The Supreme Court rejected a challenge to the Environmental Protect Agency’s air pollution rules this morning.
The case, American Petroleum Institute vs. EPA, saw the oil lobby disputing a rule adopted in 2010 that “set a tighter Clean Air Act standard for short-term spikes in nitrogen dioxide pollution near roads.” This new standard is 100 parts per billion for one hour, compared to the previous annual standard of 53 parts per billion dating back to 1971.
Nitrogen dioxide is a pungent, reddish-brown gas with a strong odor, and is emitted from auto exhaust and fossil fuel power generation. The DC Circuit upheld the rule in July of last year, finding that it addressed a real public health threat. The agency had pointed to scientific data showing the effect of nitrogen dioxide on the public, particularly asthma sufferers.
The Supreme Court’s decision to not hear the case means the DC Circuit’s 2012 decision stands — and its decision was fairly clear:
The unanimous three-judge panel ruled that EPA’s move was not arbitrary and capricious and did not violate the Clean Air Act. On a separate question over EPA’s plan for implementing the standards, the court punted, saying the statement was not final agency action and therefore not subject to review.
On the claim that EPA’s own regulations required it to rely on peer-reviewed studies, Judge Douglas Ginsburg wrote that the challengers were simply incorrect.
“Perhaps the API should have had its brief peer-reviewed,” he quipped.
Nitrogen dioxide in the atmosphere produces ozone when acted on by sunlight. The IPCC considers ozone to be the third most important greenhouse gas behind carbon dioxide and methane. A recent study by NASA’s Jet Propulsion Laboratory found that where nitrogen dioxide is cleaned up is crucial:
“When it comes to reducing ozone levels, emission reductions in one part of the world may drive greenhouse warming more than a similar level of emission reductions elsewhere,” said Kevin Bowman, lead author of the study, published recently in the journal Geophysical Research Letters. “Where you clean up ozone precursor emissions makes a big difference. It’s all about — to use a real estate analogy — location, location, location.”
Courtesy of the Supreme Court, EPA monitoring of nitrogen dioxide in this new standard can only help build that understanding of where greenhouse emissions originate.