See how the Baltic Sea is changing — and what's being done about it.
An open, source-cited map of climate change in the Baltic Sea Region: sea-level rise, a fast-warming sea, storm-surge flooding, coastal erosion and the world's largest human-made dead zones — plus a directory of real initiatives to act on them.
🔗 Live: https://mangluu.github.io/visbaltic/
This is a modern rebuild of a #b_hack Baltic Sea Region hackathon climate project. The 2025 brief asked teams to "create an interactive map to illustrate how climate change is affecting the Baltic Sea Region" and to "support planning and activism based on facts" across borders.
The earlier prototype had the right idea but three problems: its climate layers were synthetic placeholder values with no sources, it hid the map behind a login wall backed by a database it barely used, and its "community" features saved nowhere. VisBaltic keeps the good idea — risk + action on one shared map — and fixes the rest:
- Every number is real and cited. Figures come from PSMSL, HELCOM, Copernicus Marine, EEA, SMHI/FMI and peer-reviewed papers, with the load-bearing ones re-checked against the primary data. See the in-app Data & sources page.
- No backend, no login, no tracking. A fully static site. Your action shortlist lives only in your browser.
- Honest about limits. Relative vs. absolute sea level, interpolated regional
values marked
≈, and unverifiable claims dropped rather than repeated.
- Overview — four measured headline signals, the signature "north falls, south rises" sea-level paradox, and one verified fact per coastal country.
- Explore — an interactive, keyless SVG map of the Baltic with switchable layers (sea level, warming, flooding, erosion, dead zones); click any site for its measured value and source.
- Act — a curated directory of real Baltic organisations to volunteer with, support or learn from — filterable, with a private shortlist.
- Sources — the full citation list, methodology and honest limitations.
- React + Vite + Tailwind CSS,
react-router-dom(HashRouter for Pages). - Bespoke map: Natural Earth coastlines
(public domain), clipped to the Baltic at build time (
scripts/build-map.mjs) and rendered as plain SVG — no map tiles or API keys. - Self-hosted fonts (Inter + Space Grotesk); no third-party requests at runtime.
- Deployed to GitHub Pages via GitHub Actions (
.github/workflows/deploy.yml).
npm install
npm run dev # http://localhost:5173
npm run build # production build → dist/
npm run preview # preview the build
node scripts/build-map.mjs # regenerate src/data/baltic-geo.jsonVisBaltic is an educational overview, not a forecast, flood map or safety service. For planning or emergencies, consult national meteorological and coastal authorities.
Coastlines © Natural Earth (public domain). Climate figures © their respective providers (PSMSL, HELCOM, Copernicus Marine Service, EEA, SMHI, FMI, and cited authors) — see the Sources page for full attribution. Built for the Baltic Sea Region.