Global carbon dioxide levels surge to record high in 2024

The concentration of carbon dioxide in the atmosphere surged by a record amount in 2024, the United Nations reported Wednesday, underscoring the urgent need for global action to reduce emissions.

The World Meteorological Organization (WMO) said levels of the three primary greenhouse gases — CO2, methane, and nitrous oxide — all hit unprecedented highs last year. CO2 alone rose to 424 parts per million (ppm), marking the largest one-year jump since systematic measurements began in 1957. Methane reached 1,942 parts per billion, and nitrous oxide climbed to 338 parts per billion, reflecting increases of 266 percent and 125 percent above pre-industrial levels, respectively.

“The heat trapped by CO2 and other greenhouse gases is turbocharging our climate and leading to more extreme weather,” WMO Deputy Secretary-General Ko Barrett said. “Reducing emissions is essential not just for our climate but also for economic security and community well-being.”

The report comes ahead of the COP30 UN climate summit in Belem, Brazil, scheduled for November 10-21. While the latest bulletin focuses on atmospheric concentrations, a forthcoming UN report will detail global emissions trends, which are also expected to rise amid continued fossil fuel use.

The sharp increase in greenhouse gases continues to challenge commitments under the 2015 Paris Agreement, which aims to limit global warming to “well below” 2°C above pre-industrial levels — or 1.5°C if possible. WMO warned that land and oceans are increasingly unable to absorb excess CO2, leaving more of the potent greenhouse gas in the atmosphere.

2024 was also the warmest year on record, surpassing 2023, highlighting the escalating climate crisis. Of the three major long-lived greenhouse gases, CO2 contributes roughly 66 percent of the warming effect on the planet. Since the first Greenhouse Gas Bulletin in 2004, atmospheric CO2 levels have risen from 377 ppm to today’s 424 ppm, with the 3.5 ppm increase from 2023 to 2024 being the largest annual jump ever recorded.