Greenhouse gas concentrations reached unprecedented levels in 2025, raising serious concerns about global warming and long-term climate change.
The United Nations revealed the findings on Tuesday, October 27, 2026, warning that rising emissions could affect Earth’s climate for centuries.
According to the World Meteorological Organization (WMO), carbon dioxide, methane, and nitrous oxide all reached record atmospheric concentrations.
Carbon Dioxide Levels Reach Historic Highs
The WMO’s latest Greenhouse Gas Bulletin recorded carbon dioxide concentrations at 426.8 parts per million in 2025.
Methane reached 1,948 parts per billion, while nitrous oxide climbed to 339.1 parts per billion.
These figures represent substantial increases compared with pre-industrial levels.
Carbon dioxide alone accounts for approximately 66% of the warming influence from long-lived greenhouse gases.
UN Warns of More Extreme Weather
WMO Deputy Secretary-General Ko Barrett warned that increasing greenhouse gases are trapping unprecedented amounts of heat in the atmosphere.
This warming contributes to extreme weather events, threatening communities, economies, and natural ecosystems.
The organization confirmed that the past 11 years were the warmest ever recorded.
Meanwhile, carbon dioxide concentrations increased by 2.8 parts per million between 2024 and 2025.
Although this increase was below the previous year’s record, it exceeded the average annual growth rate of the past decade.
Climate Concerns Grow Ahead of COP31 Summit
Scientists attributed continued atmospheric pollution primarily to fossil fuel consumption.
The WMO also highlighted concerns about hydrogen and sulfur hexafluoride, gases associated with energy infrastructure.
The findings come ahead of the COP31 climate summit in Antalya, Turkey, scheduled for November 9–20.
World leaders face growing pressure to reduce emissions and strengthen international climate commitments.
