OK, finally read the opinion. I side with the majority.
Facts:
The EPA rejected a request from a number of petitioners, including Mass., that asked the the agency to regulate greenhouse gases. They rely on the Clean Air Act that says:
“The EPA Administrator shall by regulation prescribe (and from time to time revise) in accordance with the provisions of this section, standards applicable to the emission of any air pollutant from any class or classes of new motor vehicles or new motor vehicle engines, which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare ....”
Emphasis mine. "Shall" is imperative. This means the EPA must make SOME judgment call. It cannot simply ignore the issue.
The CAA defines "air pollutant" as:
“any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive ... substance or matter which is emitted into or otherwise enters the ambient air.”
Emphasis mine again. "Any" means the EPA has authority to regulate CO2.
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Not everyone can bring a case to a government agency. There are three requirements for standing.
1)Harm - The damage to the petitioner must be particularized (not generally shared by the population at large). Massachusettssays that its loss of coastline counts. I agree.
2)Causation - The petitioner must show a causal link between the agency action (or inaction) and the harm. I agree that EPA inaction could affect global warming. (I'm open to being swayed on this but no need to go into detail in this thread.)
3)Remedy - Agency action must be able to remedy the harm. I agree that EPA could slow the loss of Massachusetts coastline.
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What is the absolute minimum the EPA must do in response to a petition from someone with standing?
[The] EPA can avoid taking regulatory action with respect to greenhouse gas emissions from new motor vehicles only if it determines that greenhouse gases do not contribute to climate change or if it provides some reasonable explanation as to why it cannot or will not exercise its discretion to determine whether they do.
The EPA must put forward some kind of scientific and/or political finding in detail. When the EPA does so, the courts will look over their findings and give them heavy deference (also known as Chevron deference). The court should only overturn the EPA's findings if they are found to be arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.
So there...i've bored you all to tears now. Brown, feel free to correct any stupidity.