Feb 15, 2024 - News

Keeling Curve hits all-time high

Mauna Loa Observatory

The National Oceanic and Atmospheric Administration's Mauna Loa Observatory. Photo: Susan Cobb/NOAA Global Monitoring Laboratory

A long-running record of carbon in the atmosphere maintained by the Scripps Institution of Oceanography at UC San Diego hit its all-time high this weekend.

State of play: The Keeling Curve — a graph of global, atmospheric carbon dioxide concentration readings from the Hawaiian volcano Mauna Loa — registered a record carbon concentration of 426.5 parts per million.

Zoom in: Ralph Keeling, the program's director, said he hasn't recorded many one-day jumps of that size, and it occurred after a strong wind shift.

  • The extra CO2 in the atmosphere would have reached the observatory eventually, but the weather accelerated that, per Keeling.
  • "It's like hitting the fast-forward button," he said.

Why it matters: This was the first reading in the Keeling Curve's modern record that exceeded 425 parts per million. The curve first broke 400 parts per million in 2013.

  • "It is kind of humbling to see how fast and relentless this is," Keeling said. "It underscores the magnitude of the task to get this under control."

Yes, but: Daily recordings are more volatile than monthly averages.

What's next: Keeling said he expects the monthly average in May to peak above 425 parts per million.

  • "With an El Niño event, we expect CO2 to rise a little faster because it is associated with drought in some areas of the tropics, which causes ecosystems that would be absorbing or taking up CO2 to release CO2," he says.

Background: The Keeling Curve was created in 1958 by Charles David Keeling, father of Ralph Keeling.

  • "It's mainly significant because it … reinforces the message that CO2 is continuing to build up," Ralph Keeling said.

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