Record carbon dioxide levels will impact us for centuries, says UN weather agency

Levels of carbon dioxide (CO2) and other major greenhouse gases in the atmosphere caused by burning fossil fuels reached record highs in 2025, locking in more long-term global warming, the World Meteorological Organization (WMO) said on Tuesday.The agency’s latest Greenhouse Gas Bulletin indicates an average global concentration of CO2 at 426.8 parts per million (ppm) last year, or 153 per cent of the 1750 pre-industrial baseline. “Every additional part per million matters because it traps additional heat. In effect, we are supercharging the ocean and the atmosphere. That means that heat waves, tropical cyclones, and rainstorms are intensifying faster than our historical baselines prepared us for,” WMO Deputy Secretary-General Ko Barrett told journalists in Geneva.Equally worrying, levels of methane and nitrous oxide – the second and third most important long-lived greenhouse gases caused by human activities – also hit a new peak in 2025.“Another year, another new record. Greenhouse gases are trapping an unprecedented amount of heat in the atmosphere, providing energy for more extreme weather and associated risks to our economies and societies,” Ms. Barrett stressed. “The past 11 y...