When to Start Saving the Planet?

People should take immediate action to prevent climate harms. Although intuitive, this claim faces two important problems. First, no individual can avert a climate harm on their own. Second, too few people are typically willing to contribute. In response, I point out that individuals can sometimes help prevent harm to the climate, and I argue that they should take preventive action when the prospect of success is good enough. Furthermore, when too few are willing to contribute, an individual may be required to activate others to increase their number. This serves to increase the prospect of success. Crucially, this prospect may be good enough well before enough people have become willing to engage. It follows that people should start saving the planet soon, if not immediately.