At the close of trading on September 22, 2010, prices for a credit representing avoidance of one metric ton of carbon dioxide equivalent emissions in December 2010 was as follows:

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These prices reflect continuing stability in the European markets, although the prices are down slightly since summer. Market prices for offsets in the United States continue to fall, representing a 20 to 30 percent decrease in prices for the Regional Greenhouse Gas Initiative ("RGGI") and California Climate Registry since last winter, reflecting continuing doubts over the future of carbon regulation in the United States. According to a recent report, the volume of trading for RGGI allowances in the first quarter of 2010 dropped by 83 percent from the fourth quarter of 2009. The report attributes the decline to the recession and the corresponding decline in demand for electricity, as well as to falling natural gas prices. The decrease in demand for electricity has also resulted in utilities holding excess allowances, further depressing demand for allowances. In response to the depressed market, the Chicago Climate Exchange announced on October 21 that it will end its trading program for emission allowances at the end of 2010 and will focus on its emission offset registry program.

A surplus of unused emission allowances in the European Union Emissions Trading Scheme ("EU-ETS") as manufacturing production, and therefore carbon emissions, have decreased due to the global recession also explains, in part, the recent price decreases in Europe. Beyond depressing carbon prices in the near term, a recent report warns that this surplus could hinder post-recession carbon reductions in the European Union. Because the EU-ETS allows unused emission allowances to be carried over into the next trading phase (2013–2020), the wide availability of such unused allowances could blunt market incentives to reduce emissions or invest in low carbon technologies during this next phase. On the other hand, companies that have accumulated these unused permits argue that they will be necessary as the economy improves and production levels increase. Volatility or depressed prices in the carbon markets are likely to continue until the future framework for carbon regulation is more certain.