A federal court has decided California officials have the authority to require ships that stop in the state's ports to use cleaner marine fuels to reduce pollution from engine exhaust.
The 9th U.S. Circuit Court of Appeals ruled unanimously Wednesday in favor of the Vessel Fuel Rules, which mandate that ship operators use less polluting fuel if they come within 24 nautical miles of the California coast.
The decision was a blow to the Pacific Merchant Shipping Association, which argued the new rules violated the Commerce Clause of the U.S. Constitution.
In a 45-page opinion, the judges disagreed, saying the association failed to prove the shipping industry would be harmed by the regulations.
The court says the positive environmental impact makes the new rules worthwhile, citing data that diesel emissions are known to cause cancer and respiratory illnesses.