Record carbon dioxide levels and other major greenhouse gases caused by burning fossil fuels reached historic highs in 2025, locking in long-term global warming that will affect the climate for centuries. The World Meteorological Organization released its latest Greenhouse Gas Bulletin on Tuesday, revealing an average global concentration of carbon dioxide at 426.8 parts per million last year, which represents 153 per cent of the 1750 pre-industrial baseline.

Accelerating Growth Rates and Extreme Weather

Deputy Secretary-General Ko Barrett explained to journalists in Geneva that every additional part per million traps extra heat, supercharging the ocean and atmosphere. This causes heat waves, tropical cyclones, and rainstorms to intensify faster than historical baselines prepared humanity for. Methane and nitrous oxide also hit new peaks in 2025. When the Bulletin debuted in 2004, the annual average concentration was 377.5 parts per million. Growth rates have tripled since the 1960s, accelerating from an annual average increase of 0.8 parts per million to 2.4 parts per million between 2011 and 2020. An exceptional surge of 3.5 parts per million occurred from 2023 to 2024 during a strong El Niño, while the 2024 to 2025 increase was 2.8 parts per million. Senior scientific officer Oksana Tarasova noted a further increase is expected in 2026 due to fossil fuel burning and another powerful El Niño.

Trace Gases and the Energy Transition

The report also highlighted trace gases related to electricity production, such as molecular hydrogen and sulphur hexafluoride. Sulphur hexafluoride usage has risen steadily over three decades, possessing an atmospheric lifetime exceeding 1,000 years and a global warming potential roughly 24,300 times that of carbon dioxide, hitting a record high in 2025. Meanwhile, hydrogen concentration grew by 5.3 per cent from 2010 to 2024. Although hydrogen is not a greenhouse gas, its leakage from pipelines, facilities, storage tanks, and fuel cells influences atmospheric chemistry and exerts a strong indirect warming effect. The World Meteorological Organization publishes these findings to supply authoritative scientific data for negotiators attending the annual UN Climate conference, specifically the upcoming Conference of the Parties meeting in Antalya, Türkiye, scheduled from 9 to 20 November, aiming to turn climate commitments into concrete action.

Source: Cosmo News Desk