It can be difficult to be hopeful about the health of ecosystems, humans, and nonhuman animals in the 21st century. Whether it's the steady drip of depressing information about the state of our ecological systems or the sheer scale of intervention required to make a difference, engaging with either or both of these phenomena can instill a sense of powerlessness and helplessness. By first unpacking the fundamental nature of “hope,” this chapter then presents cases for both pessimistic and optimistic engagement with our 21st century ecological challenges, drawing parallels between public health and conservation science. In doing so, the chapter argues that in order for hope to be productive, it must be tied to integrative actions that are good for people, nonhuman animals, and the planet, and that considering these facets precipitates the need to consider inter-specific justice in the Anthropocene epoch. Examples of integrative actions are discussed to instill a sense of possibility for greater engagement across natural, living, and social systems to promote and protect planetary health.