EPA this week granted a petition for reconsideration of a Bush Administration memo regarding the scope of the Clean Air Act. The interpretive memo, put forward by then-EPA Administrator Stephen Johnson in December 2008, addresses when the Prevention of Significant Deterioration program applies to carbon dioxide, a chief greenhouse gas.

Concerns were soon raised about the memo’s potential impact on American communities and neighborhoods, according to EPA. The Sierra Club and other parties in early January petitioned EPA to reconsider the Johnson memorandum.

EPA’s announcement could be part of a long-term process that will dramatically shift U.S. energy and climate change policy, with the Clean Air Act being used by the Obama administration as one tool to regulate carbon dioxide emissions in transportation, manufacturing, and power generation. EPA is under an order from the Supreme Court to determine whether carbon dioxide is a pollutant that endangers public health and welfare.

“I am granting this petition because we must learn more about how this memo affects all relevant stakeholders impacted by its provisions,” said EPA Administrator Lisa P. Jackson, in a press statement. “This will be a fair, impartial and open process that will allow the American public and key stakeholders to review this memorandum and to comment on its potential effects on communities across the country. EPA’s fundamental mission is to protect human health and the environment and we intend to do just that.”

EPA said it will “vigorously review” the Johnson memo to ensure that it is consistent with the Obama administration’s climate change strategy and interpretation of the Clean Air Act. While conducting this review, EPA will abide by the three core principles outlined by Administrator Jackson: overwhelming transparency, adherence to the rule of law, and science-based policies and regulations.

To facilitate a transparent, impartial and fair review, EPA will seek comment from the general public on this memo and its potential impact on American communities. This public comment period is consistent with the recommendations of the Environmental Appeals Board and allows for a measured, inclusive approach to reviewing this memo, according to EPA. The EAB last year held that EPA had not adequately articulated why its interpretation of the PSD program did not apply to carbon dioxide.

The action is the latest in a series of steps intended to ensure EPA policies and procedures are consistent with EPA’s overall mission to protect human health and the environment.

The response letter to the Sierra Club can be accessed at: www.epa.gov/air/nsr/guidance.html