The United Nations Environment Programme released its annual Emissions Gap Report on Wednesday, highlighting the United States as the standout among G20 nations for rising greenhouse gas emissions in 2025.

According to the report, U.S. emissions rose by 133 million metric tons of CO2 equivalent last year. This increase accounted for roughly 70 percent of the net rise from the 124 countries that saw emissions grow, out of a total global addition of 189 million tons. Other major economies either reduced emissions or slowed their growth.

The report links the U.S. uptick to surging electricity demand from data centers supporting artificial intelligence, a colder winter that boosted heating needs, and a rebound in coal-fired power generation. Global emissions overall remained nearly flat compared to 2024.

U.S. withdrawal from the Paris Agreement, formalized after the 2024 pledge under the prior administration, contributed to revised projections showing the world on track for an additional 0.1 to 0.2 degrees Celsius of warming by the end of the century if current policies hold.

The findings position the United States as an outlier in efforts to curb emissions among industrialized nations. Per capita emissions in the U.S. remain among the highest in the G20, tied with Russia in some assessments, though China continues to lead in total annual output.

Rising power needs tied to technological advancement, including AI infrastructure, have strained grids and prompted greater reliance on available domestic energy sources. Policies favoring fossil fuel production and reliability have supported economic activity amid these demands.

The report notes that most other G20 members achieved slower emissions growth or outright declines in 2025. It projects continued challenges in meeting prior temperature targets without accelerated global action.

Energy analysts have pointed to the practical trade-offs in balancing emissions reductions with energy security and economic growth. The U.S. experience underscores how demand from high-tech sectors can influence short-term trends despite longer-term shifts toward natural gas and other sources.

The Emissions Gap Report serves as a benchmark for international climate discussions, though implementation of recommendations varies widely by country.