Chinese Cities Most at Risk from Rising Sea Levels

Fast-Growing Coastal Megacities, Home to 145 Million, Face Flood Threat from Climate Change

A study by Climate Central, a non-profit news organization focusing on climate science, showed that 12 other nations have more than 10 million people living on land that would be destroyed should the earth’s temperature rise to 4 degrees Celsius.

As well as China, in descending order, starting with the countries most at risk, India, Bangladesh, Vietnam, Indonesia, Japan, the U.S., the Philippines, Egypt, Brazil, Thailand, Myanmar, and the Netherlands are extremely vulnerable.

“Roughly a quarter of the world’s people who live on land at risk from 4C warming are living in China. That is more that twice as many as who live on vulnerable land in Europe and the U.S. combined,” said Climate Central’s lead scientist, Benjamin Strauss.

“The Shanghai region by itself has more than 20 million people living on land that could be lost,” he added.

The report, called “Mapping Choices: Carbon, Climate, and Rising Seas—Our Global Legacy,” published in November 2015, noted that China has the most to gain from limiting global warming to 2 degrees Celsius—one of the temperature targets agreed at the Paris climate conference in December.

A 2 degree Celsius cap would cut the number of Chinese citizens living in threatened urban areas from 145 million to 64 million.

Google Earth created a series of three-dimensional maps to accompany the study, which allow you to visualize what cities will look like under water in four different temperature scenarios: 1.5 degrees Celsius (which was also backed at the Paris summit but is seen as increasingly out of reach), 2 degrees Celsius (the internationally ratified goal), 3 degrees Celsius, and 4 degrees Celsius.

The climate group has also created “fly-over” videos for many coastal cities around the world, using 3D building data made available to the public. The interface allows viewers to type in the name of a city or postcode and explore what future flood levels could be where they live.

A carbon path that limits warming to 2 degrees Celsius would reduce exposure for more than 10 million in each listed nation (except for in China, Myanmar, and the Netherlands). In Vietnam, exposure would be reduced by 44 percent, 45 percent in Brazil, and 13 percent in the Netherlands, according to the report.

Global megacities with the top 10 populations most at risk from rising sea levels include Shanghai, Hong Kong, Calcutta, Mumbai, Dhaka, Jakarta, and Hanoi.

The predictions were based on predicted median sea level rise data and global elevation data, with a tendency to “understate exposure.”

The results do not, however, account for the building of present or future shoreline defenses, such as artificial embankments.

Google Earth video edited by Ted Blanco. Google Earth virtual cinematography by Dan Dodson.




Jeffrey Linn & David M. Barreda
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