Think of divestment as the opposite of investment. When you invest in something you hand over your money to a company or organization. When you divest, you take your money out of a company or organization.
The endowment is the sum total of the charitable donations from individuals and organizations that the university then invests in various stocks, bonds that (ideally) pay a return. University endowments can be used to pay for scholarships, fellowships, cutting edge research, recruiting faculty, and maintaining the physical infrastructure of the campus.
The burning of fossil fuels is the greatest contributor to climate change. When fossil fuels are burned, carbon dioxide (CO2) is released into the Earth’s atmosphere, warming the planet. In order to not exceed global warming of 1.5 C (the target agreed upon internationally), we have to move away from fossil fuels. When a college endowment invests in fossil fuel-related companies, they in effect support the continuation of the use of fossil fuels.
For starters, see if your campus already has a group fighting the divestment fight--seek them out and lend a hand. Many colleges have a Fossil Free group that regularly posts on social media. And you can always reach out to Divest Ed, the national training and strategy hub for student fossil fuel divestment campaigns.
Colleges have a few reasons, and none of them are very good. They claim it’s complicated...that they can have a more positive impact holding investments and trying to impose change as shareholders...that on-campus costs will go up as fossil fuel investments pay a higher dividend. The reality is that of course it’s complicated (but do it anyway), that colleges and universities haven’t been change-makers as shareholders (or the environment would be improving, not getting worse), and that numerous studies show that similar returns (if not higher) are possible with investments that don’t, you know, destroy the Earth. And really, isn’t it the job of higher ed to teach the lesson that hard, good things are worth doing, and that making money from irresponsible sources is...bad? Feels like some of these folks failed Ethics 101...