Climate Change and Respiratory Health

Current Evidence and Knowledge Gaps

Tim K Takaro; Kim Knowlton; John R Balmes


Expert Rev Resp Med. 2013;7(4):349-361. 

In This Article

Human Migration

Estimates of the extent of human migration expected due to environmental change in the next 40–50 years vary from negligible to over 200 million depending largely on the definition of migration.[121] The drivers of human migration are multiple as people move to improve social and economic circumstances, to seek better opportunities for their children and to reunite with family members or in extreme circumstances to avoid violence or persecution. Though most recent research in this area tends to overlook environmental drivers of migration, climate change can clearly influence decisions to migrate.[121] It is rare to attribute migration to one reason. Instead, climate change is one factor that interacts with many others to drive population movement.[122] Much of the decision to move can be driven by vulnerability to specific climate change induced exposure and whether that exposure is viewed as permanent, as in the case of sea-level rise, or temporary (though likely recurrent) as after a riverine flood or hurricane.[123–126] These pressures are not new.[122] In the early 20th century rising sea levels on the Chesapeake Bay led many residents to abandon their homes,[127] and in the present day rising sea levels threaten to displace millions of people in Bangladesh and other heavily populated, low-lying countries[128] as well as small communities on the arctic coast.[129] It is likely that climate-forced changes in water and food security, extreme weather events and sea-level rise will impact established migration patterns as well as contribute to novel ones. Such large scale migrations would strain existing refugee resources and potentially serve as a mechanism for the increased movement of infectious diseases[130,131] and conflict or create new sources of conflict.[9]