PARIS • Governments must provide a "major" investment in flood risk reduction to save coastal cities around the world, a charity said yesterday, as rising seas and sinking urban areas pose unprecedented threats to millions of homes.
Cities such as Jakarta - which is sinking 25cm each year - Bangkok, Houston and Shanghai risk being inundated within decades as a combination of poor planning, mega storms and higher tides wreaks havoc.
In a briefing paper, London-based charity Christian Aid studied eight coastal cities around the world that are sinking, potentially compounding the misery that rising sea levels will inflict on inhabitants.
"The impacts of climate change will be seen across the world and, as you saw this summer, we had a very warm northern hemisphere, very abnormally so," Dr Kat Kramer, global climate lead at Christian Aid, told Agence France-Presse.
"Many of the big cities in the developing world are extraordinarily vulnerable to climate change, which is why it's very important that they are given support to adapt and build resilience.
"Lives are already being lost through extreme weather events," Dr Kramer added.
The call coincides with the release next week of a major United Nations report expected to urge governments to drastically increase their efforts to limit global temperature rises.
Thursday's paper picked out Jakarta, Bangkok, Lagos, Manila, Dhaka, Shanghai, Houston and London - home to a combined 100 million people - as being particularly at risk.
The charity highlighted a host of local factors that contribute to sinkage, the majority manmade, including excessive groundwater extraction.
Dr Kramer said large infrastructure such as sea walls or London's Thames Barrier could help mitigate the damage, but also urged governments to preserve nature's own defences.
"Something noticeable with the Asian tsunami (in 2004) was that areas that had their mangroves intact had greater resilience to that kind of (sea) surge," she said.
"There are many ways that natural measures can help if they are left intact."