HONG KONG (NYTIMES) - When industrialised nations pledged in 2009 to mobilise US$100 billion (S$138 billion) a year by 2020 to help the poorest countries deal with climate change, it won over some sceptics in the developing world who had argued that industrialised nations should pay up for contributing so much to the problem.

But the money has been slow to materialise, with only US$3.5 billion actually committed out of US$10.3 billion pledged to a prominent United Nations programme called the Green Climate Fund. United States President Donald Trump's decision last year to cancel US$2 billion in promised aid did not help.

At a climate change conference in Thailand this past week, some delegates reached by telephone said that the setting - the heart of South-east Asia, a region where challenges relating to warming are readily apparent - was grimly fitting. They described the UN programme's shortcomings as a symbol of a broken promise.

"The fund of hope is becoming a fund of hopelessness," said Ms Meena Raman, legal adviser to the Third World Network, an advocacy group in Malaysia, and a former non-voting member of the Green Climate Fund's board.

The meeting in Bangkok of the UN Framework Convention on Climate Change is a prelude to a larger one in December in Poland, where countries will try to set rules for carrying out the 2015 Paris climate accord.

The Bangkok meeting did not specifically address financing to mitigate climate change. But it came two months after disagreements among the Green Climate Fund's board members prevented the fund from approving new projects at a routine meeting.

Some observers say the fund's funding shortfall and bureaucratic malaise have dimmed expectations for the talks in Poland, which were already bound to be difficult.

"The lack of real money coming through is really undermining trust in the negotiations"around how to put the Paris accord in place, said Brandon Wu, the director of policy and campaigns at ActionAid USA, an advocacy group that monitored the Bangkok meeting. "That's a big part of the logjam."

The Green Climate Fund was designed to help developing countries prepare for climate disasters and develop low-fossil-fuel economies. It was part of a larger plan, led by Hillary Clinton, as US Secretary of State in 2009, to put together US$100 billion a year for poor economies through a combination of government contributions and private investments.

Many academics see contributions to the fund by wealthy countries as a moral imperative, arguing that the developing world is most vulnerable to the effects of climate change but least responsible for causing them.

"Certainly, the richer countries should bear more of the burden in the GCF because they have more means and more at stake," said Thitinan Pongsudhirak, a political scientist at Chulalongkorn University in Bangkok, referring to the fund by its initials.

"Richer countries also have benefited from wealth accumulated over decades when climate issues were not at the forefront."

The Obama administration delivered US$1 billion of a US$3 billion pledge to the programme. But last year, Trump, while announcing plans to exit the Paris accord, said the United States would no longer pay into the Green Climate Fund. He explained his decision by saying that the contributions could eventually cost the US "billions and billions and billions" of dollars.

Raman said that while she still hoped to see other developed nations "step up" by contributing more to the fund, they had not yet made their exact commitments clear.

"We're very horrified by the stance taken by the United States, but it's not the only one," she said. "All the developed countries are united around the United States in not making any progress on finance."

World leaders vowed in Paris to avoid a warming of 2 deg C over preindustrial levels, a threshold that they deemed unacceptably risky. Yet there are widely varying estimates of how much money is being spent on fighting climate change in poor economies.

One reason for the discrepancy is that there is no consensus over which contributions should be counted in the tally.

And critics of the Green Climate Fund have questioned why much of the money it is distributing has been channelled through large development banks, or private-sector enterprises led by global investment firms. They argue that more climate aid should go directly to governments in the developing world, or the communities at risk.

"We want money, but we're hard-pressed to give our full blessing to the projects coming on board," said Lidy Nacpil, the coordinator of the Asian Peoples' Movement on Debt and Development, a regional alliance of nonprofits and community groups.

But even critics of the fund worry about the shortfall, saying it poses risks for people in poor regions where governments are either unable or unwilling to spend more on climate mitigation and adaptation.

The initial, Obama-era goal of securing US$100 billion in climate finance and investment per year by 2020 "was the amount needed by the countries to implement their ambitions," said Neha Rai, an expert on climate finance at the International Institute for Environment and Development, a think tank in Britain.

"But at the same time, irrespective of the amount, it gives a policy signal that climate-relevant investments are important."

South-east Asia 'particularly vulnerable'

South-east Asia is a case in point. People who live in the Asia-Pacific region are "particularly vulnerable" to the effects of a changing climate, the Asian Development Bank said last year in a report, which projected South-east Asia to be "most affected by heat extremes" in the wider area by the end of the century.

Of 74 approved Green Climate Fund projects worth US$3.5 billion, three are in South-east Asia and they have a combined value of nearly US$156 million, according to data provided by the programme. Nineteen others in the program's pipeline directly target the region and are worth US$904 million.

Nacpil said climate finance was important in South-east Asia partly because so many cities are in coastal areas that are vulnerable to sea-level rise and must adapt. And because the number of coal-fired power plants in the region is expected to increase, she added, governments should be encouraged to bend national policies toward investments in renewable energy.

Jenty Kirsch-Wood, a climate specialist with the United Nations Development Programme, defended the Green Climate Fund by pointing to its benefits in Vietnam, where part of a US$30 million grant from the programme has funded the distribution of free, storm-resistant housing to people in typhoon-prone coastal areas.

"The Green Climate Fund has revitalised hope for countries like Vietnam that they can meet their Paris agreement targets - embracing the green energy revolution, but also helping their citizens to adapt to climate change," Kirsch-Wood said.

But US$30 million goes only so far in a country of 93 million people with an economy worth more than US$200 billion and a long, exposed coastline. And in a 2015 climate plan submitted to the United Nations Framework Convention, Vietnam said that state investments could provide only 30 per cent of what it needs to adapt.

"Many developing countries have made clear that they will not be able to reach their Paris agreement targets without international climate finance," said Oyun Sanjaasuren, the Green Climate Fund's director of external affairs.

"For its part, GCF's pipeline of climate projects in developing countries shows that demand for climate finance already exceeds supply," she said.