New research suggests that previous estimations of rising sea levels by 2050 were overly optimistic and that three times as many people could be affected than previously expected.
The authors of the paper, which was published on Tuesday, have developed a more accurate way of calculating land elevation based using satellite readings — the standard for predicting sea-level rise.
According to the new calculations, approximately 150 million people are currently living on land that will be below the high-tide line by 2050.
Changing tides, changing predictions
If carbon emissions are not cut drastically and coastal defenses not strengthened by 2050, land that is currently inhabited by approximately 300 million people will flood at least once a year, the new study says.
The previous estimate stated that the affected number of people would be 80 million.
The findings, published in Nature, paint a gloomy picture of the effects of climate change.
Why the change?
As per The Guardian, the revision to the previous estimate comes on the back of a more sophisticated assessment of the topography of coastlines around the world.
Previous data was collected using models that overestimated the altitude of land due to tall buildings and trees. The new calculation was made using artificial intelligence that was able to factor in these issues and compensate for the misreadings.
Researchers said the huge difference from the estimates provided by the previous NASA study was not expected.
“These assessments show the potential of climate change to reshape cities, economies, coastlines and entire global regions within our lifetimes,” said Scott Kulp, the lead author of the study and a senior scientist at Climate Central.
The most devastating effects, if the estimates are true, will take place in Asia, the most populated of the world's continents.
According to the study, more than 70 percent of the total number of people worldwide that are currently living on affected land are in eight Asian countries: China, Bangladesh, India, Vietnam, Indonesia, Thailand, the Philippines, and Japan.
As The New York Times points out, southern Vietnam could all but disappear. Indonesia, meanwhile, is building a new capital city, as Jakarta is already feeling the threat of rising seas and is steadily sinking.
A small silver lining?
What's more, the new estimates are based on a scenario known as RCP2.6. This is based on the assumption that emissions cuts will be in line with the promises made under the Paris agreement. However, countries are currently not on track to meet the targeted cuts.
“The need for coastal defences and higher planning for higher seas is much greater than we thought if we are to avoid economic harm and instability,” said Benjamin Strauss, Climate Central’s chief scientist, and CEO.
“The silver lining to our research: although many more people are threatened than we thought, the benefits of action are greater.”