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Keeling Curve


Charles D. Keeling creates the “Keeling Curve,” a simple visualization of the longest continuous record of CO2 concentration in the world.

A paper published by Charles D. Keeling of the Scripps Institution of Oceanography and coauthors in the journal Tellus, “Atmospheric carbon dioxide variations at Mauna Loa Observatory, Hawaii,” tracks increases in atmospheric carbon dioxide measured at the Mauna Loa Observatory, finding that “the annual average CO2 concentration rose 3.4% between 1959 and 1971… Similar changes in rate have been observed at the South Pole and are evidently a global phenomenon.” The Keeling Curve shows measurements dating back to 1958 at Mauna Loa and as it later develops incorporates ice core records to show CO2 measurements dating back to 1700.* As CarbonBrief comments: “With the Mauna Loa measurements continuing today, the so-called ‘Keeling curve’ is the longest continuous record of carbon dioxide concentration in the world. Its historical significance and striking simplicity has made it one of the most iconic visualizations of climate change.”**

» See a video on the Keeling Curve on Vimeo
» New York Times 2010 article reflecting on Keeling’s life

*Charles D. Keeling and others, “Atmospheric carbon dioxide variations at Moana Loa Observatory, Hawaii,”Tellus, Vol. 28, Issue 6, December, 1976, ; Rob Monroe, “How are ice-core data and Mauna Loa atmospheric data made comparable?” Scripps Institution of  Oceanography, March 20, 2014,
**Roz Pidcock, “The Most Influential Climate Change Papers of All Time,” CarbonBrief, June 7, 2015,