The UN weather agency reported that atmospheric concentrations of heat-trapping greenhouse gases reached yet another record high last year, emphasizing that the upward trend shows no signs of abating.
In 2022, global average concentrations of carbon dioxide (CO2), the main greenhouse gas, were a full 50% above pre-industrial levels for the first time, the World Meteorological Organization’s (WMO) Greenhouse Gas Bulletin found. The bulletin added that they continued to rise in 2023.
The rate of increase in CO2 concentrations was slightly lower than last year and the average for the decade. But the bulletin said this was “most likely” due to natural, short-term variations in the carbon cycle, and that new emissions from industrial activities continued to rise.
Concentrations of methane were also on the rise, it said, while levels of nitrous oxide – the third main gas – saw the largest year-on-year increase on record from 2021 to 2022.
Presenting the new bulletin at a news conference in Geneva, WMO Secretary-General Petteri Taalas said that despite decades of warnings from the scientific community, “we are still heading in the wrong direction.”
Taalas warned that the current level of greenhouse gas concentrations puts the world on the pathway of an “increase in temperatures well above the Paris Agreement targets by the end of this century.”
Those increased temperatures will be accompanied by more extreme weather, including intense heat and rainfall, ice melt, sea-level rise and ocean heat and acidification, he warned.
“We must reduce the consumption of fossil fuels as a matter of urgency,” he urged.
If emissions go on, CO2 will accumulate in the air due to its long lifetime and the temperature levels already observed will persist for “several decades even if emissions are rapidly reduced to net zero,” the bulletin said.
It said that the last time the Earth experienced a comparable concentration of CO2 was three-five million years ago, when the temperature was 2-3°C (35.6-37.4F) warmer and the sea level was 10-20 meters (32.8-65.6 feet) higher than today.
The Greenhouse Bulletin was published as an information bulletin for the UN climate change negotiations, or COP28, in Dubai.