Totally 100,000 postcards with messages against climate change on the Jungfraufirn, the upper part of Europe's longest glacier Aletsch Glacier in Switzerland on November 16, 2018 Photo: VCG

 New research shows that sea levels are rising faster than expected, and by 2050, some of the greatest coastal cities, including Shanghai, will be wiped out. But some Chinese experts said the rise is not as fast, though they admitted global warming poses a huge challenge.

The Climate Central in New Jersey, the US published a new prediction on Tuesday, saying that through a more accurate way of calculating land elevation based on satellite readings, the center of East China's Shanghai and other great coastal cities in the world such as such as Mumbai and Bangkok will be under water at high tide by mid-century.

In Shanghai, water threatens to consume the heart of the city and many other cities around it, according to a New York Times report.

A map in the research shows the old and new projections for 2050 for Shanghai. The city's center becomes deep blue in the new projection, which means it will be below the high-tide line.

The research also said that a previous prediction was far too optimistic, and that southern Vietnam will disappear by 2050, where more than 20 million people, almost a fourth of the country's population, currently live.

"The sea level is not rising that fast," Zhang Zhiqiang, a deputy director of the National Center for Climate Change Strategy and International Cooperation, told the Global Times on Thursday.

According to China's third national assessment of climate change published in 2015, China's coastal sea levels rose at a rate of 2.9 millimeters per year from 1980 to 2012. The fourth assessment is under way.

Chinese experts also confirmed that rising sea levels would pose a huge threat to coastal cities if the global warming situation does not improve.

Bai Yunwen, policy director of Beijing-based nongovernmental organization Greenovation Hub, told the Global Times that regardless of how fast Shanghai or other coastal cities will be wiped out by rising sea levels, cities should be ready to deal with climate change.

"Urban planning should be improved to prevent floods," Bai said. "The government also needs to consider how to ensure fresh water supply when the city sees rising sea levels."

Bai noted that no country should ignore global warming and the disasters it causes. "All countries need to deal with global warming, especially with   carbon emissions, such as the US."