Environmental Impact of Cars

Electric CarsFor much of the early history of the car, no consideration was given to various environmental effects caused by the automobile.

American cars and trucks are a huge source of global warming pollution. U.S. autos emit more than 333 million tons of carbon dioxide each year, more than one-fifth of the nation's total carbon dioxide emissions.

Compared with the rest of the world, American auto emissions are disproportionately high. With only 5 percent of the world's population and 30 percent of the world's automobiles, the United States contributes 48 percent of the world's automotive CO2 emissions.

Any serious effort to fight global warming must include cutting auto emissions. Check out the areas below for the different ways cars impact our environment.
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There are a number of ways automobile use results in water pollution:

  • Runoff of oil, dirt, brake dust, deposited vehicle exhaust, road particles, automotive fluids, and deicing chemicals from roadways and parking lots. The effect of this is difficult to quantify, but a 1996 survey of 693,905 river miles estimated that urban runoff was the leading source of impairment for 13% of the river miles that were impaired. One EPA researcher estimated the amount of oil and grease runoff from roads surfaces to be in the hundreds of thousands of tons per year.
  • Leaking underground fuel storage tanks. As of 1998, there were approx. 892,000 underground storage tanks in the US, mostly in gasoline filling stations. A cumulative total of 1.2 million tanks had been closed, with confirmed releases (leaks) from 371,000 such tanks.
  • Improperly disposed of waste fluids, e.g. used motor oil. One quart of motor oil can contaminate a million gallons of fresh water. The US EPA estimates 13.4% of used motor oil is illegally dumped, while another 10.1% is landfilled.

Over 11 million automobiles were scrapped in 1996. About 75% of the scrapped material was recycled, while the remaining 25% was landfilled. In that same year, an estimated 266 million tires were scrapped, 76% of which was recovered and recycled, used as fuel, or exported to other countries. The 63 million tires that were not recovered were presumably dumped, adding to the approximately 800 million tires currently stockpiled in dumps around the country. These tire dumps, classified as an "ongoing environmental hazard" in one EPA report, are ideal breeding grounds for mosquitoes and a very serious fire hazard. When a tire dump catches fire, the burning tire casings emit toxic gases and are very difficult to put out completely. Some tires dumps have burned for more than a year.

Each year, the United States produces about 10% of the world's petroleum but consumes about 26% of the world's total production. Cars and light trucks are the single largest users of petroleum, consuming about 43% of the total. Overall, cars and light trucks consume about 16% of the total energy used in the U.S.

Car and truck noise has become perhaps the primary source of noise pollution in urban environments. A Federal Highway Administration brochure states that a typical pickup truck going by at 50 mph is four times as loud as an air conditioner an eight times as loud as a refrigerator. The Organization for Economic Cooperation and Development (OECD) estimated in 1980 that 37 percent of the US population was exposed to "annoying" levels of highway noise (greater than 55 decibels), while 7% was exposed to levels that made conversation difficult (> 65 dB).

Although great strides have been made at reducing air pollution from automobile exhaust over the past 30 years, on-road motor vehicles still account for a significant proportion of air pollution:

Cars require a lot of space. In urban areas, road surfaces cover about 1/5 of all available land. Rural roads in 1997 covered an estimated 13,363 square miles of land, an area larger the state of Maryland. Urban roads covered an additional 4,012 square miles, an area larger than Delaware.

With increased road-building came negative effects on habitat for wildlife, primarily through habitat fragmentation and surface runoff alteration. New roads built through sensitive habitat can cause the loss or degradation of ecosystems, and the materials required for roads come from large-scale rock quarrying and gravel extraction, which sometimes occurs in sensitive ecological areas. Road construction also alters the water table, increases surface runoff, and increases the risk of flooding.