Beginning in the 1960s and culminating in the mid-80s, the apartheid divestment movement involved investors selling their shares of companies that were benefiting economically from South Africa's apartheid regime. The movement was broad enough that it's credited with adding to the pressure on the apartheid government to begin negotiations that ultimately led to its demise. It's considered a successful case of investor activism to correct a social harm.

Flash-forward to today, and there's a growing movement to divest from hydrocarbons in order to deal with climate change. Part of this movement is, an organization that urges college and university endowments to divest their shares of fossil fuel companies. The group takes particular aim at Transcanada (NYSE:TRP) because of the heavy carbon impact of the Keystone XL pipeline, as well as those companies most exposed to the "carbon bubble," including BP (NYSE:BP), Shell (NYSE:RDS-A), and Chevron (NYSE:CVX).

John Vechey of PopCap Games recently joined The Motley Fool for a climate change summit. His first panel guests were Dr. Rachel Cleetus, a climate economist with the Union of Concerned Scientists, and Dr. Joe Casola, program director for science and impacts at the Center for Climate and Energy Solutions. In the video below, they offer divergent views on divestment and whether it is a constructive approach to take.

Sara Murphy has no position in any stocks mentioned. Follow her on Twitter @SMurphSmiles. The Motley Fool recommends Chevron. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.