CARB's Comparison

To read about California's tailpipe emissions standards, click here.

In his Dec. 19 letter to California Gov. Arnold Schwarzenegger, EPA Administrator Stephen Johnson outlined his reasons for denying the state a waiver to enforce its greenhouse gas emissions standards.

Among the facts Johnson cited in the letter was the statement that federal fuel economy regulations would create a 35 miles per gallon (mpg) standard compared to the equivalent of a 33.8 mpg standard in California and the states that have adopted its greenhouse gas emissions rules. The suggestion, then, was that the federal standards are more stringent than the California rules and more beneficial to the environment.

In response, in January the California Air Resources Board (CARB) translated fuel economy into equivalent greenhouse gas emissions rates to allow an "apples-to-apples" comparison of federal fuel economy standards and California tailpipe emissions standards.
CARB's subsequent assessment seems to prove Johnson's statement wrong:

- If only California were to adopt its greenhouse gas emissions standards, by 2020 its vehicles would show a 43.9 mpg fuel economy as opposed to a 35.7 mpg fuel economy under the federal standards.
- If the federal standards are applied to vehicles in the federal fleet, by 2020 there would be a 32.2 percent reduction in carbon dioxide emissions. Adopting the California standards would yield a 41.3 percent reduction.
- If only California--whose fleet contains more passenger vehicles--adopts its own rules, the study shows that by 2011 there would be a 14.3 percent reduction in carbon dioxide emissions from automobiles. Under the federal standards, the state's fleet would show just a 1.3 percent reduction.
- By 2020, California standards would yield a 42.8 percent reduction in carbon dioxide compared to a 29.8 percent reduction under the federal standards.
- The cumulative benefits of the California standards reductions are striking: If only California adopts and enforces its standards, by 2016 they would yield a 113 percent benefit in greenhouse gas reductions over the federal fuel economy rules. By 2020 the benefit would be 74 percent.

Staff Writer

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