In my view, the EPA's decision to deny California's application for a waiver of preemption under the Clean Air Act for the state's greenhouse gas emission controls for new motor vehicles was good law, if questionable policy. The EPA's conclusion that California was not entitled to a waiver of preemption is utterly defensible under the Clean Air Act. Assuming the agency adequately explained the basis for its conclusion, I find no legal fault with the EPA. This does not mean that the agency's decision made for good policy, however. Assuming that the agency's action was not compelled by the statutory text, I also believe that the EPA could have adopted an alternative reading of the act under which the waiver could have been granted. Insofar as I favor giving states greater leeway to experiment in environmental policy, granting California's waiver would have made for good policy -- and would have been preferable to adoption of the federal energy legislation recently passed by Congress and signed into law.

In announcing the denial of California's waiver application for waiver of preemption, the EPA explained that the Bush Administration was "moving forward with a national solution to reduce greenhouse gas emissions from motor vehicles." Explicit in the agency announcement was a preference (shared by the auto industry) for uniform federal emission standards for motor vehicles. The agency also cited the newly enacted federal energy legislation that will increase federal fuel economy standards (and thereby reduce carbon dioxide emissions) over the coming decades (albeit at a slower rate than would have been required under the California rules.

EPA Administrator Stephen Johnson explained that federal uniformity is preferable to "a confusing patchwork of state rules." This is the rationale for federal preemption of state standards in the first place. The invocation of a "patchwork" is a bit inapposite here, however, as there would be no "patchwork" of variable rules from state to state, as approval of California's request would still have left states with only two choices: adopt the California rules or settle for the federal floor. The word "patchwork" implies that each state could choose its own standard, making each jurisdiction different from all the others, much like the panels of a patchwork quilt are highly varied. A better metaphor would have been that of a checkerboard, or some other dichromatic distribution.

The Administration's stated preference for a uniform standard clearly motivated its decision, but it is not a legally sufficient basis for denying a waiver under the Clean Air Act. Rather, the law is quite specific as to what factors are to be considered when evaluating a waiver request. Under Section 209(b)(1), California must first make a threshold determination that its proposed standards "will be in the aggregate, at least as protective of public health and welfare as applicable Federal standards." Once such a determination has been made, Section 209(b) provides that the EPA must deny the waiver request if it finds that (a) California's threshold determination was "arbitrary and capricious"; (b) California "does not need such State standards to meet compelling and extraordinary conditions; of (c) California's proposed standards and enforcement measures are inconsistent with other Clean Air Act requirements. An EPA finding that any one of these three criteria is met is grounds for denying California's waiver request.

Of these, only one finding is potentially at issue: Whether California needs its own greenhouse gas emission controls on motor vehicles "to meet compelling and extraordinary conditions." Although I have not yet seen the formal petition denial, the EPA announcement suggests that this was the legal basis for rejecting the request (and distinguishing this waver request from the dozens of such requests that the EPA has approved in the past).

California's current waiver request is distinct from all prior requests. Previous waiver petitions covered pollutants that predominantly impacted local and regional air quality. Greenhouse gases are fundamentally global in nature, which is unlike the other air pollutants covered by prior California waiver requests. These gases contribute to the challenge of global climate change affecting every state in the union. Therefore, according to the criteria in section 209 of the Clean Air Act, EPA did not find that separate California standards are needed to "meet compelling and extraordinary conditions."

As I have explore at some length in this paper, the EPA would appear to be on strong legal ground in reaching this conclusion. Given the global nature of climate change, California cannot claim that it needs these measures (or any other emission controls) "to meet compelling or extraordinary conditions." Nothing California does to control greenhouse gas emissions from new motor vehicles will mitigate the threat of climate change to the state in any meaningful way.

Prior waivers were granted when California sought to control emissions that contributed to the Golden State's particularly severe urban air pollution problems. In these cases, California could claim that state-specific measures were necessary components of state-level plans to meet federal air quality standards within the state. California's extreme air pollution problems were the "compelling or extraordinary conditions," and the measures were "needed" to "meet" these conditions insofar as they would facilitate California achieving its goal of reducing instate air pollution.

Global climate change presents a different type of problem, however. It is a global phenomenon caused by the accumulation of greenhouse gases throughout the global atmosphere. Unlike with ambient air pollution, such as soot or smog, a local jurisdiction has no control over local emission concentrations because the relevant gases disperse throughout the atmosphere. Nor do local jurisdictions have any control over ambient temperature, as global climate change is a consequence of the global accumulation of greenhouse gases.

California policy makers sought to get around this problem by pointing to anticipated California-specific effects of global warming, such as local sea-level rise. It is certainly true that California will face certain consequences of climate change that will not be faced by all other states. It is even conceivable (though hardly demonstrated) that California is uniquely threatened by climate change to a greater extent than any other state. This does not matter, however, as California cannot claim that its proposed vehicle emission controls are necessary to meet these concerns, as they will not achieve any meaningful protection for the state. No matter how much California wishes to be a climate policy pathbreaker, that is insufficient to meet the language of the Act under this interpretation.

I readily admit that there is some ambiguity in the language of 209(b), and there are reasonable interpretations of this language that could justify approving California's waiver request. The problem for California, however, is that insofar as this language is ambiguous, federal courts are required to defer to the EPA's reasonable interpretation under "step two" of the familiar Chevron analysis. Thus, provided that the agency has dotted its "i"s and crossed its "t"s in the formal decision, adequately explaining the basis for its interpretation and its resulting conclusions, the waiver denial should survive the inevitable legal challenge from California and other states that wanted to adopt more stringent vehicle emission controls.

To be clear, my point here is not that the EPA was required to deny California's CAA waiver request, nor am I making a specific prediction about future litigation over this decision. Rather I am making the more modest claim that the language of Section 209(b) could well be interpreted in a way that would justify, if not compel, the agency's decision, and hold up in court.