Abstract: The term planetary health, popularized in the 1980s and 1990s, was born out of necessity; although the term was used by many diverse groups, it was consistently used to underscore that human health is coupled to the health of natural systems within the Earth’s biosphere. The interrelated challenges of climate change, massive biodiversity losses, environmental degradation, grotesque socioeconomic inequalities, conflicts, and a crisis of non-communicable diseases are, mildly stated, daunting. Despite ‘doomsday’ scenarios, there is plenty of room for hope and optimism in planetary health. All over planet Earth, humans are making efforts at the macro, meso and micro scales to promote the health of civilization with the ingredients of hope—agency and pathway thinking; we propose that planetary health requires a greater commitment to understanding hope at the personal and collective levels. Prioritizing hope as an asset in planetary health necessitates deeper knowledge and discourse concerning the barriers to hope and the ways in which hope and the utopian impulse are corrupted; in particular, it requires examining the ways in which hope is leveraged by advantaged groups and political actors to maintain the status quo, or even promote retrograde visions completely at odds with planetary health. Viewing the Earth as a superorganism, with humans as the collective ‘nervous system’, may help with an understanding of the ways in which experience and emotions lead to behavioral responses that may, or may not be, in the best interest of planetary health. We argue that the success of planetary health solutions is predicated on a more sophisticated understanding of the psychology of prevention and intervention at all scales.