Coastal communities face $14tn flooding threat as sea levels rise

Up to 287 million people could be exposed to coastal flooding by 2100, new report warns

Researchers warned of an increasing risk of coastal flooding by 2100 because of global warming. EPA

Flooding of vulnerable coastal communities threatens homes and infrastructure worth $14 trillion (Dh 62 trillion) by 2100 if the world fails to tackle the threat from rising sea levels caused by global warming, according to new research out on Thursday.

Seaside areas of the Arabian Gulf, southern Mediterranean coasts and low-lying areas of Egypt are among the places that could see a large increase of extreme events with four per cent of the world's population at risk from extensive flooding by the end of the century, one of the study's authors told The National.

The surging waters threaten assets worth up to 20 per cent of global GDP, highlighting the potential huge economic cost to low-lying areas.

North-west Europe, parts of South Asia, China, Australia and the United States are among the areas at greatest risk, says the study published in the journal Scientific Reports. In Europe, the areas at risk include the continent's most powerful economies of Germany, the UK and France.

The study is the latest to raise questions about the long-term future of coastal communities as the average global sea level rises by more than 3mm a year.

Rising waters have led to the building of improved coastal defences at the cost of billons of dollars, the mass movements of communities inland and ambitious proposals to build floating cities.

The low-lying Mediterranean coastline of Egypt makes the “region vulnerable to flooding events” even though extreme sea heights are lower compared with other areas, said one of the researchers, Ebru Kirezci, of the University of Melbourne.

The study by researchers from at-risk countries of Australia, the Netherlands, the UK and Germany examined historical data during extreme storms and the impact of greenhouse gas emissions on sea levels.

A map of the hotspots of coastal flooding risk in 2100 in the event of unchecked global warming. Courtesy Scientific Reports

With continued high emissions and no extra defences against the sea, researchers estimated that the land affected by coastal flooding could increase by 48 per cent by 2100. Some 600 million people live in low-lying coastal zones that create about $1 trillion of global wealth, said the researchers.

They said the number of people exposed to episodes of flooding would increase from 171 million to about 287 million in 2100. Its conclusions were based on 2015 population and GDP data.

“Projected sea level rise will significantly increase the frequency of coastal flooding by 2100… for most of the world, flooding associated with a present day one in 100-year event could occur as frequently as once in ten years,” the study found.

The prediction was less pessimistic than the UN’s climate change body which reported last year that extreme coastal floods that are currently expected every 100 years could happen annually by 2050.

Coastal flooding in the UK in 1953 left more than 2,000 people dead and prompted the building of a barrier on the River Thames to protect London.

MPs were told in 2011 that up to 2,000 English homes could be at risk of falling into the sea by 2029 and the government this month pledged £5.2 billion for new defences against flooding.

Climate change is likely to trigger an increase in irregular migrants by countries most affected by its impacts, say experts.