Overview
- Researchers report that most coastal studies set the water baseline too low by about 8 to 12 inches on average, based on a review of tidal-gauge measurements.
- Scientists say a long-used approach relied on global geoid models that assume calm seas and left out waves, currents, and wind that raise water along coasts.
- Satellite radar mapping of 40 major river deltas finds widespread land sinking, with 18 deltas subsiding faster than tides are rising.
- Using the higher baseline, a rise of about 3.3 feet could flood up to 37% more land and put an extra 77 million to 132 million people at risk.
- The largest gaps appear in Southeast Asia and Pacific island nations, a shift that could force updates to global risk maps and local planning for defenses and retreat.