The annual air-quality assessment published recently by the US Environmental Protection Agency contains a sleeping serpent worth stirring up before environmental alarmists appropriate it for their gloomy propaganda. It's an indicated rise in a pollution measure heretofore in strong decline. Preemptive perspective can bridle environmentalism's predisposition for catastrophe. It might also keep House-Senate conferees working on overstuffed energy legislation from genuinely reversing progress in the fight against air pollution.
The news from EPA is that air quality continues to improve, as it has done for decades. "Since 1970," the agency says in its report on air quality trends through 2002, "aggregate emissions of the six principal pollutants have been cut 48%. During that same time, US energy consumption increased 42%, and vehicle-miles traveled increased 155%." The reported improvement was unusually large in the new assessment because of adjustments made to vehicle emissions found to have been understated in the 1970s and 1980s.
Small increase
The pollution increase noted for 1993-2002 involved ozone levels. It occurred according to the stricter of two ozone parameters: the 8-hr standard adopted in 1997; by the 1-hr standard used since 1970, ozone pollution continued to diminish in 1993-2002. According to EPA, the amount of increase, 4% over the period, is too small to be statistically significant.
Those technicalities will vanish in the churn of news and political contention, of course. Also unnoticed will be the solid declines that persist for other nationally tracked components of air-quality assessment: nitrogen dioxide (NO2), sulfur dioxide, particulates, carbon monoxide, and lead. By those measures, the Clean Air Act's "criteria pollutants," air quality has steadily and greatly improved. The US has no general pollution crisis.
Specific areas within the US, however, have problems with specific pollutants. Some of those problems are chronic. On EPA's simplified list of areas not complying with federal standards for one or more criteria pollutants, particulates and ozone account for three fourths of the infractions.
Three decades of experience in the struggle against smog and soot highlight the importance of controlling oxides of nitrogen (NOx). Substances in this category are precursors of both ozone and particulates. And one of them, NO2, is a criteria pollutant. Because only one area of the country fails to meet the NO2 standard—Columbia Falls, Mont.—the contribution of NOx to formation of other pollutants is far more significant than NO2 is to further cleansing of US air.
In its latest report, EPA notes that during 1983-2002, emissions of volatile organic compounds, the other ozone precursor, fell by 40%, while those of NOx dropped by only 15%. "Additional NOx reductions will be necessary before more substantial ozone air-quality improvements are realized," the agency says, pointing to programs in place to seek those cuts.
Complex energy legislation under extended negotiation by the House-Senate conferees would work the opposite way. It contains a NOx-filled bomb: the requirement that the ethanol content of reformulated gasoline more than double within a few years. Tests have shown that adding ethanol to gasoline increases NOx emissions and that the problem is worse for ethanol than for methyl tertiary butyl ether (MTBE), which ethanol would replace. Ethanol also boosts evaporative emissions of volatile hydrocarbons.
As Houston consultant Cal Hodge has pointed out in these pages, California is a test case. In the past 3 years, while the state replaced much of the MTBE in its specially reformulated gasoline with ethanol, the number of violations of the federal ozone standard has doubled (OGJ, Oct. 6, 2003, p. 18).
Increased challenge
Mandating an increase in ethanol use is no way to fight ozone or particulate pollution. Yet the myth persists—largely because of marketing by ethanol producers and their lobbyists—that the substance makes gasoline combustion "cleaner" in air-quality terms. Ethanol does reduce emissions of carbon monoxide, which aggravates ozone formation. It does displace toxics and promote combustion—but at the cost of an energy loss relative to gasoline. The advantages, though, don't compensate for the disadvantages.
While the ozone numbers in EPA's new report shouldn't set off alarms, they do illuminate a pollutant for which further progress in nonattainment areas will be difficult. Increasing the challenge with a costly ethanol mandate would obstruct environmental efforts and discredit energy policy.
