The Keeling Curve
One man measured the air every day, and nobody could deny it afterwards
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The sawtooth pattern is the northern hemisphere's forests breathing: taking up carbon in summer and releasing it in winter. It is the planet's respiration, measured. The underlying rise — from 315 ppm in 1958 to over 420 today — is the single measurement that made global warming a fact rather than a model. Keeling had to fight for funding repeatedly; the series was nearly broken in 1964 and again in the 1970s.
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Charles Keeling began measuring how much CO₂ was in the air at the top of the Mauna Loa volcano in Hawaii — far from cities and factories. He measured every day, year after year. The curve rises and falls with the seasons, but it climbs steadily throughout. It is the longest continuous measurement we have.
Sources
- Keeling, Tellus 12 (1960)
- Scripps Institution of Oceanography: Keeling-kurven, Mauna Loa
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Report a correctionPart of Terra Saga — the story of Earth on a timeline. terrasaga.org ·