Outdoor Education for Sustainable Development: A Systematic Literature Review

Abstract

Education is the foundation of sustainable development, and the world is in the practice period of sustainable development education (ESD). Even though ESD is widely accepted in principle, there has not been much “structural change” in practice. Given the significant advantages that outdoor education provides in cultivating future sustainable leaders, it appears that outdoor sustainable development education (OESD) has a lot of space to expand. This study employs bibliometric and coding analysis to examine the features of 40 works that are indexed in Web of Science and Scopus between 2005 and 2024. It also conducts a systematic evaluation of the research emphasis and development trend of OESD. The study revealed that research has gone through a process of initial exploration, significant growth, and then decline and reflection. The study identifies the main countries and institutions active in the field of OESD and their co-operation with each other. Finally, the development path analysis reveals four key research topics and three research changes in OESD.

1. Introduction

1.1. Research Background

In the field of education in the 21st century, Education for Sustainable Development (ESD) is emerging as the center of global education reform. Through the 2030 Agenda for Sustainable Development [1,2], the United Nations has positioned education as a key pathway to achieving the Sustainable Development Goals (SDGs), emphasizing the important role of education in fostering global citizenship and promoting environmental, social, and economic sustainability. ESD empowers learners to take informed decisions and responsible actions for environmental integrity, economic viability, and a just society, for present and future generations, while respecting cultural diversity. It is about lifelong learning and is an integral part of quality education [3]. In this context, countries have been incorporating ESD into their education systems, for example, Finland has proposed in its National Core Curriculum that the key objective is to increase students’ basic education in sustainable lifestyles [4]. The UK has also emphasized the importance of environmental education in its national curriculum, and the Department for Education has introduced a number of strategies such as “Sustainability and Climate Change: A Strategy for the Education and Children’s Services Systems” to empower sustainable development through education [5].

Although ESD is widely accepted in principle and actively supported in practice, its fundamental place in the contemporary educational system is still unstable, and there are still numerous implementation challenges. First, the ambiguity of the concept of sustainability and the divergence of educational goals—sustainability is an abstract concept, which involves the balance of three dimensions: environment, society, and economy [6]. There are many explanations in different cultures, backgrounds, and disciplines. The diversity and interdisciplinary nature of this definition make it difficult for educators to reach a consensus, affecting the clarity of educational goals and the consistency of implementation [7]. Second, the limitations of teaching methods and content—this is manifested in the dependence on traditional teaching methods, the lack of diversified teaching methods, and the disconnection between teaching content and sustainability. Diversified teaching approaches are required since traditional teaching approaches are unable to adequately address the complexity of sustainability challenges [8]. The majority of environmental teaching units do not improve students’ awareness of environmental values or their capacity to take action, instead, they merely impart knowledge, values, and theories pertaining to sustainability [9,10]. In addition, traditional educational programmes fail to provide an adequate environment for the integration of interdisciplinary knowledge required for ESD, resulting in a lack of student engagement [11].

The promotion of ESD is therefore more than a simple addition of curriculum content, which means that its learning space must be expanded to meet the needs of students in many areas, such as cognitive development, critical thinking, action skills, global perspective, and social responsibility. This expansion is not only an expansion of physical space, but also a deepening of educational connotations and practices. Against this backdrop, Outdoor Education (OE) has begun to gain attention as a unique pedagogical approach that has been widely proven to be advantageous in fostering students’ environmental awareness, social responsibility, and global citizenship [12,13]. OE serves as a practical extension of ESD, translating its cross-dimensional concepts (environment, society and economy) into a tangible action framework, thereby bridging the gap between abstract awareness and concrete participation. “Outdoor” provides a testing ground for embedding the learning process in authentic social and ecological environments, where students interact with each other in different environments, and such interactions contribute to the generation of knowledge as well as to the construction of ecological identities and the recognition of themselves as part of the natural and social ecosystems. This sense of identity promotes a sense of belonging to the environment and conservation behaviors, leading to a deeper understanding of the complexity and multidimensionality of sustainable development [14,15].

Yet OE has been identified in academic research with several shortcomings. Firstly, biased pedagogical content: OE focuses too much on teaching skills and personal traits (e.g., character qualities) but neglects the relationship between humans and nature [16,17,18]. This single mode of teaching, which favours factual scientific knowledge, fails to adequately cover a wider range of environmental and ecological topics, limiting the breadth and depth of educational content. ESD emphasizes the integrity of environment and society, which can help OE pay attention to environmental protection and sustainability while paying attention to personal development. Secondly, the fixity of teaching methods: Fieldwork activities typically adhere to predetermined routes, activities, and content, exhibiting a high level of proceduralism and standardization [19]. This methodological and pedagogical rigidity hinders educational innovation and adaptability and underutilizes the wealth of outdoor learning opportunities. The integration of ESD can bring diversified teaching strategies for OE, which encourage students to actively explore and question, and thus promote the innovation of sustainable solutions. ESD requires students to connect classroom knowledge with real-world challenges, which helps to break the limitations of traditional teaching and improve the relevance and effectiveness of education. Thirdly, there is an imbalance in educational practices: outdoor education practices are often dominated by recreational or curricular enrichment, failing to adequately integrate the field trip experience and leading to an emphasis on personal and social relationships over environment [20]. In addition, fieldwork programmes may focus too much on either the “fieldwork” itself or the “education” itself, failing to balance the two, thus compromising the maximization of educational outcomes [21]. Research indicates that just leaving the classroom does not ensure that knowledge is acquired, even though OE is thought to improve the learning impact [22,23]. Furthermore, no learning benefit can be guaranteed by the environment alone, which highlights the necessity for expert assistance when educators plan and carry out outdoor activities [24]. However, ESD can provide a framework for OE to go beyond mere entertainment, turn to a wider range of environmental and social considerations, and strengthen interaction and emotional connection with nature, so as to improve the learning effect. To sum up, by integrating ESD, OE can cultivate students’ environmental awareness, social responsibility and sustainable skills in a more comprehensive way, so as to prepare for the challenges of the 21st century [25,26,27,28].

For this reason, we advocate for Outdoor Education for Sustainable Development (OESD). What connection exists between ESD and OE? First, the congruence of educational goals: Both place a strong emphasis on cultivating a profound awareness of and sense of responsibility for the environment. Understanding sustainability requires a relationship to nature [26], particularly when it comes to developing an emotional bond and a cognitive comprehension of the natural world. Experiences in natural settings can arouse students’ innate drive for sustainability, highlighting OE’s vital role in ESD [16]. Second, the educational process is interactive. OE frequently uses inquiry-based and experiential learning approaches, which allow students to learn through interaction and deepen the learning process. ESD also promotes participation, with the aim of empowering each person to become a citizen who can contribute to the sustainable development of society. In addition to teaching children about sustainability, taking them outside stresses personal accountability and gives them a chance to address community problems. Global awareness and a sense of personal accountability for environmental acts are two important citizenship traits that ESD promotes, and this educational approach aids students in developing both [8]. OE offers authentic learning opportunities and first-hand experiences in real-life situations, which can greatly improve classroom learning by supplementing classroom experiences and reiterating classroom knowledge. Furthermore, OE raises students’ knowledge of environmental issues, fosters positive attitudes, motivation, and interest in the subject matter, and connects cognitive, sensory, and emotive appeals to promote the relationship between humans and nature [29]. Third, OE’s potential worth in supporting socially integrated education can be expanded by employing it as a medium for ESD communication, exposing students to authentic social and natural settings, and utilizing learning as a means of attempting to connect with the outside world [30]. It breaks the boundaries of traditional classroom education, promotes students’ understanding of global issues, and encourages them to take action and contribute to the achievement of the SDGs.

1.2. Research Questions

As a young and vibrant field of education, OESD is progressively bridging the gap between natural environment, social responsibility, and sustainable development. After reviewing previous studies, it becomes evident that this field has achieved discernible scholarly progress. Theoretically, researchers have thoroughly examined OESD’s conceptual frameworks [7,31], consistently underscoring the transformative potential of OESD in advancing sustainability literacy [32,33]. Empirically, existing scholarship predominantly comprises specific course design and teaching methods, ranging from localized environmental stewardship programs to school-based sustainability curricula [34,35,36,37]. Despite its growing prominence, the academic discourse on OESD exhibits a notable fragmentation, which restricts the theoretical depth and practical application breadth of the field. To help promote the transformation and upgrading of OE in the context of the era of ESD and to jointly contribute to the realization of global sustainable development goals, this systematic literature review aims to provide an overview of the current situation, trends, and prospects of OESD. It also hopes to encourage more in-depth exploration and innovative practice in OESD and point out new research directions and practical strategies for the future development of this field.

The study aims to address the following research questions:

• What are the trends in the annual distribution of OESD?
• What are the research development trends and core elements of OESD?
• What are the highly productive countries and regions in OESD?
• What are the challenges and opportunities in OESD?

2. Data and Methods

2.1. Data Collection and Processing

High-quality studies, often rigorously peer-reviewed, reflect the latest research findings and scientific advances, and are essential for developing a comprehensive and in-depth understanding. We chose Web of Science and Scopus as data sources because of their high-quality indexing and citation analysis functions. They are often used to evaluate academic influence and track the research context. This study followed the PRISMA 2020 system review report specification [38]. The relevant literature was retrieved from both databases for the period 2005 to 2024. To ensure the comprehensiveness of the data, the titles, keywords, and abstracts of the literature were screened and analyzed in detail during the search process.

The initial search was conducted in September 2024, applying Boolean logic with the subject terms (“Outdoor education” OR “Experiential education” OR “Field trip” OR “Experiential tourism” OR “Study tourism” OR “Learning travel”) AND (“Education for Sustainable Development” OR “Sustainable Development Education” OR “Education for Sustainability” OR “Sustainability Education” OR “ESD” OR “EfS”). The following inclusion and exclusion criteria were established for this paper (

Table 1. Inclusion and exclusion criteria.

Types	Criteria
Inclusion criteria	The study area is from 2005 to 2024
	The data extracted align with the current study’s focus and research questions
	Full text available in English
Exclusion criteria	Without OE used
	Irrelevant to ESD
	Written in other languages
	Book chapter

). Two researchers separately finished the preliminary screening and full-text evaluation of the literature, closely adhering to the screening procedure to guarantee the accurate screening of the research literature. Furthermore, until they came to a consensus, the two researchers deliberated and discussed the contentious papers. Through a standardized operation and cross-validation mechanism, subjective deviation is effectively controlled, which offers a solid foundation for analysis.

2.2. Analysis of Document Coding

After that, the documents were loaded into NVivo Plus, a potent tool for qualitative data analysis that allowed us to code, organize, and query a significant amount of textual data from the documents. To classify the data, several nodes were made, including “pedagogy”, “teacher training”, and “discipline”. We were able to find important themes and patterns in the literature by using these codes. In order to better comprehend the connections between the literature data, we also utilized NVivo Plus’s query function to look for particular text segments and visualization tools.

3. Results

Figure 1 depicts a flowchart delineating the search and selection process, conducted in alignment with the predefined protocol and adhering to the PRISMA guidelines. After progressive screening and rigorous review, a total of 40 articles that met the established criteria were identified for the bibliometric review and subsequent in-depth analyses.

Table 2. Study characteristics.

ID	Reference	Year	Article Type	Target Group	OESD Topics
ID1	[16]	2017	Qualitative research	Teachers	Teacher Training and Pedagogical Approaches
ID2	[11]	2020	Quantitative research	Students	Community Engagement and High School Curriculum
ID3	[39]	2022	Qualitative research	Teachers	Digital Transformation and Teacher Training and Intercultural Learning
ID4	[40]	2019	Theoretical research	Teachers	Educational Practice and Development of Systems Thinking Skills
ID5	[41]	2016	Theoretical research	Teachers	Education Policy and Practice and Teacher Training and Environment and Sustainability
ID6	[33]	2019	Theoretical research	Students	Educational Practice and Learning Landscapes and Student-Centered
ID7	[24]	2017	Quantitative research	Students	Technology Integration and Virtual Field Trips and Educational Innovation
ID8	[42]	2018	Action research	Students and Learning Environment	Interdisciplinary Learning and Experiential Education and Sustainable Food Systems
ID9	[26]	2017	Quantitative research	Students and Teachers	Biology Education and Environmental Awareness
ID10	[43]	2013	Action research	Students and Learning Environment	Learning Outcomes and Environmental Education
ID11	[8]	2020	Action research	Students and Learning Environment	Place-based Education and Interdisciplinary Learning
ID12	[44]	2019	Theoretical research	Teachers and Students	Early Childhood Education and Teacher Professional Development
ID13	[22]	2018	Qualitative research	Students and Learning Environment	Environmental Experience and Educational Transformation
ID14	[45]	2017	Action research	Teachers and Learning Environment	Teacher Professional Development and Systems Thinking and Educational Sustainable Practices
ID15	[7]	2020	Theoretical research	Environmental education and ESD	Sustainability Values and Global Citizenship Education
ID16	[9]	2014	Quantitative research	Teachers	Teacher Professional Development and Environmental Awareness Enhancement and Practice-Oriented Teaching
ID17	[29]	2021	Quantitative research	Students	Environmental Knowledge Acquisition and Comparative Education Methods
ID18	[19]	2018	Quantitative research	Students	Learning Outcomes and Environmental Values
ID19	[6]	2014	Qualitative research	Learning Environment	Education Policy Evolution and Outdoor Education Practices and Environmental Education Challenges
ID20	[46]	2014	Qualitative research	Students	Community Engagement and Sustainability Practices
ID21	[20]	2012	Theoretical research	Learning Environment	Outdoor Learning Experiences and Environmental Philosophy
ID22	[31]	2013	Theoretical research	Teachers and Learning Environment	Outdoor Learning and Place-based Response
ID23	[37]	2018	Action research	Students and Learning Environment	Multicultural Education and Experiential Learning
ID24	[36]	2005	Theoretical research	Teachers and Students	Outdoor Recreation Practices and Curriculum Integration and Social Justice and Inclusivity
ID25	[47]	2017	Action research	Students	Educator Training and Student Development and Interdisciplinary Integration
ID26	[21]	2016	Quantitative research	Students	Educational Experience and Cross-cultural Communication
ID27	[48]	2018	Quantitative research	Students and Learning Environment	Environmental Knowledge Enhancement and Behavioral Intentions and Field Learning Experiences
ID28	[49]	2023	Action research	Students	Field Learning and Cultivation of Systems Thinking Skills
ID29	[28]	2021	Quantitative research	Students	Educational Integration and Community Engagement and Regional Sustainability and Interdisciplinary Learning
ID30	[50]	2024	Qualitative research	Teachers and Students	Service Learning and Digital Empowerment and Educational Transformation
ID31	[35]	2020	Action research	Students and Learning Environment	Campus Engagement and Interdisciplinary Education
ID32	[51]	2015	Action research	Teachers and Students and Learning Environment	Practice Learning and Community Engagement
ID33	[34]	2018	Action research	Students	Digital Education and Interdisciplinary Learning
ID34	[27]	2019	Theoretical research	Teachers and Students and Learning Environment	Educational Methods and Geographical Awareness
ID35	[52]	2020	Quantitative research	Students and Learning Environment	Educational Methods and Biodiversity
ID36	[53]	2019	Quantitative research	Students	Educational Methods and Interdisciplinary Learning
ID37	[54]	2020	Theoretical research	Teachers and Students and Learning Environment	Environmental Awareness and Children’s Agency and Sustainable Development Practices
ID38	[55]	2023	Action research	Teachers and Students	Artistic Practice and Mental Health and Environmental Sustainability
ID39	[56]	2023	Action research	Teachers and Students and Learning Environment	Environmental Education and Indigenous Education and Place-based Education
ID40	[30]	2018	Theoretical research	Students	Corporate Social Responsibility and Service Learning and Community Engagement

provides an overview of the gathered research.

3.1. Yearly Distribution of OESD

OESD research has gone through a process of starting from exploration (2005–2016), then fluctuating growth (2017–2020), and finally entering decline and reflection (2021–2024) (Figure 2). The strengthening and reorganization of OESD research in academia is reflected in this trend. During the early exploratory phase (2005–2016), researchers evaluated prior findings while investigating novel approaches and perspectives. The number of publications was on the rise from 2017 to 2020, which could be attributed to the advancement of international education policy and the expansion of innovation in teaching methods. A little decrease in publications occurred in 2019 due to the worldwide pandemic, but the number of publications in 2020 remained high. The number of publications continues to fall between 2021 and 2024, suggesting that the research’s focus may be changing and reflecting the in-depth analysis and integration of OESD research in academia. This may also be a result of better research quality and more sophisticated research methodologies, even though the volume of publications may have decreased. To address the new issues facing global education, researchers are looking for more creative research techniques and more successful practice tactics.

3.2. Prolific Institutions and Countries/Regions

An exhaustive visualization of research contributions and international collaborations in the field of OESD reveals the research dynamics and international collaboration among countries on a global scale (Figure 3). A collaboration network comprising 29 countries was constructed and analyzed using Cite Space, yielding 19 edges with a network density of 0.0468. This network density suggests that, despite existing collaborations, significant potential exists for expanding and deepening collaborative relationships.

The US and the UK, each contributing six studies, demonstrate their pivotal roles in shaping the trajectory and advancement of OESD research. Following the US and the UK, Germany, Canada, and Finland are significant contributors to OESD research, producing five, four, and four publications, respectively. Moreover, countries involved in this field span the globe, including Japan, Spain, Norway, Turkey, Belgium, France, Australia, New Zealand, South Korea, Switzerland, Poland, Chile, Brazil, Denmark, and the Netherlands, reflecting the global and diverse nature of OESD research.

Among these countries, some exhibit research strengths in specific topics or methodologies due to their geographical location, cultural background, level of economic development, and educational frameworks. For example, Nordic countries such as Sweden, Norway and Finland have in-depth research in environmental education and outdoor learning. Scotland’s research emphasizes the potential of OE to facilitate students’ direct engagement with the environment, thereby fostering local perception and sustainable development [41]. Similarly, several East Asian countries focus their research on the relationship between students’ learning outcomes in OE projects and the development of sustainable social-ecological systems [21]. Through international co-operation, countries are able to learn from each other, complement each other’s strengths and work together to advance OESD globally.

An in-depth visualization of the research contributions and collaborations of OESD’s prolific institutions was carried out to reveal the main institutions active in the field and their collaborative relationships with each other (Figure 4). The network mapping shows 74 nodes (institutions) and 40 edges (collaborations) with a network density of 0.0148, suggesting that there is some degree of collaboration between these institutions, but that the breadth and depth of the collaboration could be further enhanced. From the network mapping, it can be seen that the institutions involved in OESD research are spread all over the world, covering different regions and disciplinary backgrounds. The position of these institutions in the network and the size of their nodes reflect their research output and influence in the field. They mainly include Faculty of Education, School of Education, and Department of Early Childhood Education, emphasizing the key role of education faculties in promoting OESD research.

In addition, the network mapping revealed some specific research areas, Department of Agricultural Economics, Department of Organic Food Quality and Food Culture, School of Education and Social Care, Department of History Geography and Social Science, and Department of Environmental Science and Ecological Engineering. The diversity of these research themes reinforces the fact again that OESD is a multidisciplinary and cross-cutting research area that requires the participation and contribution of organizations from different backgrounds.

3.3. Research Topics of OESD

The hot keywords in this area can be found by examining the keyword co-occurrence data (Figure 5). There are 206 nodes and 119 co-cited links in the term co-occurrence graph. The network’s density is 0.0056, and the OESD indicates a notable trend of depth and diversification.

Then, by grouping related keywords into a cluster diagram, the research topics are summarized visually (Figure 6). The efficacy of these clusters is quantifiably assessed through two pivotal metrics: Modularity (Q-value) and Silhouette (S-value). The Q-value is 0.7505, which is greater than 0.3 indicating significant cluster structure. The S-value is 0.9477, with scores reflecting the homogeneity of the clusters. An S-value above 0.5 is considered reasonable, while one above 0.7 indicates highly convincing clusters. The cluster map reveals several key research topics in the OESD field: #0 Transformative Sustainability Education, #1 Systems Thinking, #2 Nature-based Experiences, #3 Community, #4 Interdisciplinary Sustainability Education, #5 Service-learning, #6 Higher Education, #7 Teacher Professional Development, #8 Place-based Education, and #9 Learning for Sustainability. The eight research topics above are categorized into four aspects for analysis.

3.3.1. Roots: Theories and Disciplines

#0 Transformational Sustainability Education (TSE) advocates transitioning from traditional educational paradigms to those that are more inclusive, participatory, and reflective of the complex realities inherent in sustainability issues. TSE provides a theoretical framework for OESD, the core of which is to promote deep-seated changes in consciousness and behavior to cope with the environmental and social challenges caused by current human activities. TSE highlights the shift from a mechanistic and segregated educational paradigm to a relational ontology-based model, which asserts that all entities are fundamentally interrelated and interconnected. This epistemology recognizes our relationship with life on earth and beyond the human world, and provides a newer and interdependent way of existence and cognition [57].

Additionally, TSE focuses on the interactions between ecological, social, and economic systems which matches the interdisciplinary nature of OESD. #4 Interdisciplinary sustainability education emphasizes the importance of interdisciplinary integration, and now OESD shows a wide range of natural disciplines, covering geography, chemistry, biology, science, and other fields (

Table 3. Discipline analysis coding results.

Discipline Classification	ID	Total
Geography	ID3, ID5, ID7, ID13, ID16, ID19, ID22, ID24, ID28, ID29, ID34	11
Chemistry	ID16, ID25	2
Biology	ID7, ID9, ID13, ID16, ID19, ID24, ID25, ID29, ID35	9
Science	ID1, ID12, ID14, ID23, ID25	5
Interdisciplinary course	ID2, ID5, ID8, ID9, ID11, ID12, ID14, ID15, ID16, ID18, ID22, ID25, ID26, ID27, ID28, ID29, ID30, ID31, ID32, ID33, ID34, ID36, ID37, ID39	24

). OESD places a high value on interdisciplinary integration in educational practice, as evidenced by the fact that interdisciplinary curricula dominate the organization and have the highest ID numbers, totaling 24. In OESD, interdisciplinary synergy is crucial since techniques and information from several fields can support and strengthen one another. Geography and biology are the most involved subjects in OESD, and geography provides knowledge of the spatial distribution and change of environment and ecosystem. For example, Hill discussed the intersection of outdoor learning and sustainable education, and pointed out that the application of geography in OESD was reflected in its deep understanding of location and environment [31]. Mammadova illustrated this by organizing a field trip centered on observing the flow direction of the Tedori River. Through this activity, students gained insights into how the river shaped Hakusan’s geographical landscape and learned about the interactions between the natural environment and human activities [28]. Biology offers critical insights into biodiversity and ecological processes within ecosystems, which are essential components of OESD. Jeronen et al. pointed out that biology was very important for understanding sustainable development, especially in the fields of ecology, biological protection and systems biology [26].

3.3.2. Practice: Experiences and Actions

#2 Nature-based experiences emphasize the direct interaction with nature, which provides learners with opportunities to learn natural systems, develop attachment to places, produce positive spillover effects [58]. OESD promotes learners’ environmental awareness and behavior changes through experiential learning, as well as their deep critical and systematic understanding of environmental issues. On this basis, #8 Place-based Education further deepens this connection, emphasizing the deep relationship and mutual connection with specific places and cultures. Place-based teaching is the most frequently used teaching method, with nine codes, which enhances the practical significance and depth of learning (

Table 4. Teaching methodology analysis coding results.

Teaching Method	ID	Total
Place-based teaching	ID1, ID6, ID11, ID14, ID21, ID31, ID32, ID34, ID39	9
Problem-based learning	ID6, ID9, ID12, ID20, ID31, ID34	6
Phenomenon-based teaching	ID1	1
Inquiry-based learning	ID1, ID9, ID12, ID16, ID34	5
Project-based learning	ID6, ID9, ID12, ID15, ID20, ID31	6
Collaborative learning	ID2, ID8, ID9, ID28, ID34, ID37	6
Mobile learning	ID28, ID36	2
Paper-and-pencil learning	ID28	1

). The coding results show that there are many teaching strategies in OESD, including problem-based teaching, phenomenon-based teaching, inquiry-based teaching, project-based teaching, collaborative teaching, mobile teaching, and paper-and-pencil teaching.

Despite their different forms and implementations, these pedagogies share three core features: student-centered, practice-oriented, and interactive and collaborative. There is a general emphasis on active student engagement and enquiry, placing students at the center of the learning process and encouraging them to construct knowledge through self-driven learning and reflection. There is a tendency to integrate learning activities with real-world contexts, enabling students to apply and validate theoretical knowledge in real-world settings. In addition, these approaches usually involve collaboration among students and interaction between students and teachers and community members. Through group discussions, collaborative learning, and the sharing of resources, students are able to develop social skills, communication skills, and collective problem-solving abilities. In addition to promoting knowledge sharing and deepening, this dynamic and co-operative teaching and learning environment gives students the opportunity to work in a variety of teams, which is essential for their future professional development and social engagement.

3.3.3. Connection: Community and Academia

#3 Community plays a vital role in OESD. Community participation not only enhances the relevance of education, but also promotes environmental awareness and responsibility through practical actions. Community projects, such as urban agriculture, community gardens, and local conservation work combine traditional knowledge with modern sustainable practices and provide a multi-dimensional learning environment for sustainable development. For example, in Thomas’s “Civic Florence” course, through co-operation with local community partners, students could deeply understand the operation of nature and civil system in cities [8]. Through the “Earth, Wind, and Fire: Sustainable Energy for the 21st Century Reu” project, Griswold provided opportunities for students to interact with local community residents and organizations involved in sustainable work, and promoted their role change in creating a sustainable society [47].

#6 Higher Education embodies the important role of higher education in promoting OESD. Firstly, higher education fosters disciplinary research by integrating diverse fields. Higher education institutions are platforms and resources for disciplinary research, which can integrate environmental science, sociology, economics, pedagogy, and other multidisciplinary knowledge. Secondly, higher education emphasizes practical applications that prepare students for future decision-making roles. Today’s students are tomorrow’s decision makers. This kind of practical education not only helps students to develop critical thinking and problem-solving abilities, but also cultivates their sense of social responsibility and leadership. Thirdly, researchers and decision-makers in higher education are instrumental in reforming educational structures and devising policies for sustainable development. Higher education institutions hold a unique and irreplaceable position in shaping these policies and strategies. For instance, Duram and Klein highlighted that university food parks, by integrating campuses with local communities and offering organic food, enhanced campus sustainability awareness [51]. Similarly, Migliorini et al. conducted an online survey across eight European universities to assess students’ knowledge and expectations regarding sustainable food systems. Their findings revealed a strong interest in outdoor field trips and experiential learning [53].

#5 Service learning (SL) represents a pedagogical approach that integrates academic objectives with community needs. This integration enhances students’ participation, cultivating students’ deeper connection, sense of responsibility, and management identity. SL is a deep learning strategy that necessitates critical reflection during community service participation. In the process of reflection after service, students link their personal actions with broader sustainable goals, thus promoting their personal growth and career development. Huda et al. emphasized that SL promoted the combination of individual needs, community responsibility awareness, and sustainable moral values by investigating SL projects implemented in several higher education institutions [30].

3.3.4. Cultivation: Educators and Learners

Teachers and students lie at the core of the educational process, with #1 systems thinking and #9 learning for sustainability being primary objectives cultivated through OESD. In the context of OESD, the role of educators as change agents has been significantly strengthened. #7 Teacher Professional Development reflects the in-depth thinking of educational researchers on how to promote OESD through reforms within the education system. Teachers are required to have future-oriented and anticipatory thinking, and are encouraged to become experimenters of educational innovation. The role of teachers has changed from traditional knowledge transmitters to guides and facilitators, and this shift has led to changes in teachers’ roles and professional growth.

OESD teachers need to constantly update their knowledge systems and experiment with new teaching methods and strategies, and they are able to improve their own professional skills and sensitivity to environmental issues while preparing for and implementing OESD. For example, Karaarslan Semiz and Teksöz designed an outdoor ESD course. Participation in this study developed the systematic thinking skills of preparatory science teachers [40]. Similarly, Ateskan and Lane implemented an ESD professional development project in Turkey. Through summer seminars and community projects, teachers improved their systematic thinking skills and achieved significant progress in understanding environmental, social, and economic interrelations [45]. Additionally, OE improved students’ ability to identify aspects of sustainable development, comprehend systemic interrelationships, and analyze systems across various spatial scales [49].

3.4. Developmental Changes of OESD

After carefully analyzing the timeline of the literature keyword clustering in the ESD field, it was found that OESD had changed in teaching content, education stage, and teaching technology, reflecting the shift of researchers’ perspective and the increase of research depth (Figure 7).

3.4.1. Change 1: Teaching Content

Before 2016, the concept of OESD began to sprout. Researchers have explored and defined the role of OE in promoting environmental awareness and cultivating a sense of environmental responsibility through educational activities. During the period from 2017 to 2020, “interdisciplinary”, “biology education”, and “geography education” showed that educators tried to enhance the depth and breadth of OESD by integrating the knowledge of different disciplines. After 2020, the content of OESD was innovatively adapted to address evolving environmental and societal needs. The innovation of educational content includes in-depth discussion on topics such as “ecosystems” and “climate justice”, which are key components of OESD. For example, O’Connell et al. argued that outdoor experiences, such as studying global climate change, the rapid loss of ecosystems and species, and the depletion of the ozone layer, enhanced students’ understanding of environmental issues. However, they stressed that although understanding these issues was essential to cultivate environmentally responsible citizens, it must be combined with feasible solutions and action skills to avoid the negative effects of apathy and cynicism [36].

3.4.2. Change 2: Education Stage

Before 2017, OESD was mainly practiced in “high schools”, “secondary schools”, and “primary education”, and around 2020 OESD paid more attention to “early childhood education” and “citizen education”. “Early childhood education” highlights the fundamental role of early childhood education in promoting OESD. Cognitive development in early childhood is realized through interaction with the environment. OESD provides young children with a wide range of spaces for exploration and rich materials to stimulate their creativity and imagination. Through direct sensory experiences, such as touching different plants and observing animal behavior, it helps to cultivate a sense of responsibility for environmental protection and a sense of sustainable development in young children, who are able to understand the world more profoundly, thus promoting the development of cognitive structures. Through hands-on activities like touching plants and observing animals, children develop environmental responsibility and sustainability awareness. These experiences deepen their understanding of the world, enhancing cognitive growth. OESD provides young children with a wealth of opportunities for social interactions. Through cooperative play and group activities, young children learn how to communicate with others, share resources, and resolve conflicts, thus developing social-emotional skills. OESD also contributes to young children’s health and promotes confidence in their physical abilities and self-efficacy. For example, Bascopé et al. thought that the Anthropocene required a new and more real education, changing to a more comprehensive and sustainability-oriented approach [44]. Wolff et al. discussed the challenges of the Anthropocene to education, including global issues such as climate change and biodiversity loss, and how outdoor learning and games could help children understand and cope with these challenges [54].

3.4.3. Change 3: Teaching Technology

From 2020 to 2024, educators began to use digital technology to enhance the interactivity and accessibility of OESD. “Digital empowerment”, “virtual field trips”, and “virtual service-learning” reflect the application of technology in OESD, and these technologies provide students with new learning methods and experiences. For example, Palaigeorgiou et al. implemented virtual field trips using drones in ESD courses and examined their impact on outdoor learning experiences. Their findings revealed that students exhibited significant interest and a positive attitude toward drone-facilitated virtual field trips, considering them an engaging and enjoyable mode of learning. In some respects, drones offered advantages over traditional field trips, such as providing more detailed perspectives from greater heights [24]. Leininger-Frézal and Sprenger studied the opportunities and challenges of incorporating virtual field trips into pre-service and in-service training for geography teachers, focusing on sustainable development in two universities. They observed that participants displayed a positive attitude and strong interest in using virtual field trips to explore geographical spaces and identify sustainability issues [39].

4. Discussion

4.1. How to Understand “Outdoor”

“Outdoor” refers to the natural environment, specifically the physical spaces where OESD takes place. Additionally, “outdoor” represents the freedom to choose an educational setting, encompassing activities conducted beyond the traditional classroom, such as in urban parks, forests, mountains, beaches, or community gardens. These locations provide opportunities for students to directly engage with nature, enabling observation, experiential learning, and the development of a comprehensive understanding of sustainable development within real-world contexts. The opportunity to observe and experience nature firsthand in outdoor settings significantly impacts students’ knowledge, attitudes, and behaviors. These experiential components are fundamental in fostering sustainability and enhancing students’ awareness of environmental challenges [26].

“Outdoor” should be understood not only as physical spaces but also as an active educational strategy incorporating multidimensional methods, content, and objectives. Firstly, “outdoor” represents an educational approach that broadens the conventional classroom framework, encouraging students to independently discover answers rather than relying on textbooks. Our findings indicate that, while each teaching approach employed in OESD possesses distinct characteristics, they all prioritize student-centered, practice-oriented, and interactive collaboration to address real-world challenges. These teaching strategies work well for increasing awareness of environmental issues and encouraging behavioral changes. Outdoor learning extends beyond acquiring factual knowledge; it includes encounters with non-human elements that may provoke discomfort and challenge students’ perspectives [22]. Therefore, unlike the fact-based teaching tradition, “outdoor” allows the brain, hands, and mind to participate in the development of transformative sustainable development learning at the same time. Secondly, “outdoor” also entails selecting educational content, with topics such as climate literacy, natural habitats, and sustainable urban development being key instructional themes identified in our research. OESD provides a variety of learning environments to understand how the natural system works dynamically and circularly, to recognize our position in this system, and to establish a solid connection with the human and non-human worlds. OESD facilitates an understanding of the Earth’s complex systems and fosters a profound connection with one’s local environment. Finally, “outdoor” in OESD reflects a primary educational objective: cultivating students’ environmental awareness and sense of responsibility. By engaging with outdoor environments, students gain an intuitive understanding of the natural environment’s fragility and the urgency of its protection. Such practical experiences help students forge connections with nature, serving as a critical foundation for understanding sustainability. OESD enables students to comprehend ecosystems, apply ecological thinking, and explore the interface between ecological science and society [7].

4.2. How to Understand “Sustainable”

“Sustainable” means “continuous engagement”. OESD is not merely a singular one-off event but a long-term process requiring learners to consistently engage with the outdoor environment and enhance their understanding of sustainability through experiential and practical activities. This engagement is cyclical, with learners’ behavior and attitudes changing over time as their understanding of the outdoor environment deepens. The key to sustained engagement is the creation of a long-term, interactive learning relationship that enables learners to continually apply and reflect on what they have learnt in different environments, leading to a sustainable lifestyle. Such dynamic engagement enhances learners’ environmental awareness, cultivates their sense of responsibility, and strengthens their capacity for action. It ensures that learners remain focused on sustainable development throughout various stages of their lives, empowering them to make meaningful contributions to sustainability in the future.

While biosphere reserves (BR) and geoparks (GP) are noted as the preferred sites for regional ESD [28], according to our research, the primary place for energizing and strengthening students’ sustainable practices is the community. Service learning plays a vital role in particular by establishing the relationship between course content and local learners’ real life. The service students perform in it is clearly related to the academic content of the course and meets the real needs of the community. In the process of continuous participation, they analyze problems, make decisions, take actions, reflect, and evaluate, and understand how to create sustainable community changes [50], allowing each member of the educational community to develop in a healthy and sustainable way and create successful sustainable development instruction. So, it can be found that OESD emphasizes capturing the educational possibilities of life. It could be a public garden, a campus food garden, or anyplace else in students’ everyday lives. By assembling curriculum materials through these nearby outdoor locations, these topics are infused with authenticity and urgency, providing additional ways to deepen learners’ interest [8]. For example, the garden is a huge untapped opportunity to reconnect the community with the natural world, which shows that connecting the network can inspire individuals’ attitudes and actions, ultimately contributing to a more sustainable future [48]. The outdoor campus is an opportunity to change the learning environment of sustainable development education [59].

“Sustainable” also denotes “continuous influence”, with OESD highlighting its long-term impacts at the individual, community, and societal levels. We discover that OESD encompasses all educational stages, including civic education, higher education, K–12 education, and early childhood education. Educational activities are not only imparting knowledge, but, more importantly, they can stimulate learners’ internal motivation and enable them to make sustainable choices in their future lives. Educated individuals not only grow but are also capable of transformation. This continuous influence is also evident in the dissemination of education. The sustainable behavior displayed by the educated in their daily lives will affect the people around them and form a good social atmosphere. This kind of influence is “slow” but “profound”. It can promote the society’s attention and practice of sustainable development in a wider range, form a virtuous circle, and promote more people to participate in the practice of sustainable development, thus realizing social changes.

4.3. How to Understand “Transformative Development”

4.3.1. Change for Teachers

Teachers play a crucial role in OESD. Their role has also become an active participant, not just a promoter of learning, their professionalism, behavior, and beliefs directly influence the success of education [16,60], yet teachers face many challenges. Firstly, the lack of personal outdoor experience is a significant factor that hinders teachers’ implementation of OESD. The successful implementation of OESD requires teachers to have the appropriate professional knowledge and skills, but the current generation of teachers who grew up indoors feel unconfident due to their lack of direct connection with nature, which limits their ability to teach in outdoor environments [9,26], leading to difficulties for teachers in designing and implementing OESD activities. Secondly, the difficulty of stepping out of their comfort zone and bureaucratic constraints are also challenges faced by teachers. Teacher training and practice are “so rooted in bureaucracy that the progress made so far may not be enough to elevate sustainability education to the level of attention it needs”, and the mechanism of standardized testing does not invite teachers to teach in a way that promotes the development of students as informed and engaged citizens [8]. These bureaucratic constraints lead to teachers feeling constrained in their attempts to conduct OESD and struggling to innovate and adapt to new teaching methods. Teachers are expected to be creators of curriculum and not merely transmitters of curriculum developed by others. Teachers must not only impart knowledge but also implement comprehensive and integrated strategies to address the complexity of sustainability issues [44]. As a result, implementing OESD programs increases teacher’ workload and adds greater responsibility for the learning process compared to traditional classroom teaching [33,42].

4.3.2. Change for Students

Can teenagers change the world? Yes, their vitality and innovation are shaping the future. Through its comprehensive education method, OESD has a comprehensive impact on students’ cognition, sentiment and social skills, laying a solid foundation for them to become responsible global citizens. Research shows that OESD can effectively improve students’ systems thinking. Systems thinking is not about components, but about the dynamic interrelationships among components [49]. Students learn to understand the interdependence and wholeness of complex problems, and to analyze and solve problems from a macro perspective, which is the key to systems thinking. By analyzing the word cloud image of the coding result (Figure 8), OESD also cultivates students’ key ability to solve environmental and social problems.

1.

Knowledge growth: Increased knowledge influences behavior, and OESD enhances students’ knowledge in areas such as environmental science, ecology and social sustainability through hands-on activities. Through OESD, students are able to train or deepen their observational skills through sensory experiences, link cognition with sensory and emotional appeal, promote the relationship between humans and nature, increase students’ awareness of environmental issues, and stimulate positive attitudes and motivation. Nature-based learning demonstrates evidence of positively influencing participants’ environmental knowledge, attitudes, and pro-environmental behavior [29].

2.

Creativity development: Education is not merely the transfer of knowledge or the imposition of predefined answers, but rather a space for dialogue that fosters new perspectives and enhances both individual and group creativity [47]. In addressing challenges in the outdoor environment, students are encouraged to be creative and to design and implement innovative solutions. This process not only stimulates students’ creative thinking, but also enhances their ability to transform ideas into practical actions.

3.

Normative competence development: OESD develops students’ moral principles and behavioral standards by emphasizing environmental ethics and social responsibility. In the process, students learn how to respect nature, respect cultural diversity, and consider ethics and sustainability in their decision-making.

4.

Improvement of communication and co-operation skills: Communication and co-operation in OESD encompass interactions with oneself, others, society, and nature. Through team projects and collaborative activities, students learn to articulate their findings, present results, defend their views, communicate effectively, consider others’ perspectives, and reconcile differing interests.

5.

Critical thinking development: OESD encourages students to critically analyze the functioning of natural environments and social systems, question existing viewpoints, form independent opinions, and make informed judgments on social and environmental issues.

6.

Future thinking and action: Developing the ability to take meaningful action is a cornerstone of OESD, emphasizing the transition from knowledge acquisition to deliberate action and problem-solving [33]. OESD emphasizes the development of long-term planning skills and forward-thinking, enabling students to consider the impact of their actions on future generations. Students are encouraged to embrace uncertainty, remain receptive to unforeseen challenges, navigate the complexities of their situations, and explore pathways toward an uncertain future.

4.3.3. Change for Learning

Interdisciplinary and cross-disciplinary integration plays a vital role in OESD, but there is tension between existing disciplines and boundaries, as well as between traditional disciplines and informal disciplines [41]. It is necessary to fundamentally reflect and reconstruct the whole education system, that is, how to transform the interdisciplinary in formal education into a sustainable world outlook in informal education.

As an important part of interdisciplinary course in OESD, geography and biological sciences have irreplaceable importance. Geographical science, with its comprehensive knowledge and methodological advantages, plays a key role in the vital needs of the country, such as rural revitalization, industrial development and urban transformation, and its integration with humanities and social sciences such as management, economics, politics, history, etc., becomes more and more obvious [61]. Biological science also provides rich knowledge background, such as biological protection, ecological restoration, and resource management, and its experimental and systematic research characteristics provide a solid scientific foundation for change learning [26]. The deep thinking and action needed to realize the educational reform requires the joint efforts of the inside and outside of the educational system, including the extensive participation and support of policy makers, educational institutions, teachers, students, and the public. In the practice of OESD, a large number of non-teachers have appeared, such as family farmers, supermarket business managers, sociologists, and environmental researchers. Their dialogue with students has aroused students’ resonance for sustainable development, encouraging students to find their own solutions instead of expecting others to act on their behalf. Because different perspectives from different backgrounds make different voices, this diversified co-operation can provide richer perspectives and solutions for educational reform.

Higher education plays an important role in OESD, which involves not only academic research, but also group responsibility. Universities can support sustainable development and deal with government issues more effectively. As the supporters of regional stakeholder co-operation, regional universities are key participants in the process of regional development [28]. Higher education institutions have the opportunity to become promoters of change and innovation [51], which not only provides scientific basis and talent support for sustainable development, but also plays a key role in shaping the values of sustainable development, promoting interdisciplinary co-operation and promoting the realization of global sustainable development goals. The importance of higher education lies in its close combination of knowledge, talents and practice, which provides a solid foundation for achieving the global sustainable development goal.

4.4. Future Opportunities and Challenges for OESD

4.4.1. Opportunities for OESD

With the increasingly serious environmental problems and the increasing social demand for sustainable development, governments, educational institutions and international organizations are actively exploring how to cultivate the next generation’s awareness and ability of sustainable development through education.

• Policy support is one of the key factors in the implementation of OESD. The United Nations Educational, Scientific and Cultural Organization (UNESCO) promoted the Global Decade of Sustainable Development in Education from 2005 to 2014, aiming at integrating the principles, values and practices of sustainable development into all aspects of education [44]. This global policy framework provides guidance and motivation for countries and promotes the development of OESD. For example, in 2006, the Japanese government made an implementation plan to promote the goal of UNESCO’s Decade of Sustainable Development in Education, emphasizing the change of behavior through education to achieve environmental, economic and social sustainability. In addition, UNESCO announced the Global Action Plan (GAP) in 2015, encouraging local communities and municipal authorities to develop community-based ESD projects, and emphasizing strengthening learning opportunities through multi-participation [28]. These policies not only provide the direction for OESD, but also promote international co-operation and resource sharing, providing a solid foundation for the implementation of OESD.
• The support of local practice and cultural background to OESD cannot be ignored. Scotland became one of the first places in the world to receive outdoor education formally in the 1960s [7]. This local practice provides OESD with rich experience and cultural soil. The influence of environmental attitude and knowledge on behavior will be different due to social and geographical background factors [48]. This means that OESD needs to consider the specific needs and challenges in different social and economic backgrounds. For example, Japan supports ESD implementation in all education sectors at the national level, and many universities have implemented ESD-related projects and activities [28]. This support at the national level provides resources and motivation for OESD.
• The existing curricula are also important to support OESD. Finland incorporates sustainability into the curriculum at all educational levels, which is reflected in the basic education curriculum [26]. Norway’s national framework plan defines sustainable development as one of the core values of kindergartens, which requires promotion, practice and embodiment in kindergarten education practice [54]. In New Zealand, the connection between outdoor learning and sustainable education has been reflected in the education system, which can be traced back to the end of the 19th century. Australia also regards sustainability as one of the three cross-curricular priorities of the new national curriculum [31]. These curriculums not only emphasize the importance of sustainability, but also provide a concrete implementation framework for OESD.

4.4.2. Challenges for OESD

However, OESD also faces many challenges, such as the contradiction between globalization initiative and localization practice, the limitation of education system, the shortage of resources and support, the challenge of management and organization, and the lack of students’ participation and perspectives.

• The contradiction between globalization initiatives and localization practices has become a significant threat. Although all countries have reached consensus on the Sustainable Development Goals (SDGs), the vast differences in ecological foundations, development stages, and cultural contexts across regions present profound challenges to the implementation of OESD. Taking developed countries as examples, their educational goals focus on post-industrial societal transformation needs: the UK advocates building sustainable community consumption systems [46], the US emphasizes creating safe and resilient cities [8], while Finland prioritizes biodiversity education [26]. These initiatives align well with SDG 11 (Sustainable Cities and Communities), SDG 12 (Responsible Consumption and Production), and SDG 15 (Life on Land) in the global agenda, yet prove difficult to directly transplant to developing countries. Developing countries face more fundamental survival challenges, such as Brazil advocates sustainable Food Program (SDG 2 Zero Hunger) [34]. The challenges in Sub-Saharan Africa are even more complex, requiring breakthroughs in environmental degradation, social conflicts, cultural hegemony, and other obstacles [62]. Therefore, the implementation of OESD must comprehensively consider regional social, economic, environmental, and cultural characteristics. Though challenging, only through this approach can the transformative value from global vision to local action be truly realized.
• The implementation of OESD is limited by the existing education system. For example, in Scotland, although the national curriculum standards allow teachers to guide young students to participate in outdoor activities, the curriculum requirements for older students are stricter, which limits the opportunities for outdoor learning. In addition, the disconnection between college students and the outdoors may be more serious, which indicates that higher education institutions may not make full use of the outdoor environment as teaching resources [8]. In Kosovo, the education system mainly serves the political power, and teaching focuses on imparting selected knowledge, leaving little room for students to explain themselves, take the initiative or think critically [9].
• Insufficient resources and support are also constraints. For example, teachers lack enough knowledge and time to provide OESD, and it is difficult to rely only on school resources [11]. In addition, the lack of technical equipment and funds is also an obstacle to implementing OESD [39,41]. Social and cultural factors also pose challenges to OESD. For example, fear and worry about students’ health and safety, as well as lack of time, are all factors that affect the implementation of OESD [26]. These factors limit the potential of OESD and make it difficult to be applied in a wider range of educational practice.
• The promotion of OESD also faces management and organizational challenges. For example, academic institutions usually have their own courses created by scientific educators, and local governments or communities are less involved in the educational process because of the barriers to co-operation, which sometimes leads to a lot of confusion in the process of education management [28]. The success of OESD also depends on students’ participation and perspective, however, educators overestimate the transformative power of a single initiative, and without in-depth study of students’ viewpoints, it is difficult to know to what extent OESD has affected students’ sustainability [33,63]. To realize interdisciplinary communication, it is necessary to modify the rigid administrative structure and unify students, teachers, employees, administrators and communities through innovative activities, so as to ensure that OESD can be effectively integrated into the education system [51].

5. Conclusions

Underpinned by the global sustainable development agenda, OESD has become a significant branch and practice area in global education. This paper meticulously reviews the literature to illuminate OESD’s development trajectory, current research landscape, and future trends. It articulates OESD’s evolution from initial exploration through substantial growth to reflective adjustment, offering researchers and practitioners a clearer understanding of its dynamics and a foundation for strategy development. The UK and US are at the forefront of OESD research, joined by key contributors Germany, Canada, and Finland. This signals research trends and collaborative models in OESD, and highlights prospects for global co-operation. It also pinpoints pivotal themes and paradigm shifts in OESD research. The field is transitioning from theoretical discourse to practical application, with escalating emphasis on technology integration and global collaboration. This not only exposes the cutting-edge of OESD research but also presents novel insights and opportunities for interdisciplinary and cross-sectoral collaboration. Furthermore, this study thoroughly examines the multifaceted challenges confronting OESD, such as entrenched education systems and inadequate resource distribution, while identifying development opportunities like enhanced policy support and synergy with local and cultural contexts. This equips education policymakers, researchers, and practitioners with a holistic perspective, aiding them in advancing OESD’s development with precision.

With its extensive expansion prospects, OESD is an educational innovation that repositions education in the Anthropocene’s ecological reality. Future research should focus on advancing OESD from macro-level advocacy to micro-level deconstruction through three priority directions. First, emphasize cultivating action competence to facilitate sustained transformation from knowledge to practice. Second, prioritize building learning communities by establishing collaborative alliances that span generations and sectors. Third, concentrate on developing SDGs-aligned thematic content to translate global sustainability goals into localized actions. It is hoped that OESD will eventually cultivate a new generation of earth citizens with systematic thinking, ecological wisdom and courage to change.