Last Friday, the U.S. Court of Appeals for the D.C. Circuit (“D.C. Circuit”) upheld the Environmental Protection Agency’s (“EPA”) “exceptional events rule,” which allows data recorded during unusually strong storms or natural disasters to be excluded when determining whether an area violates federal air quality standards.

The U.S. Environmental Protection Agency (“EPA”) has reached a proposed determination regarding whether or not greenhouse gas (“GHG”) emissions endanger public health, public welfare, or both. Not yet published, EPA’s proposed “endangerment finding” was submitted to the White House Office of Management and Budget (“OMB”) on Friday, March 20th, and is currently undergoing an inter-agency review led by the OMB.

In a Notice of Proposed Rulemaking issued by the U.S. Environmental Protection Agency (“EPA”) on March 10, 2009, EPA has proposed a nationwide system for the reporting of greenhouse gas (“GHG”) emissions by large industrial sources. In doing so, the Agency has taken the initial step toward federal regulation of GHG emissions.

A document leaked from the EPA offers an inside look on the Agency’s plans with respect to making an “endangerment finding” as a prelude to regulating GHGs under the Clean Air Act (“CAA”).

The National Ambient Air Quality Standard (“NAAQS”) for ozone established by the EPA under the Bush administration was challenged by a coalition of environmental and health advocacy groups, and is currently the subject of pending litigation in the U.S. Court of Appeals for the D.C. Circuit. EPA has now requested that the briefing schedule in that case be suspended for six months, in order for the new administration to review the existing ozone NAAQS and determine whether revision is warranted.

President Obama on Tuesday issued a memorandum directing the Departments of Commerce and the Interior to reconsider regulations they had issued in December of last year to limit the impact of the listing of the polar bear as a threatened species. Although the Interior Department found that the number of polar bears have been increasing in the last several decades, the Department last year listed the polar bear as a threatened species based on actual and modeled future loss of Arctic sea ice.

On Tuesday, the U.S. Environmental Protection Agency (“EPA”) granted a petition from the Sierra Club and others to reconsider former EPA Administrator Stephen Johnson’s December 18, 2008 memorandum interpreting the federal Clean Air Act as not requiring regulation of carbon dioxide emissions from new coal-fired power plants.