Another year, another grim record: Greenhouse gas levels surge

Global greenhouse gas levels surged to a new record in 2023, locking the planet into a path of rising temperatures for years ahead, according to a new report published by the World Meteorological Organization (WMO).

WMO’s annual Greenhouse Gas Bulletin on Monday found that carbon dioxide (CO2) concentrations have increased 11.4 percent in 20 years.

"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," WMO Secretary-General Celeste Saulo said.

Saulo added: "Every part per million and every fraction of a degree temperature increase has a real impact on our lives and our planet."

Data from the WMO’s Global Atmosphere Watch network shows that the globally averaged surface concentration of CO2 reached 420 parts per million (ppm) in 2023. Methane and nitrous oxide concentrations also increased sharply, reaching 1,934 parts per billion (ppb) and 336.9 ppb, respectively.

These figures mark a 151, 265, and 125 percent rise from pre-industrial levels for CO2, methane, and nitrous oxide, according to the WMO.

The WMO report recorded the atmospheric CO2 increase for 2023 was 2.3 ppm, higher than in 2022 but slightly below the previous three years. This increase marks the 12th consecutive year with CO2 levels rising by more than 2 ppm annually, it said.

The uptick in CO2 in 2023 was attributed to a mix of persistently high fossil fuel emissions, extensive vegetation fires, and a potential decrease in forest carbon absorption, according to the report.

Additionally, the WMO noted that natural events such as El Nino years can exacerbate the situation, leading to a vicious cycle where "drier vegetation and forest fires reduce the efficiency of land carbon sinks," intensifying the effects of greenhouse gases.

WMO Deputy Secretary-General Ko Barrett emphasised the role of natural climate patterns in the carbon cycle but warned that climate change itself could amplify greenhouse gas 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, whilst the warmer ocean might absorb less CO2. Consequently, more CO2 could stay in the atmosphere to accelerate global warming. These climate feedbacks are critical concerns to human society."

The report noted that from 1990 to 2023, the warming impact on the climate from long-lived greenhouse gases increased by over 51 percent, with CO2 alone contributing to 81 percent of that rise. This trend is expected to continue unless there is a sharp reduction in emissions, as CO2’s long atmospheric lifetime ensures that temperature levels will persist even with rapid emission reductions.