Dozens of students on Thursday morning launched a sit-in at Harvard University to demand that the institution divest its $36.4 billion endowment—the largest college nest egg in the world—from fossil fuel companies, in step with a global movement to de-fund and de-legitimize the industries driving global warming.

At the time of publication, over 30 students were still occupying Massachusetts Hall, which houses administrative offices, including that of President Drew Faust.

Jasmine Opie, member of Divest Harvard, told Common Dreams over the phone that the direct action is “open-ended” and students are prepared to stay the night. The mood at the protest is “excited and enthusiastic,” said Opie, despite the administration’s refusal, so far, to engage in meaningful and transparent discussions with demonstrators.

The protest is timed to coincide with Global Divestment Day on Friday and Saturday, which will see more than 400 actions and protests sweep the world, from France to Australia to South Africa. The growing international push to divest has already won significant victories, including the agreement of over a dozen U.S. universities, the World Council of Churches, and the British Medical Association to withdraw their funds from oil, gas, and coal companies.

Harvard students say they hope their campaign can make a meaningful contribution to these international efforts.

“By investing in fossil fuel companies, Harvard jeopardizes the future of its students and the world,” Sima Atri, a third-year student at Harvard Law School, said in a press statement. “Our action today is not just about climate change, but about larger issues of injustice. We refuse to stay silent as Harvard profits from business practices that are causing disproportionate harms on already marginalized communities.”

The sit-in stems from nearly three years of active organizing at the Boston-area campus to demand that Harvard immediately halt new fossil fuel investment, withdraw its current holdings of $79.5 million in the top 200 publicly traded fossil fuel companies, and within the next five years, reinvest this money in “socially responsible funds.”