A growing number of authors argue that states which are responsible for global temperature rise owe reparative obligations to offer asylum to climate refugees because their decisions have led to the severe harms which climate refugees suffer. The validity and significance of reparative obligations as ideal moral requirements notwithstanding, this paper argues that, in practice, relying on causal responsibility to determine who is owed asylum is likely to produce morally objectionable outcomes. This problem results from a specific attribution problem, namely, the probabilistic reasoning and inherent uncertainties involved in establishing causal responsibility within the complex causal scenario of climate-related refugee movements. Because of this attribution problem, determining who is owed asylum is likely to be both under- and over-inclusive. Both under- and over-inclusion lead to unjustified deprivations of basic rights for some climate refugees.