How low can ozone go?

July 15, 2013
Zealotry should play no role in regulation. Yet it's a hallmark of the Environmental Protection Agency since 2009.

Zealotry should play no role in regulation. Yet it's a hallmark of the Environmental Protection Agency since 2009.

The agency regulates with such abandon that it contradicts itself. Even before it and state agencies have finished developing plans for implementing the last round of toughened standards for ground-level ozone, EPA wants to lower the threshold even more. The proposed standard of 60 ppb would mean that an estimated 97% of Americans lived in nonattainment areas subject to restrictions on development. And it might be impossible to achieve.

Background levels

At a recent subcommittee hearing in the House Science, Space, and Technology Committee, witnesses warned that the proposed standard approaches natural background levels in parts of the country. While human activity contributes powerfully to the formation of ozone smog, it's not the only source. Some ozone forms in sunlight from reactions among substances not of human origin. Trees, for example, emit compounds that, like evaporative emissions from vehicle engines, combine with oxides of nitrogen (NOx) to create ozone. Wildfires, like fuel combustion, generate NOx, and ozone from the stratosphere, where it is beneficial, can intrude to ground level, where it is not.

Nature, in other words, limits the degree to which people can control near-surface ozone levels. In the heavily forested Intermountain West, those limits are coming into view. One witness in the hearing, Samuel Oltmans of the University of Colorado's Cooperative Institute for Research in the Environmental Sciences, said background ozone concentrations exceed 50 ppb "a significant portion of the time" when ozone levels are high. Meeting a standard below 70 ppb, he added, would be "very difficult" over much of the West.

EPA has insufficient reason to lower the ozone standard. The health benefits would be minor and offset by the never-acknowledged health damage that results from economic strangulation. That it wants to lower the ozone threshold even before plans are in place to meet the 2008 level, 75 ppb, testifies to its unbridled urge to regulate.

The US does not have an ozone pollution crisis. In 2010, according to the latest EPA data, ambient ozone was down 28% from the 1980 level, 17% from 1990, and 11% from 2000. Ozone smog has become a shrinking problem because emissions of ozone precursors subject to regulation are down. During 1980-2010, emissions of NOx fell by 52% and of volatile organic compounds, by 63%. The reductions took estimates of emissions in 2010, adjusted for fires, to 13 million tons of NOx and 11 million tons of VOCs. The House hearing raised large questions about the costs, feasibility, and necessity of trying further to push down those numbers.

Won't heed questions

The EPA won't heed questions of that type, though. It regulates with little regard for other national imperatives or even other elements of its own agenda. Another of its costly stretches is the Tier 3 gasoline program, which will lower the already low limit on sulfur in gasoline to 10 ppm and tighten vehicle-emission standards. As with the proposed standard for ozone, the environmental benefits of the Tier 3 scheme are low and the costs, high. To cut gasoline's sulfur concentration more than they already have, refiners will have to increase processing severities of hydrotreaters, which means raising the amount of energy consumed for a given amount of gasoline. The increased energy consumption will raise emissions of carbon dioxide, the object of yet another regulatory binge to which EPA has linked the Tier 3 program. So it's working against its own programs.

EPA's aggressiveness promises escalating cost for diminishing environmental gain. It creates uncertainty, discourages investment, and hurts job creation. The approach appeals to the relatively few Americans for whom no degree of regulation ever is enough and to others unwilling or unable to see the tradeoffs. But it hurts all Americans by miring the economy to clean air already much cleaner than it used to be and getting more so year by year.