The Clean Air Act’s (CAA’s) prevention of significant deterioration (PSD) permitting program provides an opportunity for President Joseph Biden’s U.S. Environmental Protection Agency (EPA) to make a rapid improvement on the implementation of existing greenhouse gas (GHG) regulation. EPA’s Tailoring Rule, in 2010, made the PSD permitting program applicable to GHGs for stationary sources of air pollution. But as shown in this Comment, since 2010, PSD permits, mostly issued by state environmental agencies, have required little actual control of GHGs, specifically carbon dioxide (CO2). The Comment argues the Biden EPA should conduct an annual review of CO2 technology options for stationary sources, establish a renewed commitment to review of specific draft permits, and strengthen the existing PSD permitting database. Such actions are straightforward steps to improving the existing PSD permitting program for GHGs.