The present study combined a conventional methodological approach with an innovative approach to application. While the concept of sustainability evokes opportunities for younger generations, the needs and opinions of youths are not always heard, and issues around sustainability have only recently gained space within educational curricula. Thus, the present study administered a questionnaire to explore how and whether students’ responses changed after taking a course on sustainability. All questionnaire items pertained to topics that were covered in the educational course.
After the post-course phase, the results were presented to and discussed with the students. During this discussion, the students expressed a strong interest in sustainability, whilst emphasising its complexity. They decried rhetoric, common phrases and projects in which sustainability is discussed without practical application. They also understood that, while the sustainability challenge is not simple, it is crucial for the future, particularly in light of European policies. They were ready to support change if they were given the tools and could develop the skills to meet the challenge. While the remainder of this section analyses students’ questionnaire responses in detail, in general, students’ attitudes at the end of the course were more aligned with sustainability, relative to their attitudes at the beginning of the course. Supplementary Appendix B presents all of the questionnaire items, together with the student responses.
The first block of items concerned general sustainability (e.g., the definition of sustainability) and its behavioural aspects (e.g., individual sustainability behaviours). In general, many individuals are unclear about the meaning of sustainability, tending to link it to only the environment37,38,39. Therefore, the course curriculum sought to clarify that sustainability has three dimensions: social, environmental and economic. While the vast majority of the students were clear at the beginning of the course that sustainability encompasses these three spheres, approximately 9% were convinced that it only involved environmental aspects; however, these students changed their opinion after taking the course (see question 9 in Supplementary Appendix A).
The literature shows that pro-environmental attitudes relate to certain character aspects, including altruism40,41. Therefore, students were asked to assess their degree of altruism. Approximately 75% described themselves as more altruistic than selfish (see question 7 in supplementary Appendix A). Additionally, six questionnaire items were designed to measure students’ sustainable behaviours (i.e., volunteering, playing sports, engaging with nature, using sustainable products, recycling, and taking public transportation. See questions 10–16 in supplementary Appendix A). The decision to include these items was based on previous research showing associations between: (i) playing sports and volunteering and greater sustainable behaviour42,43, and (ii) engagement with nature and improved stakeholder engagement44; as well as the use of recycling, using sustainable products and taking public transportation as proxies of pro-environmental attitudes45. An index was created to average student scores on these six items and assess any correlation with character aspects (i.e., altruism). As seen in Fig. 1, a higher degree of altruism corresponded with greater sustainable behaviours.
In more detail, the analysis sought to uncover whether and how the distribution of responses related to individual items changed after the course (all responses were measured using a Likert scale ranging from 1 (never) to 5 (always)) (see Fig. 2).
The only significant change emerged in the use of sustainable products, for which average scores increased from 2.9 to 3.1 over the course period. The main reason offered for the infrequent use of sustainable products was their prohibitive cost. In fact, students perceived these items as ‘luxury goods’ and, generally, such products were only used by students with medium to high incomes. The correlation between income and the use of sustainable products has already been noted in the literature46,47, and there is a risk that, without effective interventions, sustainable products will only be purchased by those in higher income brackets.
Concerning the other sustainable behaviours, the course did not seem to have a significant impact, as the mean values remained virtually unchanged. However, it is important to note that most students claimed to frequently sort their waste (4.5). This is an interesting finding, since it was obtained in Rome, where waste management performance is unsatisfactory. In particular, there is a need in Rome for both on-site facilities for waste disposal and a significant reduction in the amount of waste delivered outside the region48. Finally, the intermediate rating (2.9) recorded for the use of public transportation can be read in several ways: (i) the pandemic may have led many students to reduce their use of very crowded modes of transportation, and (ii) students may have been discouraged from using public transportation due to the poor time reliability.
Because sustainability is relevant to present and future generations, students were asked whether they were, in general, more anchored in the present or projected into the future. The majority (64%) of students tended to look to the future (see question 8 in supplementary Appendix A). Sustainability behaviours do not preclude living in the present, but merely call for a frugal attitude, so that resources can be maintained for future generations.
Economics of sustainable energy
The second block of questionnaire items concerned more specific energy issues discussed in the course. These items assessed students’ willingness to pay (WTP) for green items and their particular behaviours as both producers and consumers (see questions 17–20 in supplementary Appendix A). A scenario was given in which a kWh of energy obtained from renewable sources was sold at 19.1 cent€/kWh, with a green premium of 2.4 cent€/kWh. In a second scenario, a kWh of energy from renewable sources was sold at 20.2 cent€/kWh, with a green premium of 6.6 cent€/kWh. These scenarios were based on the price conditions that existed prior to the war between Russia and Ukraine.
Figure 3 shows how students changed their evaluations of these scenarios between the beginning and the end of the course. In particular, three important findings emerged. First, at the beginning of the course, students assigned, on average, the same price for buying and selling fossil energy (panel A; for fossil energy, the initial and final average values were 15.3 and 13.6 cent€/kWh, respectively, for purchasing; and 16.1 and 16.7 cent€/kWh, respectively, for selling). This signals misinformation related to the price difference between purchased and sold energy. At the end of the course, students evaluated this type of energy as ‘inferior’, recording a lower WTP than both the initially stated WTP and the WTP for renewables (panel B; for renewable energy, the initial and final average values were 19.6 and 20.2 cent€/kWh, respectively, for purchasing; and 18.0 and 19.1 cent€/kWh, respectively, for selling).
Second, there was no significant variation between students’ WTP for renewable energy between the beginning and the end of the course. This implies that students were able to assign the correct value to this type of energy from the beginning. Third, the WTP value of 6.6 cent€/kWh that emerged in the present study is slightly lower than the values of 8 cent€/kWh and 10 cent€/kWh that were previously recorded in Spain and Italy, respectively49. However the study conducted in Spain and Italy considered a reference sample characterised by older individuals. The fact that students mainly lived with their families and did not pay their energy bills themselves likely influenced the present result.
Subsidies for energy
Subsidies are a controversial topic. On the one hand, they are deemed necessary for the green transition, by reducing production costs for sustainable items to a point that they are competitive with those of fossil-based products (without considering externalities). On the other hand, their use must be metred to prevent any increase in public debt or the price paid by the final consumer. Students were asked to express their opinion on a 5-point scale about the importance of subsidies for both renewable and fossil-based energy (see questions 21–24 in supplementary Appendix A). In addition, they were asked to report the extent to which they agreed (on a 5-point scale) that they should produce energy themselves, in the absence of subsidies (see question 40 in supplementary Appendix A). Students indicated that they were generally ‘undecided’ on this latter point, though their indecision fell at the maximum value of the range (3.5). Regarding their evaluation of subsidies, they assigned a high value to subsidies for energy from renewable sources (4.5). For energy from fossil sources, their approval for subsidies for self-consumption changed from ‘sometimes’ to ‘rarely’ (2.7 vs. 2.2); this variable showed the greatest change between the beginning and the end of the course (Fig. 4).
Students were also asked to estimate the appropriate subsidy levels (within a range of 0–6 cent€/kWh and see questions 25–26 in supplementary Appendix A). As can be seen in Fig. 5, any difference in opinion vanished when students assigned these numerical values.
Citizen involvement in the energy transition may require subsidies for energy that is produced and self-consumed. In the present study, this value was quantified as 4.6 cent€/kWh for energy from renewable sources and 1.8 cent€/kWh for energy from fossil sources (decreasing by 0.5 cent€/kWh, consistent with the previous figure). Interestingly, the subsidy for the self-consumption of renewable energy was valued as high from the beginning of the course, signalling students’ sensitivity to the issue of sustainable self-consumption. In a similar vein, the equivalent subsidy for energy from fossil sources was valued as low from the beginning, and it decreased at the end of the course. This implies that students became even more aware that energy from fossil sources should be disincentivised. However, the difference in value associated with the subsidies for the production and self-consumption of green energy versus fossil energy was 2.8 cent€/kWh. The literature reports higher values for subsidies for the self-consumption of renewable energy: 3 cent€/kWh for Spain and 4 cent€/kWh for Italy (of note, in this research, only subsidies for energy from renewable sources were claimed) 49.
The International Energy Agency reports that, globally, subsidies for fossil sources amount to approximately 400 billion USD, and action must be taken to reduce this sum. To support the green transition, the state of the art must be communicated more widely and subsidies must be established. Regarding taxes, the present study found that students favoured them for giving economic weight to externalities. In particular, students felt that penalties should be higher for businesses than for citizens (4.3 vs. 3.9 and see questions 29–30 in supplementary Appendix A). However, they considered both penalties significant, in alignment with the European Commission, which has placed green taxes at the centre of its agenda.
Energy communities, sustainable certifications and sustainable competitive advantage
Students were also asked to express their opinion on the importance of energy communities, certifications and competitive advantages. These variables showed the same and a maximum increase between the beginning and the end of the course (+ 0.4) (see Fig. 6 and see questions 21, 22 and 28 in supplementary Appendix A).
Energy communities, while a fairly new concept, found enthusiastic support from students (i.e., registering an average value of 4 at the beginning and 4.4 at the end of the course). Stakeholder engagement, with shared models showing how the economic benefits are distributed, emerged as an enabling factor50. Regarding sustainable certifications, students had a clear understanding of these and, in fact, assigned them a very high value (i.e., 3.9 at the beginning and 4.3 at the end of the course). However, they noted that a limitation of such certifications is that their cost is typically passed on to the consumer. Certified products were not always linked to a higher WTP, especially for those in lower income brackets. Finally, students deemed the competitive advantage associated with the use of green sources very relevant (i.e., 3.8 at the beginning and 4.2 at the end of the course). The beginning of the war in Ukraine coincided with the course, and classroom reflections emphasised that individuals and companies that had installed renewable energy systems were not only experiencing fewer spillover effects related to inflation, but also seeing increased savings on their energy bills.
While a large proportion of engineering students (42%), who would be expected to support the use of technology, noted that current technologies should be sufficient to meet the sustainability challenge, an equal proportion of students saw an additional change in behaviour as necessary to decarbonize the Italian system (see question 42 in supplementary Appendix A). Accordingly, the students did not favour a policy based totally on electrification. Another highly debated topic was Italy’s strong energy dependence on foreign countries, and particularly Russia (noting that the funds that had previously been invested in foreign energy could have instead been invested in the development of green energy). For that reason, students were asked to assess (on a 5-point scale) the extent to which they considered the use of renewable sources important for mitigating geopolitical risk (see question 27 in supplementary Appendix A). Based on their responses, the students understood that some non-choices of the past had resulted in very large costs in the present. They recognised that short-sighted policies and ‘no’ committees—related to ‘not in my term of office’ (NIMTO) and ‘not in my back yard’ (NIMBY) attitudes—had resulted in significant costs of not doing. Thus, the idea emerged that geopolitical risks could be reduced through the use of renewables (3.9). However, in assessing whether the use of renewables could positively impact the environment (see question 32 in supplementary Appendix A), even though the students agreed that this was likely (4.4), they stressed that care must be taken to avoid an economic rebound effect, emphasizing that the use of green sources could not justify energy waste. At the start of the course, the students were generally ‘undecided’ about this aspect; while at the end of the course, the dominant attitude was ‘strongly disagree’ (2.3 vs. 2.7 and see question 35 in supplementary Appendix A). This value must still be reduced. Approximately 65% of the students considered energy efficiency interventions as relevant as the use of renewables in efforts to achieve climate neutrality (see question 41 in supplementary Appendix A). Furthermore, the students felt that green energy could contribute to changing consumption habits by exploiting economic benefits (3.9, see question 34 in supplementary Appendix A). In addition, approximately 80% of the students believed that society (in general) and value chain actors had the greatest impact on sustainable development (see question 43 in supplementary Appendix A). In contrast, approximately 18% placed the highest responsibility on consumers, while attributing minimal responsibility to the local community and no responsibility to workers.
The most perplexing student response concerned greenwashing. In fact, students were asked whether greenwashing helps sustainable development (see question 39 in supplementary Appendix A). This question was originally included in the questionnaire to mislead students, since, upon first encounter, the term ‘greenwashing’ may suggest something positive to those who are unfamiliar with its true definition. The results showed that students’ attitudes shifted from 2.8 (i.e., ‘undecided’) at the beginning of the course to 2.4 (i.e., ‘strongly disagree’) at the end of the course. There are at least two potential interpretations for this. First, the finding may be interpreted as positive, as the value reduced over the course period and the final summary judgment also changed. However, the second interpretation is that the rating of 2.4 still represents an excessive value, in need of further reflection. Some students may not have wanted to offer their true opinion on an ‘uncomfortable’ topic, and instead provided an ‘uncomfortable’ answer under the conditions of anonymity, despite knowing the real meaning of the term greenwashing. This idea emerged during the discussion of the final results, in which no student offered a plausible explanation or justification of the greenwashing finding. Also noteworthy is the high rate of student absence (approximately 25%) on a weekly basis. However, this impact could not be measured, considering the anonymity with which the questionnaires were completed. In addition, regarding distance learning support, students considered the internet influential for sustainability (3.9, see question 38 in supplementary Appendix A). They also perceived digital development as necessary, elaborating that such development needed to be calibrated to actual need.
The importance of sustainable education received the most support (see question 31 in Supplementary Appendix A), and was the only variable that received a ‘fully agree’ rating (i.e., 4.5 at the beginning and 4.7 at the end of the course) (Fig. 7). This represents a core finding. The students also attributed much importance to the development of new professional figures (4.5, see question 33 in Supplementary Appendix A). In fact, this variable was rated as the second most relevant, alongside waste collection and subsidies for green energy. The students felt that sustainability courses might change production systems and make students more attractive on the job market. Finally, their perception of the relevance of the younger generation to sustainability was unexpected. Specifically, students were asked to report the extent to which they agreed that students are able to develop a sustainable plan (see questions 36–37 in Supplementary Appendix A), and they rated this factor as 3.6 with regards to university students and 2.9 with regards to high school students. This suggests that they lacked confidence in not only their current generation, but also the younger generation. Students elaborated that the course had underlined the complexity of sustainability and, as a result, they doubted that their peers were up to the challenge of realising it. In this regard, students emphasised the importance of sustainable education and the development of sustainability projects. However, they noted that the course they had just completed was an elective, and not mandatory. Also, the younger generation was perceived to have less knowledge about sustainability.