Among the policies to be reviewed is a controversial decision to roll back guidelines put in place by the Obama administration aimed at reducing automobile greenhouse gas emissions and improving vehicle efficiency. Seventeen states are now suing the EPA over the reduced emissions standards.

Pruitt's decision to repeal the Clean Power Plan will also be scrutinized by the SAB, as will the reasoning behind the EPA's proposed transparency rule, which would limit what kind of research can be used to inform environmental regulations. "The working group is very much in favor of transparency," SAB member Alison Cullen told Nature. But she noted that the proposed rule has a "very real lack of clarity."

Though the EPA doesn't have to inform the SAB of its decisions or follow its advice, the board's responses could be used by those challenging the agency in court. "The SAB is a congressionally chartered organization," board member Steven Hamburg told Nature. "Any administration can reject our advice, but we are part of the record."

After the SAB's vote, Pruitt said in a statement, "EPA's Science Advisory Board provides valuable independent expertise that informs and improves EPA's actions. We look forward to the board's feedback and insight that develop from this meeting."