Atmospheric carbon dioxide concentrations have surged to the highest levels ever recorded, raising alarm over intensifying climate impacts and extreme weather events, according to a new report released by the World Meteorological Organization (WMO).
Between 2023 and 2024, global average CO₂ levels rose by 3.5 parts per million—the steepest annual increase since systematic measurements began in 1957. The report, published ahead of the United Nations Climate Change Conference in Brazil next month, attributes the spike to fossil fuel combustion and a surge in wildfires, particularly across South America.
“The heat trapped by CO₂ and other greenhouse gases is turbo-charging our climate and leading to more extreme weather,” said Ko Barrett, WMO Deputy Secretary-General.
The report also highlights record concentrations of methane and nitrous oxide, which have increased by 16% and 25% respectively compared to pre-industrial levels. CO₂ itself has risen by 52% over the same period.
“This gas accumulates in the atmosphere. It has a very long lifetime,” said Oksana Tarasova, WMO senior scientific officer. “Every single molecule which is emitted in the atmosphere will have a global impact.”
Carbon Sinks Under Strain
While approximately half of global carbon emissions are absorbed by natural systems such as forests, soil, and oceans, the report warns that these carbon sinks are under increasing stress and losing their capacity to mitigate emissions.
“We rely on natural systems to help us offset our impacts, and those systems are so stressed that they start reducing their help,” Tarasova explained.
She cited the Amazon rainforest as a key example, noting that rising temperatures and prolonged drought—exacerbated by the 2023 El Niño event—have impaired the region’s ability to photosynthesize and absorb carbon.
“If the tree is under stress, if it doesn’t have water and has a very high temperature…it does not photosynthesize,” she said.
Urgent Call for Action
The findings underscore the urgency of global efforts to reduce greenhouse gas emissions and strengthen climate resilience. With natural buffers weakening and emissions accelerating, scientists warn that the window to prevent irreversible climate damage is narrowing.
The WMO report is expected to shape discussions at the upcoming climate summit, where world leaders will face mounting pressure to commit to more aggressive mitigation strategies and support vulnerable ecosystems.
