The international community is out of step with Pacific Island nations' needs on covering the costs of adjusting to a warmer world, the aid agency of the Catholic Church says.
Economic modelling released at the COP29 climate conference on Thursday revealed Pacific nations need at least $US1.5 billion ($A2.3 billion) per year in climate finance.
Despite some of Australia's closest neighbours being on the front-lines of climate change, actual climate financing between 2015 and 2020 fall far short of that estimate, pointing to an annual gap of $US1 billion in the region.
Cardinal Soane Maji, Bishop of Tonga and Niue and president of Caritas Oceania, said the report addressed the "twin storms, of debt dangers and climate disasters" and practical ways to help the Pacific community be prepared.
Borrowing due to pandemic-induced loss of economic activity has already loaded many of the nations with debt even as they need to meet an urgent requirement to cover the cost of more severe and frequent disasters and make their peoples more resilient.
"Governments are paying more in interest and other debt servicing obligations than they are on health, education, or climate adaptation. Action must be to be taken to forgive debt and prevent it in the future," the cardinal said.
The IMF and World Bank rate the risk of debt distress for Kiribati, the Solomon Islands, Tonga, Tuvalu and Vanuatu as high and as moderate for Fiji and Samoa.
Extreme weather events such as tropical cyclones, storm surges and droughts were on the increase due to human-induced climate change, the report said.
Caritas Oceania, Caritas Australia and the Jubilee Australia Research Centre put forward three recommendations, including the immediate increase of climate finance - additional to official aid - to adequately fund mitigation, adaptation, and loss and damage.
The delivery of finance as grants, not loans that create more unmanageable debt for Pacific Island nations, should be via an arm of the United Nations and not banks, they said.
Further, lenders are urged to allow for the cancellation or restructuring of debts, more accurate assessment and more transparency in response to sovereign debt crises.
"We cannot make debt entrenchment part of the cost for developing countries as they manage climate impacts they have not wrought," Caritas spokesman Damian Spruce said.
"Given these Pacific countries are Australia's closest neighbours, we hope Minister (Chris) Bowen makes their needs clear in his role as Ministerial Pair for the UN's New Collective Quantified Goal on climate finance at COP29," he said.
The draft goal published on Finance Day at the climate conference in Baku, the capital of Azerbaijan, will be crucial for scaling up finance for climate action, according to advocates.
Known as the NCQG, the updated pledge to meet the needs of developing economies will apply when the existing $US100 billion per annum target ends in 2025 and will be thrashed out over coming days.
At least $US1 trillion per year in predominantly public finance was needed for a 1.5 degrees pathway, with specific funding goals for mitigation, adaptation, and loss and damage, the World Wide Fund for Nature said.
The top official creditors to Pacific Island nations are the Asian Development Bank, China, Japan, and the World Bank.
