The California Air Resources Board (CARB) unveiled sweeping regulations on June 14 that will require a 30 percent reduction in harmful greenhouse gas emissions from cars and trucks by 2015, according to a report in the Detroit News. To reduce carbon dioxide emissions — the main greenhouse gas from motor vehicles — cars and trucks will have to burn less gas, requiring automakers to dramatically boost the fuel economy of their cars and trucks. California regulators say global warming affects air quality and the health and welfare of the state. They assert that carbon dioxide should be regulated like any tailpipe pollutant. A 2002 study by the California Energy Commission found that the combustion of gasoline by motor vehicles generated 40 percent of the state’s carbon dioxide emissions. Because many states plan to follow California’s lead, the rules could force Detroit automakers to accelerate the introduction of new fuel-conserving technologies — gasoline-electric hybrids, hydrogen fuel cells, and cylinder deactivation. The initial proposal from the board’s staff would add about $300 to the price of a new car in California from 2009 through 2012, the board estimates. By 2015, the rules would add $1,000 to the cost of a new car sold in the state. During the 2003 model year, the average fuel economy of new cars and light trucks sold nationwide was 20.7 miles per gallon, down from a high of 22.1 miles per gallon in 1987, Environmental Protection Agency data show. If everything moves forward, the greenhouse gas reduction targets would take effect beginning with the 2009 model year. The next step will be a staff workshop on July 7, where board experts hope to meet with industry engineers to get feedback on their assessment of various fuel-saving technologies. The staff proposal will be finalized Aug. 6. The full Air Resources Board is expected to make a final decision on the regulations Sept. 23. Under California’s global warming law, the Legislature will review the board’s plan next year, and there could be another vote before the regulations go into effect.