Despite the scope and scale of the potential impacts of climate change on migration, political scientists have only recently begun to consider the politics of this novel driver of displacement and human mobility. This dissertation builds on the small number of studies on this subject, making both theoretical and significant data contributions. In the first chapter, I draw on a new dataset that I was instrumental in creating—the first-ever large-N cross-national public opinion survey of all of the world’s small island states and territories on the subject of climate change. The dataset covers 56 geographies, most of which have never been included in cross-national samples of this kind, and include populations most vulnerable to the effects of climate change. I find that access to financial resources interact with access to legal resources necessary to migrate, that future expectations of climate harm are more powerful predictors of aspiration to migrate than past experience, and that existing adaptation programs have done little to reduce this aspiration. In the second and third chapters, I turn to the prospects of providing protection and accommodation to people displaced from their home countries by climate change. In the second chapter, drawing on experimental evidence from a large survey of ten countries most responsible for climate change, I find a willingness to accept prospective migrants displaced by climate change that is, in general, greater than their willingness to accept economic migrants and, in some country cases, greater than their willingness to accept conventional refugees. Finally, in the third chapter, I focus on new survey experimental data in the United States. Using novel measurement strategies, I find an "expansionary port in a restrictive storm:" that linking climate change and migration can move public opinion—currently very much in favour of restrictive immigration policy—in the direction of targeted, expansionary admissions policy for climate-displaced people in the form of a special humanitarian visa. Taken together, this dissertation expands both our knowledge of the politics of climate migration and makes a contribution to the discipline in its approach to studying an emerging phenomenon with future-oriented outcomes.