Historical Temperature and Carbon Dioxide Graph

Scientists use data from tree rings, rocks, ice cores, and other materials to study what the atmosphere was like long ago. Based on that data, the graph below shows the estimated average annual global temperature and carbon dioxide levels for the last 800,000 years. Look at the graph to make observations.

Using these data, jot down your reflection or discuss the following with your class:

• Using data from the last 800,000 years, what would you expect to be the normal upper limit for CO2?

• What do you notice about the relationship between CO2 and temperature?

---

Credits

Climate Education Pathways.

Data source: U.S. Global Change Research Program, 4th National Climate Assessment, 2017 (url), adapted from EPA, 2017 (url)