Jack French of Hampden was one of hundreds who turned out to a 2017 March for Science at the University of Maine. Credit: Dawn Gagnon

AUGUSTA, Maine — Gov. Janet Mills announced Thursday that she is the 22nd governor to join a national coalition that has committed to abide by an international agreement to reduce carbon emissions that the U.S. withdrew from in 2017.

The new Democratic governor made fighting climate change a key part of her 2018 campaign to succeed former Gov. Paul LePage, a Republican who effectively put the state’s climate response on hold as research emerged during his tenure showing the Gulf of Maine has warmed more in recent years than 99 percent of the world’s oceans.

However, Mills’ agenda hasn’t been fleshed out early in her nearly two months in office, though she used her inaugural address to announce a goal of raising the share of renewables in Maine’s electricity supply and undid a LePage moratorium on many new wind projects.

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Mills spoke more on climate change at an Environmental and Energy Technology Council of Maine event in Augusta on Thursday. Many of her proposed steps were vague, aside from joining the U.S. Climate Alliance. She largely signaled a philosophical shift in state government.

“We do not have more time. The time for action is now,” she said. “Wise, prudent, informed action, but action nonetheless.”

The U.S. Climate Alliance aims to reduce carbon emissions by 2025 according to a key tenet of the Paris agreement, an international 2015 pact the U.S. left under President Donald Trump. The 21 states in the agreement — excluding Puerto Rico — represent more than half of the U.S. population and a third of 2016 energy-related carbon emissions, according to federal data.

[Janet Mills faces challenges in converting tough talk on climate change into action]

Mills also said she would present legislation to form a state-level Maine Climate Council to meet carbon reduction goals, which she pegged at achieving 80 percent renewable energy in the electricity industry by 2030 and 100 percent by 2050.

However, it’s unclear what standards Mills is using for renewables. The federal government says Maine already gets about three-quarters of its electricity from renewable sources, though the state abides by a renewable standard that does not include large hydroelectric installations.

Climate is also a part of the most controversial issue Mills has waded into in her tenure — Central Maine Power’s proposed $1 billion transmission line from Quebec to Massachusetts via Maine, which the governor came out in support of last week.

Many environmental groups who see Mills as an ally on climate policy are opposed to the corridor. One of them — the Natural Resources Council of Maine — said in a statement that her Thursday announcements were “important commitments.”

Legislative Democrats have rolled out ambitious climate proposals, including a proposed carbon tax from Rep. Deane Rykerson of Kittery that faced heavy opposition at a public hearing on Thursday in Augusta and a rally against it beforehand led by the Maine Republican Party.

The original bill would tax the carbon content of fuel and use revenue to reduce utility rates, though Rykerson told a legislative panel on Thursday he would propose an amendment to the bill to study how the money could be spent during the next year.

While 60 legislative Democrats including House Speaker Sara Gideon of Freeport back it, Mills seemed skeptical Thursday, noting to reporters that no other state has implemented a similar tax and that she would want to see how the tax would affect the fossil fuel industry without harming distributors or consumers.

Rykerson said “Maine could lead the nation in forward thinking” by passing it. Jamie Py, the CEO of the Maine Energy Marketers Association, a group that includes fuel distributors and opposes the bill, said the costs of the tax would be “exorbitant.”

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Michael Shepherd joined the Bangor Daily News in 2015 after time at the Kennebec Journal. He lives in Augusta, graduated from the University of Maine in 2012 and has a master's degree from the University...