Can the history of geology inform geoscience education and public reception of climate change? Lessons from the history of glacial theory

Climate literacy is considered of vital importance for our future citizens as we encounter new challenges resulting from climate change in our local communities. The concept of climate change is difficult for the public to comprehend. Understanding is affected by societal influences, the complexity of the subject, and a discrepancy between our typical modes of understanding and what is required to understand climate change (Weber and Stern, 2011). Education will play a role in how people respond and mitigate climate change (Mochizuki and Bryan, 2015).

As advocates of the history and philosophy of science to improve student understanding of the nature of science, we promoted the inclusion of the history of science within the classroom to facilitate students’ geoliteracy on complex issues (Clary and Wandersee, 2009, 2015a; Clary, 2017b). This research investigates student reception of an earlier proposal of climate change within the history of our understanding of past glaciations that played out in the public scientific arena more than a century ago, i.e., Louis Agassiz’s (1807–1873) glacial theory and former ice ages. Agassiz’s glacial theory proposal, its original reception, and subsequent scientific acceptance were integrated within climate change discussions in an online Earth history course (n = 24). This research probes whether the debates surrounding Agassiz’s glacial theory can inform geoscience education and lead to better understanding of the modern climate change discussion for improved climate literacy.

The International Panel on Climate Change (2014; IPCC), in its fifth summary report, noted that Earth’s warming was unequivocal, with anthropogenic influences the extremely likely culprit. Acknowledging the importance of the topic, the U.S. Next Generation Science Standards (NGSS), designed for public K–12 education, incorporated climate change within its disciplinary core ideas in Earth and Space Science (Earth and Human Activity, ESS3; Earth Systems, ESS2) and Life Sciences (Ecosystems: Interactions, Energy, and Dynamics, LS2; Biological Evolution: Unity and Diversity, LS4) (NGSS Lead States, 2013). However, some science educators perceive barriers to implementing a climate change curriculum within public schools, similar to issues encountered with the theory of evolution within U.S. science classrooms (Colston and Ivey, 2015).

Studies probing middle school students’ conceptions of climate change revealed a cognitive disconnect between the greenhouse effect and global warming, and the implications of global warming for Earth systems (Shepardson et al., 2009). This is problematic, since other researchers proposed that the greenhouse effect offers a foundation between energy cycles and increases in global temperature (Visintainer and Linn, 2015). In secondary environments, only 10% of students were able perform at the NGSS standards that target matter and energy cycles related to global climate change, such as how matter and energy are traced through carbon-transforming processes (e.g., photosynthesis, combustion) (Parker et al., 2015). Similar student misconceptions were documented among undergraduate chemistry students about the role of greenhouse effects and global warming (Versprille and Towns, 2015). For undergraduate students, a substantial majority of student views do not align with the scientific community, and environmental group membership is a greater determinant of student acceptance of anthropogenic climate change than the students’ major of study (Huxster et al., 2015). Even U.S. teachers’ practices reflect problematic climate change education, with almost 30% of teachers emphasizing in their classrooms that climate change results from natural causes, not anthropogenic ones (Plutzer et al., 2016). However, the majority of teachers in a professional development program reported that they never had received formal training in climate change (Veron et al., 2016).

When students exhibited a need for cognition (NFC), or a preference to engage and enjoy thinking processes, a positive correlation existed with their acceptance of anthropogenic climate change (Kudrna et al., 2015). Instruction that included critical evaluation of anthropogenic climate change resulted in middle school students’ significant shifts in plausibility judgments toward the scientifically accepted model (Lombardi et al., 2013), while development of critical science agency affected urban high school students’ climate literacy with a significant increase in conceptual understanding, and a change within the student majority to limit their personal impact (McNeill and Vaughn, 2012). However, although climate change instructional units resulted in middle and high school students’ increased systems knowledge understanding of climate change, students still possessed significant misconceptions about mitigation of and adaptive responses to climate change (Bofferding and Kloser, 2015). When climate change instruction was included within an undergraduate writing class, 50% of the students gained or continued an interest in science and/or climate science, but 10% of students remained uninterested, and 5% lost interest in climate science because of the course (Small Griswold, 2017).

More research is needed to determine effective methods to not only educate our K–16 students about climate change, but to also increase the climate literacy of the public. Connections to local environments are important (Sumrall et al., 2015), with the SCALE model (Clary and Wandersee, 2010a) identifying local environments as one of the important variables in curriculum design. Utilizing local climate effects in electronic simulations resulted in significant increases for U.S. grade 7 students’ climate knowledge (Nussbaum et al., 2015). Some of our previous research also examined the duration, effectiveness, and transferability of climate instruction in geographically diverse classrooms, within online environments (Clary and Wandersee, 2012a, 2014a). While six one-week instructional units resulted in increased student climate literacy, students’ transferability of climate knowledge was not well developed.

James Bryant Conant (1893–1978), then president of Harvard University, noted that the history of sciences was indispensable in science classrooms for richer student understanding of the scientific enterprise (Conant, 1947). History and philosophy of science has been considered one of three essential components for the science classroom, along with content knowledge and a teaching theory to organize instruction (Matthews, 1994). The history of science can provide a hook for student interest, demonstrate the social and cultural influences that affected progression of science, reveal the interconnectedness of science, and humanize the curriculum (Matthews, 1994; Jenkins, 1989; Suchting, 1994). Science content is often presented and taught as a rhetoric of conclusions (Schwab, 1962), and typically missing or minimized in the classroom is the restructuring and reorganization of science when new information is available, thereby presenting a “final form science” to students (Duschl, 1990, 1994). The history of science provides a platform with a predictable trajectory for classroom inquiry to promote student understanding of the nature of science (Allchin, 2013, 2014).

Methods for incorporation of the history of science in science classrooms have been developed and researched, including interactive historical vignettes that showcase scientific habits of mind in pivotal historical episodes, and involve the classroom in predicting and analyzing the situation (Clary, 2015; Clary and Wandersee, 2006; Wandersee and Clary, 2006). Historical controversy case studies expose students to all aspects of an historical science episode, even when scientists behaved badly, to demonstrate that science is a human endeavor and that poor science is eventually corrected through replication and new data (Clary et al., 2008; Clary and Wandersee, 2013, 2014b). Controversial episodes prevent suspicion and resentment of science, demonstrate that freedom of thought exists in science, and promote enlightened minds and critical thinking for our students (Brush, 1974). Controversies in educational settings hone students’ critical-thinking skills, and emphasize the nature of science (Dodick and Dolphin, 2013). When analyzed against the nature of science (NOS) matrix developed by the U.S. National Research Council (2012), controversial history of science episodes can address many, if not all, of the eight basic understandings of science that focus upon both the practice of science and crosscutting concepts between disciplines (Clary, 2017b). With both historical and modern controversies, effective controversy inclusion contains research-based argumentation, source monitoring, and developing students’ broader awareness of the controversy, for better understanding of an issue’s complex and multivariate nature (Clary and Wandersee, 2015b). Researchers also targeted aspects of the climate change controversy with the history of science. Dolphin and Dodick (2014) suggested that climate change be addressed via student investigation of historical Earth dynamic models as multiple working hypotheses. John Leaf (Charles Keeling & Measuring Atmospheric CO₂: University of Minnesota SHiPS Resource Center http://www.shipseducation.net/modules/earth/keeling.htm [accessed 2017]) used the history of the Keeling curve to address multiple NOS variables during climate change investigation.

In 1837, in the midst of debates between the uniformitarians and catastrophists, Louis Agassiz (1807–1873) proposed that former and extensive glaciations could explain the presence of erratics, glacial polish, and glacial striations observed in areas without active glaciers (Agassiz 1967). Agassiz’s 1837 address hypothesized that the Earth was subjected to widespread glaciers, of which the contemporary glaciers were only fractional remains; he proposed that glacial processes in Switzerland resulted in erratics, ice accumulation in Switzerland stemmed from climate change within a cyclical pattern, and ice once covered more of Europe (Lurie, 1960). Not all these concepts were Agassiz’s original ideas, however. Agassiz initially acknowledged that the glacial processes that deposited large boulders were previously discerned by others, including geologist Jean de Charpentier (1786–1855) and engineer Ignace Venetz (1788–1859) (Weiner, 1985). Charpentier spoke of glacial clues with Agassiz as early as 1815, then published his observations in an 1835 paper, but his more substantial volume on the topic was superseded by Agassiz’s 1840 book (Lurie, 1960, p. 102–103). Charpentier was not the only contributor who felt upstaged by Agassiz: Karl Schimper (1803–1867) invented the term Eiszeit, but was not acknowledged as its source in Agassiz’s 1840 book (Lurie, 1960, p. 104).

Even with other scientists supporting components of glacial theory, Agassiz’s 1837 proposal at Neuchâtel was still radical. Many in attendance were angry, some because glacial theory rejected the idea that a great biblical flood had moved large boulders, and the meeting almost broke up over the controversy (Weiner, 1985). Although Agassiz later stated in a lecture at Harvard University that when evidence of former glaciations from Great Britain and Scotland were recognized, glacial theory was “immediately adopted by most geologists” (Dexter, 1989, p. 77), the actual history recorded that it took 30–40 yr for this view to become established in North America and Europe (Carozzi, 1984, p. 167).

During the early discussions of glacial theory, opposing viewpoints were documented not only within scientific societies, but humorously within period scientific caricatures that encapsulated early theoretical debates (Rudwick, 1992; Clary and Wandersee, 2010b). Sopwith drew a caricature of Reverend William Buckland (1784–1856), The costume of the glaciers, in which Buckland stands on top of glacial striations, some scratched 33,333 years before creation, and some scratched by a cart wheel the day before yesterday (Fig. 1). Henry De la Beche (1786–1855) likewise constructed a scientific caricature, but noted in dismay that the simian figures in the tropical foreground (presumably Agassiz, Charles Lyell, and Buckland) accepted the eccentricities of Sol as glaciers calved in the background (Clary and Wandersee, 2014b; Fig. 2).

Many scientists initially opposed glacial theory, including William Buckland, first reader in geology at Oxford University. In an 1838 letter to Agassiz, Mrs. Buckland wrote that although they toured Oberland and viewed glaciers, “Dr. Buckland is as far as ever from agreeing with you” (Gordon, 1894, p. 141). However, after Agassiz presented his hypotheses at the British Association in Glasgow in 1840, Buckland soon converted to glacial theory (Oldroyd, 1999). Additional glacial evidence in Britain was identified, and Buckland traveled with Agassiz to Scotland to view evidence of former glaciations there. With these additional data, Buckland changed his opinion, and, according to his daughter, “become an enthusiastic convert, and was not satisfied till he had made other leading geologists recognise the importance of the discovery” including Charles Lyell (1797–1875) (Gordon, 1894, p. 141).

Buckland described in detail how he found evidence of glacial polish, scours, and erratics in Scotland and Wales, and was so successful an advocate of glacial theory that Professor Thomas Bonney (1833–1923) noted that it was Buckland’s influence that led to recognition of former glaciations within the region (Gordon, 1894, p. 143). Buckland exhibited a scientific habit of mind in that he was able to change his position when additional data and experimentation forced revision of his hypotheses and opinions (Clary and Wandersee, 2014b); his scientific demeanor also extended beyond Agassiz’s glacial theory proposal (Clary and Wandersee, 2011). Many of Buckland’s colleagues were not as flexible, however, and the Geological Society of London hosted many debates concerning past ice ages (Woodward, 1907). However, with eventual acceptance, the scientific community recognized glacial theory, and it is included in most modern geology textbooks (Clary and Wandersee, 2014b). Even within this simplified overview, Agassiz’s glacial theory proposal and debate overtly address seven of the eight basic understandings of science included in the NOS matrix: scientific investigations include a variety of methods, scientific knowledge is based upon empirical evidence, scientific knowledge is open to revision in light of new evidence, scientific theories explain natural phenomena, science is a way of knowing, science is a human endeavor, and science addresses questions about the natural and material world (U.S. National Research Council, 2012; Clary 2017b).

The history of Agassiz’s glacial theory proposal and reception does not completely parallel the modern climate change debates. Agassiz’s proposal was scientifically contested, while the current climate change discussions are more politically, not scientifically, controversial. Agassiz also argued for a former glaciation and lacked a mechanism to explain the previous ice age, although our modern discussions focus upon current and future climate changes and the public questions whether anthropogenic sources are responsible. However, the history of Agassiz’s climate change illustrates that historical debates over climate change have occurred, and that the initial proposal, further investigations, and ultimate resolution demonstrate basic understandings of science addressed within the NOS matrix (U.S. National Research Council, 2012). Therefore, the history of Agassiz’s glacial theory was integrated within a six unit (six weeks in duration) climate discussion in an online course. The research population involved students registered in an Earth history course in the fall 2015 semester (n = 24). Most students were in-service teachers who were enrolled in an online Master of Science geosciences program that is administered by a research university in the southern U.S. All courses within the program are administered entirely online, with the exception of a culminating field course.

The students in the course were randomly assigned to two discussion groups. Discussion materials for each unit (12) were available at least 2 weeks before the students’ discussion contributions were scored, and 12 discussion units contributed 10% of the final course grade. Students received guidelines for their discussion board participation early within the semester, which valued quality over the number of posts. Their contributions were scored with a modified check-plus-minus system (Bean, 2011; Clary, 2017a), where a plus (4.0, A) reflected excellent contributions, a check (2.0) represented average contributions, and a minus (1.0) represented below-average discussion posts. The instructor posted two prompts for each discussion unit, with students contributing initial responses and responding to their colleagues asynchronously. While participation in the discussion board could continue past a unit deadline, the deadline marked the point at which students’ contributions were scored for the unit.

Our earlier research demonstrated that extended, semester-long (12 units, each 1 week in duration) discussions on various facets of climate change resulted in significant gains in online students’ climate literacy within an online Master’s level Earth history course (Clary and Wandersee, 2012a). Because some students criticized the lack of variety within our discussion forum, four topics (each three weeks in duration) were included within online class discussions in 2011. However, the three-unit discussions revealed persistent nonscientific opinions among students, as well as less enthusiasm about the process when compared with the earlier semester-long climate change discussion (Clary and Wandersee, 2012b, 2014a). In 2012, we incorporated two six unit (six weeks duration) discussions on climate change and biodiversity. We observed that while the six unit discussion on climate change resulted in similar, significant gains to semester-long (12 unit) discussions in climate literacy content, students exhibited transferability issues with climate change content to other course areas, as evidenced by their application (or lack thereof) of their discussion content to other aspects of Earth history content on their final examination (Clary and Wandersee, 2014a).

In fall 2015, the Master’s level online Earth history course again implemented two six-unit discussions on climate change and biodiversity. Within the sequential six-unit climate change discussions, one unit focused upon Agassiz’s earlier proposal of glacial theory and how this episode might parallel modern climate discussions. (The historical episode of Agassiz’s glacial theory was examined for two weeks total.) Before students began the climate change discussions, they were required to access the Climate Change Survey (Clary and Wandersee, 2012a, 2014a), which probed their information sources and incoming knowledge of the IPCC reports and scientific methodology. The Climate Change Survey consists of 17 objective items, and 2 open response items. The survey has been validated through pilot study, expert review, and multiple iterations, and is readily available for educational use (Clary and Wandersee, 2012a, 2014a). After students completed the self-assessment survey (n = 24), their first unit task was to reflect upon their personal opinions on climate change, and how students addressed climate change discussions in their own classrooms, as follows.

Journal Prompt: (Please take the Climate Change Survey before reflecting in your journal.) One of the current news topics that seems divisive across political and religious groups is “climate change.” For the remainder of the semester, we will investigate this topic, against the backdrop of Earth’s history. While the majority of scientists have one position on climate change, very strong opinions exist among individuals.

• * What are your personal thoughts on climate change?

• * How do you moderate discussions in your classroom between students who have very strong opinions on the topic?

For each of the next four discussion units, students were provided multiple resources to investigate (e.g., website address for IPCC reports, summaries of peer-reviewed research), and two reflective questions to initiate discussions. These four units focused upon (1) the role of CO₂, and local versus global implications; (2) scientific accuracy and the news media; (3) a historical climate change with Agassiz’s 1837 proposal of glacial theory; and (4) CO₂ levels in the Mesozoic and Cenozoic. The final unit required each discussion group to summarize the group’s consensus on climate change, while integrating concepts from the earlier semester discussion on biodiversity.

Within the unit on an earlier episode of climate change in the history of science, students were directed to Montgomery’s (2010) Web-based resources, and asked to focus upon Agassiz’s Scottish tour, the Geological Society of London’s glacial debates, the further debates in print, final outcomes of glacial theory debates, and twentieth century updates. The reflective questions to which students responded asked for modern comparisons between the history of science, and modern climate change discussions:

• How did scientists react to Louis Agassiz’s proposal that the Earth had been more extensively glaciated in the past? Was the scientific community in immediate agreement and consensus?

• How can the historical account of Agassiz’s glacial theory inform the modern discussion of climate change? What factors influenced scientific consensus on this issue? Are these same factors important today?

Students fully discussed Agassiz and the earlier climate change episode for two weeks. The discussion contributions were coded and analyzed with Neuendorf’s (2002) content analysis guidelines. At the conclusion of the climate change discussions, students again accessed the Climate Change Survey as a self-assessment as to whether their knowledge, information sources, and understanding had changed (n = 21). Students also had an opportunity to offer anonymous feedback at the end of the semester; their responses (n = 22) were coded and analyzed.

When students (n = 21) reflected upon the historical climate change unit within the concluding Climate Change Survey, ∼76.19% of the students (n = 16) thought that Agassiz’s glacial theory proposal, debate, and eventual acceptance paralleled the modern debates on climate change. The vast majority (95.2%, n = 20) also felt that historical controversies such as glacial theory can illustrate the nature of science, and how science progresses.

Student posts within their discussion groups were coded and analyzed (Neuendorf, 2002). When students asynchronously reflected and posted about the reaction of Agassiz’s contemporaries to his glacial theory proposal, they noted that new theories were met with controversy and scientists were cautious to accept new proposals. One student (Group 1) stated, “Scientists are hesitant to change their views until significant studies and research are accomplished.” Other students (Group 2) posted similar observations, including, “Experts in the field have spent years of study and research developing particular theories, and they are not going to easily modify or replace them.”

As the online conversation progressed, students questioned the cultural and social influences of Agassiz’s proposal. One student (Group 1) pondered whether Agassiz’s proposal would have been received differently in another place or time. Student responses and additional discussion affirmed cultural importance and referenced biblical narratives. One student also noted that glacial motion was highly controversial in the 1840s (Group 1).

Group 1 students questioned whether scientific specialization led to difficulties in assimilating a big picture understanding. One student suggested that scientists such as A. Wegener and Agassiz may have been able to step back from the individual data and see the whole picture. Students in Group 2 focused on whether scientists should serve as gatekeepers for new proposals. They discussed Buckland’s and Lyell’s withdrawal of glacier theory papers for publication since they felt the “community… was unaccepting of them.” Three students (Group 2) proposed that free exchange of ideas was conducive to scientific research and discovery, and scientists should not be hindered or afraid to publish data, even if those data did not support the original intent of the research.

In both discussion groups, students affirmed science as a process. Both groups quoted physicist James Forbes in his 1842 review of glacial theory (Forbes, 1842, p. 105), specifically, “If they pronounce the theory imperfect, we acknowledge it; but we may very safely challenge them to produce a better or less improbable one, from amongst those already proposed. If they have a new one, we are ready to consider it.” One student (Group 1) claimed, “He was explaining the way the scientific process should work!”

Toward the end of the online discussion, students in both groups posted that this was how science should work. From Group 1: “Scientific discovery is a never ending process. We continue to refine, modify, change, alter, and expand what we believe and what we know over time as more evidence and new ideas are brought forth.” Another student (Group 1) noted that scientists “…should be skeptical of new evidence, especially if it’s coming from only one or two people.” Another (Group 2) stated that it took “…decades for geologists of the day to parse out their observations. … perhaps that is what it takes for a theory to hold its place in science.” Yet another student (Group 2) noted that sometimes false reports produced detrimental results (e.g., vaccinations and autism), but the benefit was that controversy “spurred further research.”

When comparing Agassiz’s glacial theory proposal to modern climate change discussions, students in both groups stated that modern communication is far quicker, and that sharing of data today is instantaneous. Whereas this has benefits (“…scientists have the greatest resources available in regards to communication and information…”; Group 1), students also debated whether that access clouds our perceptions with the internet as a double-edged sword (Group 2). (“I wonder if we are actually more bias [sic] today since we feel we already have everything we need at our fingertips…”; Group 1.)

Students acknowledged that parallels existed between our modern discussions, and Agassiz’s historical proposal; specifically, the same factors that influence consensus are still relevant today. Both groups noted Agassiz dealt with a religious agenda, while modern scientists face a political and economic one. (“We changed ‘global warming’ to ‘global climate change’ in a move that was strictly ‘public relations…’; Group 2.) Students stated that a mountain of data backs anthropogenic climate change (Group 1), and with additional research and increased knowledge, there will be greater acceptance within scientific communities (as in Agassiz’s time) and modern public audiences. One student observed that Agassiz could work with geologic data, but modern scientists must take current data and do not have the benefit of looking back in time (Group 1) and scientists today deal with evidence that seems less tangible (Group 2). Group 2 also questioned whether older adults and/or scientists are more prone to be stuck in a mindset and not as accepting of new ideas.

Both groups concluded discussions with the affirmation that science prevails over competing interests (Group 2). A student also stated that Agassiz’s reception should “serve as a warning for us to follow the data and continue to seek out truth instead of trying to find middle ground. Science is not about finding a middle ground…” (Group 1).

Within the discussion groups, students addressed many of the basic understandings of science in the NOS matrix (U.S. National Research Council, 2012), including that science (1) uses multiple methods; (2) is revised with new evidence; (3) is a way of knowing; (4) is a human endeavor; (5) addresses the natural world; (6) with its knowledge arising from empirical evidence; and (7) with its theories explaining natural phenomena.

Through coding and analysis of anonymous student responses within the end-of-semester surveys (n = 22), three stable themes emerged: (1) the history of science is beneficial in science classrooms because it provides context for the development of scientific theories; (2) the history of science facilitates broader understanding of the nature of science, including the process of science; and (3) the history of science episodes can directly relate to modern controversial topics, and reassure students that modern topics will also achieve scientific consensus.

Many students confirmed previous research findings that the history of science engages students. One student responded that “…science…becomes more interesting. Not just a bunch of facts.” However, the history of science was not simply viewed as entertainment in the classroom. Students endorsed that “…stories of how our understanding took shape are an important part of learning the science itself.” In particular, the Agassiz history was beneficial in climate change discussions and helped students to start looking at the pieces of evidence for climate. Another student remarked that “…showing the nature of science ‘at work’ in a real context makes relevant all the scientific processes utilized today.”

Another stable theme to emerge was that the historical glacial theory debates were effective at incorporating nature of science instruction. One student affirmed, “It is not only important to teach the content of science, but the nature of science as well.” Another student stated that the Agassiz episode “…gave me insight into the struggles that science has had to overcome over the years.” Students recognized that it was important to question hypotheses in science, but the goal was to uncover facts; a student remarked, “Everything is questioned and it is okay to question things… Science is not about insulting others, it is about seeking answers.” Yet another student noted that “…the common consensus isn’t always correct.”

A strong element in this theme was student recognition of the importance of scientific process. Students stated that the history of science was able “…to show the dynamic and changing nature of science unlike other academic subjects…” and that “…science is a never ending process and we can all make new discoveries.” Similarly, others noted that “…science is fluid and some issues aren’t always cut and dry…” and “…explanations can change with new information.”

The third theme to emerge was the similarities between an historical episode debating climate change and modern issues. A student remarked, “Nothing is new. The main argument just changes over time.” With regard to modern climate change discussions, Agassiz’s glacial theory brought to the “…forefront that the climate change has been a controversial topic for a long time…” and the “…whole process of climate debate has already played out and [has] similarity with today’s debate.”

Students reflected that in addition to the specific topic of climate change, the methods by which historical controversies evolved were analogous to our modern debates. One student remarked, “Science has always been complex and similar issues continue to exist today.” Another student noted, “Science is a very criticized field. It doesn’t matter what you present how much facts and data [sic] you have someone somewhere will try to disprove you and tune you out… This seems to be a repeating pattern. We’ve seen it in Science before and we will see it again.” Students emphasized the intricacy of scientific debates, and remarked “…in hindsight we can see how opinions and positions evolved…” Another student noted “…how complex it is to change a large population’s beliefs.” The complexity of the issue within the public arena and the eventual acceptance of the scientific theory was reassuring, however; one student stated “It gives me hope that one day there will be a global consensus on climate change.”

Although students recognized the benefits of an earlier episode of climate change, paired t-tests revealed no significant difference between the students’ (n = 21) pre– and post–Climate Change Survey scores (p = 0.05), although the trend was toward increased scores. This finding differed from our earlier research that documented gains with climate change incorporation (Clary and Wandersee, 2012a, 2014a). However, the 2015 students (n = 24) exhibited significantly greater incoming content knowledge than earlier 2010 students (n = 79) (p = 0.05, t = −3.001).

By the end of the six-unit discussion, the 2015 population also demonstrated greater proficiency in greenhouse gas identification (66.7% correct identification, compared with earlier 50.6% in 2010, and 22.8% in 2012). Misconceptions still existed about the causes behind observed CO₂ increases, and only 19% of the 2015 population recognized that NO_x increases result from agricultural practices. It is encouraging that >90% of students reaffirmed scientific methodology, namely that with additional data and scientific analyses, conclusions are validated or refined to correct prior claims.

Geoscientists acknowledge that our planet has undergone numerous climatic and sea-level fluctuations in its geologic history, and glaciers once extended far beyond their current positions. We recognize previous warming episodes, as well as former ice ages. However, Louis Agassiz’s proposal of glacial theory was initially met with skepticism and challenging debates.

While some scientists such as William Buckland became convinced of the theory’s validity, many resisted the theory’s acceptance until more evidence was reported. The scientific consensus on glacial theory would not come until many of the original opponents were no longer participating in the discussion.

Although Agassiz’s glacial theory debate occurred 175 years ago, it can still illustrate the nature of science and provide context for modern public discussions that focus upon controversial scientific topics. Historical episodes document how politics and religion influence public perception of science, and how skepticism can grow in spite of additional evidence; in the end, science prevails (Sherwood, 2011). Through the Climate Change Survey (n = 21), historical Agassiz climate discussion, and anonymous end-of-semester surveys (n = 22), students (n = 24) within the online Earth history course affirmed that the history of Agassiz’s glacial theory provided context for theory development, facilitated broader understanding of the nature of science, and related to our modern discussions on climate change. Students reflected that Agassiz’s glacial theory is an “…excellent example of the [sic] scientific method and what is required to have the approval of the scientific community.” Within the modern discussions on climate change, the historical episode was “…helpful to remind ourselves and others that climate change isn’t a new thing for the Earth. It kind of refocused our discussion for current climate change.” Another student acknowledged that the history can “…give reference to current debates on climate change and help make us pause.”

In contrast to earlier research, these students did not demonstrate increased climate change literacy after the six-unit online discussion forum. These results may be reflective of greater public awareness of the climate change issue since the incoming Climate Change Survey revealed that 2015 students had significantly greater incoming content knowledge than their peers in previous years. Therefore, more research is needed to determine whether the historical episode of climate change can promote greater climate literacy. While the content analysis results indicate that students enjoyed the historical controversy, considered the history of science important for understanding the nature of science, and proposed that historical episodes have value within their own K–12 classrooms, there is no indication from this research that the history of glacial theory can serve as a portal to increase climate change content knowledge for improved climate literacy.

Still, students affirmed the benefits of the history of Agassiz’s glacial theory in climate discussions, noting it was “…helpful to see his [Agassiz’s] struggle and how eventually scientists came around to the idea he was proposing. Science takes time some time [sic].” The historical introduction was positively received, and a productive experience “…to see how they handled climate change discussions in the past.” As succinctly stated by one student, “The past can assist with modern discussions.” Whether this past history can improve climate literacy has yet to be determined.

I thank Glenn Dolphin, Tamaratt Teaching Professor, University of Calgary, for comments that improved the manuscript.