The amount of CO2 in the atmosphere rose by a record amount in 2024, the World Meteorological Organisation's (WMO) annual Greenhouse Gas Bulletin on Wednesday.
The record increase is attributed to increased emissions from wildfires and reduced absorption by natural carbon sinks due to the drought. These factors are in addition to the continued high emissions from human activities.
The concentration of the main greenhouse gas in the atmosphere increased by 3.5 parts per million (ppm) between 2023 and 2024. This is the biggest increase since modern measurements began in 1957, bringing the total atmospheric CO2 concentration to 423.9 ppm – the highest level ever.
Normally, about half of the emitted CO2 ends up in the atmosphere, while the other half is absorbed by natural carbon sinks, such as oceans and forests. However, rising temperatures are reducing the oceans' ability to store CO2.
The drought, in turn, is putting pressure on the land's storage capacity. A combination of the numerous wildfires and a reduced effectiveness of carbon sinks due to the drought – fueled by the El Niño weather phenomenon and the warmest year on record – is therefore considered the explanation for this record year.
Global warming
"There are fears that carbon sinks on land and in the sea are becoming less effective, leaving more CO2 in the atmosphere and accelerating global warming," warned Oksana Tarasova, coordinator of the WMO report.
Therefore, there are fears of a vicious cycle in which increasing global warming will further reduce the effectiveness of natural carbon sinks, accelerating global warming.
2024 was also another record year for other greenhouse gases. For example, the concentration of methane rose to 1,942 ppb (parts per billion), and that of nitrous oxide (laughing gas) to 338 ppb.
