In daily life, individuals compare their environmental behavior with specific others (e.g., friends, coworkers). We hypothesized that these moment-to-moment environmental social comparisons tend to be predominantly downward due to the moral nature of this domain. Three studies, including an experience sampling study, supported this hypothesis. Participants predominantly compared downward (vs. upward, Study 1, and vs. other common domains, Studies 2 and 3). This downward comparison tendency was partially explained by morality. Delving deeper into the emotional and motivational consequences of this tendency, in Study 3, participants reported more pride and (in part) more guilt regarding their environmental behavior compared with other domains. The motivational picture was mixed, with participants reporting more coasting but also more self-improvement in the environmental domain, thus potentially still recognizing the importance of changing to a more pro-environmental lifestyle. Therefore, emphasizing upward comparisons in intervention studies could motivate environmental actions beyond people’s satisfaction with their achievements.