A New Study Shows More Cities Globally Will Be Drowned By Sea Level Rise
Shanghai in 2050 Graphics: New York Times
New research using satellite positioning more accurately determines the elevation of numerous coastal cities — and as a result, found that previous estimates of the impacts of sea-level rise were far too optimistic and 150 million people are living in areas that will be below the high-tide line by 2050. This assessment of the impacts on coastal cities is based on today’s population numbers, not counting future population growth or land lost to subsidence or coastal erosion so the actual numbers of people who will be displaced by sea-level rise globally will likely be even higher.
Why This Matters: Too optimistic may be an understatement. For example, the southern part of the country of Vietnam will be subsumed and more than 20 million people who live in that area currently — almost 1/4th of the country’s population — will have to move. The authors of the UN IPCC report on Oceans and the Cryosphere may not have had the benefit of this latest research, but they delivered a similar message. We must begin to adapt right now. And physical barriers to sea-level rise can only go so far, particularly when they are based on “overly optimistic” estimates of how much and where the impacts of rising seas will be greatest.
The New Elevation Numbers
The authors of the study that was published Tuesday in the journal Nature Communications developed a better way of calculating land elevation based on satellite readings. As one of the study’s authors explained to the New York Times, “[s]tandard elevation measurements using satellites struggle to differentiate the true ground level from the tops of trees or buildings,” so they used artificial intelligence to determine the error rate and then corrected for it.
Major Cities Under Water
The new satellite data make a big difference, as the maps demonstrate.
- In Vietnam, Ho Chi Minh City, the nation’s economic center, would disappear.
- Thailand would lose 10% of its land, and its capital, Bangkok, is particularly at risk.
- Water would inundate the heart of Shanghai, China — one of Asia’s most important economic engines.
- Mumbai, India– one of the largest cities in the world — has major portions that are at risk of being wiped out.
- Important world cultural heritage could also be lost — Alexandria, Egypt, founded by Alexander the Great around 330 B.C., could be under water.
Alexandria, Egypt in 2050 Graphics: New York Times