Abstract This article tracks the history of species suicide, a phrase that originally referred to a potential nuclear holocaust but is now increasingly cited in Anthropocene discourses to account for continued carbon emissions in the face of catastrophic climate change. With its Anglophone roots in the Cold War, species suicide discourse unites concerns about nuclear arsenals, so-called overpopulation, and environmental injustice across disciplines. Species suicide discourse is indebted to the US-based field of suicide prevention, which for more than half a century has analyzed suicide notes in search of effective prevention methods. Therefore, to theorize suicide prevention in relation to anthropogenic climate change, this article imagines a version of this genre that mediates between individual and collective subjects—called a species suicide note. As an example, the interdisciplinary and multimedia art project “Dear Climate” (2012–ongoing) by Una Chaudhuri, Oliver Kellhammer, and Marina Zurkow rewrites familiar narratives of crisis, shifting species suicide notes toward irony and unconventional techniques of hope. In analyzing these performative species suicide notes, the author complicates species suicide prevention by foregrounding narratives of irony. These notes accentuate a self-reflexive irony that works toward climate justice for vulnerable humans and more-than-human species.