Professionalisation of Teachers for Education for Sustainable Development in Germany: A Scoping Review

2.1. Subject-specific dynamics and interdisciplinarity of TESD

In recent years, ESD has been increasingly implemented in official documents for schools. The “Curriculum Framework: Education for Sustainable Development” (Standing Conference of the Ministers of Education and Cultural Affairs & Federal Ministry for Economic Cooperation and Development, 2016) and the supplementary document for upper secondary education (German: gymnasiale Oberstufe) level (2025) aim to focus more on sustainability issues from a global perspective throughout all subjects. The actual implementation of ESD in curricula or other guiding documents are found more frequently in school subjects such as geography, biology or general studies in primary school (German: Sachunterricht) than in other subjects (Brock & Holst, 2022; Hemmer, Wittlich, & Schult, 2025). These studies show: in each subject, different ways of referencing ESD can be observed, shaped by subject-specific perspectives – including distinct goals, competencies, teaching methods – as well as underlying premises and disciplinary cultures (e.g. Bagoly-Simó & Hemmer, 2017).

The state of research on TESD in the various areas of subject-specific pedagogy and didactics has so far not been investigated. In particular, it has not yet been analysed to which extent the greater prominence of ESD in individual subjects based on curricula analyses are also reflected in research on TESD. Against this background, question I can be raised: Does the integration of TESD differ across subject didactics over time?

ESD, as an educational concept, is conceptualised to address interdisciplinary challenges in a problem-oriented manner (e.g. Yasin & Rahman, 2011). Analogously, ESD is implemented in school education and curricula as a cross-sectoral task (North Rhine-Westphalia), as a general guideline (Baden-Württemberg) or as an interdisciplinary endeavour (Saxony-Anhalt). However, interdisciplinary cooperation remains a major challenge in both school practice, teacher training, and research on ESD (Didham et al., 2024), as teaching, teacher training, and research is predominantly structured alongside disciplines and school subjects. To date, there is little systematic analysis of the number of interdisciplinary research projects. In view of its relevance, question II therefore focuses on interdisciplinarity: How do interdisciplinary studies shape the TESD discourse?

With the increasing mainstreaming of the concept in schools, it can be assumed that more researchers are developing an interest in this field. It can also be anticipated that researchers from subject didactics that have already been involved in ESD for longer periods of time will be prominently represented in the discourse and are part of bigger publication networks. Publication networks can be understood as social networks that indicate knowledge transfer between individuals and therefore also between disciplines (Krischel, Halling, & Fangerau, 2012). To obtain evidence for these considerations, we analyse who has been participating in the discourse, and how, by asking question III: Is the number of people shaping the scientific discourse increasing and which subject didactics can they be assigned to?

2.2. Target groups and school types as focal points in the scientific discourse on TESD

Numerous studies conclude that competency development of teachers for ESD still requires considerable effort (e.g., Brock & Grund, 2019; Grund & Brock, 2022; Hörsch et al., 2023). In the initial phase of teacher education – the university phase – there is evidence of an insufficient implementation of ESD in study regulations and module descriptions (Brock & Holst, 2022). Similarly, shortcomings have been identified in in-service teacher training, the third phase of teacher education (Waltner, Gaubitz, & Rieß, 2017). Inadequate integration of ESD across all phases of teacher education is also reflected in teachers' self-reported levels of knowledge (Brock & Grund, 2019; Grund & Brock, 2022).

Numerous studies on, for example, subjective theories, orientations, or motives of (prospective) teachers in the context of ESD focus on student teachers (e.g., Hinzke, Herzig, & Weber, 2024) or in-service teachers (e.g., Mittrach, 2023). However, the second phase of teacher education – the trainee phase for teachers between university and professional activity without supervision – remains largely unexplored in research (Kotthoff & Terhart, 2013). This is not surprising, because access to the field for empirical research is extremely difficult. Yet, it is of high relevance, as this is the phase in which content knowledge and pedagogical content knowledge are applied and critically reflected upon in real classroom settings.

Moreover, non-formal learning environments outside the classroom – and thus also external cooperation partners – play a significant role in the implementation of ESD, as they offer complementary expertise and provide experience-based learning environments (Singer-Brodowski, 2019; Brock & Grund, 2020). Teachers' competency to cooperate with external partners is particularly crucial for productive interaction and realisation of non-formal learning (Reinke, 2021). Based on the available data, it can be expected that students and teachers are also more frequently focused in the discourse on TESD than trainee teachers or external cooperation partners. Question IV is intended to address this assumption: Are target groups of TESD addressed differently in the scientific discourse?

An imbalance can also be assumed with regard to the types of school in which the actors are engaged 2: Explicit reference to ESD is much more frequently represented in the school profiles of primary school and upper secondary schools than in other types of school (Weselek, 2022). Studies have highlighted the problem that (prospective) teachers anticipate a class- and stratum-specific interest in sustainability practices and knowledge based on stereotypes and prejudices stemming from their parental homes (Weselek, 2022). Children and teenagers from socioeconomically disadvantaged and less privileged families are not seen as having a particular interest and prior knowledge of sustainability-related topics and behavior (Weselek, 2022). This finding is evident both among student teachers (Böse & Gräbe, 2025) and among teachers in the second (Weselek, 2024) and third phase (Weselek, 2022). The unequal preconditions for engaging with sustainability continue to be reproduced in informal adult learning contexts (Costa & Kühn, 2024). Considering that the topic of social inequality in the context of socio-ecological transformation has been increasingly discussed in recent years (e.g. Mau et al., 2023), it is highly relevant to account for and analyse the full range of school types. Question V therefore addresses a potential inequality regarding the possibility to engage in ESD: Are all school types equally represented in the scientific discourse on TESD?

2.3. The ratio of theoretical, conceptual and empirical contributions in the field of TESD

In general, ESD as a scientific field was initially characterised by explorations of the rather programmatic framework of ESD emerging from policy documents, like the Agenda 21 launched in 1992 in Rio de Janeiro. In the early years, the field was characterised by publications that did not refer extensively to theoretically or empirically based argumentation. Apart from few exceptions, they were rather understood as practical recommendations for the realisation of ESD. This also applies to TESD (German-speaking network LeNa – Teacher Education for a Sustainable Development, 2014). Therefore, it is worth asking whether the ratio of work on concrete programmes or activities, such as seminar concepts, has changed compared to studies focusing on theory development or work with empirical approaches. In addition, the question of whether the thought collective (Fleck, 1993) of the TESD research community has aligned more closely with scientific standards, as called for by Gräsel et al. in 2012, is also considered. Based on this, question VI is posed: How does the ratio of conceptual, theoretical and empirical work on TESD change over time?

4.1. Search Strategy

The search for publications was based on two pillars: a database search and a manual extension. For the database search, Web of Science (Science Citation Index Expanded and Social Sciences Citation Index) and “Fachportal Pädagogik” (including FIS Bildung, ERIC and BASE) were selected. The combination of these databases is expected to provide high coverage for the research focus (Heck et al., 2024). The search was conducted using two keyword clusters – one related to ESD and the other to teacher professionalisation – and was restricted to publication abstracts (search string see Appendix section I). The specific search terms are presented in Table 1. Within each row, terms were combined using the Boolean operator OR, while the two clusters (columns) were linked using AND. The search was conducted in September 2024.

In addition to the database search, project members manually added relevant missing publications from the respective disciplines 3 to the sample. Although this process reduces the replicability of the study, as targeted by the systematic database search, it increases the breadth of coverage of the field, as not all publications are listed in databases. This approach takes various traditions of publication in the respective disciplines into account. The inclusion of publications was then discussed by other project members, and the same criteria as in the database search were applied (see section 4.3).

4.2. Screening and Selection Process

Following the PRISMA guidelines for scoping reviews (Tricco et al., 2018), all publications were screened in multiple steps (see Figure 1). The database search yielded 516 results. Cumulative dissertations (n = 5) and edited volumes (n = 51) were examined separately to identify relevant contributions. Titles and abstracts of N = 394 publications were reviewed using five inclusion criteria: (1) reference to ESD, (2) focus on teacher professionalisation (pre- or in-service), (3) focus on general education schools, 4 (4) addressing the context of teaching in Germany, and (5) language. Two project members independently screened each publication using the online tool Sysrev (Bozada et al., 2021), achieving a satisfactory interrater reliability of 88% (Cohen's Kappa κ = 0.73). Discrepancies were resolved through discussion. The quality of publications is not an exclusion criterion in scoping reviews (contrary to systematic reviews; Arksey & O'Malley, 2005).

Fig. 1

At full-text screening, two reviewers applied the same five criteria to records from the database search and manual additions. Agreement reached 91% (Cohen's κ = 0.74); differences were resolved through discussion, resulting in a final sample of 154 publications.

4.3. Data Extraction

For data extraction regarding questions I–II and IV–VI, a category system was developed in an iterative process within the project group. Coding was conducted in interdisciplinary pairs, each comprising two project members. This approach ensured that individuals from different disciplinary cultures were coding the material, thereby minimising any potential disciplinary bias in the coding process. The interrater reliability for each category, measured using Cohen's Kappa, is presented in Table 2.

The interrater reliabilities are generally satisfactory (Rädiker & Kuckartz, 2019). To explain the relatively low kappa value for the category “school type” the discrepancies were retrospectively evaluated empirically: The most common source of error relates to a margin of interpretation between the codes “unclear” and “irrelevant”. Publications with vague information on school type can, in principle, be assigned to both categories. The latter had no impact on the overall count of school types addressed. All discrepancies were discussed and resolved through consensus. The database for research question III draws on the authorship information contained in the publications.

4.4. Data Analysis

Data analysis was conducted using the statistical software R (R Core Team, 2024). To address the questions related to the characteristics of the research field (I – II and IV – VI), the frequencies of deductive categories were examined in relation to the year of publication. Visualisations were generated using the ggplot2 package (Wickham, 2023). To answer question III, a co-authorship network was constructed in R with the igraph package (Csardi & Nepusz, 2006) and visualised using ggraph (Pedersen, 2024).

5.1. Description of the sample

The sample of 154 scientific publications comprises 12 books (8%), 59 book chapters (38%), and 83 journal articles (54%). German-language publications dominate the sample, accounting for 107 texts (70%). The journal articles were published across 44 different journals. The most frequently represented journals are Sustainability (n = 17), Zeitschrift für internationale Bildungsforschung und Entwicklungspädagogik (n = 6), and Environmental Education Research (n = 5). Figure 2 illustrates the publication trend over time. As the database search was conducted during the ongoing year 2024, the data for this year are incomplete. Publications in this research field date back to 1998, with a noticeable – albeit not continuous – increase starting in 2016. However, topic-specific edited volumes and journal issues must be taken into account when interpreting publication counts (Menthe et al., 2016; n = 3; Keil, Kuckuck, & Faßbender, 2020; n = 5; Graulich et al., 2024; n = 13).

Fig. 2

5.2. Question I: Integration of TESD in subject didactics

To investigate whether the professionalisation of teachers for ESD is integrated at different times or to varying extents across different subjects, the subjects addressed within each publication were used as an indicator. The decisive criterion for assigning a publication to a specific subject was not the authors' institutional affiliation or the disciplinary focus of the publication venue, but rather the extent to which subject-specific aspects were emphasised in the text itself. If no clear subject-specific reference to TESD could be identified, the publication was coded as “subject-independent.” This category also includes publications that address, for example, cross-disciplinary didactics, educational science, or psychological perspectives. Figure 3 visualises the absolute frequencies of publications based on their coded subject reference.

Fig. 3

A subject-specific analysis of the development of the research field on teacher education for sustainable development (TESD) over time reveals differentiated patterns, allowing the identification of four distinct groups:

1. Since around 2016, there has been a notable increase in publications within the subjects of biology and geography, as well as from a subject-independent perspective. In the case of science and social studies, this trend has emerged with a slight delay.

2. Publications on TESD have also appeared in chemistry and physics during this period, though in significantly smaller numbers.

3. In subjects such as German, foreign languages, history, computer science, art, political education, religion, physical education, mathematics, and integrated science, only isolated publications on teacher professionalisation have emerged in recent years.

4. No relevant publications were identified for the subjects of music, philosophy, and economics.

The three publications which were categorised as non-subject-specific address the topic of TESD in a general way with a focus on conceptual understandings and motivations for implementing ESD, without outlining ESD in a subject-specific way. However, when taking the affiliations of the authors into account, the publications can be assigned to geography didactics (Engelhard, 1998), environmental communication (Rode, 2004) and science and social studies and biology didactics (Seybold & Rieß, 2006).

The integration of TESD into subject-specific discourses occurs at varying times and to differing extents across individual subjects. A distinction can be made between an initial, general engagement with the topic within a subject area and a subsequent, more specific discourse that either applies TESD-related considerations to the subject or responds to the broader ESD discourse from within the subject itself.

5.3. Question II: Interdisciplinarity of the projects

The analysis of interdisciplinarity within the field of teacher education for sustainable development (TESD) is based on the same coding scheme used in the previous section (see 5.2). A total of n = 21 publications in the sample adopt a subject-specific perspective that encompasses two or more subjects (n = 17 address two subjects, n = 3 address three subjects, and n = 1 addresses five subjects). Figure 4 illustrates the absolute frequencies of collaboration between two subjects.

Fig. 4

The analysis shows that two or more subject-specific perspectives are only integrated in a few cases. These include, in particular, studies linking geography and biology (n = 10, of which n = 6 between the two subjects and n = 4 with other subjects, including n = 3 with political education) as well as geography and general studies in primary school (n = 4). It should be noted that these interdisciplinary publications originate from the disciplines that were previously considered to have published frequently and to have entered the subject-specific discourse at an early stage.

5.4. Question III: Discourse-participating persons

Findings indicate that 253 different authors have been participating in the discourse on teacher professionalisation for ESD (Figure 5). Two indicators are used to analyse the development of the number: the absolute number of authors who have published in one year (= total number of authors) and the absolute number of new authors entering the discourse per year (= first-publishing authors). Editorships of thematic issues and edited volumes, which could facilitate thematic exchange between individuals and institutions beyond individual contributions, were not considered in this analysis.

Fig. 5

A steady increase in the number of individuals contributing to the discourse over time becomes evident. Peaks in authorship activity in the years 2016, 2020, and 2024 suggest that edited volumes (see section 5.1) have played a significant role in shaping publication-based academic exchange. A comparison of publication frequencies indicates that repeated contributions to TESD only begin to appear from 2013 onwards. Prior to this point, the number of first-time authors corresponds to the total number of authors, implying no multiple publications by authors. Nevertheless, the proportion of first-time contributors remains consistently high relative to the overall number of authors throughout the observed period.

To address question II in greater depth, it is also relevant to examine which authors are contributing to the field and how (interdisciplinary) research networks are structured. To visualise the degree of interconnectedness, a co-authorship network was constructed (see Figure 6). Publications authored by a single individual (n = 47) are not included in the network representation.

Fig. 6

The co-author network for the TESD discourse is characterised by the following features: There are numerous small groups of two to four authors (n = 99), most of whom publish together once and have no connections to other networks. This finding is coherent with the high number of first authors (see Figure 5). Larger groups with five (n = 5), six (n = 2), seven (n = 1) or eight authors (n = 1) rarely publish. Only six larger clusters can be identified, which are formed by several publications and include between nine and 21 authors. Overall, the discourse does not form an overarching network.

To gain further insights, also with regard to the disciplinary structure, the three largest clusters – measured by the number of people – are analysed separately.

Figure 7 visualises the largest cluster (21 people, 11 publications). None of the publications were written by the same co-authors, resulting in a variety of teams that enable personalised knowledge transfer as part of the writing process. Anne-Kathrin Lindau (University of Halle; n = 5) and Gabriele Schrüfer (University of Bayreuth; n = 4) – both professors of geography didactics – have the most co-authorships. Most of the participants belong to geography didactics, and some to biology and science and social studies didactics. There is a high degree of networking across universities (universities in Bayreuth, Duisburg-Essen, Giessen, Halle-Wittenberg, Salzburg (Austria), Wuppertal, Zurich and the University of Applied Sciences Northwestern Switzerland). The central element for the connection of two sub-networks around Lindau and Schrüfer is a contribution to the conference proceedings based on a jointly designed World Café on teacher professionalisation (Bauer et al., 2020).

Fig. 7

The second-largest cluster (see Figure 8; 20 people, 15 publications) is centred around Werner Rieß, Professor of biology didactics. In contrast to the geography didactics network, this cluster exhibits a more homogeneous team structure, particularly within the University of Education Freiburg (PH Freiburg), as evidenced by numerous strong co-authorship links. The group frequently incorporates expertise from psychology, educational research, and educational sociology, often involving researchers from other institutions. A personal connection to the geography didactics group at PH Ludwigsburg is established through Professor Stephan Schuler, based on n = 3 joint publications. Additionally, the publication by Waltner, Rieß and Brock (2018) creates a link to the Institut Futur.

Fig. 8

The third cluster (Figure 9; 15 people, 7 publications) has two centres with n = 3 publications each. On the one hand, there is Julia Lohmann (post-doc, physical education, University of Freiburg and from 2019 University of Augsburg), who publishes with alternating co-authors from various disciplines (including sports science, geography didactics, educational science) and several universities (Karlsruhe Institute of Technology, Universities of Augsburg, Bern and Freiburg). On the other hand, there is a centre around Rebecca Baumann (doctoral student, primary school pedagogy, Erlangen-Nuremberg (FAU)) with work on the professionalisation of teachers for general studies in primary school. Three out of four of her works are published in the same team of researchers from FAU, another with a co-author from the University of Freiburg. Two publications create a bridge between the clusters (Lohmann, Wegner, & Gieß-Stübner, 2019; Stössel, Baumann, & Wegner, 2021).

Fig. 9

In conclusion, the centres consist not only of professors, but also of pre- and post-docs, and disciplinary and institutional segmentations are overcome in some areas. A notable example is the network described last, which links several disciplines and universities with each other and thus realises a high level of person-based knowledge transfer. Areas of subject didactics with long-standing involvement in ESD are substantially more represented. Physical education is an exception.

Regarding question III, it can be concluded that the number of researchers taking part in the discourse has increased considerably over time. It is unsurprising that the researchers come primarily from subject didactics that have been implementing ESD for a longer period of time. There are some interdisciplinary network-connections that may depend on the individuals involved.

5.5. Question IV: Focussed target groups in the field of TESD

To explore which target groups are primarily addressed in the field of TESD, the following analysis examines the distribution of foci across different educational actors (see Figure 10).

Fig. 10

Looking at the individual target groups (dark blue columns), student teachers are the most frequent focus, followed by teachers at a considerably lower frequency. Within the sample, there is only one conceptual publication on trainee teachers (Handschuh, 2016).

Once the ‘combinations’ category, that describes publications in which multiple target groups are addressed, has been broken down, the focus remains on students and teachers (light blue columns). Only n = 9 publications also consider trainee teachers, which illustrates that teachers in the second phase are rarely analysed independently within the scientific discourse. External cooperation partners are also rarely discussed (n = 13). This underrepresentation stands in stark contrast to the previously discussed relevance of these groups for ESD

5.6. Question V: Focussed school types

The following analysis highlights which school types and levels receive particular attention in the scientific field of TESD (see Figure 11).

Fig. 11

The analysis outlines a differential focus on certain types of schools respectively school levels. In particular, the publications concentrate on (prospective) teachers for primary schools (n = 22) and secondary schools (n = 8). When the ‘combinations’ category, which again includes publications with multiple categories, is broken down, it also becomes clear that teachers from lower secondary schools (German: Mittelschule/Hauptschule), intermediate secondary schools (German: Realschule), and schools for children with special educational needs (German: Förderschule/Sonderschule) are also addressed in the publications. The integrated secondary school (German: Oberschule) and the intermediate secondary school (German: Realschule) both lead to equivalent qualifications. Combining the number of publications on these two school types would not change the overall conclusions drawn about school types. In addition, (prospective) teachers for lower secondary level (grades 5 to 10; n = 20) and upper secondary level (grades 11 to 13; n = 18) are addressed in publications as groups that include teachers from several types of school. Reform pedagogy schools are not addressed in the publications analysed.

Overall, this shows that the scientific field is dominated by publications on primary schools and secondary schools. Works relating to (prospective) primary school teachers are much more prevalent. However, the effect in relation to secondary schools could be overestimated, as the secondary school type exists in all federal states, while the other school types differ in their designation depending on the federal state. Nevertheless, there is a preponderance of secondary schools (including upper secondary level) among schools following primary education.

5.7. Question VI: Development of the field

The analysed publications on TESD can be characterised as empirical (n = 89; of which quantitative n = 36, qualitative n = 36 and papers with both shares n = 17), theoretical (n = 12; without own data collection) or conceptual (n = 47; with application-oriented products in focus) (n = 6 papers could not be assigned and are excluded from the analysis). Among the conceptual works, n = 12 also report empirical findings on the concepts implemented (e.g. an evaluation; these are included in the analysis in the absolute frequencies of both categories). Figure 12 visualises the development of the absolute frequencies per year.

Fig. 12

The following pattern can be identified: empirical approaches characterise the academic field early on in the development of the discourse; the ratio is always higher than that of other types of contribution and shows an upward trend from 2020 in particular. The number of empirical papers is only significantly exceeded by conceptual contributions in 1998 due to the low total number, and in 2024 due to an edited volume (Graulich et al., 2024; see section 5.1).

Until 2015, there were only two conceptually orientated articles (Engelhard, 1998; Hamann, 2007). In particular, the publication of edited volumes in 2016, 2020 and 2024 (see section 5.1) contributed to the increased number of this type of contribution. Theoretical articles are the least common overall - their proportion fluctuates over the years mostly between n = 0 and n = 2 (n = 5 singularly in 2016), whereby the number seems to be less dependent on the edited volumes or themed issues (see 2020 and 2024).

Overall, the analysis of the types of contributions reveals a dynamic, but fundamentally empirically orientated research field with only few but consistently occurring theoretical works and occasional conceptual focuses.