Trading Scheme (EU ETS) is the largest international multi-sector greenhouse gas (GHG) emission trading scheme world-wide. Its main objective is to support the EU in cost-efficiently achieving its Kyoto commitment of reducing GHG emissions by minus 8% until 2012 (as compared to 1990 emission levels). Currently, the EU ETS covers CO2 emissions of around 12.000 large stationary emitters. These have to surrender one emission right for each tonne of CO2 emitted yearly. The total number of emission rights in circulation is capped at EU level a