Unfortunately, as this article makes clear, social science on climate change, particularly on economic and political issues, is not as clear or as developed as the climate and meteorological science. Partly this is because humans are by nature much more difficult to predict than the interaction of molecules in the atmosphere.
As the article asks, how can we know what events will trigger climate change induced migration?
"One study says 100 million people will be displaced by global warming. Another
puts it at 250 million. Meanwhile, a sweeping report from Christian Aid warns
that 1 billion people, an almost unthinkable crush of humanity, could be forced
from their homes by midcentury because of climate change and the increase in
natural disasters, which will exacerbate regional conflicts."
There are different assumptions about human behavior in each study, and global numbers of this magnitude are almost impossible to acurately predict. Instead of presenting such large-scale, global studies, perhaps it would be better for social scientists doing research on the effects of climate change to focus on defined regional or local trends?