Threat of Sea Level Rises

Land that is currently home to 300 million people will flood at least once a year by 2050 unless carbon emissions are cut significantly and coastal defences strengthened, says the study, published in Nature Communications. 

This is far above the previous estimate of 80 million.

The authors say the calculations could still underestimate the dangers because they are based on standard projections of sea level rise in a scenario known as RCP2.6, which assumes emissions cuts in line with the promises made under the Paris agreement. Countries are currently not on course to meet these pledges. In a worst-case scenario with greater instability of the Antarctic ice sheet, as many as 640 million people could be threatened by 2100

“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. “As the tideline rises higher than the ground people call home, nations will increasingly confront questions about whether, how much and how long coastal defences can protect them.”

The biggest change in estimates was in Asia, which is home to the majority of the world’s population. The numbers at risk of an annual flood by 2050 increased more than eightfold in Bangladesh, sevenfold in India, twelvefold in India and threefold in China.

The threat is already being felt in Indonesia, where the government recently announced plans to move the capital city from Jakarta, which is subsiding and increasingly vulnerable to flooding. The new figures show 23 million people are at risk in Indonesia, up from the previous estimate of 5 million.

Benjamin Strauss, Climate Central’s chief scientist and CEO, said more countries may need to follow Indonesia’s lead unless sea defences were strengthened or carbon emissions were cut. “An incredible, disproportionate amount of human development is on flat, low-lying land near the sea. We are really set up to suffer,” he said.

https://www.theguardian.com/environment/2019/oct/29/rising-sea-levels-pose-threat-to-homes-of-300m-people-study