Twenty seven million Californians—80 percent of the state’s population—are exposed to emissions from ocean-going vessels, resulting in serious health impacts such as cancer, respiratory illnesses like asthma, as well as increasing the risk of heart disease. California estimates that the ships’ direct particulate emissions cause 300 premature deaths across the state every single year, even after excluding cancer effects.

The Ninth Circuit’s 2011 decision in Pacific Merchant Shipping Assn. v. Goldstene involved a shipping industry challenge to the Vessel Fuel Rule. The Ninth Circuit rejected industry’s claims that the ARB regulation is preempted by the federal Submerged Lands Act and contravenes dormant Commerce Clause principles. By denying certiorari, the Supreme Court has decided to let the Ninth Circuit’s decision stand.

In an ideal world we would have federal regulations that applied equally protective regulations on all ships in U.S. waters. California has led the way with its rule to reduce harmful pollution from ships. The federal government is soon to follow with the designation of most U.S. waters as an Emissions Control Area under the International Convention for the Prevention of Pollution from Ships. This designation will eventually require all vessels to meet the same fuel sulfur limits as established by the Vessel Fuel Rules.

However, the more protective standards won’t go into effect until 2015 and, tragically, the federal government exempted waters in the Alaskan Arctic from the regulations. As reduced sea ice cover allows Arctic shipping proliferate in coming years, it is essential that the same level of protections are applied in this sensitive marine environment.