It’s been a contentious year at colleges nationwide, with students mounting campaigns on more than 300 campuses.

At issue: Should colleges and universities keep investing their endowments in fossil fuel companies?

Out of the 300 campuses with divestment campaigns, only five schools have actually committed to divesting their endowments from fossil fuels, and they are all in New England.

"This is like breathing for our students," said Steven Mulkey, president of Maine's Unity College, just south of Bangor. He says fossil fuel divestment was a no-brainer.

"Our students come to Unity College because of our unflinching environmental emphasis, and our belief that the highest value proposition that higher education can give students is the tool to face the sustainability challenges that we are facing right now," he said.

But while the 533 students at Unity College embraced divestment, it was actually Mulkey himself, a scientist, who brought up the issue with the administration and board.

"I basically came to the conclusion that this was a matter of willingness, and we should begin to aggressively explore this and see if it was possible," he said.

It turned out that divesting Unity’s $14 million endowment would not be a straightforward process.

"You don’t just simply extract the fossil fuel companies from your portfolio and go on with the portfolio as it was, you make strategic decisions about how to reallocate your investments," he said.

Mulkey says so far, divestment was the right decision.

"We are beating the market indices quiet well," he said.

Unity College has proven a success story for the growing divestiture movement, which was sparked by environmentalist Bill McKibben. He’s been writing in Rolling Stone Magazine about the urgency to address climate change.

But the place where McKibben teaches, Middlebury College in Vermont, is not one of the schools that has divested from fossil fuel investments.

"I think it’s fair to say we are still looking at that issue and trying to understand what the impact would be and how difficult it would be to do that," said Bill Burger, vice president for communications at Middlebury. At $900 million, Middlebury’s endowment is significantly larger than Unity’s.

"Investing large endowments now is simply a very complex undertaking," Burger said. "It’s very difficult when you’re investing in bundled funds as we do, to necessarily extract yourself from one particular stock or even a small set of stocks."

Aside from the complexity of the process, Burger says divesting is risky.

"You have to consider what the impacts might be on future endowment returns," he said. "Middlebury, like most colleges and universities, counts on endowment returns."

Burger says endowment returns count for about 18 percent of Middlebury’s annual operating budget.

"If there is a concern that by restricting your investment opportunities it might affect the return, that’s something you obviously have to take into account," he said.

This gets to the heart of the fossil fuel divestment debate. Colleges are dependent on the money they make from current investments money that keeps many schools in business.

Still, Burger says the administration is actively engaging in conversation about the issue with students.

"We haven’t hesitated to engage in that debate or shied away from it," he said.

A similar debate among students and administrators is happening at Mount Holyoke College in Western Massachusetts.

"We have to ask the question, is divestment the most effective approach to achieving our shared objective?" said college president Lynn Pasquerella. "If not, what course should we take?"

Pasquerella says a more effective approach may be to use financial returns to promote clean energy alternatives, or to engage in shareholder activism.

Whatever the outcome at Mount Holyoke, the divestiture movement has caught the attention of colleges and universities in New England.

"We are having conversations about what stance leaders in higher education should take with respect to the growing pressure in colleges and universities to take a position on social and political questions at the center of sustainability," Pasquerella said.

Along with Unity College, the four other schools that have decided to divest from fossil fuels are College of the Atlantic in Maine, Sterling College and Green Mountain College in Vermont, and Hampshire College in Western Massachusetts.

This post originally appeared on WGBHNews.org.