The unique coping capacities and other attributes that Pacific island nations have been developing for centuries have sustained them in the face of an enormous range of local and global challenges. These include climate change-related hazards, and especially tropical cyclones and high-wave incidents that notably generate landslides and river and coastal flooding; droughts; heat waves; and ocean warming. Such hazards place resources, people, and assets at serious risk, as reflected by their vulnerability. However, measuring climate change vulnerability is problematic since climate hazards combine with anthropogenic and other physical drivers to influence the nature, levels, and variability of vulnerability. The few longitudinal studies that have been undertaken for the Pacific island countries show high and increasing vulnerabilities, despite considerable investment of money and other resources at community, island, sector, and national levels. Considering the elements of risk (hazard, exposure, vulnerability, and capacity to adapt), this chapter critically reviews the approaches used in the Pacific to assess vulnerability, analyzes recent changes in the vulnerability of island nations, and lays the foundation for some new thinking on island habitability and futures. It uses lessons learned, as well as success stories and success factors, to present priorities related to the assessment of climate change vulnerabilities, risks, and possible adaptation interventions in the Pacific islands region. These underpin a series of principles aimed at harmonizing understanding and action. Notably, the chapter concludes that transformational resilient development can provide a more effective response to increasingly unprecedented risks and higher vulnerabilities, for both high and low islands, including atolls.