LEWISTON — Twelve years after vowing to make its campus carbon neutral, Bates College has reached its goal before a self-imposed 2020 deadline.

Officials said Bates is the seventh college in the country — and fourth in Maine — to become carbon neutral from among the 700 that signed a pledge in 2007 to achieve the target.

Calling it “a huge moment for celebration,” Bates President Clayton Spencer told a crowd of students and college officials late Wednesday that fulfilling the carbon neutral obligation is “a huge deal.”

“It’s a big moment for us,” said senior Hadley Moreau, one of about 30 students who worked on the sustainability project that not only pressed for change but also figured out when Bates had met its goal.

“This achievement shows Bates at its best,” Spencer said. “Our mission statement calls for responsible stewardship of the wider world, and at this point in our history on this planet, there is no higher need than addressing climate change.”

“More important, we have met this goal through shared effort, commitment and creativity by the entire college community with students leading the way,” she said.

No longer contributing greenhouse gases to the atmosphere is a way to combat climate change while appealing to many students who are determined to pursue a greener future.

A sustainability survey in April found that 55 percent of Bates students said they were influenced to attend the 2,000-person liberal arts college by its environmental efforts. Nearly every student hailed the goal of carbon neutrality, the survey determined.

Three other colleges in Maine, including Colby, Bowdoin and the College of the Atlantic, have achieved carbon neutral status, part of a national effort by leaders in higher education to cut their reliance on fossil fuels.

That four of the seven colleges that have met the goal are in Maine is especially sweet, said Tom Twist, the sustainability manager at Bates, particularly given the necessity of heating many buildings for so many months every year, including some that date back to the Civil War.

Bates managed to reduce its carbon emissions since 2001 by 95 percent, mostly through conservation measures and switching to renewable energy sources, particularly a wood-derived liquid that serves as the primary fuel for its central heating plant.

It is the only educational institution in the country to rely on Renewable Fuel Oil for its heating fuel.

Twist said students tallied up all of the emissions produced by the college, from the steam plant that provides most of the heat to the air travel required for study abroad or conferences.

“We trust them a lot” to get it right, he said, with a little guidance along the way.

To make up for the carbon emissions that Bates hasn’t been able to stop, the college is investing in landfill methane recapture to make up the difference and ensure its overall carbon footprint is neutral. Moreau said it only cost about $6,000 annually to buy the necessary greenhouse credits to balance the equation.

Twist said Bates isn’t done tackling the environmental impact of its operation.

“Going carbon neutral makes you realize how far you still need to go,” he said. More projects are in the works that will lower Bates’ energy usage, Twist said.

Those involved in the carbon neutrality effort said they hope that putting Bates in the vanguard of change will encourage others to follow suit to help stop the worst impacts of climate change from taking place.

Scientists are increasingly alarmed at the growing impact of carbon dioxide on the planet’s atmosphere and climate.

The Mauna Loa Observatory in Hawaii announced Monday it had, for the first time, found carbon dioxide levels of more than 415 parts per million, the highest level in at least three million years.

Carbon dioxide, or CO2, is emitted from burning fossil fuels, oil, coal and natural gas. It traps heat in the atmosphere, the key driver of climate change. The CO2 level in the air has been rising at a rate of 2.5 parts per million annually.

Ralph Keeling, director of Scripps CO2 Program, said this week that “every year it goes up like this we should be saying, ‘No, this shouldn’t be happening. It’s not normal.’ This increase is just not sustainable in terms of energy use and in terms of what we are doing to the planet.”

The Fourth National Climate Assessment, issued in November by the Trump administration, found that “the impacts of climate change are already being felt in communities across the country. More frequent and intense extreme weather and climate-related events, as well as changes in average climate conditions, are expected to continue to damage infrastructure, ecosystems, and social systems that provide essential benefits.”

Spencer said Bates is trying to be green wherever it can.

She said 16 tons of dining hall grease is hauled to Western Maine to be transformed into natural gas and fertilizer. Students said they’re working on everything from recycling to a garden that can provide some of the food served in the dining hall.