Adapting to climate change will require a way to assess the potential indirect impacts of climate-induced migration.  The Climate Service should work with physical and social scientists as well as state and local agencies to develop a "Migration Index" that assesses the likelihood and extent of migration impacts resulting from climate change effects such as sea-level rise, stronger tropical and extratropical storms, drought and wildfires.  This index would "rate" community vulnerability or resilience to climate change impacts, providing an objective way to "reward" communities for efforts to build resilence and to assist communities that face impacts which cannot be overcome (such as coastal inundation).  Rewards or assistance might be in the form of favorable consideration for infrastructure grants, for example.

Migration represents an indirect climate change impact that will present a significant adaptation challenge for communities. People have always migrated because of climate, but rapid climate change has the potential to result in mass migration to areas less vulnerable to these impacts. Migration may be due to physical, economic, or lifestyle reasons, such as property inundation due to sea-level rise, inability to affordably obtain water for industrial processes in a drier climate, insurance costs, or a desire for cooler weather.

Rapid population growth from climate-induced migration may strain infrastructure, negatively impact community character, and create significant social services capacity issues, as well as create positive economic development opportunities. Rapid population decline may create negative economic impacts, but may also result in less congestion, more open space, and similar effects that may not be perceived negatively by all persons residing in the affected areas.

A "Migration Index" would indentify what climate effects might be experienced in a particular area or region and assess whether there is the potential for resilience or vulnerability based on impact type and extent or a community's ability to adapt to climate change.