The level of carbon dioxide in the atmosphere touched an all-time high in 2024, setting the ground for a long-term increase in Earth’s temperature, according to a report released by the World Meteorological Organisation (WMO) in Geneva on Thursday.
The report comes less than a month before the global COP30 climate summit gets underway in Belem, Brazil.
The report, titled WMO Greenhouse Gas Bulletin, blamed the CO2 surge on “continued emissions… from human activities and an upsurge from wildfires” besides the waning carbon absorption capacity of land ecosystems and the ocean.
It identified the atmospheric El Niño phenomenon as one of the triggers of rising CO2 in 2024 and referred to the cocktail of contributing conditions as “a vicious climate cycle”.
“The heat trapped by CO2 and other greenhouse gases is turbo-charging our climate and leading to more extreme weather. Reducing emissions is therefore essential not just for our climate but also for our economic security and community well-being,” WMO deputy secretary-general Ko Barrett said while releasing the report.
Expressing concern over the findings of the report, a climate activist said the global leaders at Belem should take it seriously.
“This is bad news. The increase in average temperature, compared to the pre-industrial period, has already crossed 1.5°C last year despite the Paris agreement in 2015 vouching to keep it within that limit. The latest report is scary,” the activist said.
The report pointed out that growth in the global average concentration of CO2 had tripled since the 1960s, accelerating from an annual increase of 0.8ppm (parts per million) per year to 2.4ppm per year between 2011 and 2020. However, it rose exponentially by 3.5ppm in 2024, the largest increase ever since modern measurements started in 1957.
In 2004, when the first bulletin was published, the annual average level of CO2 measured by the WMO’s Global Atmosphere Watch network of monitoring stations was 377.1ppm. It shot up more than 12 per cent in two decades to 423.9ppm.
The report pointed out that “the likely reason for the record growth between 2023 and 2024 was a large contribution from wildfire emissions and a reduced uptake of CO2 by land and the ocean in 2024 — the warmest year on record, with a strong El Niño”.
During El Niño years, CO2 levels tend to rise because the efficiency of land carbon sinks is reduced by drier vegetation and forest fires, the report said.
The report points out that the trends are similar for methane and nitrous oxide, the second and third most important long-lived greenhouse gases related to human activities.
Methane accounts for about 16 per cent of the warming effect on the climate and has a lifetime of about nine years. In the case of nitrous oxide, the globally averaged concentration reached 338.0ppb (parts per billion) in 2024, an increase of 25 per cent over the pre-industrial level.
The WMO said it had released the report “to provide authoritative scientific information for the UN Climate Change conference in November”, which is expected to push climate action across the globe, especially in developed countries.
“Sustaining and expanding greenhouse gas monitoring are critical to support such efforts,” Oksana Tarasova, coordinator of the Greenhouse Gas Bulletin, told this correspondent on Thursday.