Earlier estimates had put that figure at about 80 million.
CoastalDEM-derived estimates of the global population at risk are three times greater than values produced using SRTM elevation data.More news: DC Anthology Series STRANGE ADVENTURES Is Headed To HBO Max
The paper's authors - New Jersey-based nonprofit Climate Central's Scott A Kulp and Benjamin H Strauss - developed a more accurate method of estimating the effects of sea level rise, and found that about 150 million people are now living on land that may be below the high-tide line by midcentury.
The study, which appears on Thursday in the peer reviewed scientific journal Nature Communications, employs a new software called CoastalDEM. In the worst-case scenario, these countries would see 87 million, 50 million, and 38 million people below the high tide level, respectively, in 2100. This is the standard method for estimating the rise in sea levels.More news: The Rock to put belt on victor at UFC 244
Further loss of land to rising waters there "threatens to drive further social and political instability in the region, which could reignite armed conflict and increase the likelihood of terrorism", said Mr Castellaw, who is now on the advisory board of the Center for Climate and Security, a research and advocacy group in Washington. Based on human activities, sea levels could rise between about 2 and 7 feet during the 21st century, or possibly even more. Other than India, the flood risk has also been underestimated for China at 93 million, as opposed to the current estimates of 29 million; Bangladesh at 42 million vs 5 million; Vietnam 31 million vs 9 million; Indonesia 23 million vs 5 million; Thailand 12 million vs 1 million. The authors have claimed to have devised a more accurate way of calculating land elevation based on satellite readings. However, they used artificial intelligence to account for known mistakes in previous NASA models, which tended to overestimate elevation. Almost 21 million - and not 2.8 million - are expected to be living below the High Tide Line, the boundary that marks the farthest to which the sea reaches into the land at high tide.
Scott Kulp, lead author and Climate Central scientist, says, "The assessments show the potential of climate change could reshape cities and economies within our lifetimes", and that nations will increasingly confront questions on how to protect coastal population.More news: House Takes Off Kid Gloves, Votes on 1915 Slaughter
More than 20 million people in Vietnam, nearly one-quarter of the population, live on land that will be inundated. However, cities still need to step up and look to investing into greater defences.