The level of carbon dioxide in the atmosphere rose by the largest amount ever recorded in 2024, the UN has reported, as researchers warn of the dangers of feedback loops that are pushing the climate crisis to new heights and many global powers do nothing to mitigate emissions.
According to the latest bulletin by the UN’s World Meteorological Organization (WMO), the global average concentration of carbon dioxide in the atmosphere increased by 3.5 parts per million between 2023 and 2024. This is the highest single-year increase since modern records began in 1957.
The WMO noted that the annual growth rate of carbon dioxide has tripled since the 1960s, going from an average of 0.8 ppm a year to 2.4 ppm a year between 2011 and 2020. Last year’s growth far exceeds even that increase — as the climate crisis fuels wildfires, extreme flooding, and disease spread globally.
In 2024, the average level of carbon dioxide in the atmosphere was 434 ppm — up from 377 ppm in 2004, the first year the WMO published its carbon dioxide bulletin, and up from pre-industrial levels of 280 ppm. This lines up with research by the National Oceanic and Atmospheric Administration, which similarly found that atmospheric carbon dioxide hit a record high last year.
“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,” said Ko Barrett, deputy secretary-general for WMO.
The report was released just ahead of the UN’s annual climate conference in Brazil next month, COP 30.
Last year was also the warmest year on record, with average temperatures at 1.55 degrees Celsius above the global average from 1850 to 1900, WMO has previously reported.
Major contributors to the precipitous rise in carbon dioxide levels are the El Niño weather pattern, which raises temperatures; as well as wildfire emissions and lower uptake of carbon dioxide by the land and ocean, due to disruptions in crucial carbon sinks caused by the climate crisis.
In 2024, the world saw these circumstances with the record breaking wildfires and drought in the Amazon and Southern Africa.
An annual State of Wildfires report published this week found that wildfires burned an area larger than India between March 2024 and February 2025. The emissions from these fires were especially high because of an increase in burning of carbon-rich forests, researchers noted.
Scientists have long warned of dangerous feedback loops that may quickly accelerate the climate crisis and exacerbate global warming, worsen natural disasters, and more.
“There is concern that terrestrial and ocean CO2 sinks are becoming less effective, which will increase the amount of CO2 that stays in the atmosphere, thereby accelerating global warming. Sustained and strengthened greenhouse gas monitoring is critical to understanding these loops,” said Oksana Tarasova, a senior scientific officer for WMO.
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