The UN World Meteorological Organization (WMO) has alerted the global community that atmospheric levels of carbon dioxide (CO2) and other greenhouse gases have reached unprecedented heights, posing a long-term threat to societies and economies. This escalation in greenhouse gases is a significant contributor to global warming, which increases the frequency and severity of extreme weather events.
According to WMO Deputy Secretary-General Ko Barrett, the past 11 years have been the warmest on record, a trend likely to continue. With CO2’s prolonged atmospheric lifetime, its impact on global climate will persist for decades and even centuries. In fact, the WMO’s Greenhouse Gas Bulletin highlights that CO2 concentrations have risen to nearly 427 parts per million (ppm). This steady increase has been observed since 2004, with growth rates tripling since the 1960s. As CO2 emissions remain substantial, half linger in the atmosphere, and the rest are absorbed by land and oceans. Future projections suggest further increases due to fossil fuel consumption and the El Niño phenomenon, which weaken land carbon sinks.
Methane and nitrous oxide, the second and third most critical long-lived greenhouse gases, have also reached peak levels. These gases, predominantly released by human activities, compound the warming effect. Furthermore, the organization has called attention to molecular hydrogen and sulphur hexafluoride (SF6), two powerful trace gases contributing indirectly to global warming. SF6, notably utilized in electricity distribution, has marked a record high and possesses a global warming potential significantly exceeding that of CO2. With an atmospheric lifetime of around 1,000 years, SF6 underscores the urgency for heightened monitoring and control.
Despite not being a greenhouse gas, molecular hydrogen’s atmospheric leaks affect chemistry and thus exacerbate warming. Therefore, enhanced scrutiny of atmospheric composition is crucial to avoid unforeseen impacts. Most greenhouse gas emissions originate from fossil fuel combustion, which traps solar heat within Earth’s atmosphere, raising global temperatures. This leads to profound changes, including glacier melting, extreme heat, and rising sea levels.
Efforts to counter this trend include Denmark’s initiative to tax CO2 emissions from agriculture and the European commitment to cut net emissions by 90 percent by 2040. Yet, climate change challenges persist, as global temperatures in September 2026 hit 1.63 degrees Celsius, exceeding the Paris Agreement target of 1.5 degrees.
Read more about the UN’s warning regarding atmospheric greenhouse levels on JURIST. Additionally, the UN News further elucidates the far-reaching consequences of these rising greenhouse gases, emphasizing the need for robust international cooperation in addressing climate change.