Scientific Debate and the Nature of Certainty

This page authored by Laura Triplett and Mary Gaebler, Gustavus Adolphus College.
Gustavus Adolphus College, Geology
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In this 50-minute classroom activity for a religion, philosophy or ethics course, students learn about the nature of scientific knowledge. Before class, students read a popular science account of a 'controversy' in climate science. In class, the instructor describes the process of peer-review and scientific debate, and leads a conversation about how this is similar to and different from other kinds of knowledge. This may lead into further discussion of climate impacts and climate projections, but that is not included here. Students had an option to write their final paper about climate change and scientific knowledge.

Used this activity? Share your experiences and modifications

Learning Goals

The Religion professor's goals were to:
  • Examine individuals' response to public crises
  • Explore the nature of scientific knowledge, and discuss how it alone does not motivate individual action

The climate science specialist's goals were to:

  • Explain the nature of scientific certainty and consensus
  • Promote better understanding of and respect for the whole scientific process and climate consensus
This activity develops skills in critical thinking and synthesis of ideas. A follow-up activity can develop writing skills.

Context for Use

This is a 50-minute class activity that can be done in a small- to large-sized introductory lecture or seminar setting. It was developed and tested in classes of ~25 students with a variety of backgrounds including first-year students, but could be done in a larger class. The activity was developed for a religion course called "Faith, Religion and Culture," and could be used in many religion, philosophy or ethics classes.

We use it midway through the course, after students had explored where and how one's worldview is formed, what normative principles are logically associated with different worldviews, and what sorts of underlying 'authoritative' sources provide epistemic reliability. Students had read a book about Dietrich Bonhoeffer, to help them think about what it takes to maintain a moral compass in trying situations. They had already written one paper about euthanasia, to explore the roots of their own convictions. In that, they had to take a position, first from a strictly 'moral' perspective, and second, a position in relation to the legalization of euthanasia, analyzing their own epistemology as they went, (including the prioritization of sources, principles and the kinds of reasoning they were employing in their analysis.) All of these precursors could be altered or something else substituted, leading to different in-class discussion but not requiring a fundamental alteration of this class activity.

This class period was co-taught by the host faculty member (Religion) and the specialist faculty member (Geology), but the science concepts are basic and our intention was that the host faculty member would be able to teach it solo the second time around. In reality, the Religion faculty member enjoyed having the scientist there in person to engage in conversation about the nature of scientific certainty and the challenges and frustrations of being a scientist, so we have continued the co-teaching model.

Description and Teaching Materials

Before class, students were assigned to read a short "popular" non-scientific article about a scientific debate about one aspect of climate science (whether extreme weather events are caused by climate change, or would happen anyway). The article describes how Dr. Jennifer Francis's hypothesis generated an outcry among some climate scientists, and how she has responded to sometimes angry and seemingly personal attacks on her work.

During class, the instructor uses the .ppt (see below) to teach about scientific knowledge, peer review and scientific consensus. Periodically, the lecture is paused and students engage in discussion about knowledge, certainty, maintaining a moral compass in trying situations, and climate science itself. In our class periods, the Religion and Geology professors often found themselves conversing, explaining concepts or experiences to each other, and tying it back into previous class lessons or readings.

After class, students submitted their questions about climate science to the Geology instructor, who typed up answers and emailed the whole document back to the class. Or, this question/answer could be done in person in a second class period if you have time.

  • The required reading Science article is directly available to subscribers through the AAAS website, or through your library. The full citation is: Kintisch, E., 2014, "Into the Maelstrom," Science v. 344, Apr 18, p. 253.
  • PowerPoint presentation
  • Instructions for reading science articles, and vocabulary terms. The first section is only relevant if they are reading the original articles
  • To read the entire Kumar article, citation is Kumar, A., et al., 2013, Do extreme climate events require extreme forcings?, Geophysical Research Letters v. 40 p.3440-3445 doi:10.1002/grl.50657, 2013
  • To read the Francis article, citation is Francis, J.A. and Vavrus, S.J., 2012, Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophysical Research Letters v. 39, L06801, doi:10.1029/2012GL05100, 2012

Teaching Materials

Teaching Notes and Tips

Examples of discussion questions that can be interspersed during the class period:
What is scientific knowledge, and how does it differ from other kinds of knowledge we've learned about?

How did Jennifer Francis respond to other scientists who criticized her work? What must that have felt like? How has her life changed? Can you relate to her experience at all?

Is it okay for scientists to express a political or moral position?

What is your impression of climate science: Is there consensus among scientists, or controversy? Now that you know how many scientists participated in writing the IPCC reports, does that change your impression?

Some people are very worried about climate change, and are working hard to slow it down. Why? Let's analyze the source of that motivation.

What to do when students ask you science questions and you don't know the answers:
Students may ask detailed questions about the science of climate change, which the host faculty member may not feel qualified to answer. That's okay! Our non-science faculty have had success responding to that kind of situation in these ways:
"My specialty is Religion, so I do not know the specific answer to your question. However, I know enough about how the process of science works and how knowledge advances, that I trust the findings our scientists are communicating to us. They overwhelmingly agree that global warming is happening and is caused by humans. Therefore, I am confident that it is important for us to continue this lesson how climate scientists achieve "certainty", and how scientific knowledge can or cannot motivate concern about an issue like climate change, even though I do not know the scientific details."

"I do not know the answer to your question, but I would like to find out! I will consult with our campus climate specialist and get back to you with an answer during our next class meeting."

"I do not know the specific answer to your question, but I have several reliable and unbiased sources of information about climate science that I will share with you. I encourage you to educate yourselves about this topic, and that means reading websites and reports published by the scientists themselves – not just what the popular media might say *about* the science and scientists! Many highly-regarded science organizations have created easy-to-read but accurate summaries of the scientific results."

Or, you can turn this into an interesting discussion with the whole class if you have time.

"My specialty is Religion and I do not know the answer to your specific science question. How do you (whole class) suggest we find the answer? Who will we trust to answer that question, and why?"


  • Quality of class discussion
  • Exam question, e.g. "In one paragraph, make an argument for why scientific knowledge is or is not enough to motivate people to some action. Be sure to describe the specific characteristics of this type of knowledge." A complete answer would at least define 'knowledge'. It might explain that moral action is often driven by different types of knowledge (e.g., revelatory or personal), give examples from class readings.
  • Term paper about the crisis that greenhouse gas emissions are creating for our shared world, as each considers his or her place and role in relation to this growing public challenge. They can be asked to provide an epistemological analysis of the commitments which emerge as they explore their reception of this data and their considered response to this situation.

References and Resources

Kintisch, E., 2014, "Into the Maelstrom," Science v. 344, Apr 18, p. 253.

Kumar A. et al., 2013, Do extreme climate events require extreme forcings?, Geophysical Research Letters v. 40 p.3440-3445 doi:10.1002/grl.50657, 2013

Francis, J.A. and Vavrus, S.J., 2012, Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophysical Research Letters v. 39, L06801, doi:10.1029/2012GL05100, 2012