Surprisingly, Americans are no more likely to engage in environmental behavior today than 20 years ago. A novel explanation for this pattern may lie in the increased tendency to see time as money. Using large-scale survey data, we show that people are less likely to engage in environmental behavior if they are paid by the hour, a form of compensation that leads people to see their time as money. Using experimental methodology, we show that making the economic value of time salient reduces environmental intentions and behavior. This occurs in part because thinking about the economic value of time creates awareness of the opportunity costs associated with environmental behavior. We mitigate these effects by reframing environmental behavior as an act consistent with self-interest. Together, this research suggests that viewing time as money shapes environmental decisions, potentially shedding light on patterns of environmental behavior across time and around the world.