MADRID — They have arrived at these global climate talks from such places as coastal Africa, the Caribbean and tiny atolls in the Pacific — parts of the world wrestling with droughts, cyclones and ever-rising seas.

One participant from the low-lying Pacific Island nation of Kiribati said the beach she went to just three years ago “no longer exists.” Without a drastic decrease in global emissions, she said, her nation will be “erased from this planet.”

“I refuse to leave the only place I call home,” Tabita Kaitamakin Awira Awerika, 21, said through tears said at an event this week, before directly addressing the developed countries whose emissions are driving the crisis.

“Do not turn a blind eye,” she said, adding that the globe’s largest emitters “must know that they are destroying the very world we live in.”

The United Nations’ climate negotiations, an annual gathering of leaders from more than 190 countries that is a quarter-century old, has gained a reputation as slow-moving, insufficient and devoid of the necessary urgency. But as the effects of climate change deepen, negotiators from the most vulnerable corners of the world are making their frustration clear, arguing that their very existence depends on the kind of meaningful action that big countries have so far avoided.

The divide between developed and developing countries, a simmering reality for decades, came into acute focus this week. Officials from some smaller countries had to deal with climate crises — flooding and evacuations in the Marshall Islands; a devastating hurricane in the Bahamas — just before traveling to the negotiations.

Meanwhile, the United States recently confirmed it would leave the Paris climate agreement, and other major emitters have shown little appetite to make the bold promises that scientists say are critical.

The sense of emergency among smaller countries has injected raw emotion into showdowns over how the world can avert the most catastrophic impacts of climate change — and how it can help those already dealing with them.

“The window of opportunity is rapidly closing,” said Carlos Fuller, the lead negotiator for a group of 44 small islands and low-lying coastal states that work as a bloc at these talks. “This is only going to get worse and worse.”

Each nation has an equal vote at the climate talks, and vulnerable nations have flexed their muscles in the past. During final negotiations over the Paris climate agreement in 2015, they insisted on more ambitious language calling for countries to try to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit).

In 2007, one delegate after another from developing nations blasted the U.S. delegation for blocking progress on cutting carbon emissions. “If you cannot lead, leave it to the rest of us,” Papua New Guinea’s climate change ambassador declared in an open session. “Get out of the way.”

The world has warmed more than 1 degree Celsius since the late 19th century. A report from the United Nations this fall said the world would need to cut its emissions by nearly 8 percent a year through 2030 to meet its 1.5-degree goal. For many low-lying countries, even fractions of a degree could mean the death of coral reefs and entire populations displaced by the rising seas.

“The most vulnerable — atoll nations like my country — already face death row,” Hilda Heine, president of the Marshall Islands, told delegates at the beginning of the Madrid conference.

Even wealthier nations that have spent billions to safeguard themselves, like Italy and Japan, have faced intense weather-related disasters. But poorer countries say the damage they face is harder to contend with — and more existential.

Fuller noted that communities along the Gulf Coast and in Alaska have been forced to relocate because of rising seas. “The same thing is occurring in our small-island states,” he said. “Except where do we go?”

Of the roughly 80 countries that have pledged to do more to cut their emissions beginning in 2020, the vast majority are vulnerable nations. But collectively, their emissions account for only a small fraction of the world’s total.

In Madrid this week, representatives for developing nations have admonished the world’s biggest countries not only for failing to aggressively cut their carbon emissions, but also for refusing to do more to help offset climate-related damage around the world. Low-lying countries say they deserve more help in dealing with disasters that are intensified by the emissions of others.

The argument over how to deal with the loss of homes, livelihoods and other damage caused by climate change — as well as who should shoulder such costs — has been long-running and almost undoubtedly will not be resolved at these talks.

The United States, Australia, the European Union and other historically large emitters are wary of finding themselves on the hook for paying huge sums in compensation.

“No developed countries want to go there,” said Yamide Dagnet, a senior associate at the World Resources Institute who closely tracks the climate talks. “It’s a Pandora’s box.”

The U.S. delegation at these talks has remained largely out of the spotlight but has continued to resist any such commitments — a position that has spanned administrations. A U.S. official, who was not authorized to speak publicly, said the federal government already helps fund numerous international organizations that help countries deal with climate change and believes a separate U.N. fund could be duplicative.

“The U.S. government is the largest humanitarian donor in the world, and we respond based on needs,” the U.S. delegation said in a statement.

As the effects of climate change have widened, so has the number of countries that have joined ranks to push the world’s largest emitters to do more, and more quickly.

“It’s not just about sinking islands,” said Harjeet Singh, the global lead on climate change for the advocacy group ActionAid.

Singh pointed to twin cyclones that devastated Mozambique this year, killing hundreds of people, as well as spreading forest fires, droughts, ocean warming that has upended fisheries, and epic flooding in poor and rich countries alike.

Alpha Oumar Kaloga of Guinea, one of the lead coordinators for an alliance of African nations, said this week that rural communities in his country are struggling to survive, sapping the economic hopes of young people and forcing them to migrate to cities or follow treacherous migrant paths overseas.

He was tired from negotiations that had gone until 2:30 a.m. the previous night, with little to show for results.

“We want concrete actions,” he said. “But when? When will it be too late?”