Review Reports - Teaching Sustainability: Educational Approaches in Light of Sustainability Science

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The main theory used to construct this article needs to be mentioned in detail in the abstract.
The introduction is still too general, not yet describing more focus on the problem and urgency of the article.
A description of the theoretical weaknesses and views of previous experts must be presented in the discussion section, so that the new offer presented by the author becomes more relevant.
A critical review of the bibliography reveals 22 outdated references that predate the last decade. To maintain the manuscript's academic rigor and ensure it reflects the current state-of-the-art, it is essential to replace these citations with high-impact sources from the past ten years. Updating these references will significantly strengthen your arguments and demonstrate the contemporary relevance of your findings to the field.

Author Response

Dear Reviewer

First of all, we would like to thank you for your helpful review. We greatly appreciate the time and effort you invested. All comments have been carefully considered, and the manuscript has been revised accordingly. In addition, the manuscript has undergone English language editing by MDPI.

In the following, we address your comments in detail:

Comment 1: The main theory used to construct this article needs to be mentioned in detail in the abstract.

Author Response

Revised Manuscript (Excerpt)

The main theory of this article is based on Integral Sustainability Science (Shrivastava et al., 2020). We have therefore added further details in parentheses in lines 19–23 to clarify this perspective.

lines 19-23:

"Drawing on Integral Sustainability Science, sustainability-related transformation processes are differentiated along internal (the meaning-making and culture domain) and external dimensions (the behavior and systems domain), integrating both factual systemic interrelations and normative perspectives of meaning and interpretation"

Comment 2: The introduction is still too general, not yet describing more focus on the problem and urgency of the article.

Author Response

Revised Manuscript (Excerpt)

We agree that the introduction was previously too general. It focused mainly on ESD 1, ESD 2, and ESD 3. To better highlight the contribution and relevance of the article, we have revised and expanded the introduction by further elaborating how the article addresses the identified gap between educational theory and its factual grounding. Specifically, we now introduce the structure of sustainability issues as synthesized in the 3C-FSL and provide a brief outline of its conceptual derivation. In doing so, we emphasize the main novel aspect of contingency, relate it to Integral Sustainability Science.

lines 53-69:

"In doing so, sustainability issues are both treated as thematic fields and conceptualized as structurally characterized learning objects. This structure is synthesized in the 3C Framework for Sustainable Learning, which captures sustainability issues in terms of their interrelated dimensions of complexity, controversiality, and contingency. The development of this framework builds on and extends the concept of double complexity (Bögeholz & Barkmann, 2005; Eggert & Bögeholz, 2006; Mehren et al., 2015; Ohl, 2013, 2018), which has been used to describe the factual and normative challenges of sustainability-related topics, by incorporating a stronger consideration of controversiality and contingency. In particular, the sociologically grounded concept of double contingency (Luhmann, 1984) is used to conceptualize transformative learning processes as fundamentally relational, uncertain, and dependent on reciprocal expectations within social interactions (Billi et al. 2024). Drawing on Integral Sustainability Science (Shrivastava et al., 2020), we further propose a systematic integration of interior and exterior dimensions of learning. This approach connects subjective experiences, emotions, and processes of meaning-making with the structural and material conditions of socio-ecological realities. In doing so, it seeks to overcome dualistic perspectives and to foreground the relational constitution of learning processes"

Comment 3: A description of the theoretical weaknesses and views of previous experts must be presented in the discussion section, so that the new offer presented by the author becomes more relevant.

Author Response

Revised Manuscript (Excerpt)

We agree that a clearer positioning of our approach in relation to existing perspectives is necessary to highlight the contribution of the article. We have therefore revised the discussion section accordingly.

Specifically, we now more explicitly contrast our approach with existing frameworks that primarily focus on complexity (and, to some extent, controversiality) by showing how the 3C-FSL extends the concept of double complexity in particular through the integration of contingency as a constitutive dimension of sustainability issues. In doing so, we highlight the limitations of previous approaches, which tend to underemphasize the processual, relational, and uncertain character of societal transformation.

Furthermore, we elaborate on the pedagogical implications of this extended perspective by outlining guiding questions that address external and internal complexity, controversiality, and contingency, thereby demonstrating how the proposed framework can inform teaching and learning processes in ESD 3. In this way, the added sections clarify both the theoretical contribution and the practical relevance of the proposed framework.

lines 554-577:

"To understand transformative processes, we, therefore, extend the concept of double complexity to include controversiality and contingency. In doing so, the 3C Framework for Sustainable Learning goes beyond existing approaches that primarily focus on complexity by explicitly integrating contingency as a constitutive dimension of sustainability issues, thereby enabling a process-oriented perspective on societal transformation. On the one hand, this emphasizes the need to engage with, negotiate, and critically reflect on controversial sustainability issues as socio-ecologically embedded conflicts (e.g., Daengeli & Kalcsics, 2026); on the other hand, it incorporates double contingency as a sociologically grounded analytical lens, thereby avoiding a narrow focus on the analysis of complexity and controversiality and instead foregrounding processes of societal transformation. From a pedagogical perspective, this raises the question of how teachers can approach sustainability issues in ways that do justice to their complexity, controversiality, and contingency. Possible guiding questions include the following:

External complexity: What interdependencies and correlations characterize the issue within the field of tension between natural and socio-economic systems?
External controversiality: Which contrasts and incompatibilities are inherent in the issue?
Internal complexity: Which values, interests, norms, and perspectives are involved?
Internal controversiality: Which values, interests, and perspectives come into conflict with one another?
Contingency (individual and collective): To what extent can situations of individual and collective contingency be made experientially accessible and open to reflection in learning processes?"

Comment 4: A critical review of the bibliography reveals 22 outdated references that predate the last decade. To maintain the manuscript's academic rigor and ensure it reflects the current state-of-the-art, it is essential to replace these citations with high-impact sources from the past ten years. Updating these references will significantly strengthen your arguments and demonstrate the contemporary relevance of your findings to the field.

Author Response: We followed the recommendation to replace some of the cited references. At the same time, we retained certain key sources, such as Luhmann (1984), who laid the theoretical foundation for the concept of contingency, and Vare and Scott (2007) as well as Vare (2014), who initiated the discussion on ESD 1, ESD 2, and ESD 3, as they are essential for ensuring the conceptual coherence and traceability of our argument. Where older sources were maintained, we complemented them with more recent references (e.g., in the case of critical global citizenship (Andreotti, 2006), we added Dang, 2025).

Thank you again for your valuable feedback.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

The manuscript presents a timely and conceptually ambitious contribution to the field of transformative sustainability education. It offers a well-structured and theoretically coherent integration of Education for Sustainable Development (ESD 3) with Integral Sustainability Science, culminating in the proposed 3C Framework (complexity, controversiality, contingency). The article is carefully referenced, up to date, and demonstrates strong engagement with contemporary debates in sustainability science and educational theory.

Several strengths deserve particular recognition:

The systematic integration of interior and exterior dimensions, which adds conceptual depth to discussions of transformative learning.
The extension of “double complexity” toward controversiality and contingency, especially the inclusion of double contingency as a sociologically grounded lens for understanding transformative processes.
The conceptual clarification of sustainability issues as structurally characterized objects of learning, rather than merely thematic fields.

At the same time, the manuscript would benefit from further development in several areas:

Greater operational clarity of the 3C Framework. While theoretically compelling, the framework would gain considerably in impact if its implications for instructional design were made more explicit (e.g., through design principles, guiding questions, or criteria for constructing suitable learning settings). At present, the article remains highly conceptual.
Stronger articulation of the added value over existing approaches. The manuscript builds on established notions such as double complexity and controversy frameworks. A clearer statement of what the 3C Framework enables that previous models did not would strengthen its contribution.
More explicit translation into pedagogical practice. The conclusions emphasize educational implications, but the article stops short of proposing concrete design solutions. Given that transformative education ultimately unfolds in practice, a more explicit bridge between theory and pedagogical application would enhance the manuscript’s relevance.

Overall, the manuscript offers a thoughtful and theoretically rigorous contribution. Strengthening the practical and operational dimension of the proposed framework would significantly enhance its impact and usability for educators and researchers alike.

I would like to thank the authors for their thoughtful and intellectually stimulating contribution and wish them all the best in further developing this promising line of work.

Author Response

Dear Reviewer,

First of all, we would like to sincerely thank you for your very helpful and constructive review. We greatly appreciate the time and effort you invested, and found your comments extremely valuable for improving the manuscript. We have carefully considered all your suggestions and revised the manuscript accordingly.

In the following, we address your comments in detail:

Comment 1: Greater operational clarity of the 3C Framework. While theoretically compelling, the framework would gain considerably in impact if its implications for instructional design were made more explicit (e.g., through design principles, guiding questions, or criteria for constructing suitable learning settings). At present, the article remains highly conceptual.

Author Response

Revised Manuscript (Excerpt)

We agree that further operational clarification of the 3C-FSL is important to strengthen its practical relevance and impact.

In response, we have revised the Conclusions section to make the instructional implications of the framework more explicit. Specifically, we now elaborate on the pedagogical relevance of the 3C-FSL by translating its core dimensions—complexity, controversiality, and contingency—into a set of guiding questions that can support the design of learning settings. These questions address both external and internal dimensions of sustainability issues and explicitly incorporate contingency as a key aspect of transformative learning processes.

lines 564-577:

"From a pedagogical perspective, this raises the question of how teachers can approach sustainability issues in ways that do justice to their complexity, controversiality, and contingency. Possible guiding questions include the following:

External complexity: What interdependencies and correlations characterize the issue within the field of tension between natural and socio-economic systems?
External controversiality: Which contrasts and incompatibilities are inherent in the issue?
Internal complexity: Which values, interests, norms, and perspectives are involved?
Internal controversiality: Which values, interests, and perspectives come into conflict with one another?
Contingency (individual and collective): To what extent can situations of individual and collective contingency be made experientially accessible and open to reflection in learning processes?"

Comment 2: Stronger articulation of the added value over existing approaches. The manuscript builds on established notions such as double complexity and controversy frameworks. A clearer statement of what the 3C Framework enables that previous models did not would strengthen its contribution.

Author Response

Revised Manuscript (Excerpt)

To further clarify the added value of the 3C-FSL in relation to existing approaches, we have revised mainly the Introduction and the Conclusions section.

In the Introduction, we now more explicitly position the framework in relation to established concepts such as double complexity and controversy-oriented approaches in order to make its distinctive contribution clearer from the outset.

In the Conclusions section, we further highlight how the 3C-FSL extends and goes beyond established concepts such as double complexity and existing controversy-oriented approaches. Specifically, we clarify that the framework not only builds on these perspectives but systematically integrates contingency as a constitutive dimension of sustainability issues. This addition allows for a more explicit consideration of the relational, uncertain, and processual nature of societal transformation.

lines 53-69:

"In doing so, sustainability issues are both treated as thematic fields and conceptualized as structurally characterized learning objects. This structure is synthesized in the 3C Framework for Sustainable Learning (3C-FSL), which captures sustainability issues in terms of their interrelated dimensions of complexity, controversiality, and contingency. The development of this framework builds on and extends the concept of double complexity (Bögeholz & Barkmann, 2005; Eggert & Bögeholz, 2006; Mehren et al., 2015; Ohl, 2013, 2018), which has been used to describe the factual and normative challenges of sustainability-related topics, by incorporating a stronger consideration of controversiality and contingency. In particular, the sociologically grounded concept of double contingency (Luhmann, 1984) is used to conceptualize transformative learning processes as fundamentally relational, uncertain, and dependent on reciprocal expectations within social interactions (Billi et al., 2024). Drawing on Integral Sustainability Science (Shrivastava et al., 2020), we further propose a systematic integration of interior and exterior dimensions of learning. This approach connects subjective experiences, emotions, and processes of meaning-making with the structural and material conditions of socio-ecological realities. In doing so, it seeks to overcome dualistic perspectives and to foreground the relational constitution of learning processes."

lines 554-563:
"To understand transformative processes, we, therefore, extend the concept of double complexity to include controversiality and contingency. In doing so, the 3C Framework for Sustainable Learning goes beyond existing approaches that primarily focus on complexity by explicitly integrating contingency as a constitutive dimension of sustainability issues, thereby enabling a process-oriented perspective on societal transformation. On the one hand, this emphasizes the need to engage with, negotiate, and critically reflect on controversial sustainability issues as socio-ecologically embedded conflicts (e.g., Daengeli & Kalcsics, 2026); on the other hand, it incorporates double contingency as a sociologically grounded analytical lens, thereby avoiding a narrow focus on the analysis of complexity and controversiality and instead foregrounding processes of societal transformation"

Comment 3: More explicit translation into pedagogical practice. The conclusions emphasize educational implications, but the article stops short of proposing concrete design solutions. Given that transformative education ultimately unfolds in practice, a more explicit bridge between theory and pedagogical application would enhance the manuscript’s relevance.

Author Response

Revised Manuscript (Excerpt)

To strengthen the connection between the theoretical framework and its pedagogical application, we have revised the manuscript in several ways.

First, we have made the practical orientation of Section 3.4 more explicit by adding the subtitle “in Pedagogical Practice.” In addition, we have introduced this section with a short paragraph that situates the simulation game “Unk City” as a concrete example of how sustainability-related complexity, controversiality, and contingency can be translated into classroom practice, particularly for students in Grades 5 and 6.

Furthermore, we have expanded the Conclusions section by outlining how ongoing work at the UNESCO Chair [...] builds on the 3C Framework for Sustainable Learning and ESD 3 to develop models for students’ learning, teachers’ professional competencies, and the design of sustainability-oriented learning environments. In doing so, we highlight that this ongoing work explicitly addresses the bridge between the theoretical framework and its pedagogical implementation, while deliberately not anticipating the outcomes of this work.

lines 486-487:

"3.4. “Unk City” as an Example of Sustainability-Related Complexity, Controversiality, and Contingency in Pedagogical Practice"

lines 488-492:

"The simulation game Unk City described below is designed for use particularly in Grades 5 and 6 and thus directly addresses pedagogical practice. By means of a real-world-related simulation of urban development, central challenges of sustainable development become tangible for students at this age and are translated into collaborative processes of negotiation and decision-making."

lines 626-630:

"In this context, ongoing work at the UNESCO Chair [...] builds on the 3C Framework for Sustainable Learning and ESD 3, as outlined in this article, to develop models that address (1) students’ learning in sustainability, (2) teachers’ professional competencies, and (3) the design of sustainability-oriented learning environments."

Thank you again for your valuable feedback.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have revised the manuscript very well and have addressed the previous comments appropriately. The revised version shows clear improvement in terms of clarity, structure, and overall presentation. The responses to the reviewers are adequate, and the revisions made are consistent with the concerns raised during the review process.

In its current form, the manuscript is much stronger and demonstrates that the authors have carefully considered the suggestions provided. The content is now clearer, more coherent, and better supported. Overall, the revision is very good, and the manuscript is suitable for publication in its present condition.

I have no further major comments. The paper is worthy of publication as revised.