With dire warnings of planetary catastrophe and urgent pleas to protect vulnerable populations, world leaders Friday implored one another to stop burning fossil fuels and swiftly reduce the greenhouse gas emissions that are dangerously heating the planet.

At the United Nations climate conference in Dubai, a parade of dignitaries invoked faith, science and economics in their calls for a rapid transition away from coal, oil and gas, and toward clean energy.

"We cannot save a burning planet with a fire hose of fossil fuels,” U.N. Secretary-General Antonio Guterres said. "We must accelerate the just, equitable transition to renewables.”

The annual meeting, known as COP28, comes near the end of what scientists forecast will be the hottest year in recorded history. Greenhouse gas emissions, mainly driven by the burning of fossil fuels, have now warmed the planet by about 1.2 degrees Celsius above preindustrial levels. Floods, fires, droughts and storms made worse by climate change are unleashing destruction around the world.

"We are taking the natural world outside normal balance and limits and into dangerous uncharted territory,” King Charles III of Britain said. "Our choice now is a starker and darker one: How dangerous are we prepared to make our world?”

Yet, the heads of state calling for a major overhaul of the world’s energy system are confronting an existential problem with no easy solutions.

While many developed countries are installing more wind and solar power, global greenhouse gas emissions and fossil fuel demand continue to rise. Under the current trajectory, the planet is on track to warm at least 3 degrees Celsius, a level that scientists say will unleash extreme weather around the globe and lead to a rise in sea levels that will wipe out coastal cities.

"Unless there is a significant and radical shift in our economic and industrial patterns, we are hurtling at a perilous velocity on a trajectory toward the dire scenario of a world that is warmer by 3 degrees Celsius,” President William Ruto of Kenya said.

The intractable nature of the problem was driven home by the setting of this year’s conference. The United Arab Emirates is one of the world’s biggest oil producers, and Dubai is a city built using the enormous profits reaped from exporting crude. The president of COP28, Sultan al-Jaber, is also the head of the Emirati state oil company, Adnoc, an arrangement that injected a sense of disillusionment into the talks for some people.

"Future generations will wonder about the fact that during the hottest year on record, the world met in one of the biggest oil-producing countries to work out our response to the oil crisis,” said Mohamed Adow, director of Power Shift Africa, a research organization participating in the conference. "If we don’t make serious progress here, they will see it as a sign of utter folly of this period of climate diplomacy.”

There were some notable absences from this year’s event. Neither President Joe Biden of the United States nor President Xi Jinping of China were in attendance, although Vice President Kamala Harris was a last-minute addition and was scheduled to speak Saturday. Pope Francis had planned to attend but pulled out at the last minute on the advice of his doctors.

Reminders of the war between Israel and Hamas punctuated the speeches on a day when fighting resumed after a weeklong ceasefire. Isaac Herzog, the president of Israel, and Mahmoud Abbas, the president of the Palestinian Authority, were both scheduled to address the attendees Thursday, but neither spoke.

Nevertheless, other Middle Eastern heads of state used their time at the climate summit to support Palestinians.

King Abdullah II of Jordan sought to link the war and the issue of climate change, saying that "the massive destruction of war makes the environmental threats of water scarcity and food insecurity even more severe.”

Iraqi President Abdul Latif Rashid also called for protections for civilians and said he supported Palestinians’ "right to self-determination.”

And President Recep Tayyip Erdogan of Turkey called the Israeli attack on the Gaza Strip a "war crime” and said "the perpetrators must be held accountable under international law.”

On social media, Herzog shared photographs from the sidelines at the summit. He met with world leaders, including the Emirati president, Sheikh Mohammed bin Zayed, and shook hands with Qatar’s ruler, Sheikh Tamim bin Hamad, whose country mediated the cease-fire negotiations between Israel and Hamas.

The rift between rich and poor countries was on display throughout the day. While the United States and Western European countries are responsible in historical terms for most of the emissions that are warming the planet, developing nations are the ones bearing the brunt of climate change, and they often lack the funding to develop renewable energy and rebuild after disasters.

"Over the past century, a small section of humanity has indiscriminately exploited nature,” Indian Prime Minister Narendra Modi said. "However, all of humanity is paying the price for this, especially people living in the Global South.”

Many leaders described the ways in which extreme weather is wreaking havoc in their home countries.

"In Brazil, the climate emergency is already a reality,” Brazilian President Luiz Inacio Lula da Silva said. "The Amazon region is going through an unprecedented drought. The level of the rivers is the lowest in 120 years. I could never imagine that this would happen in a place where we have the greatest reservoir of freshwater of the world.”

For years, developed countries have pledged to spend hundreds of billions of dollars helping poorer nations adapt, but those funds have been slow to appear.

"We are at yet another COP, and I am disheartened to state that most of these commitments are yet to be fulfilled,” said Wavel Ramkalawan, president of the Seychelles, an archipelago off the coast of East Africa.

Yet, there were signs that some developed countries were renewing their efforts to support poorer nations. On Thursday, delegates reached an agreement in principle on a fund that would help poor countries cope with climate disasters. And throughout the day, leaders discussed reforming the global financial system in ways that would make it easier for developing countries to borrow money to finance their efforts to combat climate change.

Over the next 11 days, negotiators from more than 170 nations will write a final agreement that must be ratified by every country in attendance. The need for unanimous consent means that each word in the final document will be scrutinized. In previous years, representatives from oil-producing nations have vetoed language calling for a rapid phaseout of fossil fuels.

Already, the fight over what a final agreement might say about fossil fuels was playing out among world leaders Friday.

French President Emmanuel Macron was among the few Western leaders to call for an end to coal, oil and gas. He said it should be a "top priority” for developed countries to phase out fossil fuels.

And Guterres, an outspoken critic of the fossil fuel industry, weighed in on the specific words that he hoped negotiators would include in the final agreement, saying it was only possible to avert the worst effects of climate change by eliminating the burning of fossil fuels.

"Not reduce. Not abate,” he said. "Phase out.”

This article originally appeared in The New York Times © 2024 The New York Times Company