According to the World Meteorological Organization (WMO), global greenhouse gas levels surged to a new record in 2023, locking the planet into a trajectory of rising temperatures for the foreseeable future. The WMO’s annual Greenhouse Gas Bulletin reveals a sharp increase in the globally averaged surface concentrations of carbon dioxide (CO2), methane, and nitrous oxide.
Over the past 20 years, CO2 concentrations have risen by 11.4 percent. WMO Secretary-General Celeste Saulo expressed concern, stating, “Another year, another record. This should set alarm bells ringing among decision-makers. We are clearly off track to meet the Paris Agreement goal of limiting global warming to well below 2°C and aiming for 1.5°C above pre-industrial levels.”
The data shows that the average surface concentration of CO2 reached 420 parts per million (ppm) in 2023. Methane and nitrous oxide also saw significant increases, reaching 1,934 parts per billion (ppb) and 336.9 ppb, respectively. These figures represent a 151%, 265%, and 125% rise from pre-industrial levels for CO2, methane, and nitrous oxide.
The report highlights that the atmospheric CO2 increase for 2023 was 2.3 ppm, which, while higher than in 2022, is slightly below the increases seen in the previous three years. This marks the 12th consecutive year with annual CO2 levels rising by more than 2 ppm.
The uptick in CO2 levels is attributed to persistently high fossil fuel emissions, extensive vegetation fires, and a possible reduction in carbon absorption by forests. Natural phenomena, such as El Niño events, can exacerbate the situation, creating a vicious cycle where drier vegetation and wildfires diminish the effectiveness of land carbon sinks, further intensifying greenhouse gas effects.
WMO Deputy Secretary-General Ko Barrett emphasized that while natural climate patterns influence the carbon cycle, climate change itself could amplify emissions from natural sources. “The Bulletin warns that we face a potential vicious cycle,” Barrett stated. “Wildfires could release more carbon emissions into the atmosphere, while warmer oceans might absorb less CO2, allowing more CO2 to remain in the atmosphere and accelerate global warming.”
The report also noted that from 1990 to 2023, the warming impact of long-lived greenhouse gases increased by over 51%, with CO2 alone accounting for 81% of that rise. This trend is expected to continue unless there is a significant reduction in emissions, as CO2’s long atmospheric lifespan ensures that elevated temperature levels will persist even with rapid emission cuts.
