"COP27 must demonstrate that the world is making progress on all pillars of the Paris Agreement. We urgently need to address loss and damage in a meaningful and credible way," he said in a video message for the Alliance of Small Island States (AOSIS) leaders' breakfast.
Loss and damage are happening now - at 1.1 degrees of warming. The floods in Pakistan have inundated a third of the country, he said. "We can only imagine the fate of small islands if we go beyond 1.5 degrees. Two degrees of warming is unthinkable and must be avoided at all costs."
"We need a targeted, ambitious global response, including how to finance loss and damage, beyond our capacity to adapt," he said. "Polluters must pay. At the same time, we need to resolve access to finance. Grants and concessional financing currently fail to account for your islands' unique vulnerabilities."
AOSIS has long championed the highest level of ambition on climate, often leading by example, he said. "You have also brought solutions and built consensus. Your voices, as climate leaders, problem-solvers and bridge-builders, are needed now more than ever."
The United Nations will continue to push for more ambition and climate action by all, especially the Group of 20, which account for 80 percent of global emissions.
It will continue to call for a renewables revolution, and for developed countries to provide developing countries with the finance and technology they need to transition to a net-zero and climate-resilient future, he said.
"We will continue to push developed countries to make good on their 100-billion-U.S. dollar climate finance commitment. We will push for developed countries to provide clarity this year on their Glasgow commitment to double adaptation finance. And we will push to ensure your eligibility and access to that finance," said Guterres.
"You can count on the continued support of the United Nations for your priorities, and those of all developing countries," he said.