Finding gives US EPA power to regulate greenhouse-gas emissions

The US government has authorised itself to regulate greenhouse-gas emissions, with potentially costly consequences for the oil and power sectors

CARBON dioxide (CO2) and five other greenhouse gases (GHGs) present a public health hazard, according to a December ruling by the US Environmental Protection Agency (EPA). The organisation "is now authorised and obligated to take reasonable efforts to reduce greenhouse pollutants under the Clean Air Act (CAA)", said EPA head Lisa Jackson. It is "perhaps the most significant decision ever reached in environmental law", she claimed. The announcement fulfils a mandate established by a 2007 Supreme Court ruling that the EPA has the authority to regulate GHG emissions if they pose a threat to human health and welfare. At the time, it directed the EPA to review the latest scientific data on climat