CO2 emissions in the first half of 2025
Thirty-one billion tons: that is the total amount of CO2 emissions recorded in the first half of 2025, according to Climate TRACE, a nonprofit coalition of more than 100 universities, research centers, scientists and AI experts. The figure is slightly higher than in the same period of 2024, precisely 0.13% more than in the first six months of last year. The increase comes at a time when sharp cuts are needed to keep the Paris Agreement climate goals within reach.
Fossil fuels and manufacturing drive CO2 emissions
In the first half of 2025, fossil fuel activities accounted for the largest share of climate pollutants, marking a 1.5% increase, or 77.65 million tons. The United States was responsible for more than half of this rise. Manufacturing sector releases also grew in the same period, climbing 0.3% (18.75 million tons of CO2), driven by industries in India, Vietnam, Indonesia and Brazil.
Decline led by the energy sector
By contrast, in the first half of 2025, global energy sector emissions recorded the largest decline, down 0.8% (a reduction of 60.27 million tons of CO2). The drop was driven almost entirely by China and India, where energy emissions fell by 1.7% and 0.8%, respectively, compared with the same period in 2024.
Progress in China, Mexico and Australia
The first six months of 2025 showed modest but meaningful advances in decarbonization in China, Mexico and Australia. China’s atmospheric releases fell by 45.37 million tons, a 0.51% decrease from the first half of 2024. Mexico’s dropped by 7.78 million tons (down 1.71%), while Australia’s declined by 6.56 million tons (down 1.51%) compared with the previous year.
Increases in the US, EU, India, Indonesia and Brazil
However, other major economies, including the United States, the European Union, India, Indonesia and Brazil, registered increases in CO2 emissions:
- US emissions rose by 48.57 million tons of CO2, up 1.43% from the first half of 2024.
- India’s emissions increased by 4.44 million tons of CO2, up 0.21%.
- EU emissions rose by 2.90 million tons of CO2, up 0.15%.
- Indonesia’s emissions increased by 3.06 million tons of CO2, up 0.39%.
- Brazil’s emissions grew by 9.84 million tons of CO2, up 1.24%.
Read the full Climate TRACE report [here].