Education is seen as a key instrument for overcoming global challenges and contributing to the sustainable development of society (Ibisch et al. 2018). The United Nations has also recognized the potential of education and emphasizes its relevance with Goal 4 "Quality Education" of the 2030 Agenda for Sustainable Development (UNESCO, 2021). However, the number of schools focussing on sustainability - so-called ECO schools or green schools - is only slowly increasing (Hedefalk et al., 2015).

Principals are important in achieving sustainability goals and are multipliers of sustainable development (Rieckmann, 2018). ESD is a leadership issue: School management has a key role to play in the comprehensive anchoring of ESD (Müller, Lude, & Hancock, 2020). Müller, Lude, and Hancock (2020) emphasize that despite extensive literature on ESD, the role of school leaders has been neglected to date.

Mogaji and Newton (2020) conducted an analysis revealing that school leaders frequently possess a limited comprehension of ESD, typically interpreting it primarily through environmental perspectives (Mogaji & Newton, 2020), and therefore find it difficult to implement ESD in their schools. Accordingly, the authors point out the following research gap: There is a need to investigate what specific knowledge and skills (competencies) school leaders need to implement ESD in their schools (Mogaji & Newton, 2020). The second review on the topic by Laurie, Nonoyama-Tarumi, Mckeown, and Hopkins (2016) also found similar findings. In their review, which consisted of a literature synthesis of studies from 18 countries, they discussed that 1) the implementation of ESD in the school as a whole has a positive effect on teaching, but that teachers need professional support and 2) it requires school management that has an understanding of ESD and competences in the field of sustainability management (Laurie, Nonoyama-Tarumi, Mckeown & Hopkins, 2016). Empirical studies such as the one from Bottery, Wright and James (2012) emphasize the need to rethink the understanding of leadership in educational institutions to integrate ESD. Zala-Mezö, Strauss, and Müller-Kuhn (2020) confirm that schools with distributive leadership strategies experience more effective ESD transformation processes. Leo and Wickenberg (2013), Mogren and Gericke (2019), and Verhelst, Vanhoof, and Van Petegem (2021) emphasize that specific sustainability management skills are crucial for the successful implementation of ESD.

Based on the findings of the two literature reviews (Laurie, Nonoyama-Tarumi, Mckeown & Hopkins, 2016; Mogaji and Newton, 2020) and empirical studies (Bottery, Wright & James, 2012; Leo & Wickenberg, 2013; Müller, Lude, & Hancock, 2020; Verhelst, Vanhoof & Van Petegem, 2021), there is a clear research-gap on the question of what competences school leaders need to be able to implement ESD in schools. In this context, Verhelst, Vanhoof and Van Petegem (2021) emphasizes the urgency of further developing school leadership education. Accordingly, this research project examines the role of school leaders in the implementation of ESD in schools as part of a comprehensive systematic literature review:

RQ: What sustainability-specific competencies do principals need to implement Education for Sustainable Development (ESD) in schools?

The hypothesis is that targeted promotion of knowledge and skills on the topic of ESD among school leaders will lead to improved implementation of ESD in schools. The education of school leaders plays a key role in this.

The systematic literature review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) procedure, whereby individual steps are adapted according to the guidelines for a systematic review in the social sciences (Petticrew & Roberts, 2006). The systematic review is conducted using DistillerSR software (DistillerSR, 2023). The most important steps of the systematic literature review according to Page et al. (2021) and Petticrew and Roberts (2006) are summarised below: 1. Formulation of the research question and definition of the review protocol: The research question was developed based on the PRISMA criteria for systematic literature reviews. Furthermore, the PICo framework (Mogaij & Newton 2020) is used to promote an effective search. 2. Definition of inclusion and exclusion criteria: The criteria set the boundaries for the review and determine which studies are included in the analysis and which are not. 3. Search strategy: Relevant databases (e.g., ERIC, Web of Science) were identified, followed by defining key terms in German and English (e.g., "Schulleitungen", "Education for Sustainable Development"). The strategy involves creating and implementing database-specific searches (e.g., school management AND education for sustainable development OR ESD). 4. Selection of relevant studies: The studies found are selected based on the inclusion and exclusion criteria. The selected articles are read independently by the research team and a selection is made, which is justified based on the inclusion and exclusion criteria. In the event of differences of opinion, a consensus is reached through discussion. 5. Data extraction from the selected studies: The data from the studies are extracted and recorded in the data extraction form which contains important information about the study (e.g. study design, information about the sample, results). 6. Assessment of quality, safety, and bias: The assessment of study quality in a systematic literature review is important to avoid bias and to promote the plausibility and accuracy of conclusions. We suspect that the selected studies are not randomized. For this reason, the Critical Appraisal Skills Programme (CASP) (n.d.) can be used to assess the risk of bias in non-randomized studies. 7. Analysing and interpreting the results: The studies are too heterogeneous to be statistically summarised in a meta-analysis. For this reason, a narrative synthesis of the data is made (Petticrew, & Roberts, 2006). The analysis and interpretation process is supported by the Critical Appraisal Skills Programme (CASP) to promote the accuracy and plausibility of conclusions.

The systematic literature review conducted to identify the competencies school leaders need for effective implementation of ESD reveals a complex landscape. Primary findings indicate that school leaders often possess a limited understanding of ESD, frequently interpreting it primarily through an environmental lens. However, ESD is a comprehensive educational approach that encompasses a wide range of subjects, including sociology, economics, and cultural studies. ESD aims to empower people with the essential knowledge, skills, and attitudes needed to confront global challenges, extending beyond climate change and biodiversity loss to also address critical issues like poverty and inequality. The results show that the narrow perspective of school leaders regarding the scope of ESD hinders its full integration into school curricula. Empirical studies, such as those by Bottery, Wright and James (2012), Zala-Mezö, Strauss, and Müller-Kuhn (2020) and others, highlight the necessity of rethinking leadership in educational settings to incorporate ESD successfully. The results of this study show that distributive leadership which includes teacher leadership is particularly conducive to ESD implementation. Involving teachers and distributing leadership responsibilities, appear to foster more ESD integration. Furthermore, raising awareness and understanding of sustainability topics is important for the implementation of ESD in schools. The results highlight the necessity for school leaders to be well-informed about ESD, pointing to a shortfall in existing leadership training. It underscores the importance of improved educational programs designed to equip school leaders with the competencies to be able to integrate sustainability. This review highlights the importance of school leadership in ESD implementation and identifies a gap in leaders' understanding and skills. It suggests distributive leadership for better ESD integration and stresses the need for reform in leadership education to include sustainability. Promoting ESD knowledge among leaders is essential for effective implementation, aligning with the SDGs of the United Nations' 2030 Agenda.

- Bottery, M., Wright, N., & James, S. (2012). Personality, moral purpose, and the leadership of an education for sustainable development. Education 3-13, 40(3), 227-241. - Critical Appraisal Skills Programme. (n.d.). CASP Checklisten. Verfügbar unter https://casp-uk.net/casp-tools-checklists/ - DistillerSR. (n.d). DistillerSR [Computer-Software]. Evidence Partners. Verfügbar unter https://www.evidencepartners.com/products/distillersr-systematic-review-software/ - Hedefalk, M., Almqvist, J., & Östman, L. (2015). Education for sustainable development in early childhood education: A review of the research literature. Environmental Education Research, 21(7), 975-990. - Ibisch, P. L., Molitor, H., Conrad, A., Walk, H., Mihotovic, V., & Geyer, J. (2018). Der Mensch im globalen Ökosystem. Eine Einführung in die nachhaltige Entwicklung. München: Oekom Verlag. - Laurie, R., Nonoyama-Tarumi, Y., Mckeown, R., & Hopkins, C. (2016). Contributions of education for sustainable development (ESD) to quality education: A synthesis of research. Journal of Education for Sustainable development, 10(2), 226-242. - Leo, U., & Wickenberg, P. (2013). Professional norms in school leadership: Change efforts in implementation of education for sustainable development. Journal of Educational Change, 14, 403-422. - Mogaji, I. M. & Newton, P. (2020). School leadership for sustainable development: A scoping review. Journal of Sustainable Development, 13(5), 15-30. - Mogren, A., & Gericke, N. (2019). School leaders’ experiences of implementing education for sustainable development: Anchoring the transformative perspective. Sustainability, 11, 1-21. https://doi.org/10.3390/su11123343 - Müller, U., Lude, A., & Hancock, D. R. (2020). Leading schools towards sustainability. Fields of action and management strategies for principals. Sustainability, 12(7), 3031. - Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., et al. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, n71. https://doi.org/10.1136/bmj.n71 - Petticrew, M. & Roberts, H. (2006). Systematic reviews in the social sciences: A practical guide. Malden, MA: Blackwell Publishing. - Rieckmann, M. (2018). Learning to transform the world: Key competencies in Education for Sustainable Development. In A. Leicht, J. Heiss, & W. J. Byun (Hrsg.), Issues and trends in Education for Sustainable Development. (S. 39-60). Paris: UNESCO. - UNESCO (2021). Bildung für nachhaltige Entwicklung. Eine Roadmap. Paris: UNESCO. - Verhelst, D., Vanhoof, J., & Van Petegem, P. (2021). School effectiveness for education for sustainable development (ESD): What characterizes an ESD-effective school organization?. Educational Management Administration & Leadership, 51(2), 502-525. - Zala-Mezö, E., Bormann, I., Strauss, N. C., & Müller-Kuhn, D. (2020). Distributed leadership practice in Swiss “eco-schools” and its influence on school improvement. Leadership and Policy in Schools, 19(4), 673-695.