Rising sea levels could have a devastating impact on three times more people by 2050 than previously thought, a new report has warned.
The new projection by a US-based science organisation, Climate Central, suggests more than 300 million people, including 42 million in Bangladesh, will be affected by coastal flooding in the next 30 years.
It’s estimated that the greatest effects will be felt in Mainland China, Bangladesh, India, Vietnam, Indonesia, and Thailand, which together account for roughly 75 percent of the 300 million people in low-lying coastal areas.
Additionally, high tides may permanently rise above land that is home to 150 million people.
“The threat is concentrated in coastal Asia and could have profound economic and political consequences within the lifetimes of people alive today,” it says.
Bangladesh, where coastal land is currently home to 42 million, could be threatened with saltwater flooding at least once per year at midcentury.
By that time, average annual coastal floods are projected to rise higher than a wide swath of the country, including parts of the cities of Dhaka and Chittagong
“Today, one in every four Bangladeshis lives on land that could flood at least once a year, on average, by 2050,” says the report.
“Even the country’s most infamous refugee crisis could be exacerbated by sea level rise,” it adds.
In India, projected sea level rise could push average annual floods above land currently home to some 36 million people. West Bengal and coastal Orissa are projected to be particularly vulnerable, as is the eastern city of Kolkata.
Much of Mumbai, India’s financial capital and one of the largest cities in the world, is at risk of being wiped out.
The Climate Central report says the new figures are based on a “new dataset of digital elevations that uses machine learning to more accurately identify vulnerable coastlines”.
Previous assessments used satellite data that overestimated terrain elevation due to tall buildings and trees.
"These assessments show the potential of climate change to reshape cities, economies, coastlines, and entire global regions within our lifetimes," said Dr. Scott Kulp, lead author of the report.
"As the tideline rises higher than the ground people call home, nations will increasingly confront questions about whether, how much, and how long coastal defenses can protect them," he added.
Sea level rise is the result of global warming, which causes ice sheets and glaciers to melt and adds to the volume of water in the oceans. Based on human activities, sea levels could rise between about 2 and 7 feet during the 21st century, or possibly even more.
In fact, even if the world acts quickly to address the concerns of climate change by limiting carbon emissions, there will be millions of people displaced by rising sea levels. But the numbers will be much higher if we continue on the current path, says the report.