Where humans live vs. where they can live

Population impact

	Safe	—
	SLR only	—
	Climate only	—
	Both	—
	Total impacted	—

Denominator: GHS-POP R2023A, 2020. ~7.84 B people.

Capacity check

	Need to move	—
	New land	—
	Capacity at today's density	—

Need-to-move = current population in cells that become hot-out or SLR-flooded. New land = cells that go from cold-out to in-niche. Capacity assumes the gained area settled at the current in-niche population density. Real distribution will favor land adjacent to existing cities.

Bivariate legend

Each cell is read on two axes: existing settlement (green, darker = denser) × incoming new pop (orange, darker = denser). The far corner (densest of both) pops to saturated magenta. Lost and stable-out cells are stripped, so the map shows only the post-warming settlement picture.




existing ↑ / incoming →

Cells of 5 km. Quartile cutoffs: 200 / 10 000 ppl/cell on both axes. Incoming migration is nucleated onto existing urban cores by per-cell existing-pop ^ 1.2 (superlinear at the cell level, so cities win over the rural band) plus discrete frontier hubs on newly-viable land. Water-stress penalty applied per WRI Aqueduct 4.0 SSP5-8.5/2080. See MIGRATION.md for the full model.

Map layers

The View, SLR, and climate sliders above drive the main raster. These overlays stack on top of whatever it shows.

Topography

Hillshade Mapzen / Nextzen DEM via AWS Open Data, MapLibre client-side shading

Populations & migration

Today's settlements (GHS-SMOD) Where humans live in 2020 — GHS-SMOD R2023A class >= 13

Preference model (calibrated)

Attractiveness, present Calibrated where-people-would-live utility, fit to 2020 settlement. Dark = low, bright = high.

Attractiveness, future Same weights, SSP5-8.5 × 70 m future climate + coastline. Drowned / hot-out land is blank.

Price / affordability, future Bid-rent that clears the market: utility above the local margin. Bright = expensive.

Capacity, future (FAR 3) People housable at FAR 3 on buildable, above-water, in-niche land.

Two cities

Impermanent / Permanent City Black is everything at or below the 70 m all-ice-melted ceiling or outside the climate niche at SSP5-8.5; white is the land that is neither. Flooding is ocean-connected, not bathtub, and Greenland’s interior is the bay it becomes once the ice is gone. Full diagram.

Climate signals

Climate signals News, papers & official reports on climate migration, sea-level rise, and climate change, geocoded to the place each describes. Click a point for the source. Orange = news, teal = paper, red = report.