Among the different tactics that activists employ to stop climate change, divestment from fossil fuels has recently drawn a lot of attention. The idea is simple: if it is immoral to invest in fossil fuels, we should no longer do it. In a famous article in Rolling Stone, Bill McKibben from showed that, if we are serious about stopping climate change, we cannot afford to extract many more fossil fuels – most of what’s available must be left underground. According to the divestment movement, this means that investment in fossil fuel extraction is now immoral.

While Desmond Tutu has endorsed the divestment movement, Harvard University has refused to divest. The website Go Fossil Free lists a large number of campaigns around the world, and every day seems to bring more and more stories, debates, and arguments to the forefront.

Can divestment work? On a mechanical level, the answer is almost certainly no. As more and more activists divest from fossil fuels, others use the opportunity to invest profitably in fossil fuels. There is no shortage of potential investors, and divestment probably cannot stop fossil fuel extraction as long as demand for energy remains high and continues to grow in the world. That much should be clear.

However, the divestment movement may have deeper, beneficial effects on the society. Even if activists fail to really hurt the bottom line of fossil fuel companies, casting fossil fuels in moral terms may effect changes in attitudes and opinions. The publicity surrounding divestment forces people to consider their own views of fossil fuels. If the divestment movement succeeds in turning the public against fossil fuels, radical change becomes possible. If a large majority of the American public thought that burning coal is truly evil, the days of the coal industry in the United States would be numbered. Social movements against slavery, apartheid, racial discrimination, and gender inequity succeed when they win the battle for hearts and minds.

So, divestment from fossil fuels is a campaign worth following and, in my personal opinion, supporting. Robert Stavins has made a the case against divestment, arguing that it carries a high opportunity cost, but his argument depends on the assumption that we can stop climate change without a radical change in how we talk and think about climate change and fossil fuels. If a change in our morals and beliefs is necessary for real action, then divestment from fossil fuels is a strategy worth considering. Without great social change, I am skeptical about our ability to implement policies that impose, explicitly or implicitly, a high price on carbon. So, consider me a supporter of the divestment movement.