The same framework — exposure layers, buffer versus envelope, and absorptive capacity — applied region by region. The headline is convergence of method, divergence of outcome: the binding constraint differs sharply by region, and so does how much buffer is available.
Latin America
Share of 2100 population: ~7–9%
| Binding constraint | PM basins + drought-power + informality |
| Worst-exposed | N. Brazil, Caribbean, Central America |
| Buffer zone | Andes, Southern Cone |
| Any-layer exposure (~2050) | ≈85% of regional population |
Warming taxes development but does not foreclose it. Stratified region — buffered upland cities versus a lowland chronic-risk envelope. Elevation buys time on physiology, not on basin PM.
Sub-Saharan Africa
Share of 2100 population: ~20–25%
| Binding constraint | Agriculture labor + weak grid + low cooling |
| Worst-exposed | Sahel-adjacent, East Africa lowlands, coastal W. Africa |
| Buffer zone | Highland East Africa, selected capitals |
| Any-layer exposure (~2050) | ≈88% of regional population |
Highest exposure growth × lowest buffer. Adaptation IS development here — where D and power do not compound early, warming can eat the development window before middle income.
South & Southeast Asia
Share of 2100 population: ~35–40%
| Binding constraint | Scale + humid heat + PM |
| Worst-exposed | Indo-Gangetic plain, coastal SE Asia |
| Buffer zone | Highland nodes, high-D coastal corridors |
| Any-layer exposure (~2050) | ≈90% of regional population |
The global ceiling on exposed population — and on adaptation if India and the region deploy grid and cooling at scale. The worst wet-bulb belt globally on weak paths.
East Asia
Share of 2100 population: ~18–22%
| Binding constraint | Industrial PM + datacenter thermal + coastal heat + aging |
| Worst-exposed | N. China plains, poor coastal zones |
| Buffer zone | High-D coastal corridors (China coast, Korea, Japan) |
| Any-layer exposure (~2050) | ≈82% of regional population |
Sharpest within-continent inequality. Strong stock in places makes heat costly-but-mitigable; interior and poorer coasts lag. Determines whether the century's growth is shared.
Eastern Europe
Share of 2100 population: ~3–4%
| Binding constraint | Coal/solid-fuel PM + fastest interior heat rise |
| Worst-exposed | S. Romania, Bulgaria, Moldova, Pannonian basin |
| Buffer zone | Carpathians, Baltic rim |
| Any-layer exposure (~2050) | ≈84% of regional population |
Does not develop a tropical uninhabitability belt — it Mediterraneanizes inward. Pollution–industrial trap + steep heatwave growth; Ukraine/Belarus/Moldova fork dominates the map.
The cross-regional pattern
Two variables explain most of the divergence: exposure growth (how fast hot, humid, polluted conditions expand over where people live) and buffer availability (elevation, building stock, grid, cooling, institutions). Sub-Saharan Africa and South Asia carry the highest exposure-growth × population; Eastern Europe and the Andes/Southern Cone retain the most buffer. Everywhere, the within-region gap between buffered and envelope populations widens.
In high-exposure, low-buffer regions, adaptation is development. Where grid, water and cooling are installed early and absorptive capacity compounds, warming becomes a costly-but- survivable tax. Where they are not, warming can eat the development window before middle income.