Much is said, written, and proposed about the climate-migration-health nexus with many efforts and suggestions put forward regarding its governance at multiple levels, including regionalism and interregionalism. Rarely asked is how real the nexus is and its governability or lack thereof. This chapter explores both these points, covering three key areas. First, “climate”, “climate change”, and “human-caused climate change” are often conflated. Governance material can use “climate” or “climate change” when they mean “human-caused climate change”, thereby confusing what is being governed, how, and why. Second, while climate and climate change have influenced migration and health throughout human history, additional links or influences from human-caused climate change are currently seen as limited. Meanwhile, governing migration requires accepting that it sits on a forced-voluntary continuum and on a mobility-immobility continuum with multiple factors interacting. Third, links between migration and health tend to be more about governance of health systems and governance of migrants than about climate or climate change impacts. Fundamentally, if the aim of governing the climate-migration-health nexus is to support migrants’ health or to avoid health issues leading to mainly forced migration or forced immobility, then governing climate and climate change is far less important than governing migration and health. Other possible aims of governing the nexus make it similarly unclear how including climate or climate change would support governability, including at regional and interregional levels.