On November 9, 2023, Australia and Tuvalu signed an unprecedented cooperation agreement. It offers 280 Tuvaluans—2.5 percent of the islands’ population—permanent residency in Australia each year. The agreement, which stems from a recognition that Tuvalu’s long-term future is endangered by climate change, offers new possibilities for migration and adaptation but is not without its challenges. This note unpacks the agreement’s context; its possible effects; next steps for Australia and Tuvalu; and lessons for other countries.