Greenhouse gas levels once again reach record high

illuminem summarises for you the essential news of the day, reviewed by our editorial team. Read the full piece on the World Meteorological Organization blog or enjoy below:

🗞️ Driving the news: Global concentrations of greenhouse gases reached unprecedented levels in 2025, according to the World Meteorological Organization (WMO), committing the planet to further long-term warming
• Carbon dioxide, methane and nitrous oxide all recorded new highs, intensifying climate risks despite ongoing decarbonisation efforts

🔭 The context: Atmospheric CO₂ reached 426.8 parts per million (ppm) in 2025, equivalent to 153% of its pre-industrial level. Methane climbed to 1,948 parts per billion, while nitrous oxide reached 339.1 ppb
• CO₂ growth rates have tripled since the 1960s, averaging 2.4 ppm annually during 2011–2020
• Although the 2025 increase was partly moderated by recovering land carbon sinks and fewer wildfire emissions, fossil fuel combustion continues to drive atmospheric accumulation

🌍 Why it matters for the planet: Greenhouse gases trap heat, intensifying global warming and increasing risks from extreme weather. CO₂ persists in the atmosphere for decades to centuries, meaning today's emissions will influence climate conditions long into the future

⏭️ What’s next: The WMO expects atmospheric CO₂ concentrations to rise further in 2026, driven by fossil fuel burning and a developing El Niño that could weaken land carbon sinks
• Ahead of COP31 in Türkiye, the report provides scientific evidence to support stronger climate action
• The WMO also highlights the need to monitor SF₆ and hydrogen leakage as electrification and clean energy infrastructure expand

💬 One quote: “CO₂ has a very long life-time and so will affect the global climate not just for years but for decades and even centuries,” - WMO Deputy Secretary-General Ko Barrett

📈 One stat: 426.8 ppm — the globally averaged atmospheric CO₂ concentration in 2025, equivalent to 153% of the pre-industrial baseline

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