The term used to describe carbon markets outside the regulatory carbon framework that does not involve international agreements. These markets are driven by voluntary commitments from organizations (e.g., energy companies, airlines) and individuals.
"Glossary", Eco securities Limited. "Challenges for a business case for high-biodiversity REDD Projects and Schemes."- A Report for the Secretariat of the CBD, February 2009, Version1.2 http://www.illegallogging.info/uploads/ecosecuritiesREDD.pdf
Transactions of Verified Emissions Reductions generated from projects certified under the voluntary certification standards comprise the voluntary carbon market. It is currently the only global market for the trade of REDD+ credits.