Given the increasing overshoot of planetary boundaries (Richardson et al., 2023) and growing global inequality (Chancel et al., 2021), the transformation to sustainability is becoming more relevant and urgent. For over 50 years, international and national efforts have been made to address sustainability challenges through education and learning (e.g. Macintyre, Tilbury, & Wals, 2024). While in the 20th century, Environmental Education as well as Developmental Education and later Global Education were the most prominent concepts for addressing issues of sustainability, since the turn of the century, educational policy documents have increasingly focused on Education for Sustainable Development (ESD) (Singer-Brodowski et al., 2019). Activities during the UN Decade of ESD (2005–2014), the UNESCO Global Action Program (2015–2019) and the UNESCO ESD for 2030 program, which has been running since 2020, have contributed significantly to the diffusion of ESD in central documents of the educational systems (UNESCO 2021; National Platform, 2017). Implementing ESD generally requires a specific qualification of educators.
ESD teacher training (TESD) is undergoing dynamic development (e.g. McKeown & Hopkins, 2007). This applies both to practice, in which implementation is highly dependent on individuals and divergent across subjects (e.g. Uitto & Saloranta, 2017), and to research (German-speaking network LeNa – Teacher Education for a Sustainable Development, 2014).
For the international discourse, there are initial efforts of mapping the field of TESD, such as the systematic review by Fischer et al. (2022). This analysis focuses on general international trends and highlights key topics across different countries (five categories, including ‘measuring learning outcomes’) as well as various methodological approaches (such as single case studies). Out of 158 publications reviewed in this study, only 11 originate from Germany. For this reason, no conclusions can be drawn regarding the professionalisation of teachers at the single national level. In educational systems, that are mainly organized on a (sub-)national level, a focus on this national level, can provide a more detailed picture about certain trends and patterns that can be used for developing the field of research, inspiring practice and policy-making processes. Studies of national ESD monitoring provide indications that ESD is only rarely addressed in Germany's teacher education on the document level (Brock & Holst, 2022; Hemmer, Wittlich, & Schult, 2025), but there is an overall lack of differentiated insights into the structure of the research field. The present study addresses this gap by analysing the scientific discourse on TESD in Germany with a scoping review. The central research question captures characteristics as patterns of the TESD field that produce focal points and blind spots and that originate in certain discourses (1): Which characteristics and discourses can be identified in the scientific field of TESD in Germany?
To approach the scientific field, six key questions based on the current state of research are presented in the following sections. They specify the aforementioned research interest, structure the analysis and ultimately guide the discussion, so that the review extends beyond a descriptive mapping of the field and contributes to the identification of desiderata and development of the practice and policy discourse.
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?
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?
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?
This scoping review aims to provide a systematic analysis of the national scientific discourse on professionalisation of teachers for ESD. Given the increasing prominence of ESD in key documents of the German education system, especially compared to related educational concepts (Singer-Brodowski et al., 2019), our study focuses on ESD. The goal is to identify the characteristics and research gaps of this discourse in order to develop a consolidated body of research on TESD in Germany and as a result also support professionalisation efforts in a systematic way.
Six indicators and key questions form an analytical framework for answering the general research question: What characteristics and discourses can be identified in the field of ESD teacher education and practice in Germany?
The characteristics of the scientific field are conceptualised as aspects of the discipline, the interdisciplinarity of projects, target groups, types of schools and types of contributions to the field (questions I–II and IV–VI). The discourses of the research field are conceptualised by people participating and their joint publications (question III).
To answer the research question, a scoping review was conducted (Arksey & O'Malley, 2005; Gutierrez-Bucheli et al., 2022; Tricco et al., 2018), which is characterised by a systematic approach and a broad search strategy that includes various types of contributions, aiming to provide an overview of a wide research field and to identify knowledge gaps (Gutierrez-Bucheli et al., 2022; Tricco et al., 2018). To answer the research questions, we combined qualitative content coding to reveal characteristics of the TESD field and a bibliometric approach to gain further insights into discourse-participating persons and their publication networks (Krischel, Halling, & Fangerau, 2012).
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.
Search terms used in the databases ‘Fachportal Pädagogik’ and ‘Web of Science’, combined with the criteria of publication language (German or English) and the publication year criteria of 1992 to 2024 inclusive), without limiting the type of publication.
| Keyword cluster Search terms | ESD | Teacher professionalisation |
|---|---|---|
| Bildung für nachhaltige Entwicklung | Lehr*bildung | |
| BNE | Lehr* | |
| education for sustainable development | profession* | |
| ESD | teacher education | |
| education for sustainability | teach* sustainability education | |
| ESE |
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).
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).
Overview of the database search and the manual extension based on the PRISMA recommendations (Page et al., 2021)
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.
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.
Cohen's kappa coefficients by category
| category | subject area | target group | school type | type of contribution |
|---|---|---|---|---|
| κ | 0,68 | 0,60 | 0,33 | 0,77 |
| N | 235 | 211 | 295 | 173 |
Note: κ: Cohens Kappa; N = frequency of the codes
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.
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).
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).
Absolute frequencies of the publications included per year
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.
Bubble chart showing absolute frequencies of publications by subject and year, including marginal sums per subject and per year; bubble size and colour intensity correspond to the frequency represent the absolute frequency
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:
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.
Publications on TESD have also appeared in chemistry and physics during this period, though in significantly smaller numbers.
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.
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.
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.
Bubble chart showing absolute frequencies of cross-subject publications; bubble size and colour intensity correspond to the absolute frequency of interdisciplinary publications between subjects, which is also indicated numerically at the corresponding position
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.
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.
Development of total number of authors per year and first authors per year; dark blue bars represent the total number of authors and light blue bars represent the number of first-time authors per year
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.
Co-author network showing authors (nodes), co-authorship connections (edges), and collaboration frequency (edge thickness)
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).
Co-author network around Gabriele Schrüfer and Anne-Kathrin Lindau
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.
Co-author network around Werner Rieß
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).
Co-author network around Julia Lohmann and Sabine Martschinke
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.
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).
Absolute frequencies of target groups addressed; dark blue bars show single-target publications, 'combinations' show multi-target publications; light blue bars display the distribution with combinations split into individual groups
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
The following analysis highlights which school types and levels receive particular attention in the scientific field of TESD (see Figure 11).
Absolute frequencies of addressed school types; dark blue bars show frequencies for individually targeted school types, light blue bars show distribution with combinations split into individual types; the category system is highly differentiated to enable precise text-based coding, including state-specific school types; secondary levels I and II are included as separate codes since publications often use these group designations without specifying particular school types
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.
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.
Absolute frequencies of contribution types per year (empirical (light blue), theoretical (medium blue), and conceptual (dark blue) contributions)
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.
The aim of this scoping review was to explore the structures, patterns, and dynamics of the scientific field of teacher education for sustainable development (TESD) in Germany using six indicators or key questions as an analytical heuristic and to determine areas in need of further research. This first indicator-based national overview enables the derivation of specific implications for TESD in Germany.
Overall, the scientific field is expanding and has increased in publication output since 2016. Whether the increase in publications from 2015 onwards is related to the adoption of the international sustainability agenda and/or the UNESCO Global Action Programme, which focuses on training educators, is unclear at this point. The finding is consistent with the results of Fischer et al. (2022) for the international community. It should be noted that the field of teacher training has overall grown, and empirical research has increased (Terhart, 2019). At the same time, however, the field of research on TESD is rather fragmented. One aspect of this fragmentation is already apparent in the data used to describe the sample: numerous publications appear in edited volumes, and in a variety of journals with different research foci. A further question that could be addressed in future studies is whether this also has a negative impact on the coherence of the discourse and the exchange of ideas.
The key findings regarding the six indicators are summarised and discussed below.
Question I: Does the integration of TESD differ across subject didactics over time?
There are particularly many publications on ESD in the subjects of biology, geography and general studies in primary school. According to national monitoring, these subjects are those in which ESD is highly integrated into curricula, modules and course descriptions (Brock & Holst, 2022). There are only a few publications in other subjects (for example in religion didactics (Tacke et al., 2022) or foreign language didactics (Surkamp, 2022). The reasons and dynamics underlying the initiation of the discourse in the respective subjects cannot be clarified based on the available data and would require further research. We hypothesise that a subject-specific approach to ESD must first be established before subsequent discussions on concepts and subject-specific empirical studies in teacher training can take place. Overall, topics and didactic approaches in the context of ESD have been addressed prior to the establishment of the educational concept in teacher education. In some subjects that have so far published relatively little on ESD or TESD, respectively, ESD-adjacent educational concepts are currently still in focus, for example Global Education in foreign language didactics (Surkamp, 2022) or environmental ethics in religion education (e.g. Altmeyer, 2021). Here some longitudinal studies that trace the usage of certain educational concepts over time appear promising: in ESD and TESD in general and in various subjects in particular.
The results also show that many publications on TESD are not subject-specific. While these are also written by researchers embedded in specific subject didactics (e.g. Engelhard, 1998), TESD is primarily addressed in a more general way across subject didactics. A more in-depth content-analytical assessment of the publications would likely reveal facets of the various subject didactic communities. Here secondary analysis of our sample would allow deeper insights. Overall, TESD seems to be a young and dynamic field of research that is currently being pursued to varying degrees in different subject-specific areas of teacher education.
Question II: How do interdisciplinary studies shape the TESD discourse?
Interdisciplinary projects with subject-specific profiles tend to be less common in the field of TESD. The few interdisciplinary publications are in clear contrast to the requirements and expectations generally imposed on ESD (e.g. Didham et al., 2014). Nevertheless, the findings align with the existing structure of subjects in schools and universities, as well as the challenges associated with realising interdisciplinary research projects (Defila & Di Giulio, 1998). Furthermore, an interdisciplinary approach to TESD presupposes the existence of disciplinary debates and viewpoints that can be related to each other in an interdisciplinary manner (see question I). In (research) practice such dialogue needs time, which is a strong justification for communicative spaces (conference, publications, practical materials), where disciplinary perspectives can be exchanged and mediated.
Question III: Is the number of people shaping the scientific discourse increasing? And which subject didactics can they be assigned to?
A growing number of people are participating in the academic discourse on TESD. Once more, the confounding effect of the increase in academic work within teacher training should be noted (Terhart, 2019). The proportion of first authors or people publishing once on TESD is surprisingly high. This suggests that only a few people specialise in TESD over time. The relatively high number of publications by teams of two to eight co-authors reflects general trends in scientific publications (Larivière et al., 2015) within the TESD discourse. Overall, the findings describe a field in a state of dynamic development which may also be 'fragile' due to the changing authorship, which should be given more attention in future research.
Initially, the co-author network analysis shows that there are only a few large clusters and, consequently, a small number of central actors (professors, pre-docs and post-docs). The analysed clusters correspond with findings on question II (TESD focal points within certain subject didactics). Focal points within universities and universities of education (German: Pädagogische Hochschulen) can also be identified using the co-author network analysis, with subject and institutional boundaries breaking down at certain points. In this respect, the cluster centred on physical education (see section 5.4, Figure 9) is notable, particularly when the results on subject-specific publications (see section 5.3) are considered, as these are rarely found in the context of physical education.
The institutional and, in particular, the subject-specific structure of the discourse can be classified as a challenge with regard to the development of a joint research agenda. In this context, specific conferences, thematic edited volumes and the establishment of professorships could also play an important role, as they contribute to further shaping of the discourse.
Question IV: Are target groups of TESD addressed differently in the scientific discourse?
The data indicate an imbalance in the target groups of research on TESD. The focus of scientific publications is primarily on students and thus on the university phase of teacher training. Pragmatic reasons, such as ease of access to respective samples, can be assumed as a possible cause of this focus. A gap can be identified in relation to the target group of trainee teachers and TESD, although the findings are consistent with teacher education research in Germany in general (Kotthoff & Terhart, 2013). We consider this to be problematic, given that this phase is particularly relevant for teacher professionalisation due to the specific conditions and practical application of knowledge gained during the first phase of teacher education.
The target group of external partners is rarely considered. Considering the focus on their importance as partners in collaboration (Reinke, 2021; Singer-Brodowski, 2019; Brock & Grund, 2020), as well as the difficulties associated with collaboration (Bludau, 2016), this finding is surprising and highlights a pivotal research gap.
Question V: Are all school types equally represented in the scientific discourse on TESD?
Based on the analysed publications, a body of work on (prospective) primary and upper secondary school teachers can be identified. In contrast to lower and intermediate secondary school teachers, both are considered as individual groups. However, when the differences found are considered in relation to the number of students in the different school types (see Federal Statistical Office, 2025), it becomes clear that the ratio is relative, given that far more students attend primary school (N = 3.098.664) and upper secondary school (N = 2.280.967) than lower secondary school (N = 333.907) and intermediate secondary school (N = 771.330). Against this background, the practical implications of the findings must be acknowledged.
Therefore, it cannot be clearly stated based on the data whether research on TESD nevertheless risks the reproduction of social inequalities, as research increasingly takes place in areas where ESD is implemented in school practice (or vice versa). Considering an increasing societal polarization with relation to social-ecological transformation processes (Eversberg et al., 2024) the connection between stratification, social inequality and ESD nevertheless needs further attention in research.
Question VI: How does the ratio of conceptual, theoretical and empirical work on TESD change over time?
An analysis of the types of articles reveals a dynamic academic publication landscape that is empirically oriented, with few theoretical works and occasional conceptual focuses. The latter are particularly moderated by edited volumes and special issues. The ratio of contribution types does not change substantially or systematically over time. The low number of theoretical contributions can be seen as part of the general trend that theory is usually dealt with as a component of empirical contributions. A content analysis is needed to determine whether theory development is being neglected in favour of empirical approaches. The high proportion of empirical papers could initially indicate a stronger orientation towards scientific standards (Gräsel et al., 2012), but the quality of these papers would need to be examined.
Overall, when reviewing the developments, it must be considered that contributors to the discourse also bring subject-specific traditions (e.g. questions and methods) from their respective disciplines to the discourse on TESD, in line with Fleck's (1993) concept of thought collectives. Due to the small number of cases, it is not possible to analyse whether the development of contribution types yields differentiated findings for different disciplines (see question I). The high number of empirical and, above all, quantitative studies also raises the question of the extent to which TESD is sufficiently grounded in theory and where theory development is taking place.
Summarising the results, we nevertheless see a vibrant, multi-perspectival and engaged research field that has been growing along with the urgent necessity of TESD.
The present study has limitations resulting from the decisions on methodology. The search string for identifying relevant publications required that ESD is explicitly mentioned. Thus, publications that address ESD-related concepts (including Environmental Education, Global Education, Civic Education) were not included. Further studies could broaden the focus about the restriction to the ESD concept defined in the search string and thus generate further insights into subject-specific developments.
In addition to the search in two databases, a manual extension was carried out. While this increased the coverage of relevant publications from the field, it can introduce bias due to the representation of many, but not all, disciplines working on TESD within the project.
The level of agreement achieved when coding the content of the publications can largely be considered satisfactory when measured by Cohen's kappa reliability indicator. However, only moderate agreement was found for the school type category. However, as all publications were coded by two people and any differences in assessment were discussed in a consensual process, the reliability and validity of the coding can be rated as overall sufficient.
The lack of information in the texts also limited the number of data-based statements that could be made. For instance, some publications do not specify the type of school, which impedes categorisation.
In light of the necessity of educating the educators for ESD the research field of TESD is one of exceptional relevance. This scoping review systematically analysed the field of research on TESD in Germany with regard to six key questions. We produced a first national overview about the research discourse on TESD in Germany and provided insights for future practice and policy initiatives for strengthening TESD. In conducting this review, we benefitted a lot from our interdisciplinary research team itself, which included representatives of mostly all subject didactics and could cover many perspectives.
The results reveal the following development opportunities for the discourse:
There is a need for more interdisciplinary projects on TESD that integrate different subject didactics. At the same time, interdisciplinary projects could encourage researchers in disciplines that have been less common in the ESD discourse to adopt a subject-specific approach. This could be achieved through contrastive work (cf. Bray, Adamson, & Mason, 2014), which focuses on similarities and differences, turning cooperation itself into an additional research objective. Furthermore, it would be interesting to conduct another survey of developments within the various disciplines in around ten years' time. However, due to the different ways in which ESD can be linked to the respective subject objectives, subject concepts, competence models and subject topics, it can hardly be expected that (T)ESD research will be evenly distributed across the subject didactics. Furthermore, an analysis of the content of publications that link subjects would be of interest for identifying prerequisites or reasons for cooperation. To this end, it would be useful to analyse the contributions in order to determine which research questions are being addressed in each case and whether the research questions of different contributions can be combined. It would also be useful to establish under which more abstract questions they can be clustered. This would provide a clearer picture of existing research needs. This would also contribute to the development of a self-reflective, disciplinary meta-theory of ESD, which could be enriched by future contributions to specific research (Kminek, 2025).
The number of empirical studies is already high, but there are blind spots regarding, for example, the target groups. In particular, when focusing on students, the selection of the sample for research projects must be considered as an aspect of methodological quality; sometimes results cannot be transferred by relying on ad hoc or convenience samples. Regarding the target groups of TESD, the second phase of teacher training has not yet been widely researched. Future studies should focus more on this phase to address the specific challenges and needs of teachers when teaching ESD for the first time. In general, there is a need for longitudinal and impact studies. Furthermore, transitions between the phases should receive more attention – also in policy initiatives.
Since external cooperation partners are considered to be of great importance for the implementation of ESD, while challenges for successful cooperation have been identified, this aspect should be examined more closely in the context of ESD research. Additionally, this comes with a strong plea for accounting for the relevance of non-formal learning organisations (Widany & Schulte-Südbeck, 2025).
All in all, the current study about the state of TESD in Germany has shown that the research field is a vibrant area of different studies in all subject didactics and has laid the foundation for a broad variety of future studies. As the education of educators is a basic requirement for empowering all learners to contribute to sustainable development (SDG 4.7), TESD will probably maintain its pivotal importance in the future.
The concept of discourse used here differs from that of Foucault, as it does not focus on what knowledge is considered ‘normal’ or ‘valid’ and who has the power to shape these attributions (Jorgensen & Phillips, 2002). Instead, we focus on the scientific discourse as a communicative practice between researchers within a certain field, in which ideas are exchanged (e.g. through publications).
In descriptions of the German school system, a distinction can be made between school types and school levels. School levels are overarching terms for year grades across different school types (secondary level I: grades 5 or 7 to 10; secondary level II: from grade 11 onwards).
The project members represent the disciplines of subject didactics in biology, chemistry, German, English, geography, history, art, mathematics, physics, politics, religion, general studies in primary school (German: Sachunterricht), and physical education, as well as the fields of educational sciences, pedagogy, and psychology.
This excludes specific types of schools for vocational training.