Directions for teachers:
Have students read the online Science News article “Earth’s oceans are storing record-breaking amounts of heat.” A version of the story, “Earth’s oceans broke heat records in 2020,” appears in the February 13, 2021 issue of Science News. Use the first set of prompts to identify data that researchers used as evidence to support a scientific claim. The final two sets of prompts ask students to discuss how effective a graph and an analogy is at helping the reader interpret the claim. As a final exercise, have students propose an alternative method of displaying or explaining the oceanic heat data.

Want to make it a virtual lesson? Post the online Science News article “Earth’s oceans are storing record-breaking amounts of heat” to your learning management system. Pair up students and allow them to connect via virtual breakout rooms in a video conference, over the phone, in a shared document or using another chat system. Have each pair post its answers to the questions, or conduct a class discussion to allow groups to share out.

Define the claim and supporting data
Answer the following questions individually before discussing them with a partner.

1. What claim does the article make about the ocean?

Researchers state that the total amount of heat stored in the upper 2,000 meters of Earth’s oceans was higher in 2020 than in any other year on record dating back to the 1950s.

2. What data, or evidence, is given to support the claim?

Ocean temperature data from moored sensors, underwater robots and other instruments were used in mathematical models to estimate the average amount of heat energy stored in the upper oceans in 2020. That data was compared with historical ocean temperature data going back to the 1950s.  

Communicate the findings
Discuss the following questions with a classmate. Write down your thoughts and be prepared to share your answers with the class.

1. What analogy did scientists come up with to describe their findings? What information was likely needed to create the analogy?

Scientists used the difference in the amount of heat energy stored in upper the oceans from 2019 to 2020 to calculate the approximate number of kettles of water that could be boiled with that energy. In order to create the analogy, one must know the increase in the amount of energy, the heat of vaporization of water (typically given in J/mol), the molar mass of water, the density of water, and the volume of a typical water kettle.

2. Based on the information given in the article, can you to figure out the calculation used to come up with the analogy? What assumptions do you have to make? Explain.

The main assumptions that you would have to make in this calculation are the starting temperature of the water and the volume of a typical water kettle. If we don’t know the what assumptions the researchers made, then it might be challenging to get the same answer.

3. Does the analogy present the relevant data in a way that supports the claim? What usefulness do analogies have in communicating concepts? Explain.

The analogy provides a relative value for the amount of heat mentioned in the article and shown on the graph. The analogy doesn’t directly support the claim, but it does help readers understand the magnitude of the increase in heat content from 2019 to 2020. When communicating data and information to a general audience, familiar references help give perspective and meaning to quantities that difficult to conceive or are otherwise unusual.

Display the data
The graph below appears with the story in the February 13, 2021 issue of Science News. Study the graph and discuss the following questions with a partner. Be prepared to turn in your answers to your teacher.

1. What information was needed to create the graph? Describe how that information is displayed on the graph.

Data on annual average ocean heat content (in sextillions of joules) from the 1950s to 2020 was needed to create the graph. The average ocean heat content from 1981 to 2010 is used as a baseline and is represented as zero on the y-axis. Yearly change from that baseline is plotted as upward or downward pointing bars on the graph. Upward pointing bars indicate a positive rate of change of annual heat content compared to the average, and downward pointing bars indicate a negative rate of change of annual heat content compared to the average.

2. What overall trend in data does the graph display? Does the graph’s design present the relevant data in a way that supports the claim? Explain.

The graph shows a general increase in average annual ocean heat content since 1958, though there are some years that haven’t followed that general trend. The rate of increase is gradual from 1958 until about 1985, at which point the rate of increase appears to be larger until 2020. The graph gives the reader a historical trend in ocean heat content, which is beneficial when supporting the claim that the total amount of heat stored in the upper oceans was higher in 2020 than in any other year on record dating back to the 1950s. The graph provides the evidence to the reader, but does not directly interpret it.

Analyze the strategies
Discuss the following questions with a classmate. Write down your thoughts and be prepared to share your answers with the class.

1. Did you find the analogy or the graph more beneficial to your understanding? Is it effective to pair the strategies? Explain. 

Student answers will vary. Answers should mention that the graph provides a comprehensive dataset that the reader must interpret whereas the analogy provides a familiar interpretation of the data for the reader. However, the analogy does not provide any factual data to support the scientific claim.

2. What other strategies could be used to communicate the findings to the public?

Other diagrams, graphs, data visualizations or analogies could be used to communicate the claim to the reader.

Extension: A new alternative
Propose an alternative method of displaying or explaining the oceanic heat data described in the Science News article. Or, create your own analogy for another Science News article that appears in the February 13, 2021 issue. The analogy should communicate the magnitude of quantitative data used to support a scientific claim.