The role of climate change education on individual lifetime carbon emissions

Education scenario we assume that a) each student reduces their carbon emissions by 2.86 tons of CO2, similar to the COMM 168 course and b) the adoption of this type of education grows from less than 1% of all secondary students today to 16% of all secondary students by 2050 (note: the number of secondary students is restricted to only high income and upper- middle income countries where residents have higher carbon emissions). The results of this comparison show that education, if designed appropriately, can poten- tially be as effective as other established climate change mitigation techniques. Based on the scenario we developed, the implementation of climate change education over a 30-year period (2020–2050) could reduce emissions by 18.8 GT of CO2 eq, an amount that would rank in the top quarter (15 out of 80) of the presented solutions in Project Drawdown. Although at scale, the use of education as a climate change mitigation technique is still untested, our analysis sug- gests that if the educational approach is sound, and if we take the effort to measure the impact of education, we may realize the potential to reduce carbon emissions using education. We also acknowledge that although barriers to developing a successful large-scale climate change Fig 6. Comparison of various existing technologies that can be applied over a 30-year period (2020–2050) to help reduce global carbon emissions. The potential role of climate change education programs is calculated using the per student carbon reductions estimated from the COMM 168 course.

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education program exist, significant social and political challenges exist with most large-scale solutions to climate change. 7. Uncertainties and study limitations In the following section, we describe a number of uncertainties and study limitations that are important to the interpretation of the results. Although we believe the COMM 168 course provides unique insight into the long-term role that education can have on individual behav- iors, especially given the lack of existing studies that look at how education can shape behavior over many years, we also acknowledge the potential limits of such a research design, and thus we are careful here to identify uncertainties and describe limitations in the study. The exposure of such uncertainties and limitations provides the research with a context for interpreting the results and also provides an avenue for researchers to undertake additional studies to investi- gate the impact that education can have on long-term behavior change. 7.1. Uncertainties The study methodology and analysis include a number of assumptions that contribute to the uncertainties associated with this study, and these are discussed below. Student enrollment. Because the course is titled “Global Climate Change,” students inter- ested in environmental issues may have self-selected into the course. These students may respond more favorably to the course design, and may be more willing to change their behav- ior in the future given their initial interest in the environment. Although the impact of incen-

tives on bias is not clearly understood [52], the year-long course included a 3-unit incentive where a passing grade in the 9-unit course provided students with an additional 3 units of general education credit. We heard that many students reported that they signed up for the course because of the extra requirements satisfied. Further, we note that when this incentive was removed from the course design in 2014, the initial broad distribution of majors who enrolled in the class declined quite dramatically. In the earlier years with the 3-unit incentive (2007–2013), four colleges (i.e, Social Sciences, Humanities and the Arts, Business, and Health and Human Sciences) each had at least 10% of the registered students. However, once the 3-unit incentive was removed in 2014, only two colleges (i.e., Social Sciences, Humanities and the Arts) had significant enrollment (i.e., more than 10% of students), with the course now having more enrollment from Environmental Studies and Communication Studies. The 3-unit incentive thus appears to have been effective in drawing students from across campus, and this suggests that the course topic was not the only reason students enrolled in the course. Energy calculations. The household carbon footprint calculator was used to estimate how student responses would impact carbon emissions. Although the calculator has been used in a number of studies, various assumptions were made as described in Table 1 of S2 Text. It is clear that some of the carbon reductions attributed to the course experience may have inherent

uncertainties. For example, actions such as carpooling regularly, making food choices to reduce emissions and buying energy-star appliances all suggest actions to reduce emissions, and yet the actual reduction amount depends on specifics of the action that are difficult to obtain without a more detailed survey tool. In contrast, the goal of this analysis was to docu- ment actions attributable to the course and develop a practical methodology for estimating the carbon reductions using the best tools available. Behavior changes. Another uncertainty that this research only partially uncovered was the motivation for the reported changes. Did participants make lifestyle changes because of environmental concerns or for other reasons, such as financial considerations or ethical con- cerns? In our focus group, participants reported that pro-environmental outcomes were the The role of climate change education on individual lifetime carbon emissions PLOS ONE | https://doi.org/10.1371/journal.pone.0206266 February 4, 2020 17 / 23

primary reason for their choices, but we do not know if this was also the case with all students. Further, without a more detailed survey, it is difficult to understand whether other factors (e.g., social circumstances) also contributed to these changes. This is one reason we chose to use the California per capita emission reduction as a control group, so that pro-environmental trends seen throughout California could be accounted for. Other considerations. We also acknowledge a number of other uncertainties in the design of this study. Participants were surveyed at least five years after taking the course, and we recognize the limits of human memory may skew some of their responses. There may be students who incorrectly remember aspects of the course, and this may have influenced some of our conclusions. This is in part why we chose to do a focus group to more accurately investi- gate aspects of the course that may have been important. 7.2. Study limitations One limitation in this study is the lack of a control group or a pre-survey. We acknowledge that without such accompanying data, determining the precise relationship between students’ participation in the course and their current attitudes and behaviors is difficult. We did attempt to control for how pro-environmental behaviors in California have become more common over the last decade, but we do not have any data that measured student attitudes or behavior before taking the class. Although further studies should consider the various ways to

measure changes in participant attitudes and behaviors, measuring such changes over many years remains a challenge. Another limitation in the study is the potential for selection bias. Although we attempted to determine whether students self-selected into the course based on their environmental lean- ings or the 3-unit incentive, we do not have independent data to quantify the role that selection bias had on student enrollment. If students did select this course because of their initial interest in environmental stewardship, this could bias the outcomes of the study. Another concern is related to biases in participant responses to survey and focus group questions. We acknowledge that a socially-agreeable response bias with regard to behaviors being attributed to the course may exist in the participant responses to surveys and focus group questions. Although we took measures in our survey design and focus group protocol to reduce such biases, it cannot be ruled out that such self-reporting response biases may be pres- ent and could influence the reliability of the results. Finally, we recognize that among the uncertainties identified in section 7.1, none of them have been adequately quantified. Although some of these uncertainties, such as the reliability of the carbon footprint calculator and the related carbon emissions, probably would not influ- ence the primary outcomes of the study, other uncertainties such as initial attitudes of partici- pating students may have a larger influence on the study results.

As we have generally described, establishing linkages between an educational campaign and long-term behavior can be challenging. Other studies that attempt to establish causal links between education and environmental quality also faced similar challenges (e.g., [5]), and yet the insights gained from such work provide a strong motivation for environmental education and this type of research [7]; [53]. Our work is similar. Despite the limitations we have identi- fied, our analysis provides important insights into understanding the role that well-designed climate change education can play on long-term attitudes and behavior. 8. Conclusions The potential role of education on individual carbon emissions was studied using data from stu- dents who completed an intensive university course on climate change. Students were surveyed The role of climate change education on individual lifetime carbon emissions PLOS ONE | https://doi.org/10.1371/journal.pone.0206266 February 4, 2020 18 / 23

at least five years after having taken the course, and their responses were used to provide both qualitative and quantitative measures of the impact of the course on their attitudes and behavior regarding solutions to climate change. The university course was designed to be impactful, including various elements from the environmental education literature to engage students around personal and social activism. In open-ended feedback and the focus group interviews, students recounted how the course has changed their lives, both personally and professionally. Examples of personal changes included the type of car they drive and the type of food they eat. Examples of professional changes included how they create environmental benefits through their job. The results from the survey data also suggest that the course was impactful, even many years later. Student behavior related to waste decisions, home energy decisions, transpor- tation and food choices all showed significant behavior change that was attributed to the COMM 168 course, and these changes were quantified using a reputable online carbon emis- sions calculator. The estimated reductions in carbon emissions attributed to the COMM 168 graduates are 3.54 tons/year, compared with the carbon emissions for an average California res- ident of 25.1 tons/year. It was found that the participants who had personally experienced the effects of global warming, or felt that global warming will harm them personally, had the largest reductions in carbon emissions. Although a number of studies have established links between

The potential to use education as a climate change mitigation measure would be valuable and in line with other mitigation measures if such reductions as achieved in the COMM 168 course could be achieved in other classrooms. We illustrate this through comparisons with other climate change solutions, and show that at scale, climate change education can be as effective in reducing carbon emissions as other solutions such as rooftop solar or electric vehi- cles. The notion that education is an important part of responding to climate change is not novel (e.g., [29]; [58]), and yet rarely has it been quantified and measured [53]. This paper sheds light on how such measurements could be taken, and it offers a pedagogical insight for how to make education an effective climate change mitigation strategy. At present, the authors are using similar design approaches to develop a comprehensive sci- ence curriculum focused around environmental stewardship and climate action (e.g., [59]; [60]) for middle schools. The Next Generation Science Standards now emphasize applying integrative science fields to solving real-world problems, and this serves as an ideal platform for applying the type of educational platform developed in COMM 168 towards a broader science curriculum for schools. The middle school science curriculum [61] is currently being The role of climate change education on individual lifetime carbon emissions PLOS ONE | https://doi.org/10.1371/journal.pone.0206266 February 4, 2020 19 / 23

used in a number of school districts in California, and studies examining changes in student attitudes and behavior will be reported in the future. Supporting information S1 Text. Survey instrument used for the graduates of the COMM 168 course. (DOCX) S2 Text. Procedure for estimating reductions in carbon emissions from the survey responses. (DOCX) S3 Text. Focus group protocol. (DOCX) S4 Text. COMM 168 syllabus. (PDF) Acknowledgments We are grateful to the students involved in this study for their time and participation, and Dr. Elizabeth Walsh for her helpful suggestions on our data analysis. We also thank Liz Palfreyman for her help in gathering some of the student demographic data. Author Contributions Conceptualization: Eugene C. Cordero, Anne Marie Todd. Formal analysis: Diana Centeno. Funding acquisition: Eugene C. Cordero. Investigation: Eugene C. Cordero. Methodology: Eugene C. Cordero, Anne Marie Todd. Project administration: Eugene C. Cordero. Supervision: Eugene C. Cordero. Writing – original draft: Eugene C. Cordero. Writing – review & editing: Diana Centeno, Anne Marie Todd. References 1. United Nations. United Nations Framework Convention on Climate Change. New York: United Nations, General Assembly; 1992. 2. Læssøe J, Mochizuki Y. Recent trends in national policy on education for sustainable development and climate change education. J Educ Sustain Dev. 2015; 9: 27–43. 3. United Nations Educational, Scientific and Cultural Organization (UNESCO). UNESCO strategy for the

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