How to read these figures
This resource synthesizes published climate, health and development research into a structured analytical frame. The scores are judgments designed to make coupling legible — not measured quantities with decimal precision.
What the scores are
HCPI dimension scores (0–10) are structured analytical judgments synthesizing the sources above — not measured quantities. They are designed to make coupling and medium-impact legible, not to assert decimal precision.
Why coupling and medium are weighted highest
A narrow tail risk that hits one system ranks below a problem that breaks grids, schools, farms and finance at once. Weights (K 0.25, M 0.20) encode that a coupled, productivity-eroding problem is structurally worse than an isolated one.
Temperature bands, not points
All late-century figures are ranges across a middle (SSP2-4.5) and weak (SSP5-8.5) path. “Feels-like” uses heat-index; WBGT is the work-safety metric; MAT is the chronic-niche metric. They answer different questions and are not interchangeable.
Population-weighting
Regional figures are weighted toward where people actually live (lowland megacities), not land-area averages — which is why population-weighted MAT runs hotter than territorial means.
Uncertainty
Ranges widen with time horizon and weaken with path certainty. Treat post-2060 figures as scenario envelopes, not forecasts. Figures are rounded; see each chart for the metric used.
The six dimensions & weights
| Code | Dimension | Question | Weight |
|---|---|---|---|
| E | Exposure | What share of humanity is hit? | 15% |
| U | Urgency | When does damage peak / lock in? | 15% |
| L | Lock-in | How reversible? (10 = permanent) | 10% |
| K | Coupling | How many other systems does it drag down? | 25% |
| M | Medium | Impact on labor, cognition, health, learning | 20% |
| D | D-gap | Institutional need minus installed stock | 15% |
HCPI = 0.15·E + 0.15·U + 0.10·L + 0.25·K + 0.20·M + 0.15·ΔD
Source register
| Organization | Work | What it informs |
|---|---|---|
| World Bank | Unlivable: What the Urban Heat Island Effect Means for LAC ↗ | Extreme-heat-day projections and within-city UHI stratification. |
| World Bank | Economics of Climate Adaptation (ECA) — Heat | Cooling demand, labor productivity and adaptation cost framing. |
| IPCC | AR6 WGI & WGII | SSP scenario temperature ranges, committed warming, reversibility. |
| CMIP6 / SSP | Scenario ensemble | SSP2-4.5 (middle) and SSP5-8.5 (weak) used for band ranges. |
| Scientific Reports (2025) | City mean-annual-temperature niche exceedance | Cities and population crossing >29°C MAT by period. |
| SALURBAL | Salud Urbana en América Latina | Urban heat and health across Latin American cities. |
| Nature Sustainability | Human climate niche | Population pushed outside the historical temperature niche. |
| WHO | Ambient air quality guidelines (2021) | PM₂.₅ 5 µg/m³ guideline; ~94% of population above it. |
| Lancet Countdown | Health and climate change | Heat mortality, labor-hour loss, aging interaction. |
| Frontiers | Urban heatwave exposure projections | Compound exposure under SSP pathways. |
Citations identify the bodies of work synthesized; specific figures are rounded and combined across scenarios. This resource is an analytical synthesis for reasoning, not a primary data source. Verify against originals before operational use.