United Nations Secretary-General Antonio Guterres warned world leaders in Antalya on Wednesday that the climate crisis is now “outrunning us”, telling the COP31 climate summit that humanity’s slow response has put the planet on “the path to mutually assured destruction”. Opening two days of speeches at the World Leaders’ Summit, Guterres said record emissions, shattering heat records and worsening disasters were the price of delay — and that the fossil-fuel era must end. “But science is not telling us to surrender,” he said. “It is telling us to fight harder.”

Key Points

• Guterres told COP31 leaders in Antalya on Wednesday, November 11, that the climate crisis is “outrunning us” and the world is on “the path to mutually assured destruction”.
• Emissions hit all-time highs in 2025, heat records keep falling, and the last four years were the hottest ever recorded.
• He said “fossil fuels must go the way of the dinosaurs” and accused the fossil-fuel lobby of delaying climate action.
• Nearly 200 countries are negotiating a plan to raise electricity’s share of global energy use and revive the shift away from fossil fuels.
• It was Guterres’s final climate push as UN chief, with his second term ending on December 31, 2026.

What Happened

Guterres delivered the warning on the first of two days of speeches at the World Leaders’ Summit, the high-level opening of COP31 in Antalya. Leaders speak on Wednesday and Thursday, November 11 and 12, before negotiators settle into detailed talks running until Friday, November 20.

Wednesday’s speakers included Brazil’s Luiz Inacio Lula da Silva, European Commission President Ursula von der Leyen, Chinese Vice-President Han Zheng and Marshall Islands President Hilda Heine. Turkish President Recep Tayyip Erdogan hosted, with the leaders of Qatar, Iran and Pakistan also attending. Britain’s Andy Burnham, the only G7 leader present, speaks on Thursday.

Guterres pointed to rising emissions, temperatures and disasters as evidence the world is losing the race against warming. Emissions in 2025 hit all-time highs, heat records keep shattering, and the last four years were the hottest ever recorded. The United States sent no official federal delegation, the second successive year without American officials.

Background: A Summit a Decade in the Making

COP31 opened on Monday, November 9, in Antalya, ten years after the Paris Agreement entered into force. It is chaired by Turkey’s Murat Kurum, with Australia’s Chris Bowen presiding over negotiations.

Days earlier, Guterres had called the talks a “moment of truth”, urging every country to do more, now. “We can no longer wait, we can no longer have endless discussions in which everybody tries to push the responsibility to someone else,” he said. “Everybody must do more, everybody must do more now.”

A World Meteorological Organization report released as COP31 opened found 2026 on track to be one of the four hottest years on record, the January-to-September average 1.47 degrees Celsius above pre-industrial levels. The Global Carbon Budget projects fossil-fuel CO2 will fall 0.4 percent in 2026 to 38.2 billion tonnes, but total CO2 will still hit a record 43.3 billion tonnes, and the remaining 1.5-degree budget is just 150 billion tonnes, under four years at current rates.

Guterres and the COP31 Climate Warning

At the heart of the speech was a blunt diagnosis: the world is not moving fast enough, and delay itself has become the danger. “The brutal truth is that the climate crisis is outrunning us,” he said. “This is the path to mutually assured destruction.” His sharpest words were for fossil fuels: “Fossil fuels must go the way of the dinosaurs,” he said, accusing the fossil-fuel lobby of delaying action even as the damage mounts.

Negotiators from nearly 200 countries seek agreement on a plan to increase electricity’s share of global energy use and revive the shift away from fossil fuels. Clean power — wind, solar, hydro and nuclear — is the fastest way to cut emissions from transport, heating and industry, but only if grids expand and fossil generation shrinks with it.

Guterres framed the choice as survival, not economics: “But science is not telling us to surrender. It is telling us to fight harder.”

Reactions and Quotes

The speech set the tone for the leaders’ summit. Heine, speaking for a low-lying island nation exposed to rising seas, joined Lula da Silva, von der Leyen and Han Zheng on Wednesday’s programme. Guterres’s words echoed his pre-summit message: “Take it seriously because it is an existential threat. And the first thing we need to fight is for our own lives.”

Attendance told its own story. With the US absent at federal level, China, the EU and host Turkey carry more weight, and leaders from the Gulf, South Asia, Latin America and the Pacific islands reflect a summit shaped as much by the countries facing the worst impacts as by the biggest emitters.

Why It Matters

COP31 is where the world’s climate promises are tested. The Paris goal of 1.5 degrees is slipping away: 2026 is all but certain to be the second year after 2024 to pass it, and the remaining carbon budget is nearly gone. What is agreed in Antalya will shape energy investment for years. A credible plan to grow clean electricity would give investors, cities and companies a clear direction; a weak outcome would leave the transition drifting.

For Guterres it was personal. His second term expires December 31, 2026, making COP31 his final climate push as UN chief, and the “mutually assured destruction” line his parting verdict on a decade in which warnings grew louder while emissions kept rising.

What Happens Next

The leaders’ summit continues on Thursday, with Burnham addressing the gathering as the only G7 leader present. Negotiators then work through to Friday, November 20, on the electricity plan and the wider package of finance, adaptation and fossil-fuel measures. The key test is whether nearly 200 countries can agree a text that genuinely accelerates the shift away from fossil fuels, rather than restating old pledges.

A US congressional delegation is expected, and more than 100 American state and local leaders are attending independently.

Frequently Asked Questions

What did Guterres say at COP31?

He said “the climate crisis is outrunning us”, warned of “mutually assured destruction”, and said “fossil fuels must go the way of the dinosaurs”.

Where and when is COP31?

It opened Monday, November 9, 2026, in Antalya, Turkey, and runs to Friday, November 20, with a leaders’ summit on November 11 and 12.

Why is this his final climate push?

His second term as UN Secretary-General expires December 31, 2026, so COP31 is his last climate summit as UN chief.

What are negotiators trying to agree?

A plan to raise electricity’s share of global energy use and revive the shift away from fossil fuels, plus finance and adaptation measures for developing countries.

Is the United States at COP31?

No official federal delegation was sent, the second year running. A congressional delegation is expected, and US state and local leaders are attending independently.

Related: Guterres calls COP31 a ‘moment of truth’, US sends no official delegation to COP31, 2026 among the four warmest years ever.