Despite considerable debate about whether or not climate change will cause large numbers of people to migrate, there has been little consideration of how such displacement might be caused. Three effects of climate change are identified as possible drivers of migration: loss of or reduction in land security, livelihood security, and habitat security. Where these are destroyed by climate change, migration will be forced and would require the abandonment of some locations. Such community relocation is likely to be a disruptive form of climate-change migration, and past experience indicates that there are numerous social, cultural, emotional, and economic costs associated with such moves, even at relatively small distances. Where the loss of security is partial, voluntary or induced migration may be a practical adaptive response, reducing pressure on declining local life-support systems and providing remittances to supplement declining livelihoods. Most attention has been focused on atoll communities, but most Pacific communities (with the exception of Papua New Guinea) are coastal, and the security of some inland areas may be threatened by increasing magnitude and frequency of droughts. Destinations for climate-change migrants may range from locations within customary lands to foreign countries within and beyond the region. A key issue is the essential link between Pacific Islands people and their land, which poses major problems not only for those forced to leave but also for communities within the region that may be required to give up land for relocatees.