Global Warming: Questions and Answers
and is replicated here as part of the SERC Pedagogic Service.
Detailed Example of Using Socratic Questioning in Class
This sample of plausible questions and responses is designed to help guide the instructor through a Socratic lesson. It will help instructors learn how to create Socratic questions and to design a session of Socratic questioning. The content focuses upon the nature of evidence for modern global warming.
The instructor/teacher is identified as T, and the student as S. Some of the questions below are identified in terms of the type of question, as follows:
- Questions of clarification (C)
- Questions that probe assumptions (A)
- Questions that probe reasons and evidence (R&E)
- Questions that probe implications and consequences (I&C)
T. What is happening to the modern global climate? (C)
S. It's getting warmer.
T. How do you know that it's getting warmer? What evidence supports your answer? (R&E)
S. It's in the news all the time. It's not as cold as it used to be.
T. Are you saying that you learned that global warming is occurring from journalists and newscasters? Are you assuming that they know that it is warming? (A)
S. Yeah, I learned about it from the news reporters, but they learned about it from scientists.
T. If scientists have reported to the news media that it's getting warmer on Earth, how do they know that? (R&E)
S. They measure climate. Scientists measure Earth's temperature.
T. How long have scientists been measuring Earth's temperature? (C)
S. Maybe 100 years.
[Show the Intergovernmental Panel on Climate Change (IPCC) graph of the average annual global temperature for the past ~140 years. Don't show them the caption; instead, read it aloud slowly (all but the last sentence) and discuss the axes of the figure, the error bars, and so forth. Graph is Figure 1a from the Summary for Policymakers in the Third Assessment Report of Working Group I of the IPCC. Additional source is Figure 2.7c in Chapter 2 of the full IPCC report.
T. You can see from this graph of average annual Earth temperature that scientists have been keeping track of Earth's temperature, which is an indicator of the state of the climate system, for about 140 years, since about 1860. During that time, how much has the average global temperature increased? (C) [Have students refer to the graph to get an answer.]
S. About 0.4 to 0.6 degrees Celsius.
T. Yes,the black line is a filtered annual curve of temperature change with time, and it shows an increase of about 0.6???0.2°C. That's about 1°F. Is that very much? Is it enough to say that global warming is occurring? (R&E)
S. One degree Farenheit doesn't sound like much, but there is a trend, and it looks like it's getting warmer, especially for the last 20 years or so. It looks like global warming to me.
[Here the instructor can show a graph of temperature change over an even longer time period, one that represents the past 1000 years of Earth history. Source is Figure 1b from the Summary for Policymakers in the Third Assessment Report of Working Group I of the Intergovernmental Panel on Climate change (IPCC). Additional source is Figure 2.20 in Chapter 2 of the full IPCC report. As with Figure 1a, discuss the plot, axes, error bars, and so forth, and read the caption aloud.]
T. What is the most significant aspect of this plot of average annual temperature for the last 1000 years? (C)
S. The 20th century got really hot compared to the previous 1000 years.
T. Can you suggest a hypothesis for why Earth started to get warmer at the close of the 19th century? (
S. Pollution in the atmosphere.
T. I'm going to ask you what evidence supports your hypothesis, but first, what are you assuming when you say that pollution in the atmosphere caused global warming in the 20th century? (I&C)
S. Well, certain things in the atmosphere, like carbon dioxide from automobiles, can make Earth get warmer. I'm assuming that such things can cause warming.
T. Do you know how those substances can make it get warmer? (I&C)
[At this point, the instructor can take time to ask questions about the greenhouse effect, or give a brief mini-lecture on the greenhouse effect.]
T. Let's take a minute to review what we know. Scientists have monitored Earth's temperature with thermometers for 140 years, and it's gotten a little warmer. If we look at proxy data for temperature, as is found in coral and tree rings, for example, the 20th century is anomalously warm compared to the previous 9 centuries. We also know that certain gases in the atmosphere can cause warming if more of those substances are able to accumulate in the atmosphere. Based on this information, how can we test your idea that pollution is causing the temperature increase of the past 140 years? (R&E)
[Students might need help here in coming to an answer. Teacher might need to pose several questions to get to the following point.]
S. If scientists monitored the composition of the atmosphere, not just the temperature, maybe they saw that the amount of greenhouse gases increased also.
T. Let's look at some real data, then. The next figure shows the amounts of three important greenhouse gases in the atmosphere for the past 1000 years. The gases are carbon dioxide, methane, and nitrous oxide, all of which are emitted to the atmosphere from various human acitivites (as well as natural processes, such as volcanic eruptions). Look closely at the diagram of greenhouse gases. Is there any evidence that the amounts of these gases might be responsible for the global warming noted for the past 140 years? If so, what is that evidence?
[Source is Figure 2 from the Summary for Policymakers in the Third Assessment Report of Working Group I of the Intergovernmental Panel on Climate change (IPCC). Additional sources are Figures 3.2b (carbon dioxide), Figures 4.1a and 4.1b (methane), and Figure 4.2 (nitrous oxide) of the full IPCC report. As with Figure 1a, discuss the plot, axes, error bars, and so forth, and read the caption aloud.]
S. The amounts of all three greenhouse gases are increasing, mostly in the last 140 years since the Industrial Revolution. This is the same time period during which Earth's temperature seems to start increasing.
T. Yes. We know that increases in these gases can have a forcing effect, in that they can cause Earth's atmosphere to trap more of the outgoing heat from the Earth (i.e., the radiative forcing effect). We can see from the graph that the amounts of these gases have increased exponentially in the last 140 years, and that the increase looks similar to the increase in Earth's temperature. Because scientific theory indicates that the gases can cause warming, and because of the correlation in time between a possible cause and effect, can you conclude with certainty that Industrial pollution is the cause of global warming?
[At this point, the teacher can continue the discussion with consideration of scientific uncertainty. The ICPP report contains an excellent summary of how the panel scientists assessed the uncertainty of each of their conclusions. The report provides material that could be used in leading a discussion of this important issue with students.]