What the International Monetary Fund calls “fragile and conflict-affected” states of Africa’s Sahel and neighboring countries (From Senegal to the Red Sea, and the band of countries below that) are going to be most adversely affected by climate change. These countries have very high fertility rates. Outmigration will remain very high.
Climate change-related migration can be hard to discern because the affected countries and sub-regions may have long standing seasonal migration and migration from rural areas into cities. I think that the Sahel will command much of our attention for the definite impact of a warming globe.
The IMF writes:
From the Central African Republic to Somalia and Sudan, fragile states suffer more from floods, droughts, storms and other climate-related shocks than other countries, when they have contributed the least to climate change. Each year, three times more people are affected by natural disasters in fragile states than in other countries. Disasters in fragile states displace more than twice the share of the population in other countries.
And temperatures in fragile states are already higher than in other countries because of their geographical location. By 2040, fragile states could face 61 days a year of temperatures above 35 degrees Celsius on average—four times more than other countries. Extreme heat, along with the more frequent extreme weather events that come with it, will endanger human health and hurt productivity and jobs in key sectors such as agriculture and construction.