As United Nations climate talks kick off in Turkey on Monday, Secretary-General António Guterres has an urgent message for world leaders: “This is a moment of truth.”

He’s delivered variations of this ominous warning about climate change, caused by the burning of fossil fuels like oil and gas, in the past decade, often with increasingly hyperbolic language. Three years ago, he even said, “the era of global boiling has arrived, ” referring to rising temperatures and increasing extreme weather, both results of climate change.

But this time, it will be his last global warming sermon as head of the United Nations as his second and last term expires at the end of the year. And the sense of urgency is palpable in a world with worsening killer heat waves, storms, floods and droughts amid ever higher temperatures and, on top of all of it, El Niño, a naturally occurring climate pattern that scrambles weather systems around the globe.

“This is a moment of truths. We can no longer wait, we can no longer have endless discussions in which everybody tries to push the responsibility to someone else. Everybody must do more, everybody must do more now,” Guterres said he will tell leaders of the U.N. climate conference, known as COP31, scheduled Nov. 9-20.

The “moment of truth” message weighs so heavily that the Secretary-General used the phrase three times in 20 minutes during a recent exclusive interview with The Associated Press from his 38th floor conference room at U.N. headquarters. He discussed his one last push in the fight against climate change and a ten-year tenure where he became one of the most visible advocates urging often recalcitrant countries to do more to reduce their emissions of heat-trapping gases.

One of the most difficult days

The gravity of global warming reality also weighs heavily as he recalled his personal climate moment of truth. It was, he said, “one of the most difficult days of my life.”

It came last year when he consulted with scientists before a major speech on climate. As he had for nine years, Guterres was going to insist that the 2015 Paris Agreement’s main goal — limiting warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since pre-industrial times — was still alive. He was going to say the world needs to do far more to keep below that threshold, and that it was doable.

“Scientists told me you cannot say that because that’s no longer true,” said Guterres, an engineer before his political career. Too much carbon dioxide and other greenhouse gases, the result of burning fossil fuels, had been released into the atmosphere.

“That was an enormous shock for me,” he said. Now the U.N. is trying to limit how much past that threshold the world heads.

It felt like a failure, Guterres said.

“But it’s not the world that’s failed, it’s the political leadership that’s failed,” Guterres said. Protecting the planet, he said, requires a long-term strategic view. Yet in many political systems “there is no strategic view. And policies change frequently, not allowing the kind of constant determined investment that is necessary,” Guterres said.

He pointed to his tenure as Portugal’s prime minister in the late 1990s to show it’s possible to invest long term in a greener future. He added that a worldwide boom in wind and solar power as cheaper alternatives to fossil fuels gives him hope.

With wars raging in Ukraine and Iran and worries about artificial intelligence — which he also tried to rally world leaders around — there are a lot of threats out there, Guterres said.

“The problem is that all these things are getting combined,” Guterres said, noting the huge electricity and water consumption and carbon emissions of AI.

War-related energy shocks show that relying on fossil fuels is a fundamental security problem, he said.

Warning of a disaster that then came

Three years ago, Guterres toured the highest peaks of Nepal, warning of a future with swollen glacier-fed lakes bursting and devastating floods and landslides.

“I am here today to cry out from the rooftop of the world: Stop the madness,” Guterres said in 2023. “The glaciers are retreating, but we cannot,” he said. “We must end the fossil fuel age.”

“Unfortunately they came sooner than what I expected,” he recalled in the interview. Floods in August killed more than 1,400 people with another 5,600 missing. Scientists said climate change played a role in the disasters.

Guterres said someone needs to pay to help the victims of climate change, who often didn’t cause the problem.

“Fossil fuel companies are making huge profits and obviously those windfall profits should be taxed and those taxes should be applied in supporting the countries that are having the more dramatic impacts of climate change,” Guterres said.

Talking earlier this month with a science team on a drifting platform in the middle of the Arctic Ocean, Guterres mentioned that his trip to Mount Everest and chats with researchers changed him. He said the conversations created “a sense of fury in relation to those who go on, if not denying, at least refusing to take the measures that are necessary to stop this madness.”

Praised as a climate champion despite limitations

“António Guterres has consistently been eloquent, forceful and right on target in all of his many statements and initiatives to address the climate crisis,” former U.S. Vice President Al Gore said. “He’s been so active on this issue because he understands clearly that it is the greatest challenge facing humanity.”

European Climate Foundation CEO Laurence Tubiana, who presided over the negotiations that resulted in the Paris Agreement, said Guterres “has done what he could, even pushing the ball much, much farther than any other SG, to the point that he may have been represented in a very adversarial context.”

Because nations don’t have to do what the U.N. or its leaders ask and superpowers have veto authority, Guterres said his position as secretary-general “has no real power. We have not much money you know. But there is one thing we have: A voice.”

That’s why he simply has three words of advice to whoever succeeds him: “Tell the truth.” The U.N. Security Council is still deciding on who will be the next secretary-general.

The one message Guterres said he wants the public to remember on climate change: “Take it seriously because it is an existential threat. And the first thing we need to fight is for our own lives.”

___

The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.