[originaltext] According to a recent report by the UNEP, if car numbers keep

According to a recent report by the UNEP, if car numbers keep increasing at the present rate, there will be more than a billion on the road by 2025. Today, motor vehicles put out 900 million tones of carbon dioxide a year--about 15 percent of our total output. More vehicles will mean more global warming. Also by 2025, two-thirds of the world’s people will live in cities, so traffic jams and pollution will loom large in most people’s lives.