On March 20, 2009,the Environmental Protection Agency submitted a proposed rule on greenhouse gas regulation to the Office of Management and Budget for OMB's review.  The proposed rule, entitled "Proposal for Endangerment Finding for Greenhouse Gasses Under the Clean Air Act," must be submitted to OMB under Executive Order 12,866 so that the OMB can determine the financial impacts the proposed rule may have prior to its issuance.  Assuming OMB approves the proposed rule, it can then be released by the EPA for public notice and comment. 

The proposed rule is not yet available to the public, however, it is presumed to be a response by the agency to the Supreme Court's decision in Massachusetts v. EPA, 127 S. Ct. 1438, 549 U.S. 497, 167 L.Ed.2d 248 (2007), which held that the EPA could not avoid its statutory obligation under the federal Clean Air Act to regulate greenhouse gas emissions from motor vehicles simply because there was uncertainty surrounding the issues related to climate change.  Citing these uncertainties, EPA argued that it would be better if EPA did not regulate greenhouse gas emissions at all.  The Court disagreed and held that if the uncertainty was so profound that EPA could not make an informed decision on greenhouse gas regulation, EPA needed to delve into the science and affirmatively say that the uncertainty was too great to allow it to make an informed decision on regulation.  The Court reasoned that since EPA was statutorily required under sections 109 and 202 of the Clean Air Act to make endangerment findings when air pollution would cause an undue impact to human health or the environment, EPA had to make its endangerment finding or else declare that it is unable to do so due to scientific uncertainty.  Without such inquiry, however, EPA could not simply decide not to regulate this subset of pollutants. 

The proposed rule's title, along with the Obama Administration's public pronouncements in favor of a nationwide cap-and-trade program for carbon emissions, indicates that the proposed rule will find sufficient scientific evidence that would warrant EPA's regulation of greenhouse gas emissions, although such information will not be known until the proposed rule is made available to the public.  Even if the proposed rule does make an endangerment finding, the proposed rule itself would not provide for regulation of carbon emissions.  Rather, the proposed rule would give EPA the statutory basis to begin drafting such regulations.  It has been suggested that EPA is considering developing regulations for the automotive and electricity generation industries, and this proposed rule would be the first step towards such regulation.