I used to live in North Carolina. Just before I left the state and started to work for REASON, I bought a new car. Because my move to California left me strapped for cash, I waited several months to register the car. I had two worries: I knew my insurance rates would increase (indeed, they quadrupled); and I feared my car wouldn't pass the state smog check. California's clean-air rules are the toughest in the country. New cars sold there often have extra pollution-control equipment that costs hundreds or dollars to install.
Because I didn't have enough money to purchase extra pollution gear, I hesitated to take the smog check. (Eventually I did take the test and passed easily.) But I didn't question the need for tougher emissions standards in smoggy Los Angeles. After all, air quality there is terrible. Tough regulations of some kind are necessary, and these regulators know what they're doing, right?
Maybe not. Last December, a study by the prestigious National Academy of Sciences concluded that the nation's environmental regulators have no idea how bad urban air pollution is. Couched in the careful language of researchers, the 450-page study, Rethinking the Ozone Problem in Urban and Regional Air Pollution, is one of the most important documents in the history of pollution regulation. It cites scores of shortcomings in the methods researchers and regulators have used to both develop and implement pollution-control programs during the last two decades.
The authors recommend "major changes…to correct scientific and technical difficulties in the nation's regulatory programs" that control urban smog (or, in the nomenclature of pollution researchers, "tropospheric ozone"). As federal and state pollution regulators implement the massive Clean Air Act of 1990, NAS researchers send two clear signals: Urban smog is worse than the Environmental Protection Agency admits, and current regulations won't do much about it.
The Clean Air Act of 1970 requires the EPA to set national air-quality standards and then to develop policies to maintain them. In 1978, EPA Administrator Douglas Costle set the tropospheric ozone standard at 120 parts per billion; the 1990 Clean Air Act maintains that same standard.
The NAS study, which Congress mandated as part of the 1990 law, didn't ask whether 120 ppb is an appropriate standard—and, because individuals respond differently to air pollution, medical researchers aren't sure what that standard should be. Any standard requires a tradeoff between scientific, political, and economic factors. So the NAS researchers instead focused on the models the EPA uses to estimate ozone levels, the information the agency receives from those models, and the policies it has used to maintain air-quality standards.
Ozone is a variety of oxygen that forms when ultraviolet rays from sunlight combine volatile organic compounds (hydrocarbons that often come from paint or gasoline fumes or from unburned fuel in badly tuned cars) with oxides of nitrogen (which come from burning fossil fuels). Some volatile organics react with NOx more readily than others. And ozone forms most rapidily in the lower atmosphere on days when the temperature is 90 degrees or warmer and the air is relatively still.
But ozone formation is a complicated process. The NAS researchers say regulators have ignored these complexities and followed one-size-fits-all policies that actually increase pollution.
Consider the proportion of VOCs to NOx in an air basin. Ozone forms when the ratio of VOCs to NOx is between 8:1 and 20:1. When the ratio is outside that range, it's tougher for smog to develop. Federal pollution-reduction plans, the NAS scientists say, have assumed that the ratios in heavily polluted areas are in that range and have focused almost exclusively on reducing VOCs. (Caltech chemical engineering professor John Seinfeld, the study's principal author, says VOCs are easier to control than NOx.)
But if the VOC/NOx ratio in an area is higher than 20:1, reducing VOC emissions alone can reduce that ratio to a level that encourages smog. When that happens, without controls to reduce NOx, VOC cuts may lead to more pollution.
So it's essential for regulators to accurately measure VOC and NOx levels in a region before they impose pollution controls. The NAS scientists say these measurements haven't been done. They say ozone-reduction plans depend "too much on the assumption that emissions inventories are accurate, and not enough on adequate checks and tests of these inventories."
For example, the EPA bases its inventories of VOC and NOx emissions on the amount of pollutants that should accumulate in the atmosphere if state pollution-reduction plans are at least 80-percent effective. The NAS study calls this assumption "a major fallacy." Rarely do regulators back up their estimates with actual measurements of pollutants in the atmosphere. Because some technologies don't work as well as expected, and because other regulations aren't enforced, state regulators say their plans deliver only half the pollution reductions the EPA claims.
Also, the data the EPA uses to report on national ozone trends are faulty. The EPA caused enormous alarm when it reported that 98 metropolitan areas were out of compliance with national air-quality standards in 1990, up from 63 areas in 1987. But the NAS study questions the accuracy of these readings. It says the yardstick the EPA uses to measure compliance—the number of days an area is allowed to exceed 120 ppb—"varies considerably from year to year." Most of the variation comes from "natural fluctuations in the weather," not from "year-to-year changes in emissions."
Regulatory plans, says the study, have failed for at least two reasons: Emissions models have ignored naturally occurring VOCs, and regulators have designed ineffective inspection-and-maintenance programs for cars.
One of Ronald Reagan's memorable gaffes occurred in the 1980 presidential campaign, when he alleged that trees cause smog. The pundits of that time enjoyed a chuckle, but the Gipper was right. Plants "exhale" both oxygen and VOCs. Indeed, the NAS study reports that in Atlanta and other parts of the Southeastern United States, vegetation produces more VOCs than cars or factories. Even in the Northeast, trees and other vegetation from rural and suburban areas produce a hefty amount of volatile organics. And when wildfires (or people) burn trees or undergrowth, NOx results. "Killer trees" really exist.
Unfortunately, the NAS team reports, air-pollution models have ignored these naturally occurring pollutants. VOC emissions from trees and other vegetation would cause many areas along the eastern seaboard to have summertime ozone levels of 120 ppb or higher even if all the region's cars and factories somehow stopped running. In these areas, policies that reduce VOC emissions but ignore NOx cost billions but cut smog little if at all.
Regulators assume that motor vehicles cause about 40 percent of the VOC and NOx emissions and 90 percent of the carbon-monoxide emissions in cities. They base these estimates on measurements taken from cars hooked up to pollution-testing devices in garages, not from actual measurements of cars on the road. Cars in use pollute more heavily than they do when idling. Pollution from older cars also increases rapidly as these cars fall out of repair. The NAS scientists conclude that "the percentage of VOCs from mobile sources [cars and trucks] is much greater than the percentage of mobile-source emissions used in each State Implementation Plan"—perhaps two to four times greater.
Enhanced inspection-and-maintenance programs (a.k.a. smog checks) and proposals to make new cars run 99-percent cleaner than they did in 1970 will do little to cut pollution. Only programs that clean up dirty cars in use will help.
Not surprisingly, then, the scientists who wrote the NAS study, led by Seinfeld, enthusiastically support the portable, infrared pollution-testing device designed by University of Denver chemistry professor Donald Stedman. (See "Going Mobile," Aug./Sept. 1990.) Stedman's device can accurately measure the carbon-monoxide and hydrocarbon pollution of cars in motion; this machine can identify the 10 percent of cars that cause 50 percent of all automotive pollution.
Seinfeld believes that pollution regulators could use the device to locate these grossly polluting cars and require their owners to repair them. If, as the NAS scientists fear, cars cause much more than 40 percent of VOC and NOx emissions in cities, enforcing pollution regulations with Stedman's device could cut smog cheaply and in a hurry.
The study also examined proposals that mandate the use of alternative automotive fuels—a growing component of state pollution-control plans. Most of the VOCs caused by cars come from evaporating gasoline fumes and from fuel that hasn't completely combusted. Such "oxygenated" fuels as gasohol and methanol tend to burn more completely than gasoline; but the NAS study found that, on balance, use of alternative fuels would do little to cut overall pollution.
For example, when a methanol-fueled engine is cold, it emits formaldehyde, the science-project hydrocarbon that is not only unpleasant to breathe but may be carcinogenic. The study says that "high [formaldehyde] emissions, if not properly controlled, may negate any potential advantage of [methanol-fueled vehicles]." Also, the study continues, it "is not clear methanol use would lead to lower NOx emissions."
As for ethanol, the alcohol-based fuel so prominent on Sunday talk-show commercials, "limited tests [of ethanol-fueled vehicles] show high emissions." The study also says "using ethanol as a blending agent in gasoline [that is, as gasohol] would not achieve significant air-quality benefits, and in fact would likely be detrimental."
The study does praise natural gas as an automotive fuel, but there are few natural-gas vehicles or fueling outlets. Perhaps the most convenient way to increase natural-gas use would be to replace diesel-fueled bus fleets with buses that run on natural gas.
Electric cars, which California and other states may force people to buy, don't get off the hook either. An electric car in use produces no air pollution. But the electricity to power the car has to come from somewhere. The study says if that power comes from a coal-fired electric power plant, "increased NOx emissions from electricity-generating stations could lead to increased regional ozone that can be transported [by wind currents] into cities." In other words, using electric cars might not cut smog at all.
Because the National Academy of Sciences is a research body, not a policy-making agency, its study recommends few regulatory changes. However, environmental and industry groups were happy to provide their own conclusions from the study.
David G. Hawkins, senior attorney for the Natural Resources Defense Council and an EPA assistant administrator during the Carter years, said the study reveals a need to clamp down on existing regulations. Hawkins told The New York Times, "We've been doing the wrong thing in neglecting nitrogen oxide control. It's not that we should do less volatile organic control."
By contrast, Terry Yosie of the American Petroleum Institute said the study shows that policy makers have "a fundamental lack of knowledge about ozone [formation]." If the NAS concludes "we're flying blind," Yosie continued, "why trust the pilots in charge of the aircraft now?"
"They're both right," says Seinfeld. He calls the air-quality models excellent tools to help craft policies. "The problem is what goes into the models." As the study points out, inaccurate emissions inventories, pollution-control plans that overstate their own effectiveness, and the failure of regulators to check their data make it impossible to design strategies that have any serious impact on urban smog. Above all, the NAS scientists urge carefully designed policies that consider such local factors as weather patterns and naturally occurring emissions.
Not likely. Sadly, this report has already reached the remainder pile. Scientific studies that don't project apocalypse, or that question the actions of regulators, just don't cut it as policy guides. The 10-year, $500 million federal NAPAP study said acid rain was no big deal. Yet after NAPAP was complete, the federal government used an acid-rain terror campaign to justify the 1990 Clean Air Act. (See "Acid Test," January.)
The Bush administration could use this NAS survey of peer-reviewed studies to revamp its smog regulations. Instead it is promoting methanol production, electric cars, and a program to buy back old cars—not gross polluters, but any old clunker. Perhaps the president's pledge to review and revise overly burdensome regulations was just another campaign promise to be broken. At least he could have waited until after the election.
Rick Henderson is Washington editor of REASON.
This article originally appeared in print under the headline "The Environment: Insufficient Data".