Twice as Much Land in Developing Nations Will be Swamped by Rising Seas than Previously Projected, New Research Shows More accurate mapping of terrain in coastal regions will allow countries to better assess flood risk.
By Bob Berwyn
February 7, 2023
Rising seas will swamp farmlands, pollute water supplies and displace millions of people much sooner than expected, scientists said last week, as they released new research that accurately calculates the vulnerability of coastal areas, especially in developing countries that have not had access to expensive coastal mapping technologies.
Sea level rise keeps speeding up, and “many coastal areas are lower than scientists thought they were,” said Ronald Vernimmer, lead author of the new study published last week in Earth’s Future, a journal of the American Geophysical Union.
Up until a few years ago, most estimates of how fast rising seas will inundate shorelines were based on radar measurements that can’t distinguish between tops of plants and buildings and the actual elevation of the ground beneath them, “and therefore overestimate surface elevation,” said Vernimmen, who works with the Dutch research firm Data for Sustainability.
The study he led analyzed global data from NASA’s ICESat-2 satellite, which uses light detection and ranging (lidar) to get more accurate measurements. A lidar instrument combines information from laser pulses, a scanner and a specialized GPS receiver to generate detailed three-dimensional information of features on the surface of the Earth.
The new study shows that every increment of sea level rise will cover more than twice as much land as older models predicted, and marks another advance in providing more accurate models of rising seas said Stefan Rahmstorf, a climate scientist with the Potsdam Institute for Climate Impact Research, who was not involved in the study.
“It is no surprise that, particularly for moderate sea-level rise, the improved elevation data are bad news,” he said. “More flooding can be expected for a given rise of 1 meter or 2 meters, and more people live in areas vulnerable to rising seas than was estimated with the old elevation models.” |
