As United Nations climate talks open in Turkey on Monday, Secretary-General António Guterres is framing the negotiations as a moment of truth for governments to accelerate efforts to curb global warming.
Guterres has delivered similar warnings for years about the risks posed by burning fossil fuels, at times using stark language to describe rising temperatures and intensifying extreme weather. This address carries added weight. It will be his final climate appeal as UN chief, with his second and last term ending later this year, and it comes amid worsening heat waves, storms, floods and droughts during an El Niño that is disrupting weather patterns worldwide.
“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 plans to tell leaders at the UN climate conference, known as COP31, scheduled for Nov. 9-20.
UN climate talks and a moment of truth
The moment of truth message dominated a recent interview at UN headquarters in New York, where Guterres reflected on his last push to confront climate change and a decade in which he became a prominent voice urging reluctant nations to cut heat-trapping emissions.
One of the most difficult days
He recounted what he described as “one of the most difficult days of my life.” Before a major address last year, he consulted scientists as he had done for nine years, intending to argue that the Paris Agreement goal of limiting warming to 1.5 degrees Celsius since preindustrial times remained within reach if countries accelerated action.
“Scientists told me you cannot say that because that’s no longer true,” said Guterres, who trained as an engineer. Too much carbon dioxide and other greenhouse gases had already been emitted. The UN is now focused on limiting the extent to which temperatures overshoot that threshold.
The realization felt like a personal failure, he said. But he argued the shortfall reflects political choices, not public indifference. Protecting the planet requires steady, long-term strategy, he said, yet many political systems lack continuity and shift policies too often to sustain the investment needed. He pointed to his tenure as Portugal’s prime minister in the late 1990s to show that long-horizon investments are possible, and he noted rapid growth in wind and solar power as a hopeful sign.
He also cited overlapping global risks, from wars in Ukraine and Iran to the rapid rise of artificial intelligence, which he warned draws heavily on electricity and water and contributes to emissions. Energy shocks linked to conflict highlight that dependence on fossil fuels is a core security vulnerability, he said.
Warning of disaster, then watching it arrive
Guterres visited Nepal’s highest peaks three years ago and warned that retreating glaciers could swell lakes and trigger catastrophic floods and landslides. “Stop the madness,” he said at the time. “The glaciers are retreating, but we cannot. We must end the fossil fuel age.”
“Unfortunately they came sooner than what I expected,” he recalled, noting August floods that killed more than 1,400 people, with another 5,600 missing. Scientists said climate change contributed to the disasters.
Guterres argued that those suffering the worst impacts, often the least responsible for emissions, deserve support. He said fossil fuel companies’ windfall profits should be taxed and the proceeds directed to countries facing the most severe climate damage.
He added that time with scientists, including a recent discussion on a drifting platform in the Arctic Ocean and a past visit to Mount Everest, left him with “a sense of fury” toward those who deny or delay needed measures.
Praised as a climate champion, despite limits
Prominent figures have lauded his efforts. Former U.S. Vice President Al Gore said Guterres has been eloquent and forceful because he recognizes climate change as humanity’s greatest challenge. Laurence Tubiana, head of the European Climate Foundation and a key architect of the Paris Agreement, said he pushed further than previous secretaries-general, even in adversarial settings.
Guterres acknowledged the institutional constraints. Countries are not obliged to follow UN requests, and major powers hold vetoes. “The position has no real power. We have not much money you know. But there is one thing we have: A voice,” he said.
To his eventual successor, the Security Council’s choice still pending, Guterres offered three words of advice: “Tell the truth.” His final message to the public on climate change is similarly direct. “Take it seriously because it is an existential threat. And the first thing we need to fight is for our own lives.”