In Massachusetts v. Environmental Protection Agency, 549 U.S. 497 (127 SC 1438, 167 LE2d 248) (2007) the Supreme Court held that CO2 and other "greenhouse gases" qualify as "air pollutants" under section 302 (g) of the CAA; that the EPA therefore has authority to regulate emissions of these pollutants from new motor vehicles under section 202 (a) (1) of the CAA, and that the CAA requires the EPA to exercise this regulatory authority if the EPA Administrator makes the predicate finding that emissions of these pollutants cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare. 549 U.S. at 528-535. The Court found that CO2 qualifies as an air pollutant under the CAA, established that CO2 is a pollutant "subject to regulation under the CAA" for purposes of the PSD permit. The court also found that regulations monitoring or reporting CO2, but not controlling or limiting CO2 emissions under the CAA, establish that CO2 is a pollutant "subject to regulation under the CAA" for purposes of the PSD permit. The court then ruled that, because CO2 was "subject to regulation under the CAA," CO2 was by definition a "regulated NSR pollutant" for which an emission limitation was required pursuant to BACT to obtain a PSD permit. It followed, the court concluded, that the Georgia SIP (which incorporates the applicable CAA provisions) required the EPD to control the power plant's CO2 emissions using BACT.