Surging Seas Sea level rise analysis by Climate Central

Risk Zone Map - Global

Climate Central’s Surging Seas global Risk Zone Map provides the ability to explore inundation ​risk ​up to 30 meters across the world's coastlines as well as local sea level rise projections at over 1,000 tide gauges on 6 continents. Map areas below the selected water level are displayed as satellite imagery shaded in blue indicating vulnerability to flooding from combined sea level rise, storm surge, and tides, or to permanent submergence by long-term sea level rise. Map areas above the selected water level are shown in map style using white and pale grays. The map is searchable by city, state, postal code, and other location names. The map is embeddable, and users can customize and download map screenshots using the camera icon in the top right of the screen.

For map areas in the U.S., the Risk Zone map incorporates the latest, high-resolution, high-accuracy lidar elevation data supplied by NOAA, displays points of interest, and contains layers displaying social vulnerability and population density. For map areas outside the U.S. the map utilizes elevation data from NASA's Shuttle Radar Topography Mission (SRTM).

Science Behind the Tool

The research behind the Risk Zone Map is based on peer-reviewed science. That 2012 analysis used the best available U.S. national coverage elevation dataset at the time. Risk Zone Map now uses far more accurate laser-based (lidar) elevation data in the U.S.

Outside of the U.S., very little lidar data is available. Instead, we use radar satellite-based data collected from NASA’s Shuttle Radar Topography Mission (SRTM). This elevation data covers nearly the entire populated world, but is less accurate than lidar. SRTM’s pixel resolution is lower, and in areas of dense urban development and vegetation, SRTM tends to overestimate elevation. Recent work also suggests that SRTM usually underpredicts exposure from sea level rise and coastal flooding. Outside the U.S., our flood maps should therefore be seen as likely lower bounds on the extent of potential inundation for each water level.

Further detail is provided in the “Learn about this map” documentation accessible via the information icon in the header of the map page.