Warned that mounting economic crises should not delay action on increasingly obvious global warming threats, climate negotiators agreed at U.N. talks on Sunday to start discussions on a funding plan to help climate-hit countries cope with surging losses.

As the COP27 climate summit opened in Egypt, U.N. climate chief Simon Stiell said concrete action to tackle emissions and climate risks, delayed over decades, could no longer wait as dangerous effects worsen.

"There is no one single crisis as critical, as impactful, as climate change," he said.