Compassion shown towards victims often decreases as the number of individuals in need of aid increases, identifiability of the victims decreases, and the proportion of victims helped shrinks. Such "compassion fade" may hamper individual-level and collective responses to pressing large-scale crises. To date, research on compassion fade has focused on humanitarian challenges; thus, it remains unknown whether and to what extent compassion fade emerges when victims are non-human others. Here we show that compassion fade occurs in the environmental domain, but only among non-environmentalists. These findings suggest that compassion fade may challenge our collective ability and willingness to confront the major environmental problems we face, including climate change. The observed moderation effect of environmental identity further indicates that compassion fade may present a significant psychological barrier to building broad public support for addressing these problems. Our results highlight the importance of bringing findings from the field of judgment and decision making to bear on pressing societal issues.