UN Secretary-General António Guterres delivered another speech critical of the failure to make progress on climate action. In the opening remarks for his Climate Ambition Summit, he said "humanity has opened the gates of hell" warning we are heading toward a "dangerous and unstable world."

"Our focus here is on climate solutions – and our task is urgent. Humanity has opened the gates of hell. Horrendous heat is having horrendous effects. Distraught farmers watching crops carried away by floods, sweltering temperatures spawning disease and thousands fleeing in fear as historic fires rage. Climate action is dwarfed by the scale of the challenge," Guterres said in his remarks.

"If nothing changes, we are heading towards a 2.8-degree temperature rise – towards a dangerous and unstable world."

Guterres set a high bar for world leaders set to speak at the summit, saying they must offer a significant new climate pledge. Major voices like the Unites States, the United Kingdom and China did not speak, although California Gov. Gavin Newsom had a scheduled slot at the summit.

"We must make up time lost to foot-dragging, arm-twisting and the naked greed of entrenched interests raking in billions from fossil fuels," Guterres said.

"The proposed Climate Solidarity Pact calls on major emitters – who have benefitted most from fossil fuels – to make extra efforts to cut emissions, and on wealthy countries to support emerging economies to do so."

Guterres also emphasized that the future is not fixed, and credited climate activists and Indigenous Peoples for their activism as well as business executives, mayors and governments who are taking major steps to phase out fossil fuels.

In an interview with Christiane Amanpour, Guterres admitted he has no power over the UN Security Council in forcing them to make decisions on the major issues like climate change but said using his voice and bringing people together is how he can make an impact.

"The Secretary-General of the United Nations has no power and no money, what we have is a voice and that voice can be loud, and I have the obligation for it to be loud," he told CNN.

"But the power is in the member states and the problem is the exercise of that power today is blocked. We have a level of division among superpowers that has no precedent since the second World War. Even in the Cold War things were more predictable than they are today."