The Triad has made it to mid-July with nary an ozone-alert day, and North Carolina is having its best smog season since regulators began measuring the stuff back in the 1970s. Only time will tell if the air will remain as clear for the rest of the summer, but 2004 has already shattered previous records by a large margin.
This year’s low smog levels follow on the heels of record-low smog in 2003. What’s causing the improvement? Is it just unusually favorable weather, or are ozone-forming emissions actually dropping? The answer is probably a combination of both.
Ozone forms when nitrogen oxides and hydrocarbons react in sunlight. The former come mainly from automobiles, diesel vehicles, and power plants, while the latter come mainly from automobiles.
Warm, dry, sunny weather favors ozone formation, but this year has been unusually cloudy and humid. Pollution reductions are also a factor. In a recent News and Record article, a spokesman for the North Carolina Division of Air Quality credited state regulations such as the Clean Smokestacks legislation for power plants, and vehicle emissions inspections as key reasons that emissions are going down.
Regulations have reduced emissions. But Clean Smokestacks can’t be a factor, because its requirements don’t come into effect until 2007 and neither can vehicle inspections, because they simply don’t work. Evaluations show inspection programs fail to repair high-polluting cars or to get them off the road. And because only a few percent of vehicles have high emissions, most money spent on the program is wasted on testing clean cars, rather than repairing dirty ones.
Here’s why pollution has been dropping: First, average automobile emissions are declining about 10 percent per year as the fleet turns over to newer, inherently cleaner models. Driving is increasing about 3 percent annually in North Carolina. This translates into a 7 percent reduction in auto emissions each year. Better technology, rather than inspections, accounts for the improvements.
Improvements will continue. Automobiles meeting recent federal standards, which will make up almost the entire fleet in 15 years, are about 90 percent cleaner than the average car currently on the road.
Second, starting in May of this year, EPA required a 60 percent reduction in nitrogen oxides from coal-fired power plants during the May-September “ozone season.”
Besides power plants and automobiles, there are only two other significant sources of pollution: diesel trucks and off-road diesel equipment such as construction vehicles. EPA implemented three rounds of emission standards for new diesel engines during the last decade. Standards that come into effect in 2007 for trucks and 2010 for off-road equipment require an additional 90 percent reduction below previous levels.
Putting this all together, it’s clear that air pollution has been solved as a long-term problem by actions we’ve already taken.
But that doesn’t mean we can’t speed-up progress. Studies show that the worst five percent of cars produce about half the hydrocarbon emissions from automobiles. Inspection programs fail to deal with these “gross polluters.” But an inexpensive and accurate on-road pollution measurement technology called remote sensing could find these cars as they drive on the road, and their owners could then be required to repair the vehicle or voluntarily scrap it for a cash incentive.
Remote sensors shoot a beam of light across a traffic lane to measure the concentration of pollutants in the exhaust. A single unit can measure more than 1,000 cars per hour on a busy road. The technology has already been implemented in several cities around the country.
Low-income motorists could be given a repair subsidy to encourage compliance. The program could be funded by exempting cars up to 10 years old from the ineffective scheduled inspection program and requiring the exempt motorists to instead pay a $10 surcharge annually at registration.
A gross-polluter program would cost no more than a few thousand dollars per ton of pollution eliminated. In contrast, the billions North Carolina plans to spend on light rail will cost millions per ton of pollution eliminated.
Activists and planners promote public transit and restrictions on driving and housing choices in the name of air quality. Beyond principled concerns about government interference in private choices, these restrictions are unnecessary if technology is solving the problem.
And if already-adopted measures will eliminate most remaining air pollution, then beyond enforcement of existing requirements, most regulatory activity confers few or no benefits in exchange for the costs imposed.
Knowing the real causes of air pollution improvements tells us what we should—and should not—be doing to reduce it.