Regulatory risk hits US emissions markets

Confidence in emissions trading in the US has been shaken by regulatory changes to the traded markets for sulphur dioxide (SO2) and nitrogen oxide (NOx).

The Clean Air Interstate Rule (CAIR), enforced by the US Environmental Protection Agency (EPA) since 2005, requires reductions in emissions of NOx and SO2 from large fossil fuel-fired electric generating units. The rule is set up in several phases, with the first phase of NOx reductions in 2009 and the first phase of SO2 reductions in 2010.

The t