Automobiles are a major source of carbon dioxide, which scientists believe to be one of the principle causes of global warming. In the United States more than 300 million tons of carbon dioxide is emitted into the atmosphere each year from cars and trucks alone. In fact vehicles are the principal source of one-third of the gases that cause global warming. Hybrids provide an alternative to conventional vehicles by emitting a considerably less amount of these gases. When compared with the carbon dioxide emissions of SUV’s hybrids emit only a fraction of that amount.

Automakers are responding to consumer demand for better fuel economy standards while creating better images for themselves as more responsible stewards of the environment.

Failures in fuel economy standards are largley due to the rise in popularity of fuel efficiently challenged SUV’s. The average car mileage received today is worse than what they were in the 1980’s resulting in an increase in carbon emissions and auto pollution. A gallon of gas weighs 6 pounds, after it is burned and mixed with oxygen, the result is a compound that weighs nearly 20 pounds. A typical SUV such as the Jeep Grand Cherokee weighing just under two tons emits three times its body weight per year.

The effects of increasing carbon dioxide emissions that lead to global warming carry severe consequences such as dramatic effects on ecosystems affecting sensitive plant and animal species. Human health may also be affected though the increase of day and night thermal extremes.