GENEVA (dpa): The concentration of carbon dioxide (CO2) in the atmosphere rose more sharply last year than in any other since records began in 1957, the World Meteorological Organisation has reported.
The annual increase in CO2 had tripled since the 1960s, the UN agency reported. Other long-lived greenhouse gases, including methane (CH4) and nitrous oxide (N2O), had also risen to record levels, the WMO said.
In the 1960s, CO2 concentrations rose by 0.8 parts per million (ppm) annually. This increased to 2.4 ppm on average between 2011 and 2020. Between 2023 and 2024, the figure increased to 3.5 ppm.
This meant a rise in atmospheric CO2 concentration last year to 423.9 ppm.
CO2, which is produced when fossil fuels are burnt, exerts an influence on the climate for centuries, as between 15% and 40% is still in the atmosphere after 1,000 years, according to the estimates.
The WMO noted that wildfires were adding to the CO2 in the atmosphere, while the capacity for CO2 absorption in forests and oceans was in decline as a result of climate change. It referred to a vicious cycle.
The effect was exacerbated last year by the El Niño weather phenomenon that leads to droughts across South America and southern Africa, as well as more wildfires. Drought causes ecosystems to absorb less CO2.
Temperature records show that 2024 was the hottest year since the start of the industrial era in around 1750, with a rise of more than 1.55 Celsius degrees above the pre-industrial average. The world's seas were also warmer than ever before, both at the surface and at depths of up to 2,000 metres.
Around half of the CO2 emitted stays in the atmosphere, while the rest is absorbed by ecosystems, including the sea. The WMO notes that the world's seas absorb less CO2 as their temperature rises and that CO2's ability to be absored on land is affected by increased drought.
It called for greenhouse gas emissions to be cut radically, or the 2015 Paris climate targets will be missed. The Paris Accords called for global warming to be restricted to considerably less than 2.0 degrees above pre-industrial levels and to 1.5 degrees if possible.
The WMO noted that while the rise topped 1.5 degrees last year, a rise in a single year was not as important as the long-term trend. The next UN conference on climate change will be held in Brazil next month. - dpa
