One year after world leaders made a landmark promise to move away from fossil fuels, countries have essentially made no progress in cutting emissions and tackling global warming, according to a United Nations report issued on Thursday.

Global greenhouse gas emissions soared to a record 57 gigatons last year and are not on track to decline much, if at all, this decade, the report found. Collectively, nations have been so slow to curtail their use of oil, gas and coal that it now looks unlikely that countries will be able to limit global warming to the levels they agreed to under the 2015 Paris climate agreement.

“Another year passed without action means we’re worse off,” said Anne Olhoff, a climate policy expert based in Denmark and a co-author of the assessment, known as the Emissions Gap Report.

The report comes a month before diplomats from around the world are scheduled to meet in Baku, Azerbaijan, for annual United Nations climate talks, where countries will discuss how they might step up efforts to address global warming.

Lately, those efforts have faced huge obstacles.

Even though renewable energy sources like wind and solar are growing rapidly around the world, demand for electricity has been rising even faster, which means countries are still burning more fossil fuels each year. Geopolitical conflicts, from the U.S.-China rivalry to war in places like Ukraine and Gaza, have made international cooperation on climate change harder. And rich countries have failed to keep their financial promises to help poor countries shift away from oil, gas and coal.

At last year’s climate talks in Dubai, United Arab Emirates, representatives from nearly every nation approved a pact that called for “transitioning away from fossil fuels” and accelerating climate action this decade. But the agreement was vague on how to do so and on which countries should do what, and so far there has been little follow-through.

The new U.N. report finds that at least 151 countries have formally pledged under the Paris climate agreement to curb their greenhouse gas emissions by 2030. If every country followed through on its stated plans, which is far from assured, then global emissions could be 3 percent to 11 percent lower at the end of the decade than they are today.

But that would still put the Earth on track to heat up an average of roughly 2.6 to 2.8 degrees Celsius (4.7 to 5 degrees Fahrenheit) over preindustrial levels by the century’s end, the report found. The planet has already warmed roughly 1.3 degrees Celsius (2.3 degrees Fahrenheit). That may not sound like much, but every fraction of a degree of warming brings greater risks from deadly heat waves, wildfires, drought, storms and species extinction, scientists have said.

Under the Paris Agreement, world leaders vowed to hold global warming to “well below” 2 degrees Celsius, and preferably closer to 1.5 degrees Celsius, to limit the risks from climate catastrophes.

Current policies don’t come close to meeting those goals, the report found. To stay below 2 degrees Celsius, global emissions would need to fall roughly 28 percent between now and 2030. To stay at 1.5 degrees Celsius, global emissions would need to fall about 43 percent, requiring a blindingly fast transformation of the global energy system.

Over the past year, only the island nation of Madagascar has submitted a new, stronger pledge to curb emissions by 2030, despite exhortations by United Nations officials for all countries to bolster their plans. And with each year that goes by without additional action, the cuts needed to hold warming to those low levels become more and more extreme.

“Theoretically, it’s still possible to stay below 1.5 degrees, but it’s not really feasible anymore,” said Christoph Bertram, an associate research professor at the University of Maryland’s Center for Global Sustainability.

Inger Andersen, the executive director of the United Nations Environment Program, said it was still important for nations to accelerate their efforts to cut emissions and keep warming as low as possible.

“Even if the world overshoots 1.5 degrees Celsius, and the chances of this happening are increasing every day, we must keep striving” to bring emissions down to zero as soon as possible, Ms. Andersen said. “Every fraction of a degree avoided counts in terms of lives saved, economies protected, damages avoided, biodiversity conserved.”

In the coming year, countries are expected to submit new formal targets for cutting emissions by 2035. It remains to be seen how ambitious those goals will be and whether countries will take concrete steps to follow through.

One of the big topics at the climate talks in Baku will be money. For years, developing countries like India and Indonesia have said they would be willing to accelerate efforts to cut emissions if they received financial assistance from wealthier countries to do so. According to the U.N. report, cutting global emissions to zero could require an extra $900 billion to $1.2 trillion per year in global investment.

That amount, the report said, is “substantial” but also manageable in the broader context of the global economy and financial markets worth close to $110 trillion.