U.S. Climate Retreat Drives Global Emissions Higher

The United States added 133 megatons of carbon dioxide equivalent in 2025, more than any other country, and accounted for 70% of the emissions increase among countries whose pollution rose, a United Nations report said. Higher electricity demand and a rebound in coal power drove the increase. The consequences of that national policy direction reach far beyond the people who set it.

Mohamed Adow, director of Power Shift Africa, said: “This report shows that America's retreat isn't just a political embarrassment. It has real consequences for the planet and for millions of people around the world.” He said an extra tenth of a degree could mean “more dangerous heat waves, more destructive floods, more failed harvests and more lives lost.” Vulnerable communities in Africa, he added, are already “living on the front lines of the climate crisis.”

Who Sets the Course

The United States alone among major economies failed to reduce its carbon pollution or even slow the growth in emissions from burning fossil fuels, the report said. Every other economy among the top 20 reduced pollution or slowed its growth. Of 124 countries that increased emissions, 63 countries, including most European nations, reduced theirs.

The United Nations Environment Programme’s updated calculations attribute a worse warming outlook partly to “the formal withdrawal of the United States of America from the Paris Agreement and revised estimates of historical emissions.” If countries meet their submitted climate plans, Earth will likely warm another 2.2 degrees Fahrenheit (1.2 degrees Celsius) above current temperatures. That is about two-tenths of a degree Fahrenheit (0.1 degrees Celsius) higher than the same science team projected last year.

By 2100, those plans would still leave the globe 2.6 degrees Celsius (4.7 degrees Fahrenheit) hotter than pre-industrial times. Without national promises, warming on the current path would reach 2.8 degrees Celsius (5 degrees Fahrenheit), unchanged from last year’s projection. Both outcomes exceed the Paris climate pact’s goal: keeping warming below 2 degrees Celsius (3.6 degrees Fahrenheit), preferably 1.5 degrees Celsius (2.7 degrees Fahrenheit).

The world is now about 1.4 degrees Celsius (2.5 degrees Fahrenheit) warmer than pre-industrial times. United Nations officials have conceded that limiting warming to 1.5 degrees is no longer possible. Instead, they hope to limit it to about 1.8 degrees Celsius (3.2 degrees Fahrenheit) before removing enough carbon dioxide from the air to bring temperatures back down to 1.5 degrees.

The Costs Travel Downward

Anne Olhoff, director of UNEP Copenhagen Climate Centre and the report’s lead author, said the U.S. policy change would most likely add one-tenth of a degree Celsius (nearly two-tenths of a degree Fahrenheit) to global temperatures by the end of the century. Hare said that extra warming would put another 140 million people “into dangerously hot conditions” and raise the odds of the Amazon rainforest or ice sheets in Greenland and Antarctica collapsing.

University of Pennsylvania climate scientist Michael Mann said the added warming would cost the world and shave about $1.2 trillion from the global economy. Adow said the figures describe human consequences, not an abstraction: “These are not abstract numbers. They are human lives.”

Australian climate scientist Bill Hare, CEO of Climate Analytics, said the United States is going “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.” He said the country was “looking at the fire, denying there is a fire, and then pouring more petrol on it.” Hare didn't take part in the U.N. report, but he and several other outside scientists said it was scientifically sound.

Warnings From the Top

United Nations Secretary-General António Guterres said the world is falling “dangerously short” of its goals, “but we have the tools to change course and pull back from the brink.” UNEP Executive Director Inger Andersen said cutting global carbon emissions by 18% by 2030 and 69% by 2040 “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 and not part of the study, said: “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.” Johan Rockstrom, director of the Potsdam Institute for Climate Impacts Research in Germany, warned that the U.S. effect could be larger than the U.N. calculation if other nations ease their efforts. Malte Meinshausen said the rest of the world is “exhausted” by the damage the U.S. is willingly doing to allies, multilateral structures, economic cooperation and disaster relief.