Oct 29, 2019

New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding

Scott A. Kulp, Benjamin H. Strauss
Nature Communications
  • States that most estimates of global mean sea-level rise this century fall below 2 m
  • Uses CoastalDEM, a new digital elevation model (DEM), to assess global and national population exposures to extreme coastal water levels
  • CoastalDEM uses neural networks to reduce Shuttle Radar Topography Mission (SRTM) error
  • Shows that 190 M people (150–250 M, 90% CI) currently occupy global land below projected high tide lines for 2100 under low carbon emissions, up from 110 M today, for a median increase of 80 M
  • These figures triple SRTM-based values
  • Under high emissions, CoastalDEM indicates up to 630 M people live on land below projected annual flood levels for 2100, and up to 340 M for mid-century, versus roughly 250 M at present
  • Estimates one billion people now occupy land less than 10 m above current high tide lines, including 250 M below 1 m