Global 70m map

An interactive world map of every place on Earth at or below 70 meters elevation — the upper-bound geographic envelope for maximum-possible long-term sea level rise. See Max SLR for why 70m, and what “maximum” means on multi-millennial timescales.

▷ Open the map

The map is built from the Copernicus GLO-30 global digital elevation model (~30m resolution), thresholded at 70m and vectorized into a single PMTiles archive. It renders directly in the browser via MapLibre GL and pmtiles.js — no tile server, no account needed.

What the map shows

The dark layer is land that would flood under the maximum possible long-term sea level rise. Everything else either survives, is already ocean, or is beyond the Copernicus land coverage.

Notable places worth a look:

• Bangladesh — most of the country
• Nile Delta — Egypt’s agricultural heart
• Netherlands — already below sea level in many places, vulnerable everywhere
• Florida — the state mostly disappears
• Mekong Delta — Vietnam’s rice bowl
• Caspian Basin — a real inland depression at −28m, would be reached by any sea level rise that breaches the Bosporus
• Boston, Massachusetts — coastal city, mixed fate (Beacon Hill stays)
• Worcester / I-495 corridor — the safe upland that Max SLR argues for as Massachusetts’s long-term center of growth

Data

The underlying PMTiles archive is published as an open dataset under CC-BY-4.0 on HuggingFace:

huggingface.co/datasets/nelsn/global-70m-slr

You can use it directly in MapLibre, QGIS, deck.gl, or any other tool that supports the PMTiles format — see the dataset README for code snippets.

Resolution and accuracy

The map is built to zoom level 12, the natural cap for the 30m source data. At z12 each pixel at the equator is about 38m, very close to one source pixel. Past z12 you would only see the raster grid as staircase artifacts at coastlines — that’s not extra information, just visual noise.

The 70m contour itself has roughly ±40–80m of horizontal uncertainty due to the Copernicus DSM’s ±4m vertical accuracy on typical coastal slopes. The map shows the shape of the future ocean basin, not its precise edge.

Known artifacts

• Inland water: large lakes and reservoirs at low elevations are included (Caspian, parts of the Great Lakes basin). They are real low-lying areas but disconnected from the rising ocean.
• Real inland depressions: Death Valley, the Dead Sea, Qattara Depression, and the Netherlands’ polders all show as vulnerable because they are genuinely below 70m.
• River corridors: the Amazon and Mississippi basins extend the layer far inland. Under multi-millennial sea level rise these corridors do become marine inlets, so the layer is arguably correct on this point.
• Coastal slop: Copernicus tiles extend a few pixels offshore at the coast, so the polygon bleeds slightly into the present-day ocean in some places.

A future revision may optionally subtract Natural Earth land/lake polygons for a strictly continental land-only view.

Related

• Max SLR — the underlying long-term sea level rise scenario
• A world to design for — the surrounding worldview
• Organized migration — what populations do when large areas become uninhabitable