Although market-based environmental policy instruments feature prominently in economic theory and are widely employed, they often meet with public resistance. We argue that such resistance may be driven by a feeling of moral responsibility where citizens prefer to tackle environmental problems themselves, rather than delegating the task to others by means of a market mechanism. Using a laboratory experiment that isolates moral responsibility from alternative explanations, we show that moral responsibility induces participants to incur a sizable cost on themselves as well as on other participants. We discuss the implications of this finding for the design and implementation of environmental policies.