The United Nations Secretary-General has said that ocean temperatures are rising in the Pacific Islands at three times the rate worldwide, and its population was "uniquely exposed" to the impact of rising sea levels.
Speaking to reporters in Tonga where the Pacific Islands Forum is being held, Antonio Guterres highlighted the findings of a report that showed the southwest Pacific was worst hit by sea level rises, in some places by more than double the global average in the past 30 years.
"I am in Tonga to issue a global SOS - Save Our Seas - on rising sea levels," he said.
"Rising seas are amplifying the frequency and severity of storm surges and coastal flooding. These floods swamp coastal communities. Ruin fisheries. Damage crops. Contaminate freshwater. All this puts Pacific Island nations in grave danger," he added.
"Water expands as it warms, contributing to sea level rise," he said.
Climate change and security are dominating discussions at the week-long annual leaders meeting, where the 18 members of the Pacific Islands Forum span atoll nations threatened by sea level rise such as host Tonga, and one of the world's biggest exporters of coal, Australia.
Asked by a reporter about Australia's export of fossil fuels, Mr Guterres said fossil fuels must be phased out globally, although "the situation in different countries is different" and there would be different ways to do this.
The report released by the World Meteorological Organisation showed ocean temperatures in the southwest Pacific are increasing at up to three times the rate worldwide.
"Pacific islands are uniquely exposed. This is a region with an average elevation just one to two metres above sea level," Mr Guterres said.
"Half the infrastructure is within 500 metres of the sea," he added.
Without cuts to global emissions, the Pacific Islands can expect additional sea level rise of 15cm by 2050 and 30 days a year of coastal flooding, he said.
He called for global leaders to "massively boost climate adaptation investments" in vulnerable countries.
A "loss and damage" fund to help poor nations cope with costly climate disasters was approved at last year's UN climate summit, after years of lobbying by groups including the Pacific Islands, but the challenge remains to attract significant contributions to the fund from wealthier nations.
"Developed countries must deliver on their finance commitments - including the commitment to double adaptation finance to at least $40 billion (€35bn) a year by 2025," Mr Guterres said.
At the COP28 Climate Summit in Dubai last year, then taoiseach Leo Varadkar said that Ireland will contribute €25 million over the years 2024 and 2025 to the Loss and Damage Fund.
