Maine Gov. Janet Mills addresses the Climate Action Summit in the United Nations General Assembly on Monday at U.N. headquarters. Jason DeCrow/Associated Press

AUGUSTA — Gov. Janet Mills made a surprise announcement when she addressed world leaders at the United Nations Climate Action Summit last week: She had issued an executive order pledging that Maine will be carbon-neutral by 2045.

The pledge followed commitments enacted by the Legislature this spring to reduce the state’s greenhouse gas emissions by 45 percent from 1990 levels by 2030 and 80 percent by 2050, moves that will require swapping fossil fuels for solar, wind and hydro-powered alternatives, from electric cars and heat pumps to fuel cell-driven trucks, buses and boats over the next 30 years.

But what does the added carbon-neutral pledge mean and how much more would have to be done to achieve it? It would be a major symbolic achievement – only one small Himalayan country and no U.S. state has done it – but in the case of forest-rich Maine, it might not actually require much more action beyond those needed to slash our greenhouse gas emissions.

Going carbon-neutral – a goal Boston, New York, Hawaii, Sweden, France, Costa Rica and other polities have pledged to achieve by midcentury – means your city, state or country makes no net contribution of carbon dioxide to the atmosphere. In practice, this entails finding ways to reduce the burning of fossil fuels and buying or creating carbon-devouring “offsets” to make up for what you have left, usually by planting trees, which store carbon dioxide.

The effort is considered imperative to mitigating the effects of accelerated climate change, as carbon dioxide and other greenhouse gases released by human activities are largely responsible for the problem.

Maine’s advantage is that it’s a little like Bhutan, the only country in the world that’s already carbon-negative, gobbling up more carbon dioxide than it emits. Bhutan – an isolated Himalayan kingdom less than half the size of Maine – is 71 percent forest-covered and has only 800,000 people. Maine has a lower population density and 90 percent forest cover, the highest proportion in the country.


Nobody has done a “carbon budget” to know for sure, but having all those trees and not so many people means we’re probably not too far from being carbon-neutral to begin with, says Hannah Pingree, director of the governor’s Office of Policy Innovation and the Future and co-chairwoman of the Maine Climate Council, the 39-member body tasked with developing the detailed climate action plans to achieve the greenhouse gas and carbon neutrality targets.

“I actually think that because of Maine’s forestlands and what we will be able to do in the farming sector, I think we will be able to go beyond carbon neutrality and will be able to sell carbon credits to other places in a future offsets market,” Pingree says. “It is one of the reasons it won’t need to be scary.”

The governor agrees. “I think 2045 is a very reasonable goal, and I’m optimistic we’ll reach it before then,” Mills told the Portland Press Herald/Maine Sunday Telegram after meeting with European Union leaders in New York last week. “We have sustainable forest practices that go back 30 years and the opportunity to sequester carbon in our soils and forests.”

Like any other place trying to achieve carbon neutrality, Maine will have to first calculate the state’s carbon budget – figuring out how much greenhouse gas we produce and how much our forests and soils store away. The Maine Climate Council will then have to come up with a detailed plan to reduce our emissions – or expand carbon-storing forests – enough so that the state contributes no net greenhouse gases to the atmosphere.

Three wind turbines atop a ridge just south of Webb Lake in 2015. Gabe Souza/Staff Photographer

Renewable power drives everything

So what is that likely to look like?

The key to any carbon neutrality effort is simple, says Mark Z. Jacobson, an environmental engineer at Stanford University whose clean-energy road maps for all 50 states and 139 countries helped drive Hawaii and California to adopt 100 percent renewable energy goals and landed him on David Letterman’s television show.


“You electrify everything,” he says, and generate all your power from renewable sources that don’t emit greenhouse gases.

The good news is that Maine has massive renewable power potential, especially in regard to offshore wind, a sector the University of Maine is on the cutting edge of, having developed a floating turbine platform. Jacobson’s team already developed an all-renewable energy plan for Maine consisting of 35 percent offshore wind, 35 percent onshore wind, 15 percent commercial solar plants, 5.8 percent hydropower, and the remainder in rooftop solar and tide and wave power technologies, a sector for which Maine-based Ocean Renewable Power Co. is an industry leader.

“It’s pretty straightforward, because you have pretty good resources in your state,” he says.

Making the shift may have economic advantages. Burlington, Vermont – which owns its own electric utility – became the first city in the country to run entirely on renewable power when it purchased a small hydro station.

“It wasn’t economically devastating at all,” says Burlington Mayor Miro Weinberger, who is driving an effort to make the city self-sufficient in all energy applications. “In fact, our electric utility got its credit rating upgraded because the ratings agencies realized we had insulated Burlingtonians and their businesses from the volatility of the fossil fuel markets.”

Rates for electricity – which is also generated by a wind farm, and a biomass plant burning the slash of sustainable lumbering operations – haven’t risen in 11 years, Weinberger says. “No other utility in Vermont has been able to sustain that.”


Lee Auto Malls chairman Adam Lee charges a Honda Clarity at Lee Honda in Auburn. Sun Journal photo by Daryn Slover

Transportation is the big lift

In Maine, unlike the United States as a whole, transportation accounts for the lion’s share of climate-altering emissions: 54 percent of them, compared with just 37 percent nationally. Tackling that sector will be essential to meeting both the state’s greenhouse gas targets and the governor’s carbon neutrality pledge.

Increasing the use of electric vehicles – via incentives and the construction of charging stations – is an obvious tool, but equally important is to change the way we use our land, says Kristina Egan, a former executive director of the Massachusetts Smart Growth Alliance and Transportation for Massachusetts, a transport reform coalition, who now heads the Greater Portland Council of Governments.

“In order for us to make the transition to a more climate-friendly transportation system, we need to think about building more affordable housing near jobs and connecting our village centers with rapid public transportation,” Egan says. “To boost economic development and public health, we need great downtowns and villages and cities, and we need to plan ahead to absorb growth into these places that are more sustainable for our society.”

Jack Doherty installs a solar panel on a home at OceanView at Falmouth. Ben McCanna/Staff Photographer

Residential energy use a challenge

The second largest share of Maine’s greenhouse gas emissions comes from the residential sector: 18 percent, which is triple the proportion of the United States as a whole, according to federal data presented to Maine Climate Council members by the Department of Environmental Protection. The driving factors: Maine has a cold climate and the sixth-oldest housing stock in the nation, with nearly a third built before 1950.

“Decarbonizing building stock is the hardest part because it requires doing deep energy retrofits of existing buildings, which sets up many complications as to who oversees and finances it,” says Ariella Maron, a Philadelphia-based adviser on local government climate action who has worked on carbon neutrality efforts in New York and Boston. “That becomes more of a challenge in colder climates as it becomes more technologically challenging to fully provide heat when temperatures get below a certain level.”

Electric-powered heat pumps are the go-to technology – they’re cleaner and cheaper to operate than oil and gas – but most models available at the residential level are less efficient and effective in the dead of the Maine winter, when the temperature regularly falls into the teens or colder.


“Weatherization and energy efficiency should be an early step in any net-zero effort,” says Mayor Weinberger in Burlington, where incentives to weatherize buildings have been in place since 1989, resulting in no growth in energy demand since. “Both cold-climate heat pumps and electric vehicles are getting better at an impressive rate.”

A farm in Freedom in 2016. Gregory Rec/Staff Photographer

Forests present an opportunity

Maine’s big advantage is its forest cover, the highest level of any U.S. state. Trees take carbon dioxide out of the atmosphere and store the carbon in their roots, trunks and limbs, acting as carbon “sinks.” By some accounts, northern forests can soak up 1 to 2 tons of carbon per acre per year.

Maine forests could store more, both by letting trees grow longer and bigger in the industrial forests, and by small landowners making a commitment to leave more big trees standing, and more slash and dead branches on the ground to decompose slowly. Half of the carbon is stored in the forest soil, so employing logging methods that don’t disrupt the floor is also important.

As the world decarbonizes in response to climate change threats, cities and states that can’t grow big new forest tracts will likely have to buy offsets from places that do. Hannah Pingree predicts that will create huge opportunities for Maine, if the state can demonstrate its forests can provide verifiable, sustainable new carbon sinks.

“Our ability to sequester carbon in Maine will be enormous,” she says. “It’s an economic opportunity.”


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