New Delhi, Oct 5 (IANS): As an Intergovernmental Panel on Climate Change (IPCC) report next week is expected to call for urgent cuts limiting global warming to 1.5 degrees, a study on Friday said world's biggest coastal cities like London, Shanghai and Bangkok may face a flood-hit future.

The report published by Britain-based Christian Aid said some of the cities were set to become extremely vulnerable to storm surges and flooding.

Sea level rise was expected to exceed 40 cm if global warming is not limited to 1.5 degrees Celsius. With the world's urban population expected to grow to 59 per cent by 2030, city dwellers would increasingly come under threat.

Author of the report Kat Kramer, Christian Aid's Global Climate Lead, said: "Some of the world's most famous cities are sinking under the waves as climate change drives up sea levels."

"We're starting to see what happens when climate change acts as a threat-multiplier, compounding poor development decisions."

"We're already at around one degree of warming and we are getting a picture of what happens if we exceed 1.5 degrees. The world is currently on track for more than three degrees of warming, which would have disastrous consequences for the millions of people living in these coastal cities," Kramer said.

"It's vital that governments heed the findings of the IPCC and agree to increase their Paris Agreement pledges.

"These global metropolises may look strong and stable but it is a mirage. As sea levels rise, they are increasingly under threat...," she said in a statement.

The cities featured in the 'Sinking Cities, Rising Seas' report include Jakarta, Houston, London, Shanghai, Lagos, Manila, Dhaka and Bangkok.