Reminding people of their own mortality can either turn them off environmentalism or reinforce their commitment to it, depending on how important the cause was to them in the first place. That's according to Matthew Vess and Jamie Arndt who asked 57 students to think about what will happen when they die, or to imagine physical pain (this served as a non-morbid control condition).
After completing an irrelevant distraction task, the students next read an article about a lawsuit concerning a city council's decision to prohibit development on parkland. Finally, the students gave their opinions on the lawsuit and chose further pro- or anti-environment articles to read.
Students who said being an environmentalist was unimportant to their self-esteem, and who'd earlier thought about their own death, subsequently showed less environmental concern in response to the development article than did non-environmentalists who had earlier thought about physical pain. This is consistent with previous work showing that thoughts of death lead people to reject their earthly origins (for example, one study showed that people reminded of their mortality subsequently rated a wilderness scene less favourably and a cityscape more favourably).
By contrast, students who said environmentalism was important to their self-esteem, and who'd earlier thought about their own death, subsequently showed far greater environmental concern than environmentalist students who'd earlier thought about physical pain.
"It appears that certain people derive existentially important feelings of self-esteem from pro-environmental behaviour and thus respond to concerns about mortality with increased concern for the well-being of the natural world," the researchers said. "These self-esteem investments can thus transform the protection of the natural world into an existentially relevant behaviour which can similarly function to mitigate concerns with our vulnerability to death."
M VESS, J ARNDT (2008). The nature of death and the death of nature: The impact of mortality salience on environmental concern Journal of Research in Personality, 42 (5), 1376-1380 DOI: 10.1016/j.jrp.2008.04.007