The Keeling curve
This page delivers no verdict; it presents claims and evidence with their sources. No theory in science is absolute. Method
For everyone
In 1958 Charles Keeling began continuous measurements of atmospheric carbon dioxide at the Mauna Loa Observatory in Hawaii. The measurements show a steady rise together with a yearly up-and-down linked to the plant growing season. CO₂ concentration was about 315 ppm in 1958 and exceeded 420 ppm in 2024.
For specialists
That the added CO₂ is of fossil origin is supported by isotopic signatures: fossil fuels contain no ¹⁴C and are depleted in ¹³C, so the atmospheric ¹³C/¹²C ratio is falling (the Suess effect). Atmospheric O₂ is also declining at a rate consistent with fossil-fuel combustion. Ice cores show CO₂ staying between about 180 and 300 ppm over the past 800,000 years.
Claims
Evidence
Supporting
Continuous measurements at Mauna Loa and other stations worldwide show the same rising trend.[2]
Challenging
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Connections
Sources
- Article (1960). The concentration and isotopic abundances of carbon dioxide in the atmosphere. Tellus 12(2), 200–203DOI 10.3402/tellusa.v12i2.9366archive
- DatasetTrends in Atmospheric Carbon Dioxide (Mauna Loa)gml.noaa.govarchive
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Cite this page
Athena contributors. (2026). The Keeling curve. Athena: The tree of human knowledge. Retrieved November 1, 2026, from https://latifkedi.github.io/athena/en/d/keeling/
@misc{athena_keeling,
title = {The Keeling curve},
author = {{Athena contributors}},
year = {2026},
howpublished = {\url{https://latifkedi.github.io/athena/en/d/keeling/}},
note = {Athena: The tree of human knowledge. Accessed: 2026-11-01}
}Added: September 27, 2026 · Last changed: September 27, 2026 · Page history