"In most of Asia, if you put that on a list of priorities it falls off the bottom of the page," said Steve Williams, head of Energy Solutions, which does consultancy work on industry services such as ports and infrastructure.

One in 10 people, mainly in Asia, live in coastal areas most at risk, an international study published last month found.

The researchers said many countries cannot afford Dutch-style dykes but urged governments to make billion-dollar policy shifts in long-term planning to encourage more settlements inland.

Limiting global warming to a 2 degrees centigrade rise would cost just 0.12 percent of global Gross Domestic Product (GDP), with the technology available, a UN climate change report said on Friday after days of wrangling at talks in Bangkok.

The Thai capital could be under water in 20 years because of rising seas from global warming and subsidence, a top Thai climate expert, who warned of a tsunami years before the 2004 disaster, told Reuters in an interview this week.

Smith Dharmasaroja, head of Thailand's National Disaster Warning Centre, said the city of 10 million people was sinking at an alarming rate and to avert disaster it needed to construct a massive sea wall. He said the government did not pay attention.

RECLAIMED LAND

For fellow southeast Asian country Singapore, where low-lying land has been reclaimed from the sea in recent decades, global warming is a big threat to its future, the city-state's founder Lee Kuan Yew told Reuters in an interview last week.

"What dykes can we build? Where do we get materials for the dykes? Do we excavate the sea bed? We are into a very serious problem," Lee said.

Even so, experts say wealthy Singapore -- known for organisation and efficiency -- is the most likely country to push ahead with sea defences to avoid being partly submerged under six metres (20 feet) of water in a worst case scenario.

"The first country that would really start thinking about this is Singapore -- they have a lot of landfill," said Energy Solutions' Williams.

Neighbouring Indonesia, which banned sand exports for land reclamation to Singapore this year, has said it could lose 2,000 islands by 2030. It has been drafting a national strategy to deal with climate change.

Ranked by population, China is most at risk to rising sea levels with 143 million people living by the coast, followed by India, Bangladesh, Vietnam, Indonesia and Japan.

Regional powerhouse China is expected to be vulnerable along its storm-prone southeastern coastline, though government environmental protection efforts have been more committed to tackling rampant air and water pollution.

In India, where ports are being expanded to boost fuel shipments from its booming oil refining sector to a region hungry for more fuel, environmentalists say coastal development has reduced natural sea defences such as sand bars and mangroves.

"We need to understand these things, their implication and certainly a strategy needs to be worked out -- but it's not that we have a plan tomorrow," said P.S. Goel, Secretary at the Ministry of Earth Sciences. "Something needs to be done for the ports ... certainly we all are worried."