UN Warns World Losing Ground on Climate Fight

Humanity is losing ground in the fight against climate change, and the United States is a major reason why, according to a new United Nations report released Wednesday. The United Nations Environment Programme’s update says Earth is now heading for a hotter world than experts projected just last year. For millions already living on the front lines, that’s no abstract warning. It’s a shrinking margin for survival.

The numbers are stark. If countries meet their promised emissions cuts, the planet will likely warm another 2.2 degrees Fahrenheit (1.2 degrees Celsius) above current temperatures. That’s about two-tenths of a degree Fahrenheit (0.1 degrees Celsius) more than last year’s projection from the same science team. The gap may sound small. But every fraction of a degree brings more heat, more water stress, and more pressure on the poorest communities least equipped to adapt.

Washington’s Retreat and Rising Emissions

The report attributes the worsening outlook to two factors: the United States’ formal withdrawal from the Paris Agreement and revised estimates of historical emissions. It also finds that U.S. emissions rose last year, while all other top 20 major economies either cut carbon pollution or slowed the growth of emissions from burning coal, oil and gas. Rising electricity demand and a rebound in coal-fired power generation drove the American increase of 133 megatons of CO2 equivalent.

The U.S. contribution stands out. Of the 124 countries that increased emissions in 2025, the United States accounted for 70% of the added 189 million tons of carbon dioxide. That’s a remarkable share for one nation, even as most European nations moved in the opposite direction and cut their own emissions.

Australian climate scientist Bill Hare, CEO of Climate Analytics, which tracks countries’ climate plans, didn’t mince words. He said the United States is “hell-for-leather trying to block renewables while actively promoting and subsidizing dirty coal — and its diplomacy is trying to make other countries also pull back on action. It is looking at the fire, denying there is a fire, and then pouring more petrol on it.” Hare wasn’t part of the U.N. report, but he and several other outside scientists called its findings scientifically sound.

Who Pays the Price

The human stakes reach far beyond the thermometer. Hare warned that the extra one-tenth of a degree would push an additional 140 million people “into dangerously hot conditions” and raise the odds of collapse for the Amazon rain forest or the ice sheets in Greenland and Antarctica. University of Pennsylvania climate scientist Michael Mann said the shift would also cost the world about $1.2 trillion from the global economy.

Mohamed Adow, director of Power Shift Africa, described the stakes in personal terms. “This report shows that America’s retreat isn’t just a political embarrassment,” he said. “It has real consequences for the planet and for millions of people around the world.” He pointed to more dangerous heat waves, more destructive floods, more failed harvests and more lives lost. “For vulnerable communities in Africa, already living on the front lines of the climate crisis, every fraction of a degree matters. These are not abstract numbers. They are human lives.”

The Gap Between Promises and Reality

Under countries’ submitted climate plans, the globe would be 2.6 degrees Celsius (4.7 degrees Fahrenheit) hotter than pre-industrial times by 2100. If the world continues on its current path without national promises, warming would reach 2.8 degrees Celsius (5 degrees Fahrenheit) above the last half of the 19th century, matching last year’s projection. Both outcomes exceed the 2015 Paris climate pact’s goal of limiting warming to less than 2 degrees Celsius, preferably 1.5 degrees Celsius.

The world is already about 1.4 degrees Celsius (2.5 degrees Fahrenheit) above pre-industrial levels. United Nations officials acknowledged earlier this year, and again in the report, that they can’t hold warming to the 1.5-degree goal they had embraced. They now hope to limit warming to about 1.8 degrees Celsius (3.2 degrees Fahrenheit), then remove enough carbon dioxide from the air to bring temperatures back down to 1.5 degrees.

United Nations Secretary-General António Guterres said the world is falling “dangerously short” of even those goals. “But we have the tools to change course and pull back from the brink.” UNEP Executive Director Inger Andersen said the way forward requires drastically cutting global carbon emissions by 18% by 2030 and 69% by 2040. That, she said, “is the only way that we can get back to a semblance of a reality that is still largely manageable without major impacts.”

Climate scientist Adelle Thomas, vice chair of a United Nations scientific assessment on climate impacts, put the choice plainly. “The report’s message is clear. We know what needs to be done. We have the tools to do it. And delay only makes the challenge more dangerous and more expensive for all.” Thomas wasn’t part of the study.

Anne Olhoff, the report’s lead author and director of the UNEP Copenhagen Climate Centre, said the U.S. policy change will likely add one-tenth of a degree Celsius to global temperatures by the end of the century. Australian climate scientist Malte Meinshausen was blunter about the broader cost. “The rest of the world is exhausted when it comes to counting the damage that the U.S. is willingly doing to allies, multilateral structures, economic cooperation, disaster relief,” he said. “The rest of the world should probably continue to focus even less on the U.S.”

Johan Rockstrom, director of the Potsdam Institute for Climate Impacts Research in Germany, argued that the American effect may exceed the U.N. estimate. He suggested other nations may ease their efforts if the world’s largest historical climate polluter does little. That’s the kind of dynamic multilateral cooperation exists to prevent.

Why This Matters:

The report makes clear that the climate crisis isn’t a distant problem for future generations. Its consequences already fall hardest on communities that did the least to create it, from African nations facing failed harvests to coastal populations threatened by flooding. The projected addition of 140 million people to dangerously hot conditions and $1.2 trillion in economic losses measure human suffering and public cost, not just abstract statistics. The findings also spotlight institutional accountability. When a single major economy steps back from the Paris Agreement and its emissions rise while others fall, everyone else carries more of the burden. Governments’ responses—renewed cooperation, enforceable commitments, and public investment in clean energy—will shape who breathes safer air, who keeps their homes, and who absorbs the damage.