In this hands-on activity, students simulate the effects of decreasing pH caused by rising levels of atmospheric carbon dioxide.
Human activity is causing the concentration of atmospheric carbon dioxide to increase. In addition to its role as a greenhouse gas, carbon dioxide reacts with water to form a weak acid called carbonic acid, which lowers the pH of seawater. In this activity, students simulate this process by blowing through a straw into a beaker of artificial seawater and measuring the change in pH. Using the provided graph, they determine the atmospheric carbon dioxide concentration that would produce the same pH change in the oceans. Finally, students determine how many years it would take to reach this concentration at the current rate of emissions.
Student Learning Targets
- Explain the role of atmospheric CO2 in ocean acidification.
- Collect, analyze, and interpret data to draw conclusions.
- Use models of atmospheric CO2 concentrations to make predictions on the impact of ocean acidification on marine ecosystems.
acidification, alkalinity, calcium carbonate, chemical reaction, concentration, exoskeleton, food web, marine biology, oceanography, pH, soluble
Caldeira, Ken, and Michael E. Wickett. “Anthropogenic Carbon and Ocean pH.” Nature 425, 6956 (2003): 365. https://doi.org/10.1038/425365a.
Fine, Maoz, and Dan Tchernov. “Scleractinian Coral Species Survive and Recover from Decalcification.” Science 315, 5820 (2007): 1811. https://doi.org/10.1126/science.1137094. To access this article, set up a free AAAS account.
Accessibility Level (WCAG compliance)
HS-LS2-2, HS-ESS3-6; SEP2, SEP6
AP Biology (2019)
SYI-1.H, SYI-2.B; SP1, SP2, SP3
IB Biology (2016)
AP Environmental Science (2020)
Topic(s): 1.1, 9.7
Learning Objectives & Practices: ERT-1.A, STB-4.H, SP1, SP2, SP4
IB Environmental Systems and Societies (2017)
Common Core (2010)
Vision and Change (2009)
CC5; DP2, DP3