- Participant recruitment and retention;
- Data collection;
- Data quality.
2. Methods and Analysis
2.1. Study Design
2.2. Study Status
2.4. Recruitment Strategy
2.6. Social Identity Model of Pro-Environmental Action as Tentative Programme Theory
2.7. Allocation of School Classes to Intervention or Control Group
2.8. Allocation Concealment and Blinding
2.9.1. Process Measures
- Participant recruitment and retention:
- Proportion of students in participating classes completing the baseline survey;
- Proportion of students in participating classes completing the follow-up survey;
- Proportion of students in participating classes completing both baseline and follow-up surveys.
- Data collection:
- Proportions of students participating in the online and paper–pencil surveys;
- Problems during data collection.
- Data quality:
- Proportion of missing data for outcome and sociodemographic measures;
- Basic psychometric properties of scales used to assess programme effectiveness (Table 1) including scale distributions, floor and ceiling effects and internal consistency.
2.9.2. Outcome Measures
2.9.3. Sociodemographic Measures
2.10. Data Collection
2.11. Sample Size Considerations
2.13. Reporting, Ethics and Study Registration
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
- Solomon, C.G.; LaRocque, R.C. Climate change—A health emergency. N. Engl. J. Med. 2019, 380, 209–211. [Google Scholar] [CrossRef] [PubMed]
- Woodward, A.; Smith, K.R.; Campbell-Lendrum, D.; Chadee, D.D.; Honda, Y.; Liu, Q.; Olwoch, J.; Revich, B.; Sauerborn, R.; Chafe, Z. Climate change and health: On the latest IPCC report. Lancet 2014, 383, 1185–1189. [Google Scholar] [CrossRef]
- Hathaway, J.; Maibach, E.W. Health implications of climate change: A review of the literature about the perception of the public and health professionals. Curr. Environ. Health Rep. 2018, 5, 197–204. [Google Scholar] [CrossRef]
- Clayton, S.; Manning, C.M.; College, M.; Speiser, M.; Hill, A.N. Mental Health and Our Changing Climate: Impacts, Implications, and Guidance; American Psychological Association; EcoAmerica: Washington, DC, USA, 2017. [Google Scholar]
- Costello, A.; Abbas, M.; Allen, A.; Ball, S.; Bell, S.; Bellamy, R.; Friel, S.; Groce, N.; Johnson, A.; Kett, M.; et al. Managing the health effects of climate change. Lancet 2009, 373, 1693–1733. [Google Scholar] [CrossRef]
- IPCC. Summary for policymakers. In Global Warming of 1.5 °C. An IPCC Special Report on the Impacts of Global Warming of 1.5 °C above Pre-Industrial Levels and Related Global Greenhouse Gas Emission Pathways, in the Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty; Masson-Delmotte, V., Zhai, P., Pörtner, H.-O., Roberts, D., Skea, J., Shukla, P.R., Pirani, A., Moufouma-Okia, W., Péan, C., Pidcock, R., et al., Eds.; Cambridge University Press: Cambridge, UK; New York, NY, USA, 2018; pp. 3–24. [Google Scholar]
- IPCC. Summary for policymakers. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change; Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S.L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M.I., et al., Eds.; Cambridge University Press: Cambridge, UK; New York, NY, USA, 2021; pp. 3–32. [Google Scholar]
- McMichael, A.J.; Campbell-Lendrum, D.; Kovats, S.; Edwards, S.; Wilkinson, P.; Wilson, T.; Nicholls, R.; Hales, S.; Tanser, F.; Le Sueur, D.; et al. Global climate change. In Comparative Quantification of Health Risks: Global and Regional Burden of Disease Due to Selected Major Risk Factors; Ezzati, M., Lopez, A.D., Rodgers, A.A., Murray, C.J.L., Eds.; World Health Organization: Geneva, Switzerland, 2004; pp. 1543–1649. [Google Scholar]
- Sanson, A.V.; Van Hoorn, J.; Burke, S.E.L. Responding to the impacts of the climate crisis on children and youth. Child Dev. Perspect. 2019, 13, 201–207. [Google Scholar] [CrossRef]
- Burke, S.E.L.; Sanson, A.V.; Van Hoorn, J. The psychological effects of climate change on children. Curr. Psychiatry Rep. 2018, 20, 35. [Google Scholar] [CrossRef]
- Van Susteren, L.; Al-Delaimy, W.K. Psychological impacts of climate change and recommendations. In Health of People, Health of Planet and Our Responsibility; Al-Delaimy, W.K., Ramanathan, V., Sánchez Sorondo, M., Eds.; Springer: Cham, Switzerland, 2020; pp. 177–192. [Google Scholar]
- Clayton, S. Climate anxiety: Psychological responses to climate change. J. Anxiety Disord. 2020, 74, 102263. [Google Scholar] [CrossRef]
- Hickman, C.; Marks, E.; Pihkala, P.; Clayton, S.; Lewandowski, R.E.; Mayall, E.E.; Wray, B.; Mellor, C.; van Susteren, L. Climate anxiety in children and young people and their beliefs about government responses to climate change: A global survey. Lancet Planet. Health 2021, 5, e863–e873. [Google Scholar] [CrossRef]
- De Moor, J.; Uba, K.; Wahlström, M.; Wennerhag, M.; Vydt, M.D. (Eds.) Protest for a Future II: Composition, Mobilization and Motives of the Participants in Fridays for Future Climate Protests on 20–27 September, 2019, in 19 Cities around the World. 2020. Available online: https://www.diva-portal.org/smash/get/diva2:1397070/FULLTEXT01.pdf (accessed on 1 March 2022).
- Treude, K.D. Environmental Action in Germaringen-Young People Plant Trees for Climate Protection. Allgäuer Ztg. 2021. Available online: https://www.allgaeuer-zeitung.de/allgaeu/kaufbeuren/klimaschutz-im-allgaeu-jugendliche-pflanzen-baeume-in-germaring_arid-343120 (accessed on 1 March 2022).
- Kasser, T. Living both well and sustainably: A review of the literature, with some reflections on future research, interventions and policy. Philos. Trans. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci. 2017, 375, 20160369. [Google Scholar] [CrossRef]
- Grund, J.; Brock, A. Why we should empty Pandora’s box to create a sustainable future: Hope, sustainability and its impli-cations for education. Sustainability 2019, 11, 893. [Google Scholar] [CrossRef]
- Keller, L.; Stötter, J.; Oberrauch, A.; Kuthe, A.; Körfgen, A.; Hüfner, K. Changing climate change education: Exploring moderate constructivist and trans-disciplinary approaches through the research-education co-operation k.i.d.Z.21. GAIA-Ecol. Perspect. Sci. Soc. 2019, 28, 35–43. [Google Scholar] [CrossRef]
- Grund, J.; Brock, A. Education for Sustainable Development in Germany: Not Just Desired but Also Effective for Transformative Action. Sustainability 2020, 12, 2838. [Google Scholar] [CrossRef]
- Holst, J.; Brock, A.; Singer-Brodowski, M.; De Haan, G. Monitoring Progress of Change: Implementation of Education for Sustainable Development (ESD) within Documents of the German Education System. Sustainability 2020, 12, 4306. [Google Scholar] [CrossRef]
- UNESCO. Learn for Our Planet: A Global Review of How Environmental Issues Are Integrated in Education. 2021. Available online: https://unesdoc.unesco.org/ark:/48223/pf0000377362 (accessed on 1 March 2022).
- Boeve-de Pauw, J.; Gericke, N.; Olsson, D.; Berglund, T. The effectiveness of education for sustainable development. Sustainability 2015, 7, 15693–15717. [Google Scholar] [CrossRef]
- Boeve-de Pauw, J.; Van Petegem, P. The effect of flemish eco-schools on student environmental knowledge, attitudes, and affect. Int. J. Sci. Educ. 2011, 33, 1513–1538. [Google Scholar] [CrossRef]
- Boeve-de Pauw, J.; Van Petegem, P. The effect of eco-schools on children’s environmental values and behaviour. J. Biol. Educ. 2013, 47, 96–103. [Google Scholar] [CrossRef]
- Olsson, D.; Gericke, N.; Pauw, J.B.-D.; Berglund, T.; Chang, T. Green schools in Taiwan–Effects on student sustainability consciousness. Glob. Environ. Chang. 2019, 54, 184–194. [Google Scholar] [CrossRef]
- UNESCO. Education for Sustainable Development Goals: Learning Objectives. 2017. Available online: https://www.unesco.de/sites/default/files/2018-08/unesco_education_for_sustainable_development_goals.pdf (accessed on 1 March 2022).
- UNESCO. Education for Sustainable Development: Building a Better, Fairer World for the 21st Century. 2012. Available online: https://unesdoc.unesco.org/ark:/48223/pf0000216673 (accessed on 1 March 2022).
- Skivington, K.; Matthews, L.; Simpson, S.; Craig, P.; Baird, J.; Blazeby, J.; Boyd, K.; Craig, N.; French, D.; McIntosh, E.; et al. A new framework for developing and evaluating complex interventions: Update of Medical Research Council guidance. BMJ 2021, 374, n2061. [Google Scholar] [CrossRef]
- Bundesministerium für Bildung und Forschung. What is Education for Sustainable Development? 2021. Available online: https://www.bne-portal.de/bne/de/einstieg/was-ist-bne/was-ist-bne_node.html;jsessionid=BAF2E8BCBFE90DAF2C33E22B3CEFB6D5.live381 (accessed on 22 December 2021).
- Cardinale, B.J.; Duffy, J.E.; Gonzalez, A.; Hooper, D.U.; Perrings, C.; Venail, P.; Narwani, A.; Mace, G.M.; Tilman, D.; Wardle, D.A.; et al. Biodiversity loss and its impact on humanity. Nature 2012, 486, 59–67. [Google Scholar] [CrossRef]
- Schlosberg, D.; Collins, L.B. From environmental to climate justice: Climate change and the discourse of environmental justice. WIREs Clim. Chang. 2014, 5, 359–374. [Google Scholar] [CrossRef]
- Dietz, S.; Stern, N. On the Timing of Greenhouse Gas Emissions Reductions: A Final Rejoinder to the Symposium on “The Economics of Climate Change: The Stern Review and its Critics”. Rev. Environ. Econ. Policy 2009, 3, 138–140. [Google Scholar] [CrossRef]
- McPhearson, T.; Iwaniec, D.M.; Bai, X. Positive visions for guiding urban transformations toward sustainable futures. Curr. Opin. Environ. Sustain. 2016, 22, 33–40. [Google Scholar] [CrossRef]
- Gabrys, J.; Yusoff, K. Arts, Sciences and Climate Change: Practices and Politics at the Threshold. Sci. Cult. 2012, 21, 1–24. [Google Scholar] [CrossRef]
- Ogilvie, D.; Foster, C.E.; Rothnie, H.; Cavill, N.; Hamilton, V.; Fitzsimons, C.F.; Mutrie, N. Interventions to promote walking: Systematic review. BMJ 2007, 334, 1204. [Google Scholar] [CrossRef] [PubMed]
- Fritsche, I.; Barth, M.; Jugert, P.; Masson, T.; Reese, G. A Social Identity Model of Pro-Environmental Action (SIMPEA). Psychol. Rev. 2018, 125, 245–269. [Google Scholar] [CrossRef] [PubMed]
- Ajzen, I.; Fishbein, M. The influence of attitudes on behavior. In The Handbook of Attitudes; Albarracín, D., Johnson, B.T., Zanna, M.P., Eds.; Erlbaum: Mahwah, NJ, USA, 2005; pp. 173–221. [Google Scholar]
- Klöckner, C.A. A comprehensive model of the psychology of environmental behaviour—A meta-analysis. Glob. Environ. Chang. 2013, 23, 1028–1038. [Google Scholar] [CrossRef]
- Schwartz, S.H.; Howard, J.A. A normative decision-making model of altruism. In Altruism and Helping Behavior; Rushton, J.P., Sorrentino, R.M., Eds.; Erlbaum: Hillsdale, MI, USA, 1981; pp. 89–211. [Google Scholar]
- Wallis, H.; Loy, L.S. What drives pro-environmental activism of young people? A survey study on the Fridays for Future movement. J. Environ. Psychol. 2021, 74, 101581. [Google Scholar] [CrossRef]
- Mackay, C.M.; Schmitt, M.T.; Lutz, A.E.; Mendel, J. Recent developments in the social identity approach to the psychology of climate change. Curr. Opin. Psychol. 2021, 42, 95–101. [Google Scholar] [CrossRef]
- Ojala, M. Hope and climate change: The importance of hope for environmental engagement among young people. Environ. Educ. Res. 2012, 18, 625–642. [Google Scholar] [CrossRef]
- Ojala, M. How do children cope with global climate change? Coping strategies, engagement, and well-being. J. Environ. Psychol. 2012, 32, 225–233. [Google Scholar] [CrossRef]
- Gagné, J.; Krause, L.-K. Unifying or Divisive? Climate Action and Social Cohesion in Germany. 2021. Available online: https://www.moreincommon.de/media/13ip5esl/more_in_common_studie_klima_zusammenhalt.pdf (accessed on 1 March 2022).
- Pihkala, P. Anxiety and the ecological crisis: An analysis of eco-anxiety and climate anxiety. Sustainability 2020, 12, 7836. [Google Scholar]
- Pihkala, P. Eco-Anxiety and Environmental Education. Sustainability 2020, 12, 10149. [Google Scholar] [CrossRef]
- Breyer, B.; Bluemke, M. German Version of the Positive and Negative Affect Schedule PANAS. 2016. Available online: http://zis.gesis.org/DoiId/zis242 (accessed on 22 December 2021).
- Van der Linden, S. The social-psychological determinants of climate change risk perceptions: Towards a comprehensive model. J. Environ. Psychol. 2015, 41, 112–124. [Google Scholar] [CrossRef]
- Wesley Schultz, P. The structure of environmental concern: Concern for self, other people, and the biosphere. J. Environ. Psychol. 2001, 21, 327–339. [Google Scholar] [CrossRef]
- Helm, S.V.; Pollitt, A.; Barnett, M.A.; Curran, M.A.; Craig, Z.R. Differentiating environmental concern in the context of psychological adaption to climate change. Glob. Environ. Chang. 2018, 48, 158–167. [Google Scholar] [CrossRef]
- Ojala, M. Coping with climate change among adolescents: Implications for subjective well-being and environmental engagement. Sustainability 2013, 5, 2191–2209. [Google Scholar] [CrossRef]
- Hamann, K.R.S.; Reese, G. My Influence on the World (of Others): Goal Efficacy Beliefs and Efficacy Affect Predict Private, Public, and Activist Pro-environmental Behavior. J. Soc. Issues 2020, 76, 35–53. [Google Scholar] [CrossRef]
- Gardner, B.G.; Neuber, M. Fighting Every Crisis in the Wake of COVID-19: Shifting Grounds for Mobilization among Fridays for Future Protesters in Germany. 2021. Available online: https://osf.io/rsy92 (accessed on 1 March 2022).
- Van Zomeren, M. Four Core Social-Psychological Motivations to Undertake Collective Action: Four motivations for collective action. Soc. Personal. Psychol. Compass 2013, 7, 378–388. [Google Scholar] [CrossRef]
- van Stekelenburg, J.; Walgrave, S.; Klandermans, B.; Verhulst, J. Contextualizing contestation. Framework, design and data. Mobilization 2012, 17, 249–262. [Google Scholar] [CrossRef]
- Bamberg, S.; Rees, J.; Seebauer, S. Collective climate action: Determinants of participation intention in community-based pro-environmental initiatives. J. Environ. Psychol. 2015, 43, 155–165. [Google Scholar] [CrossRef]
- Hoebel, J.; Müters, S.; Kuntz, B.; Lange, C.; Lampert, T. Measuring subjective social status in health research with the German version of the MacArthur Scale. Bundesgesundheitsblatt 2015, 58, 749–757. [Google Scholar] [CrossRef] [PubMed]
- Eldridge, S.M.; Costelloe, C.E.; Kahan, B.C.; Lancaster, G.A.; Kerry, S.M. How big should the pilot study for my cluster randomised trial be? Stat. Methods Med. Res. 2016, 25, 1039–1056. [Google Scholar] [CrossRef] [PubMed]
- Graham, J.W. Missing Data Analysis: Making It Work in the Real World. Annu. Rev. Psychol. 2009, 60, 549–576. [Google Scholar] [CrossRef]
- Tabachnick, B.G.; Fidell, L.S. Using Multivariate Statistics; Pearson: New York, NY, USA, 2019. [Google Scholar]
- Chan, A.-W.; Tetzlaff, J.M.; Altman, D.G.; Laupacis, A.; Gøtzsche, P.C.; Krleža-Jerić, K.; Hróbjartsson, A.; Mann, H.; Dickersin, K.; Berlin, J.A.; et al. SPIRIT 2013 Statement: Defining Standard Protocol Items for Clinical Trials. Ann. Intern. Med. 2013, 158, 200–207. [Google Scholar] [CrossRef] [PubMed]
- Eldridge, S.M.; Chan, C.L.; Campbell, M.J.; Bond, C.M.; Hopewell, S.; Thabane, L.; Lancaster, G.A. CONSORT 2010 statement: Extension to randomised pilot and feasibility trials. BMJ 2016, 355, i5239. [Google Scholar] [CrossRef] [PubMed]
- Thabane, L.; Lancaster, G. A guide to the reporting of protocols of pilot and feasibility trials. Pilot Feasibility Stud. 2019, 5, 37. [Google Scholar] [CrossRef] [PubMed]
- Autorengruppe Bildungsberichterstattung. Education in Germany 2020—An Indicator-Based Report with an Analysis of Education in a Digitised World; Wbv Publikation: Bielefeld, Germany, 2020. [Google Scholar]
- Neuber, M.; Gardner, B.G. Germany. In Protest for a Future II: Composition, Mobilization and Motives of the Participants in Fridays for Future Climate Protests on 20–27 September, 2019, in 19 Cities around the World; De Moor, J., Uba, K., Wahlström, M., Wennerhag, M., De Vydt, M., Eds.; 2020; Available online: https://www.diva-portal.org/smash/get/diva2:1397070/FULLTEXT01.pdf (accessed on 1 March 2022).
- Neuber, M.; Kocyba, P.; Gardner, B.G. The same, only different: Fridays for Future protesters in European comparison. In Fridays for Future-Youth against Climate Change. Contours of the International Protest Movement; Haunss, S., Sommer, M., Eds.; Transcript Verlag: Bielefeld, Germany, 2020. [Google Scholar]
- Eldridge, S.; Kerry, S. A Practical Guide to Cluster Randomised Trials in Health Services Research; Wiley: Chichester, UK, 2012. [Google Scholar] [CrossRef]
- Ivers, N.M.; Halperin, I.J.; Barnsley, J.; Grimshaw, J.M.; Shah, B.R.; Tu, K.; Upshur, R.; Zwarenstein, M. Allocation techniques for balance at baseline in cluster randomized trials: A methodological review. Trials 2012, 13, 120. [Google Scholar] [CrossRef]
- Bandura, A. Self-Efficacy: The Exercise of Control; W. H. Freeman; Times Books; Henry Holt & Co.: New York, NY, USA, 1997. [Google Scholar]
|Outcomes||Source of Scales and Adaptations||Response Options|
|Intentions to reduce one’s ecological footprint||Adaptation of the pro-environmental behaviour scales of Ojala (2012) [42,43] assessing intentions to reduce one’s ecological footprint during the upcoming seven days (five items).||six-point Likert scale|
|Intentions to enlarge one’s ecological handprint||Adaptation of the pro-environmental behaviour scales of Ojala (2012) [42,43] assessing intentions to enlarge one’s ecological handprint during the upcoming seven days (four items).||six-point Likert scale|
|Pro-environmental behaviours||Adaptation of the pro-environmental behaviour scales of Ojala (2012) [42,43]. Based on Ojala’s (2012)  distinction between everyday behaviour and communication with others we developed two new scales: one targeting ecological footprint reduction behaviours (five items) and the other targeting ecological handprint enlargement behaviours (four items). Behavioural options were selected that were specifically related to climate protection and that may have occurred with a certain probability in the last seven days. These items were supplemented by two statements about protest and political behaviour in the past 12 months.||six-point Likert scale|
|Climate change-related emotions||A list of 19 emotions based on terms for emotional reactions from de Moor et al. (2020) , Gagné and Krause (2021)  and Hickman et al. (2021) as well as from two reviews of Pihkala (2020) [45,46]. Feelings with positive connotations were added to the negative feelings surveyed in most studies of emotional responses toward climate change to mitigate a negative emotional bias.||five-point Likert scale (based on the Positive and Negative Affect Schedule (PANAS) .|
|Climate change-related risk perception||Based on the risk perception instrument by van der Linden (2015)  with the three areas probability, severity, and current extent of the consequences of global warming (two items each) with one personal and one collective reference point each. Items on the extent of concern were excluded to avoid redundancy (see below).||five-point Likert scale|
|Climate change-related concerns||Based on the measure of Schultz (2001)  used by Helm et al. (2018)  with the three dimensions egoistic, altruistic and biospheric concerns. For the egoistic and biospheric dimension, we selected one item each from the original scale, and for the altruistic dimension, we selected two items to distinguish between closer and more distant people.In addition, we survey the tendency to deny the climate crisis with four items based on Ojala’s (2012)  coping scale de-emphasising the seriousness of climate change.||six-point Likert scale|
|Climate change-related efficacy expectation||Following the work of Ojala (2013) , Hamann and Reese (2020) , Gardner and Neuber (2021)  and van Zomeren (2013) , we created one scale each for self-efficacy expectations (four items) and collective efficacy expectations (three items) related to action directed at the climate crisis. Following Hamann and Reese (2020) , we considered both scales to distinguish between private and public efficacy.||six-point Likert scale|
|Climate change-related values and norms||Two scales consisting of four items each to measure altruistic values and biospheric values . A scale to assess perceived environmental norms was developed based on the biospheric values scale (four items) of Ojala (2012) . Classmates were chosen as a reference group for the perceived norms.Three items on (post-)materialistic values  were used to cover the political dimension.||six-point Likert scale|
|Identification with civil engagement groups involved in climate action||We used the scale of Bamberg et al. (2015)  adapted by Wallis and Loy (2021)  to measure in-group identification with civil engagement groups involved in climate action (three items).||six-point Likert scale|
|Climate change-related knowledge||In the absence of previously validated scales, we developed a set of items on self-assessed climate change-related knowledge including environmentally sound products, climate change and possible actions for climate protection (three items).||six-point Likert scale|
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).