The Keeling Curve Hits 420 PPM

Levels of the greenhouse gas carbon dioxide eclipsed 420 parts per million for the first time in human history in 2021. Scripps Institution of Oceanography updated this animation, which explains the rise of carbon dioxide concentration in the atmosphere over the past 300 years and the measurement our researchers collect at Hawaii’s Mauna Loa, known as the Keeling Curve. When Scripps Oceanography scientist Charles David Keeling first began taking measurements in 1958, CO2 levels were at 315 parts per million.

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How Scientists Measure Carbon Dioxide

In honor of the 60th anniversary of the Keeling Curve, Ralph Keeling of the Scripps CO2 Program showed how scientists make carbon dioxide measurements and gives a guided tour of the original instruments his father, Charles David Keeling, developed to start the famous record known as the Keeling Curve. In 2018, carbon dioxide levels are expected to exceed 410 parts per million (ppm) on a regular basis for the first time in human history.  Sixty years earlier at the beginning of the records, CO2 levels were at 315 ppm.

Charles Keeling (1928-2005) and NOAA’s Mauna Loa Observatory

This short video produced by NOAA tells the story of how Charles David Keeling of Scripps Institution of Oceanography, UC San Diego, worked with scientists from the U.S. Weather Bureau and NOAA at NOAA’s Mauna Loa Observatory to create what is now an iconic record of carbon dioxide in our atmosphere. The measurements of carbon dioxide in the atmosphere taken from 1958 to the present have become the most widely recognized record of mankind’s impact on the Earth, linking rising levels of carbon dioxide from man’s burning of fossil fuels to the warming of the planet.

As Told by the American Museum of Natural History

The Keeling Curve Turns 50

This 2008 film made for the 50th anniversary of the Keeling Curve features interview footage with the measurement’s creator Charles David Keeling originally filmed for the 2004 Finnish documentary “The Venus Theory.”