The global market in carbon credits tripled to £15 billion last year up from £5bn in 2005, according to a World Bank report published last week. State and Trends of the Carbon Market 2007 attributed the bulk of carbon trading, valued at approximately £12.5bn, to the sale and re-sale of allowances under the European Union’s emissions trading scheme. Officially-backed carbon offsetting projects, where under the Kyoto agreement companies and countries can invest in emission reduction schemes in developing countries and economies in transition, nearly doubled to £2.5bn, the report said. The carbon market intelligence study estimated that carbon purchases raised £8bn in “associated investments” supporting clean energy in developing countries since 2002. The study also found that the voluntary market, whereby actions by companies and individuals are not required by the Kyoto Protocol or other regimes, is estimated to grow to 400 million tonnes by 2010. However, the report warned that this voluntary market, with its lack of associated robustness, risked undermining the overall growth of the regulated market.