A lot has been done to reduce automobile pollution, from development of innovative emission control technologies like catalytic converters, to the establishment of inspection and maintenance programs. But each year there are more cars on the road, traveling more miles, and the pollution control measures taken so far have not been sufficient to solve the ozone problem in many cities. Diesel-powered vehicles are small in numbers compared to the total vehicles in California, but diesel engines account for 40 percent of the total nitrogen oxide emissions and about 60 percent of the total particulate matter from mobile sources. Ozone, better known as smog, is the most widespread air pollution problem. It is formed when sunlight hits hydrocarbons and nitrogen oxides, chemicals emitted from vehicle tailpipes.
Ozone is particularly dangerous for children, senior citizens and people with chronic lung disease.
It also hurts the lungs of healthy people who exercise outdoors. Alternative fuels have a number of inherent properties that make them cleaner than conventional gasoline or diesel. Combustion of any carbon-based fuel produces carbon dioxide. But the overall impact of a given fuel on global warming depends on how the fuel is made. Electricity Battery-powered vehicles produce virtually no pollution and offer one of the best options for reducing motor vehicle emissions in polluted cities.