The National Academy of Science has published studies showing strong scientific evidence that global warming is caused by human consumption of fossil fuels, yet recent surveys have shown young adults in the U.S. are disengaged or disagree with this fact. Accordingly, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) published learning objectives to educate the world population on global warming and renewable energy by 2030. In this paper, we introduce a reflective writing activity physics educators can employ to foster a deeper understanding of global warming in introductory college physics and physical science courses, without overloading their teaching time.