Greenhouse gas emissions in the United States increased last year, ending a two-year period of decline, according to a new report released on Tuesday. The rise was mainly caused by colder winter temperatures that boosted heating fuel demand and a sharp increase in electricity use linked to the rapid growth of artificial intelligence.

The report, prepared by the Rhodium Group think tank, said emissions in the world’s largest economy rose by 2.4 percent.

Policy Shifts Add Pressure on Climate Action

The increase came as President Donald Trump and Republicans in Congress rolled out several policies that are unfriendly to climate action. However, the report’s authors said the full effect of these decisions will only become clear in the coming years.

At the same time, the slowdown in emissions cuts is not limited to the United States. Other rich countries, including Germany and France, are also reducing emissions more slowly, even as global temperatures continue to rise. Scientists expect 2025 to be confirmed as the third-hottest year on record.

Recent Emissions Trends Explained

Before the latest rise, US emissions had been falling. They dropped by 0.5 percent in 2024 and by 3.5 percent in 2023. These declines followed a rebound after the Covid pandemic, when emissions increased by 6.3 percent in 2021 and 1.2 percent in 2022 as economic activity picked up.

Buildings and Power Sector Drive Increase

The report showed that emissions from buildings rose sharply, increasing by 6.8 percent. This was followed by the power sector, where emissions climbed by 3.8 percent.

“Weather is bumpy year-to-year -- we tend to see building emissions bump around like this due to higher fuel use for heating,” Rhodium Group analyst and co-author Michael Gaffney told AFP.

He said the rise in power-sector emissions had a different cause.

“But in the power sector this is about growing significant demand from data centers, cryptocurrency mining operations and other large load customers,” he added.

Coal Makes a Temporary Comeback

Higher natural gas prices, pushed up by strong heating demand and rising liquefied natural gas exports, allowed coal to return to the power mix. Coal, described as the “dirtiest” fossil fuel, generated 13 percent more electricity than in 2024.

This shift added to emissions growth, even as cleaner energy sources continued to expand.

Solar Power Surges Despite Slower Wind Growth

Solar energy recorded a strong year, growing by 34 percent. This helped raise the share of zero-emission power sources on the US grid by one percentage point, reaching a record high of 42 percent.

In contrast, wind power growth slowed, while nuclear and hydropower output remained largely unchanged.

Transport Emissions Stay Flat

Transport remains the highest-emitting sector in the US. However, emissions from transport were nearly unchanged last year. This happened despite a fifth straight year of record road traffic.

The report said improved vehicle efficiency played a role. In addition, many consumers rushed to buy electric and hybrid vehicles before tax credits were set to expire.

Long-Term Emissions Picture

The United States is the world’s second-largest emitter after China. It also has the highest cumulative emissions since the start of the industrial era in the mid-19th century.

Overall, US emissions have generally declined since peaking in 2007. On average, they have fallen by about one percent per year. This trend has been supported by natural gas replacing coal, rising use of renewable energy, and better energy efficiency.

Trump Policies Target Clean Energy

Since returning to office, President Trump has taken steps against renewable energy. These include halting wind farm permits, ending clean energy tax credits earlier than planned, and revoking incentives for electric vehicles.

His administration has also opened more public land for oil and gas drilling. In addition, it has tried to roll back rules aimed at cutting methane emissions from oil and gas facilities.

Experts Still See Signs of Progress

Despite these policy changes, the report’s authors say progress has not stopped entirely. Co-author Ben King told AFP that rising solar power generation and strong electric vehicle sales point to continued momentum.

However, the US is far from meeting its earlier Paris Agreement goal. Under former President Joe Biden, the country aimed to cut emissions by 50–52 percent by 2035 compared to 2005 levels.

“Solar, wind, batteries, these are some of the cheapest things to bring onto the grid right now and some of the most available things,” King said.

“So there's some economic impetus to be doing that, regardless of whether the White House or Congress, or whoever likes it or doesn't.”

Data Challenges Ahead

The Rhodium Group prepares its annual estimates using official data along with economic and power-generation modeling. This approach is needed because official government emissions inventories are released with long delays.

However, the report warned that future forecasts could become harder to produce, as the Trump administration is no longer expected to collect some of the key data needed for accurate tracking.