When the ESA was drafted, no one could have foreseen climate change, much less thought seriously about how the ESA should address species loss on a warming earth. Climate change blows up the ESA’s operative mandate for federal agencies to prevent human disturbance of especially vulnerable species. Species loss due to climate change operates on an altogether different paradigm, muddling all causal connections between human actions and harm to a particular species. Unlike traditional problems of preserving endangered species, there is no spatial connection between the cause of the jeopardy and the species’ habitat—most greenhouse gases are emitted far from the areas that endangered species inhabit. In a warming planet, human disturbance has much less to do with physical encroachment into sensitive space than with disrupting ecosystems such that food resources and mating opportunities diminish, leading to eventual extinction. Shorn of any geographic connection between where adverse activity may occur and an endangered species’ habitat, the question of what and how to regulate becomes ephemeral: How does one protect a habitat from activity that is global, with multiple causes and impacts? This question poses unique and intellectually challenging dilemmas for courts.