Supreme Court won't hear challenge to Calif. fuel standard

The Supreme Court on Monday declined to hear a challenge from oil companies to a California law mandating fuel producers lower the amount of carbon pollution emitted from fuels in the state.

The justices turned away an appeal from fuel makers that claim the law unfairly targets out-of-state producers.

Under the mandate, petroleum refiners and fuel distributors will have to make cleaner-burning fuels for California's market, cutting carbon pollution 10 percent over the next 15 years.

But out-of-state oil refiners and companies argue the law gives in-state producers an unfair advantage when placing a higher "carbon-intensity" rating on fuels transported into California from other states, The Associated Press reports.

The Supreme Court's refusal to hear the challenge keeps the ruling from the 9th U.S. Circuit Court of Appeals in place, which stated the law affords fuel producers options for getting their product to market.

California's law is the first of its kind in the U.S.