Does EPA support regulating the emissions of greenhouse gases from aircraft? If not, why not?"

This is but one of the seven questions put to EPA Administrator Stephen Johnson in a January 8, 2008 letter from Rep. Edward Markey (D.-Mass), chair of the House Select Committee on Energy Independence and Global Warming. The letter references EU plans to include aircraft emissions in the ETS beginning in 2011 and seeks "specific answers" regarding EPA's intent to address "the link between aviation and global warming." It comes on the heels of an investigation Markey launched last summer into whether the FAA had considered the effects of climate change in developing a long-term plan to deal with the expected tripling in U.S. air travel over the next 20 years, as well as a petition submitted to EPA last month by several states and environmental groups demanding that the agency regulate GHG emissions from aircraft under the Clean Air Act. The letter cites a 2007 EPA GHG inventory for the proposition that in 2005, combustion of aviation fuel was responsible for approximately three percent of U.S. GHG emissions.