Study Blasts Carmakers on Carbon Dioxide

Automakers are generally doing a poor job in lowering emissions that contribute to global warming, despite continued success in reducing pollution that causes smog, an environmental group said Tuesday.

Japanese manufacturers again made the cleanest-burning vehicles, according to the Union of Concerned Scientists’ biennial report, which focused on the 2003 vehicles from the six largest automakers in the U.S. market in terms of sales.

Honda Motor Co. got the highest overall rank in the report, with its Honda vehicles producing less than half the smog-forming pollution of the industry average. General Motors Corp. had the worst overall ranking, with a fleet that generated a third more smog-producing pollution than average.

Nissan Motor Co. ranked second-best overall and Toyota Motor Corp. was third, followed by Ford Motor Co. and DaimlerChrysler. Nissan and DaimlerChrysler moved up from their positions in the group’s report two years ago.

The group said Nissan had the largest improvement in reducing carbon dioxide, key among the greenhouse gases that many scientists believe are causing the Earth to become warmer. Nissan registered the second-largest improvement in reducing smog-forming pollution. DaimlerChrysler showed a modest improvement in the fuel economy of its trucks, which make up a substantial portion of its sales.

The six automakers produce more than 90% of vehicle emissions in the United States, the group said.

David Friedman, research director of the Union of Concerned Scientists’ Clean Vehicles Program and an author of the report, said anti-smog regulations had forced automakers to improve smog emissions. But carbon dioxide emissions haven’t shown much improvement.