What are the environmental pros of hybrid cars?

The United States is the world's largest producer of CO2. U.S. motor vehicles use over eight million barrels of oil per day, costing roughly $200,000 per minute to import. More than 50% of U.S. oil is imported-25% from Persian Gulf countries. Petroleum products supply more than 95% of America's transportation energy requirements. Besides air quality, the process of extracting oil creates other harmful effects-oil spills, underground fuel storage tank leaks and tropical forest destruction In addition, the U.S. dependence on foreign oil poses economic and security hazards. The quantity of CO2 released by a vehicle is basically proportional to the amount of fuel consumed, therefore fuel-efficient cars can definitely contribute to stopping global warming. HEVs have the potential to decrease CO2 gas emissions by one-third to one-half and at the same time cut U.S. dependence on foreign oil. Compared to a conventional car, the hybrids burn far less gas per mile and produce much less pollution, especially greenhouse gases. The Toyota Prius, for example, reduces normalized tailpipe emissions by up to 90% and greenhouse gas emissions by around 50%. In December of 1997, many world nations met in Kyoto, Japan to establish a treaty to regulate greenhouse gas emissions. The Kyoto Protocol, ratified by all the leading industrial nations except the U.S., required the more prosperous nations to show the way in reduction of emissions by the years 2008-2012.