Rylee Brooke Kamahele helped forge a landmark legal settlement requiring Hawai‘i to eliminate carbon emissions from the state’s transportation system in the next 20 years, including cars on all islands, ships and airplanes used for interisland flights.

Now, Kamahele and other plaintiffs in the historic Navahine settlement are pushing back against a major element of the Hawaiʻi Department of Transportation’s plan for reaching the goal. The issue: the department’s proposal to use what’s known as sustainable aviation fuel or SAF— essentially the airplane equivalent of biodiesel — for interisland flights.

The department’s proposed plan to use the fuel aligns with the view of the aviation industry and fuel producers — as well as a local grower of oily plants that can be converted into sustainable aviation fuel — that SAF is the most practical choice to reduce emissions.