Objective The social capital literature suggests generalized trust should work to motivate individuals to engage in environmentally beneficial behavior as it is associated with altruistic outcomes, moderation, and self‐sacrifice. The environmental justice literature, however, suggests certain populations are understandably more skeptical about who they can trust with respect to environmental threats in their communities, thus undermining the hypothesis that greater trust results in positive environmental outcomes. We seek to test the relative direct and indirect influences of generalized trust and knowledge of environmental issues on individuals’ willingness to make sacrifices for the environment. Methods Based on established theory in the social capital, environmental concern, and environmental justice literature, this study conducts structural equation modeling using data from the 2010 General Social Survey. Results This analysis finds support for both social capital and environmental justice arguments. However, the positive direct effect of generalized trust on a willingness to sacrifice outweighs its indirect negative effect via perceived environmental threats by a factor of four to one, suggesting generalized trust is a net catalyst for environmental action. Knowledge of issues is positively associated with both perceived environmental risks and a willingness to sacrifice. Conclusion Generalized trust is an important motivator for self‐sacrifice in the realm of environmental behavior. We should nonetheless be skeptical of efforts to promote it that ignore the unequal distribution of environmental threats in the population.