Two public advocacy groups won a Hawaii Supreme Court appeal Tuesday over whether greenhouse gas emissions outside the state need to be considered for fuel imported by a local utility.

The unanimous decision affects a rate case by Hawaii Gas, a regulated utility supplying nearly 70,000 residential and business customers statewide with gas for heating water, cooking and other uses.

Hawaii Gas had asked the state Public Utilities Commission in 2017 to approve a 14.6% rate increase to cover expenses including new equipment related to importing liquefied natural gas from the mainland as a way to reduce production of natural gas in Hawaii using a byproduct of imported oil.

Two advocacy groups, Life of the Land and Hui Aloha ‘Aina o Ka Lei Maile Ali‘i, sought to participate in PUC hearings to address climate change impacts on the environment and Native Hawaiians related to Hawaii Gas operations.

The PUC, however, didn’t allow the two groups to explore impacts from imported natural gas on greenhouse gas emissions outside the state where the gas is produced and transported.

Life of the Land and Hui Aloha argued that greenhouse gas emissions outside the state connected with natural gas imports affect Hawaii’s climate and native population.

Part of the contention by the groups is that greenhouse gas emissions from fracking on the mainland affect the climate in Hawaii, and that there should be a detailed comparison of impacts between natural gas produced locally and on the mainland.

Hui Aloha argued that climate change represented “another overthrow” for Hawaiians and could include impacts such as higher sea levels that force outmigration, threaten shoreline burials, destroy fishponds and eliminate seafarer navigation points.

Other concerns raised by the group included higher ocean temperatures affecting marine species and cultural practices, damage to forest health and reduced snow on Mauna Kea.

Hawaii Gas said importing natural gas would be better for Hawaii environmentally than local production, but no scientific analysis was conducted.

The PUC in 2018 approved a 8.4% rate increase that was less than what Hawaii Gas sought, and also concluded that Life of the Land and Hui Aloha did not show that imported natural gas would increase greenhouse gas emissions.

In the appeal to Hawaii’s high court, the advocacy groups argued that the PUC didn’t consider “hidden” greenhouse gas emissions including the extraction and transportation of imported natural gas affecting Hawaii even though those things happen outside the state.

“We agree with this contention,” the court ruling said, noting that greenhouse gas emissions have a global impact. “There is no (greenhouse gas) emissions information about the (imported natural gas Hawaii Gas) uses. Therefore, the PUC could not have fulfilled its affirmative duty to reduce the state’s reliance on fossil fuels through energy efficiency and increased renewable energy generation.”

Lance Collins, an attorney representing the two groups, noted that the PUC has an obligation to uphold a public trust protecting Hawaii natural resources even in a case about utility rates, and that this will have a tremendous impact on similar cases.

Henry Curtis, Life of the Land executive director, said satisfying the energy needs of Hawaii needs to be done with consideration of environmental impacts.

“We must reduce our emissions, and we can’t do that without first identifying how much we are emitting,” he said. “We must solve the climate nightmare mindful of justice and equity.”

The court ruling requires the PUC to reopen the rate case to consider greenhouse gas emissions in more detail.

No immediate change in rates for Hawaii Gas customers will take place, according to the company.

Nathan Nelson, general counsel for Hawaii Gas, said the company looks forward to addressing the issues mandated by the court.

“Hawaii Gas believes these projects are essential for greater energy supply resiliency and diversity and will support the state’s 2045 carbon neutrality goals,” he said.