Help Curb Global Warming
Car Emissions — A Problem?
According to the U.S. Environmental Protection Agency (EPA), driving a car is the single most polluting thing that most of us do. Motor vehicles emit millions of tons of pollutants into the air each year. In many urban areas, motor vehicles are the single largest contributor to ground-level ozone, a major component of smog. Ground-level ozone is the most serious air pollution problem in the northeast and mid-Atlantic states. Cars also emit several pollutants classified as toxics, which cause as many as 1,500 cases of cancer in the country each year. Auto emissions also contribute to the environmental problems of acid rain and global warning.
Pollution control measures have drastically reduced emissions per vehicle in the past 20 years. However, during that time the total miles traveled has doubled, resulting in higher levels of air pollutants in many parts of the country.
What Pollutants Do Motor Vehicles Emit and What Are the Health Effects?
Motor vehicles generate three major pollutants: hydrocarbons, nitrogen oxides, and carbon monoxide.
- Hydrocarbons react with nitrogen oxides in the presence of sunlight and elevated temperatures to form ground-level ozone. It can cause eye irritation, coughing, wheezing, and shortness of breath and can lead to permanent lung damage.
- Nitrogen oxides (NOx) also contribute to the formation of ozone and contribute to the formation of acid rain and to water quality problems.
- Carbon monoxide is a colorless, odorless, deadly gas. It reduces the flow of oxygen in the bloodstream and can impair mental functions and visual perception. In urban areas, motor vehicles are responsible for as much as 90 percent of carbon monoxide in the air.
Motor vehicles also emit large amounts of carbon dioxide, which has potential to trap the Earth's heat and cause global warning.
Where Do These Pollutants Come From?
Cars release pollutants from the tailpipe as the result of the fuel combustion process, and from under the hood and throughout the fuel system when heat causes fuel evaporation. Evaporative emissions occur at these times:
- When outside temperatures on hot, sunny days cause a car's fuel to evaporate
- When the hot engine and exhaust system of a running car cause the fuel to become heated
- When the car is shut off and remains hot enough to cause fuel to evaporate
- During refueling, when gasoline vapors escape into the air from the gas tank and the nozzle
The greatest amount of tailpipe pollutants are released during the "cold start" phase, or the first few minutes it takes a car to warm up. Since a car warms up faster when it is moving, drivers are advised to limit warm-up time. Combining trips also decreases motor vehicle emissions since it reduces the number of cold starts.
What Can Motorists Do to Reduce Emissions?
Drivers can help reduce motor vehicle emissions in the following ways:
- Reducing the number of vehicle miles traveled by carpooling, using public transportation, and planning ahead to combine trips. One person using mass transit for an entire year, instead of driving to work, can keep an average of 9.1 pounds of hydrocarbons, 62.5 pounds of carbon monoxide, and 4.9 pounds of nitrogen oxides from being discharged into the air. One full, 40-foot bus also takes 58 cars off the road. A 10 percent nationwide increase in transit ridership would save 135 million gallons of gasoline a year.
- Traveling at moderate, steady speeds (ideally between 35 and 45 miles per hour), and reducing idling time. High speeds result in greater emissions. Idling for more than half a minute burns more gas than it takes to restart the engine. Avoid drive-through windows.
- Keeping vehicles in good running condition. Poorly maintained or malfunctioning vehicles can release as much as 10 times the emissions of a well-maintained one. Motorists should follow the manufacturer's instructions on routine maintenance, such as oil and filter changes. Use an energy saving grade of motor oil (labeled ECII or Energy Conserving II).
Environmental Links -
www.commengineering.com/ - A global leader in energy and environmental solutions that positively change the world.
www.climate-check.com/ - ClimateCHECK offers innovative and practical assurance, consulting, and management solutions
concerning climate change activities and assertions.www.cantorco2e.com/ - CantorCO2e is a leading global provider of financial services to the world’s environmental and energy markets, offering finance, advice, technology and transaction services to clients engaged in using energy and managing emissions across the world.
www.fueleconomy.gov/ - Air pollutants cause health problems and smog. The air pollutants coming out of a vehicle's tailpipe are tightly controlled by EPA's emission regulations.
www.autolife.umd.umich.edu/ - Emissions from the internal combustion engine, however, have proved to be the most significant environmental consequence of oil production.
