|
In the past century, automobiles have revolutionized our lives in many positive ways,
but their impact on the environment has been negative.
Can we change the way we use cars?
It is hard to imagine our lives without cars, but what if an environmentally
friendly car could be made? Electric cars have been in production since 1997, and are
available in some states. These cars run on batteries that must be
recharged frequently by plugging them into standard outlets. Switching to
electric cars could cut an estimated 99 percent of smog-forming emissions
and 70 percent of carbon dioxide emissions. However, charging electric cars
still relies on the use of electricity from power plants.
Perhaps the most important innovation in the short-term has been the development
of the hybrid engine, now used in several cars sold in the United States. Hybrid
cars can get away with using smaller, more fuel-efficient (and less polluting)
gasoline engines because they have a battery-powered electric motor for extra power.
The batteries are recharged as the car moves, eliminating the need to plug the car in for recharging.
 Other sources of energy for cars are solar power and fuel cells. Solar cars,
studied for many years, have yet to show that they can become a viable transportation
alternative. However, competitions among university researchers have helped advance the
technology. Cars powered by fuel cells show greater promise. Fuel cells are battery-like
devices that combine hydrogen and oxygen to generate electricity. One advantage of fuel
cells is that they are far more efficient than gasoline engines and have far lower emissions
of greenhouse gases. Recognizing these advantages, several car manufacturers are designing
fuel-cell cars for the consumer market.
Credits: (detail) Killer whale show © John Warden/Getty Images; Rainforest clearance
© Tony Morrison/South American Pictures; Cars on a highway © 1997 Chris Salvo/Getty
Images; Piles of cars © Photri; Blurry people © Getty Images / Royalty Free;
Solar-powered car © Peter Menzel/Getty Images.
Top of Page
|
