A group of young plaintiffs reached a historic climate settlement with the state of Hawaii and Hawaii Department of Transportation in a deal that will push the state to clean up tailpipe pollution.

The 13 youth plaintiffs filed suit in 2022 when they were all between the ages of 9 and 18. In the suit, Navahine F. v. Hawaii Department of Transportation (HDOT), they alleged that the state and HDOT had violated their right to “a clean and healthful environment,” which is enshrined in Hawaii’s constitution.

The settlement, reached on Thursday, affirms that right and commits the DOT to creating a plan to reach zero greenhouse gas emissions from transportation by 2045. To hit that goal, the state will have to dedicate at least $40 million to building out its EV charging network by the end of the decade and complete new pedestrian, bicycle, and transit networks over the next five years. The settlement also creates a new unit within HDOT tasked with coordinating CO2 emission reductions and a volunteer youth council to advise HDOT.

“I am so proud of all the hard work to get us to this historic moment. We got what we came for, and we got it faster than we expected,” the lead plaintiff, Navahine F., said in an emailed statement.

Back in 2018, Hawaii committed to reaching net-zero carbon dioxide emissions by 2045 — in line with what climate research determined was necessary to meet the Paris climate accord goal of stopping global warming. But the state wasn’t doing enough to reach that goal, the plaintiffs alleged. Transportation makes up the biggest chunk of the state’s greenhouse gas pollution.

“Climate change is indisputable,” Ed Sniffen, HDOT director of transportation, said in a press release. “Burying our heads in the sand and making it the next generation’s problem is not pono.”

Youth in Montana scored another historic legal win last year after the first climate case of its kind to go to trial. A state court found that a Montana policy that barred officials from considering the consequences of climate change when permitting new energy projects violated the rights of the plaintiffs to a “clean and healthful environment.” The lawsuit in Hawaii was expected to be the next landmark youth climate case to go to trial in the US. Several other state and federal youth climate suits are still pending in the US.