United Nations Secretary-General Antonio Guterres speaks during a session at the COP27 U.N. Climate Summit, Wednesday, Nov. 9, 2022, in Sharm el-Sheikh, Egypt. AP
Guterres made his plea as nations were deadlocked over the contentious issue of creating a "loss and damage" fund, with one day left before the COP27 conference is scheduled to end.
"There is clearly a breakdown in trust between North and South, and between developed and emerging economies," Guterres said after arriving from a G20 summit in Indonesia.
"This is no time for finger pointing. The blame game is a recipe for mutually assured destruction," he said.
"The most effective way to rebuild trust is by finding an ambitious and credible agreement on loss and damage and financial support to developing countries."
Poorer countries least responsible for global emissions have pressed rich polluters to agree at COP27 on the creation of a "loss and damage" fund for nations devastated by climate impacts.
After dragging their feet over loss and damage, the United States and European Union somewhat softened their stance by agreeing to discuss the issue at COP27.
But rich and developing nations remain divided over details.
"The time for talking on loss and damage finance is over," Guterres said. "We need action."
The UN secretary general urged nations to renew their commitment at COP27 to the aspirational goal of limiting global warming to 1.5 degrees Celsius compared to preindustrial levels.
"The 1.5C target is not simply about keeping a goal alive -- it's about keeping people alive," he said.
Developing nations have also sought assurances at COP27 that rich countries will finally fulfil promises to provide $100 billion a year to help them green their economies and adapt to future impacts.
"The parties must act on the crucial question of finance," Guterres said.
"The climate clock is ticking, and trust keeps eroding. The parties at COP27 have a chance to make a difference -- here and now. I urge them to act -- and act quickly," he said.