Global energy-related carbon dioxide emissions reached an all-time peak of nearly 38.4 billion tonnes in 2025 because of unusual weather patterns and a resurgence of fossil fuel use in advanced economies, according to the authors of the newly released report. Although clean energy technologies are expanding rapidly, extreme cold and dry spells forced several regions to burn more coal and natural gas to compensate for a lack of wind and water power.
“We estimate that the net impact of weather-related factors – including temperature variations and shortfalls in hydropower and wind – pushed up CO2 emissions from the combustion of fossil fuels by around 90 million tonnes in 2025, driven by higher natural gas consumption.” The report further notes that “drought conditions in several regions, particularly in Europe and across Central and South America, reduced hydropower output, further contributing to the increase in carbon dioxide (CO2) emissions as the shortfall was largely met by fossil fuels.”
Simply put, the world’s energy systems were tested by nature. A colder winter in places like the United States and Europe meant people needed more heat, which resulted in higher consumption of natural gas. At the same time, many parts of the world suffered from dry weather that left rivers and dams too low to produce enough electricity from water power, while a lack of wind further reduced clean energy supplies, forcing countries to turn back to traditional fuels like coal and gas to prevent blackouts.
The report “Global Energy Review 2026” was published by the International Energy Agency in France in April 2026. Prepared by the IEA’s Energy Modelling Office under the direction of Laura Cozzi, the comprehensive study was led by authors Alex Martinos and Thomas Spencer.
