissions reductions that are not compliant with the Kyoto protocol, for sale to corporations and individuals who want to offset their emissions for non-regulatory purposes. Emissions offsets in this latter category are verified by independent verifiers, but are not certified by a regulatory authority for use as a compliance instrument, and are commonly referred to as Verified Emission Reductions (VER's).

• The Chicago Climate Exchange (CCX): a US voluntary trading scheme
  Chicago Climate Exchange is a self-regulatory exchange that administers the world's first multi-national and multi-sector marketplace for reducing and trading greenhouse gas emissions. CCX represents the first voluntary, legally binding commitment by a cross-section of North American corporations, municipalities and other institutions to establish a rules-based market for reducing greenhouse gases.
• California Climate Action Registry
  The California Climate Action Registry (the Registry) was established by California statute as a non-profit voluntary registry for greenhouse gas (GHG) emissions. The purpose of the Registry is to help companies and organizations with operations in the state to establish GHG emissions baselines against which any future GHG emission reduction requirements may be applied.
• Canada and Japan are setting up own GHG emissions trading scheme for large emitters
  Those National schemes are expected to be implemented in 2008 and link to Kyoto respectivley the EU ETS

Other than these formalised voluntary schemes, a retail market exists consisting of small project-based emissions reductions (not for compliance or trading). These are difficult to monitor in terms of traded volumes.