Although 174 nations approved the admittedly flawed Kyoto accords to reduce carbon levels, the arguments between the US and the EU on this issue still exist.

Environmental groups are also backing Britain's call for the EU to cut carbon emissions by 30 percent by 2020, instead of their agreed 20 percent.

That cap will be cut each year after 2013: this should help to support carbon prices in the EU's Emissions-Trading Scheme.