The largest class of refugees is environmental, a situation which will become worse with ongoing climate change. With eventual sea level rise , even of only a few inches, unprecedented human migration will be necessary as most of the human population live in coastal areas. Erosion of land area in some regions is likely. Agricultural production will change, either local increase or decrease. Decreases are more likely since crops are chosen for their ability to grow under contemporary climatic conditions.
Climatic changes are likely to lead to food security issues.
This will disrupt co-evolved mutualistic interactions, and change habitat associations. Synergisms with widespread habitat loss and fragmentation will lead to an inability to migrate successfully. The impact this will have on extinction rates is unknown, but may be severe. It will not be negligible. These are areas of extreme endemism, so losses in these habitats will have a disproportionately large effect on extinction rates.