: Here you will find clear descriptions of what you just saw, how they know what they said they knew, why they know it to be trustworthy information. Finally we will ask the question, "So what!" and explore why the information is important.
In this clip from a 2006 public lecture, "Will the Living Climate Save Us From Climate Change?", climate scientist Peter Cox describes the scientific heroism and pioneering measurements of Charles David Keeling. By 1958, Keeling had established an observatory for the continuous monitoring of atmospheric carbon dioxide at Mauna Loa - a remote site on the slopes of a Hawaiian volcano. Carbon dioxide turned out to play a huge role in determining Earth’s climate, and the “Keeling Curve” that Cox presents shows the rise of carbon dioxide concentrations measured at Mauna Loa between 1960 and 2005.
To watch the full video of the public lecture, click here.
Keeling gathered his data by using gas detectors placed at a remote Mauna Loa site. Since carbon dioxide (CO2) is a trace gas, comprising less than 1 % of the atmosphere, measuring it requires very sensitive instruments. To read how CO2 is measured at Mauna Loa today, click here.
Keeling was a scientist with a reputation for careful scientific measurements. One sign that his instruments were successfully measuring carbon dioxide (CO2) is that concentrations went up and down in a seasonal pattern (the wiggles in the graph). This fits logical expectations that plants in the northern hemisphere would use more CO2 during the spring/summer growing season, and thus atmospheric concentration of CO2 would go down at those times.
The measurements made by Charles David Keeling were responsible for awakening scientists to the fact that carbon dioxide is increasing in Earth’s atmosphere. Keeling was dedicated to this work before others commonly recognized how important atmospheric carbon dioxide concentration is to determining Earth’s climate. This is why Dr. Cox states, “This record sets the stage for today’s concerns about climate change. Some people consider this to be the most important environmental record that’s been taken in the 20th century.”
Reflect on the clip using these questions. Then, record your thoughts in a science journal or discuss them with a friend.
Reading the Graph
The associated graph is an updated version of the one shown by Dr. Cox. According to the trend in the graph of measurements from Mauna Loa, how did the concentration of carbon dioxide change in the 40 years between 1960 and 2000?
The CO2 concentration (measured in ppm=parts per million) has...
a.) stayed the same except for annual variations.
b.) increased by about 365 ppm.
c.) increased by about 75 ppm.
d.) decreased by about 300 ppm.
To watch the complete public lecture from Peter Cox, visit the AGCI website.
"The History of the Keeling Curve." The Keeling Curve: A Daily Record of the Atmospheric Carbon Dioxide from Scripps Institution of Oceanography at UC San Diego, University of California, San Diego.