Millions of people are threatened by rising ocean levels
By 2050, coastal areas with 300 million people may be threatened by rising ocean levels linked to climate change, according to a study released recently.
The region most at risk is Asia, says a study published in Nature Communications. More than two-thirds of the population under threat are in China, Bangladesh, India, Vietnam, Indonesia and Thailand.
Using an artificial intelligence method, the researchers corrected existing altitude data for coastal areas, which may have been incorrect and could have underestimated the extent of lands threatened by heavy storms and flooding.
“Predictions about rising ocean levels have not changed,” Ben Strauss, one of the study’s co-authors and chairman-director of Climate Central, a US-based research institute, explained to the French agency. “But when we use the new ground-based data, we find that more vulnerable people live in the vulnerable areas than we had previously estimated,” he continued.
Free data provided by NASA through the SRTM program – with 95% of the Earth mapped – may contain errors. About five years ago, Ben Strauss and Scott Kelp found, comparing these data with others, that the SRTM system consistently overestimated the height of the sea shore because it confused the roofs of the houses and the trees with the ground level.
“For most coastal areas around the globe we didn’t know the height of the ground beneath our feet,” Ben Strauss explained.
The population of the planet, which now stands at 7.7 billion, can grow by 2 billion by 2050 and by another billion by the end of the century. Many of these people live in seaside big cities.
Today, about 100 million people live in areas below sea level. Some are protected by dams but most have no protection.
“Climate change has the potential to reshape cities, economies, entire regions of the globe,” said Scott Kelp, the lead author of the study.
For these populations the threats are manifold: one is the rising ocean levels as the ice melts in Greenland. Since 2006 the level has risen by four millimeters a year, a rate that could be multiplied by hundreds if gas emissions remain at current levels, a group of climate experts warned last month.