This chapter debates the displacement impacts of climate change. Is there a need for some sort of law on ‘climate migration’? Above all, does it make sense to talk about climate migration as a discrete phenomenon? Ingrid Boas argues that ‘climate mobility’ is real and observable and takes many forms (hence climate mobilities), including that of immobility (the decision to stay put despite the pressures to move). She makes the case for this phenomenon being a proper subject of research and governance. Calum Nicholson, by contrast, argues that climate migration researchers literally have no idea what they are talking about. These scholars, he claims, have made a virtue of imprecision in order to keep attracting research grants to study the individual experiences of those allegedly affected by the impacts of climate change, from which no generalizations could possibly be drawn.