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Atmospheric CO2 Levels Reached Another High in 2018

The concentration of the greenhouse gas is now one-and-a-half times what it was before the Industrial Revolution, the World Meteorological Association says.

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Shawna Williams

Shawna joined The Scientist in 2017 and is now a senior editor and news director. She holds a bachelor's degree in biochemistry from Colorado College and a graduate certificate and science communication from the University of California, Santa Cruz.

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Nov 26, 2019


The level of CO2 in the Earth’s atmosphere hit a record 407.8 parts per million last year, the World Meteorological Association announced yesterday (November 25) in a report. The findings “underlined the glaring—and growing—gap between agreed targets to tackle global warming and the actual reality,” the WMO says in a statement.

The increase in CO2 levels from 2017 to 2018 was “just above the average over the last decade,” according to the WMO’s press release, and puts the total concentration of the gas at nearly 150 percent what it was in 1750, before the Industrial Revolution accelerated the rate of human-induced carbon emissions. The concentrations of two other major greenhouse gases, methane and nitrous oxide, also rose last year at a higher rate than average for the decade. 

“There is no sign of a slowdown, let alone a decline, in greenhouse gases concentration in the atmosphere despite all the commitments under the Paris Agreement on Climate Change,” says WMO Secretary-General Petteri Taalas in the organization’s statement. “It is worth recalling that the last time the Earth experienced a comparable concentration of CO2 was 3–5 million years ago. Back then, the temperature was 2–3°C warmer, sea level was 10–20 meters higher than now.” 

“The [CO2 concentration] number is the closest thing to a real-world Doomsday Clock, and it’s pushing us ever closer to midnight,” John Sauven, head of Greenpeace UK, tells The Guardian. “Our ability to preserve civilisation as we know it, avert the mass extinction of species, and leave a healthy planet to our children depend on us urgently stopping the clock.”

Shawna Williams is an associate editor at The Scientist. Email her at swilliams@the-scientist.com or follow her on Twitter @coloradan.