This article argues that this decision was wrong as a matter of statutory construction and sound as a matter of sound social policy: the CAA is the wrong vehicle to deal with either carbon dioxide of global warming. On the present state of the evidence, the case for strong restraints on carbon dioxide emissions has not been made. The evidence in favor of the close linkage between carbon dioxide and global warming has not been clearly established and domestic American initiatives are in any even likely to produce no discernible reduction in carbon dioxide levels in the absence of any agreement that binds other nations, especially China and India.