Vehicles Blamed for a Greater Share of Smog
Cars and trucks are responsible for a much larger share of California’s smog than previously documented--a revelation that may force air quality officials to redouble their efforts to clean up vehicle emissions, according to new data released Friday.
The tonnage of smog-forming gases that waft from vehicles in the Los Angeles Basin is two to three times greater than the California Air Resources Board had been estimating, according to a new emissions inventory developed by the state agency.
The inventory is vital for guiding the region’s multibillion-dollar war against smog, and experts will now spend months analyzing how the new calculations will alter plans for achieving healthful air quality in the Los Angeles area and the rest of the state.
The new inventory does not mean that smog is worse than experts believed. Instead, it means that vehicles are responsible for a bigger share of the problem, and that industry, consumer products and other sources of pollution are now blamed for a smaller proportion. The amount of ozone--the prime ingredient of smog--in Southland air has been steadily declining, reaching record smog-season lows this year.
One of the main reasons for the undercalculation of emissions is that the Air Resources Board had misreported the number of cars on California’s roads. There are about 4.5 million more cars than it had originally figured, the agency determined. Also, gasoline leaks from many cars have gone undetected in smog checks, the agency said, and emissions from heavy-duty trucks were based on flawed data provided by diesel engine manufacturers.
The board’s deputy executive officer, Tom Cackette, said the new data in many ways renew the importance of regulating all aspects of pollution from cars, trucks and other vehicles.
“There’s more emissions than we thought, so there are more emissions to go after. These programs are even more important than we thought,” he said.
How to Get Old Cars Off the Road
After 30 years of regulations, California will probably have to devote even more attention to finding ways to get old, polluting vehicles off the roads and accelerate the pace at which new, clean ones are purchased.
The new data may prompt strengthening of the state’s widely hated Smog Check program and put extra pressure on auto makers and truck engine manufacturers to promote sales of new technologies to motorists.
“The implications of this are pretty clear that we have to go much further with our motor vehicle controls,” said Roland Hwang, senior analyst at the Union of Concerned Scientists, an environmental group that has pushed for stronger emission controls on cars. “It clearly puts more pressure on the motor vehicle sector to clean up.”
Air quality officials say they are not surprised by the magnitude of the shift in data. They have always cautioned that their emissions estimates are questionable, especially for cars, because so many variables are involved--from the speed at which motorists drive to the hidden leaks from fuel tanks. As a result, they mount a major revision every two years, incorporating improvements in data collection to get a better grasp on how much vehicles contribute to smog.
For one important pollutant--the fine particles of soot that can lodge in lungs and cause respiratory disease--the volume spewed by vehicles is 162% greater in the Los Angeles Basin than the Air Resources Board had been estimating.
Cackette said the overhauled inventory especially reinforces the need to crack down on diesel trucks, the main source of particulates.
Engine manufacturers say they are close to commercializing advanced technologies for diesel engines that will cut nitrogen oxides, which cause ozone, and particulates. Tighter state and national standards for diesel engines and fuel are in planning stages now.
Emissions From New Cars Already Slashed
The auto industry, facing smog standards set by the Air Resources Board, has already cut emissions from new cars more than 90% from the level of new cars in the late 1960s. Some major auto makers are now selling small numbers of electric cars, and they will soon begin marketing electric-gasoline hybrids and super-low-emission models of gasoline-powered cars.
An environmental official at Honda Motor Co.--considered a leader in new smog-control technology for cars--was unavailable for comment on the new data Friday.
In general, the auto industry contends that new cars are about as clean as they can get and that new smog efforts should focus on giving consumers incentives to scrap their old cars and buy newer, less polluting ones.
Air board Chairman Alan Lloyd, appointed this year by Gov. Gray Davis, is a fervent supporter of emission-free vehicles. He has said his goal is no emissions, or nearly none, from any car, bus, truck or other mobile source in California.
Under a state mandate that takes effect in 2003, 10% of new cars that major manufacturers sell in California must produce zero emissions--which essentially means that they must be battery-powered.
So far, though, electric cars and natural-gas trucks have not caught on with drivers. Hwang said the pace at which consumers are buying the vehicles clearly needs to be accelerated--either with tougher state mandates or with market incentives such as subsidies and tax breaks. Also, he said, smog control equipment on gasoline-powered cars needs to be more durable.
The increase in the emissions estimate is especially striking in the Los Angeles Basin. Here, the air board has been underestimating the hydrocarbons from vehicles by 113% and nitrogen oxides by 84%.
One reason that the old inventory was skewed was that the board had not been factoring in cars that were in the process of being registered or that were being driven without proper registration. That amounts to 4.5 million cars statewide, increasing the total number included in the inventory to about 26 million. The added cars--which tend to be older--were responsible for 20% of the increase in hydrocarbons reported in the new inventory, the air board says.
In addition, the inventory changed dramatically because the board incorporated tests that better mimic real-life driving conditions, such as slow driving during congested rush hours. They also changed estimates of the number of times cars are started--which is when their emissions are greatest.
Also, the staff discovered that some older cars and some new fuel-injection cars are leaking gasoline not detected by the Smog Check program, which tests only exhaust. The leaks are large enough to evaporate and help form smog but small enough to escape the notice of motorists and mechanics.
Cackette suggested that a test for the leaks may be needed in smog checks. Such changes, however, require approval of the Legislature, which has fought for years over the Smog Check program because it is extremely unpopular with many motorists.
The South Coast Air Quality Management District and the state air board are developing new smog plans that will outline regulations and programs for the next 10 years.
The overhaul of the vehicle emission data does not mean that other sources of smog should be let off the hook, Cackette said.
If every rule outlined in the current smog plans were adopted, the Los Angeles Basin would still not have air clean enough to satisfy federal health standards by 2010, as the law requires.
“This does not in any way change what we already are doing,” Cackette said. “There’s nothing here that says, ‘Oops, we controlled the wrong thing.’ It shifts around the pie, but it doesn’t change it in such a way to rethink what we are doing.”
