Small islands and coastal cities in Asia-Pacific need more funds to assist vulnerable communities and help them decide whether to relocate or stay and defend against rising sea levels and extreme weather, climate experts have said.
Indonesia last month said it would relocate its capital from the sinking city of Jakarta, while Fiji plans to move dozens of coastal villages inland, and the Marshall Islands is building sea walls to protect coastal communities.
"As much as possible, we must try to adapt and mitigate in situ because that's where people have their homes, land and livelihoods," said Harjeet Singh, global climate change lead at charity ActionAid.
"But more places are becoming uninhabitable because of land degradation, rising sea levels or other weather impacts, and there is no choice but to relocate," he said at the sidelines of a United Nations climate event in Bangkok.
More than 20 million people are uprooted every year by floods, storms, landslides and other extreme winter conditions, with the vast majority of such displacement occurring in the Asia-Pacific region, according to the International Federation of Red Cross and Red Crescent Societies.
Displacement can have devastating impacts on those who have to move, as well as on communities that receive them, said Victor Bernard, Asia-Pacific programme officer at human rights advocacy the Raoul Wallenberg Institute.
"Countries must ensure relocations are not forced, and that the rights of vulnerable communities are protected," he said.
Fiji moved its first coastal community inland in 2014, and may have to move dozens more to higher ground as sea levels rise, said Nilesh Prakash, the country's head of climate change and international cooperation.
"Moving them inland means they lose access to livelihoods. There are also socio-cultural and traditional ties to consider."
Fiji, with 900,000 people on hundreds of islands, plans to set up a fund to pay for loss and damages caused by the effects of climate change, including relocation, he told the Thomson Reuters Foundation.
Sea-level rise and erosion are set to make most island atolls uninhabitable by 2050, and for the Marshall Islands, home to 75,000 people, moving to higher ground is not an option.
The islanders are already seeing the effects of warming oceans in damaged reefs and fish stocks, said Angeline Heine, the country's national energy planner.
"We don't have the luxury of more land or mountains to move to. We are just focused on our survival, and wondering whether we will still be here 30-40 years from now," she said.
Even wealthy city-state Singapore faces serious threats.
Prime Minister Lee Hsien Loong last month said protecting the low-lying island against rising sea levels could cost S$100 billion ($72 billion) or more over the coming decades.
Where possible, cities should be investing to adapt, with infrastructure such as seawalls, as well as nature-based solutions, said Diane Archer, research fellow at the Stockholm Environment Institute in Bangkok.
"It is also vital to ensure an urban plan which preserves essential natural features such as wetlands and mangroves, and that appropriate regulations are in place to manage groundwater extraction and reduce greenhouse gas emissions," she said.