On July 11, 2008, the Environmental Protection Agency issued an Advance Notice of Proposed Rulemaking (ANPRM) regarding the regulation of greenhouse gas emissions under the Clean Air Act. Included in the ANPRM was a discussion by the EPA of how to respond to petitions that were filed in December 2008 for the regulation of aircraft emissions of greenhouse gases. In essence, the EPA is deferring decisionmaking until the next Administration, but also soliciting input from the public regarding how to address greenhouse gases generally and aircraft specifically.