Trends in Atmospheric Carbon Dioxide
This activity analyzes a figure showing the atmospheric carbon dioxide concentration from 1958 to 2023.
Records from polar ice cores show that the natural range of atmospheric CO2 over the last 800,000 years was 170 to 300 parts per million (ppm) by volume. In the early 20th century, scientists began to suspect that CO2 in the atmosphere might be increasing beyond this range due to human activities, such as burning fossil fuels and making changes in land use. At that time, however, there were no clear measurements of this trend. In 1958, Charles David Keeling began measuring atmospheric carbon dioxide at the Mauna Loa Observatory on the big island of Hawaii. This figure is a graph of the observatory’s measurements over time, which is now called the Keeling Curve.
The “Educator Materials” document includes a captioned figure, background information, graph interpretation, and discussion questions. The “Student Handout” includes a captioned figure and background information.
Student Learning Targets
- Analyze and interpret data from a scientific figure.
- Describe recent patterns and trends in atmospheric carbon dioxide concentrations.
global warming, greenhouse gas, Keeling Curve, line graph
“The Keeling Curve,” Scripps Institution of Oceanography, UC San Diego, accessed March 24, 2023, https://scripps.ucsd.edu/programs/keelingcurve/.
The resource is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license. No rights are granted to use HHMI’s or BioInteractive’s names or logos independent from this Resource or in any derivative works.
Accessibility Level (WCAG compliance)
HS-LS2-5, HS-ESS2-6, HS-ESS3-5; SEP2, SEP4, SEP5
AP Biology (2019)
SYI-2.B; SP1, SP4
IB Biology (2016)
AP Environmental Science (2020)
Topic(s): 1.4, 5.2, 6.5, 7.4, 9.4
Learning Objectives & Practices: ERT-1.D, EIN-2.B, ENG-3.E, STB-2.D, STB-4.E, SP2, SP4, SP6
IB Environmental Systems and Societies (2017)
Common Core (2010)
Math.S-ID.3, Math.S-IC.1; MP2, MP5
Vision and Change (2009)
CC5; DP2, DP3