This afternoon, the U.S. Environmental Protection Agency will announce that it has made a formal determination that, in the judgment of the EPA Administrator, the emission of greenhouse gases cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare. This is the so-called “endangerment finding” which will trigger the EPA’s obligation to regulate greenhouse gas emissions under the Clean Air Act. Regulations limiting such emissions from motor vehicles and other sources will follow. Here is coverage from the Washington Post, and New York Times’ Green Inc. blog.
There is little doubt the announcement is timed to bolster the U.S. position at the Copenhagen climate summit, and create the impression of greater U.S. action on climate change. Although regulation under the Clean Air Act is unlikely to produce substantial emission reductions — certainly not the level of reductions the Obama Administration has called for — the willingness to proceed with such regulation is a sign that the current Administration wants to act. The threat of such regulation could also provide a spur for climate legislation in Congress. However bad the cap-and-trade proposals in Congress are (and they’re pretty bad), there’s a strong case that greenhouse gas regulation under the Clean Air Act would be much worse, particularly for major corporations.
The timing of the announcement also makes it clear that the EPA was not troubled by the ClimateGate revelations. Decisions of this sort are not made quickly, and it takes time to prepre the relevant documents. Does this matter? Probably not, though it will depend in part on how the EPA defends its decision. Judicial review of the EPA’s endangerment finding will be quite deferential. The EPA is not required to prove global warming is an imminent threat, only that the Agency could conclude that it “may reasonably be anticipated to endanger public health or welfare.” Further, the Act makes clear that this is up to the “judgment” of the EPA Administrator. This means that all the agency has to show is that its decision is a reasonable interpretation of the relevant scientific information — not the best interpretation, just a reasonable one — and any reviewing court will defer to the Agency’s assessment of the relevant scientific literature.
The only way ClimateGate creates a real problem for the Agency is if the EPA’s attorneys didn’t do their job, and relied uncritically on some of the specific studies called into question by the controversy, and this would only happen if the EPA’s attorneys were asleep at the switch. In a field where the science is so highly contested, what an Agency should do is lay out all of the evidence, acknowledge some degree of uncertainty, and then note explicitly that even if some pieces are contested or disproven, ample evidence remains to support its ultimate conclusion. At the same time, the Agency should note that the Act empowers the Administrator to take a precuationary view of the relevant scientific evidence. If this is what the Agency did, then it does not matter if one data series or another is undermined, nor is it relevant that reasonable people may have a basis to be skeptical of the agency’s scientific conclusions. What matters is whether the EPA could reasonably have come to the conclusion that greenhouse gases are a threat, and that should be an easy case to make, ClimateGate notwithstanding.
With the endangerment finding on the books, Clean Air Act regulation of greenhouse gas emissions will follow. Indeed, once the endangerment finding is made, the EPA is compelled to act. As a consequence, the only way to prevent the regulation of greenhouse gases under the Clean Air Act is through new legislation. The cap-and-trade monstrosities proposed in Congress are one option. A revenue-neutral carbon tax, such as that proposed by James Hansen or Rep. Bob Inglis and Arthur Laffer, would be another. But the bottom line is that unless Congress passes something, EPA regulation of greenhouse gases will proceed.
NOTE: The Washington Post story noted above erroneously reports “Facilities that produce at least 250,000 tons of carbon dioxide or its equivalent yearly account for more than 70 percent of the nation’s greenhouse gas emissions.” This sentence is wrong. Rather, facilities that emit at least 25,000 tons of carbon dioxide or its equivalent (the threshold for this proposed EPA rule) are responsible for “nearly 70 percent” of stationary source emissions, according to the EPA, which in turn represent approximately two-thirds of domestic greenhouse gas emissions. [UPDATE: The Post story is now fixed.] I should also note (as I did here) that the 25,000 ton threshold embraced by the EPA is an arbitrary threshold entirely of the agency’s creation, as the relevant provision of the Clean Air Act applies to all stationary sources that emit over 250 tons of regulated pollutants.