EPA calls greenhouse gases a public threat

The Environmental Protection Agency on Friday took the first step toward regulating greenhouse gas emissions by proposing a ruling to declare greenhouse gases a cause of global warming and a threat to public welfare.

EPA Administrator Lisa Jackson proposed the ruling after completing the scientific review ordered by the Supreme Court in 2007, when it ruled that the agency has the authority to regulate emissions from vehicles. Before the EPA can officially adopt the ruling or take any regulatory actions, the proposed ruling must undergo a 60-day public comment period.

"This finding confirms that greenhouse gas pollution is a serious problem now and for future generations," Jackson said in a statement. "Fortunately, it follows President Obama's call for a low carbon economy and strong leadership in Congress on clean energy and climate legislation. This pollution problem has a solution-one that will create millions of green jobs and end our country's dependence on foreign oil."

The proposed ruling is based on a peer-reviewed scientific analysis of the six gases in question: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.

"The current global atmospheric concentrations of the six greenhouse gases are now at unprecedented and record high levels compared to both the recent and distant past," the ruling (PDF) says. "It is also unambiguous that the current elevated greenhouse gas concentrations are the primary result of human activities."

It also calls the U.S. transportation sector is a "significant contributor" to U.S. and global carbon emissions.

In addition to saying human emissions have caused an increase of global temperatures and subsequently changes like increased drought, more intense storms, and more flooding, the ruling says climate change has serious national security implications.

"Climate change can aggravate existing problems in certain regions of the world such as poverty, social tensions, general environmental degradation, and conflict over increasingly scarce water resources," it says.

While the proposed ruling could lead to regulatory action, Jackson, President Obama, and other administration leaders have said they would prefer to see comprehensive legislation to address the issue.

"There are things that can be done that won't quite work within the existing law," White House "energy czar" Carol Browner said Monday.

Congressional hearings are set to begin on Tuesday on a cap-and-trade bill under consideration.

Washington is also attempting to address climate change and carbon emissions in conjunction with other nations. President Obama and Mexican President Felipe Calderon announced Thursday that Mexico and the U.S. are establishing a "bilateral framework on clean energy and climate change" that will allow for greater political and technical cooperation and facilitate joint efforts to develop clean energy economies. Players in the global carbon market expect actions by the United States to have a significant impact on the market.