gross polluters

California has been a world pioneer for decades in reducing vehicle emissions, including its 20-year effort to get significant numbers of zero-emission vehicles on the roads. It's also had intermittent programs to encourage the trade-in of older cars that qualify as "gross emitters" for newer and...

China will step up enforcement of emissions standards, removing 6 million of the worst-polluting vehicles from its roads.

While it's not quite the 2009 Cash for Clunkers program, it's a nice gesture with a clear mission: get the most polluting cars off Colorado roads. If you're a Coloradan who owns a pre-1990 car, donate it to the Clear the Air Foundation and the ReForest Colorado program will plant a tree in an area...

Not only do old cars pollute more than new ones, they pollute a lot more. According to a rule proposed by the California Bureau of Automotive Repair, fully “75 percent of vehicular pollution is caused by just 25 percent of the vehicle fleet" in the state. Those vehicles were built before 1995...