The supply of carbon offsets hit an all-time high of 29 million tons (Mt) of carbon dioxide equivalent (CO2e) in 2009, a 13% increase from 2008 levels. A total of 19.4 Mt of CO2e worth $74 million changed hands in offset transactions conducted last year, according to a report released this week by Point Carbon, US offset markets in 2010: The road not yet taken.

Overall, 65% of buyers purchased credits for use in a future cap-and-trade scheme, according to the report, spending a total of $48