How do the United States Courts of Appeals decide environmental cases? More specifically, how do courts evaluate decisions of statutory interpretation made by government agencies that deal in environmental law? While research on judicial decisionmaking in environmental law has primarily focused on the D.C. Circuit, the Environmental Protection Agency, and the influence of ideology, only recently have legal scholars begun to consider the role of legal factors in judicial decisionmaking in environmental law. Yet, too little is known about environmental jurisprudence outside the District of Columbia, the other environmental agencies, and the influence of legal interpretive approaches and legal doctrine - as opposed to ideology - in environmental law cases. With special attention paid to how courts implement the Chevron doctrine, this Article empirically and doctrinally analyzes environmental law cases decided in the U.S. Courts of Appeals over a three-year period (2003-2005) to investigate what factors, including ideological, legal and institutional variables, impact judicial review of administrative agency interpretations of environmental statutes. Relying on empirical analysis and descriptive data, this Article finds that environmental cases of statutory interpretation, usually litigated in the D.C., Second and Ninth Circuits, are dominated by EPA involvement and interpretation of the Clean Air and Clean Water Acts. This Article's findings confirm earlier research that judges vote in their perceived ideological direction and show the Chevron doctrine, when employed in environmental cases, works as expected - courts find most statutory provisions ambiguous and then affirm agency action. There is limited evidence that judges strategically use Chevron step one to achieve desired policy preferences - at the ideological extremes, conservatives deferred to Bush Administration agencies under Chevron step two, while liberals were more likely to reverse the agency by finding the statute unambiguous under step one. Legal preferences, however, do play some role in judicial decisionmaking, and not necessarily to achieve an individual judge's policy preferences. Invoking legislative history mildly corresponds to a liberal vote, yet ideology does not predict its invocation - suggesting a judicial philosophy toward legislative history actually impacts voting outcomes and lends support for the legal model of judicial decisionmaking. This Article also makes a number of qualitative findings. Doctrinally, there remains much confusion and conflation in the circuits over how to apply the Chevron doctrine, manifested through poor opinion organization, befuddlement over the application of Chevron step zero, and multiple understandings of the difference between arbitrary and capricious review and the two Chevron steps. The circuits have shown, however, a strong willingness to defer, under any doctrine or framework, to agency action when environmental scientific expertise is required. Ultimately, this Article supports a more nuanced notion of judging in environmental cases that depends upon policy preferences, interpretive philosophies, standards of review, and scientific complexity
