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FYI
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Cutting smog-forming pollution from vehicles costs about $500 per ton through a
vehicle - emissions program; reducing the same amount of pollution in major industries costs from $2,000 to $10,000 per ton, according to the EPA.
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(Source: Sam Howe Verhovek, "Texas Joins Parade of States Colliding
with Clean Air Act," New York Times, February 14, 1995.)
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Today's automobile produces approximately 90 percent less pollution than cars built in the 1960s.* Leaded gasoline has been phased out, and government-mandated manufacturing improvements such as the catalytic converter
and the fuel injector have significantly reduced tailpipe emissions. However, the benefits of these improvements have been largely offset by several factors: a rapid
expansion in the number of cars on the roads, including an increase in gas-guzzling light trucks and sports utility vehicles; an increase in the number of miles driven
each day; and changes in the composition of gasoline. (As lead has been phased out, refineries have made up for the loss in octane with changes in the gasoline
formula that make auto fuel more likely to release smog-forming VOCs into the air.*) As a result, motor vehicles (onroad) still contribute significantly to air
pollution, accounting nationwide for a quarter of the CFCs in the air, 51 percent of the carbon monoxide, 30 percent of the carbon dioxide, 34 percent of the nitrogen
oxides, nearly one-third of VOCs emitted in the United States, and 10 percent of
fine particulate matter (PM 2.5).. In addition to these on-road vehicles, off-road forms of transportation like farming
equipment and construction vehicles contribute some 25 percent of carbon monoxide, 22 percent of NOx, 18 percent of
hydrocarbons, and 18 percent of fine particulate matter. Taken together, transportation is a significantly greater source
of pollution than are industrial sources, power plants or small businesses*
Under the 1990 federal Clean Air Act, pollution control equipment (e.g., fuel injectors and catalytic converters) on all
1994 cars were required to last for 100,000 miles, rather than the 50,000 miles required by previous federal clean air
acts. In addition, engines for diesel trucks must be designed to reduce particulate releases by 90 percent. Finally, the
act requires the automobile industry to manufacture vehicles by 2004 that emit 35 to 50 percent less VOCs, nitrogen oxides, and carbon dioxide than did 1994 vehicles.*
EPA emission limits for cars and light trucks -- which includes most pick-ups, minivans, and sport utility vehicles --
were last set in the mid-1990s. Emission limits of smog-producing nitrogen oxides are 20 to 100 percent higher for light
trucks than for cars. In 1975 there were only about 20 million light trucks on U.S. roads; in 1997, there were 65 million, or three times as many.* The effect overall has been to increase total vehicle emissions of nitrogen oxide and carbon dioxide.
Since then, the EPA has either adopted or proposed a number of new emission and/or fuel standards which when
implemented should reduce emissions from cars, SUVs, trucks and on and off-road diesel vehicles. These include:
- New Emission Standards for Light-Duty Vehicles. In 1999 the EPA proposed new emissions standards
beginning in 2004 that would for the first time subject cars and light trucks to the same basic standards.* Under
the proposal, which since has been modified slightly, but approved, SUVs, minivans and pick-up trucks would be
77 to 95 percent cleaner than todays light-duty vehicles, and the sulfur content of fuels would be reduced by 90
percent. While most light-duty vehicles would still be dirtier than small cars, the difference will be much less than today's vehicles.
- Cleaner Diesel Trucks and Buses. In 2000, EPA finalized a major regulation that reduces sulfur content in
diesel fuels by 97 percent for heavy-duty trucks and buses. This lower sulfur fuel will be required in many areas
by 2006. In addition, tough new emissions standards were required for diesel engines which -- together with the
new low-sulfur diesel fuels -- should reduce emissions from these surces by up to 95 percent. Diesel engine
manufacturers will have up to 2010 to design the new cleaner engines, though significant improvements will be required by 2007.
- Nonroad Diesel Emission and Fuel Standards. Under a new Clean Diesel Proposal, in April 2003, the EPA
proposed new emission standards for nonroad diesel engines used in construction, agricultural and industrial
operations which would reduce emissions of nitrogen oxide and particulate matter by more than 90 percent and require the use of low-sulfur diesel fuels.
Because of Texas' high-ozone level in major metropolitan areas, Texas has had to address pollution from cars and
other forms of transportation at the state-level. The federal Clean Air Act requires states to develop a plan to bring
nonattainment areas into compliance with national air quality standards. In 1995 the Texas Natural Resource
Conservation Commission submitted a mobile-sources implementation plan to the EPA for the state's four ozone
nonattainment areas. However, due to bills passed by the Texas legislature in 1995, the TNRCC was forced to
significantly alter the plan's inspection and maintenance programs for cars in the nonattainment areas, as well as the
clean fuel fleet program, and resubmit its implementation plan in 1996. In 1997 changes mandated by the Texas legislature forced the TNRCC once again to prepare an updated state implementation plan for the Texas clean fuel fleet
program. In addition, an employer trip-reduction plan previously required for the Houston area was dropped due to
changes in EPA requirements in 1995. The effect of these changes has been to make the mobile source programs more
flexible, but at the same time it has reduced the possibility of cutting vehicle emissions further.*
In 2001, in large part because air was not improving fast enough in Dallas and Houston and because two provisions in
th SIP -- one requiring diesel-powered equipment to be upgraded, and one requiring a limit on the use of construction
equipment -- were removed, the Texas Legislature created the Texas Emissions Reduction Plan (TERP). TERP created
a number of fee-based programs to generate money to help clean up engines faster than regulations required. After
some fees to generate money for the program were thrown out in court, the Legislature made changes to the program in 2003.
There are three obvious ways to reduce pollution from cars and trucks: lower emissions from existing vehicles through tighter standards and emission testing, reduce the number of cars on the road, and manufacture alternative vehicles which use fuels like natural gas, propane, electricity, fuel cells and hybrid technology.
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