In 2007, the Supreme Court affirmed the EPA’s ability to regulate greenhouse gas emissions under the Clean Air Act. Designing a regulatory scheme for GHGs, however, is difficult. Carbon dioxide, a ubiquitous GHG, is a byproduct of almost every industry in America, and regulating it places a heavy burden on emitters and administrators alike. The EPA sought to alleviate this burden by promulgating two new rules, the Timing and Tailoring Rules, designed to phase in regulation over a period of years. States and industry groups recently challenged these rules in the D.C. Circuit court in the case Coalition for Responsible Regulation, Inc. v. EPA, but could not show the type of concrete injury necessary for Article III standing. This ostensible victory for environmental advocates contains a sting in the tail: The court’s narrow construction of standing will hinder future challenges to GHG regulation, including those intended to spur greater action.