As the effects of climate change intensify, time is running out for millions living in Asia Pacific coastal and island communities. Many will be forced to leave their homes within the next half-century because of increased intensity and frequency of storms and floods, sea-level rise, and desertification. The low-lying small island states of the Pacific are especially endangered; residents there may lose not only their homes, but their entire nations. Planning aimed at avoiding humanitarian disaster and political chaos should already have begun, but a stumbling block is international law, which is not prepared to address the cross-cutting impacts of climate and migration. Finding viable solutions will require new ways of thinking, pushing the law to a new frontier that calls for a reconsideration of existing legal boundaries.