Students camped out Sunday night outside the president's office at Harvard University. (Mallory Noe-Payne/WGBH).

Students woke up Monday morning on the ground outside of Harvard University's oldest building. They had spent the night there, protesting the university's choice to invest part of its endowment in fossil-fuel companies.

Students and climate change activists will gather in Harvard Yard in Cambridge all this week, demanding that nation's oldest - and the world's wealthiest - university drop its stocks in fossil fuel companies. Hundreds of alumni and dozens of students say they're willing to be arrested.

Beginning Sunday night, the student-led group Divest Harvard blocked Massachusetts Hall, preventing President Drew Faust from entering her office.

Senior Chloe Maxmin, 22, is founder of the group. She said "hundreds of alumni and dozens of students" are prepared to be arrested.

"Last year, when we did our first civil disobedience, we could barely get six students to commit," Maxmin said. "Watching all of these people willing to sacrifice something for our campaign is incredibly humbling." 

Organizers say they won't move until Faust commits to divest the university's $36 billion endowment from top fossil fuel companies, such as Exxon Mobil, and Chevron. 

Related: Divestment Is More Difficult Than Most Think

These protests are part of a broader movement. Earlier this month, Syracuse University said it will stop investing in fossil fuels. Then, on Thursday, 19 students at Yale University were arrested while participating in a sit-in to reopen the conversation about fossil-fuel divestment.

At Harvard, Faust has repeatedly responded to protesters by saying divestment from fossil fuels is not "warranted or wise."

Still, alumni have descended on campus to support students. Wen Stephenson, class of 1990, has been camping outside Massachusetts Hall. 

"Nothing serious is going to happen on climate change until there is a political counterweight to the disproportionate political power of the fossil fuel lobby," Stephenson said.

Greater Boston: Bill McKibben Brings The Divestment Debate To Harvard

Robert Stavins teaches environmental economics at Harvard's Kennedy School of Government. He says the divestment movement is fundamentally misguided.

"We need to focus on actions that are going to make a real difference - as opposed to actions that may feel good, or look good, but have little real-world impact," Stavins said.

Stavins says symbolic actions divert the public from taking real action on climate change.

In a statement, Harvard says it respects the right of students to make their voices heard through peaceful protest, but the university hopes they won't disrupt business.

The week of protests commenced Sunday evening at the First Parish Church in Cambridge where environmentalist and 350.org founder Bill McKibben spoke to students.

"Any institution that paid attention to students three and four years ago when they started demanding [divestment] has made out like a bandit since," McKibben said, standing outside the church. "Fossil-free portfolios have heavily outperformed the stock market in the last five years."

This is the first story from WGBH's On Campus in a week-long series, The Cost of Divestment. The series was done in partnership with WCAI's Living Lab, a forum for the stories behind science headlines.