Greenhouse gas levels set records in 2025, U.N. says, expressing alarm

Key Points:

• In 2025, atmospheric concentrations of the three main greenhouse gases—carbon dioxide (CO2), methane, and nitrous oxide—reached record highs, according to the UN's World Meteorological Organization (WMO), signaling long-term climate impacts.
• CO2 levels rose to 426.8 ppm, methane to 1,948 ppb, and nitrous oxide to 339.1 ppb, representing significant increases from pre-industrial levels and contributing to ongoing global warming, with CO2 responsible for about 66% of the warming effect.
• The annual increase in CO2 from 2024 to 2025 was 2.8 ppm, slightly lower than the previous year's 3.6 ppm surge, partly due to recovery of land carbon sinks and reduced fire emissions following the 2023/2024 El Niño event.
• Methane, accounting for about 16% of warming by long-lived greenhouse gases, arises from both natural sources and human activities such as agriculture and biomass burning, while emerging concerns include rising levels of trace gases like molecular hydrogen and sulfur hexafluoride linked to energy production.
• The WMO warns that greenhouse gas concentrations are expected to continue rising in 2026, driven by fossil fuel use and a developing El Niño, emphasizing the need for intensified climate action ahead of the COP31 summit in Turkey.