Deconstructing the constraints of justice-based environmental sustainability in higher education

ABSTRACT

The omission of epistemologies from the Global South inhibits holistic pedagogical approaches for effective sustainability teaching and learning. Employing the theoretical lens of ecology of knowledges, the structures and dynamics that frame and constrain sustainability education in higher education were critiqued. Six constraints of environmental sustainability pedagogies were also deconstructed: epistemic inequity, globalisation, neoliberalism, pedagogical incompatibility, anthropocentrism, and social inequity. Consequently, ideas for justice-based environmental sustainability were proffered, especially for eco-justice and epistemic justice. The need for sustainability education to be relevant, relatable, critical, holistic, inclusive, and transformational was also argued. Keycontributions of this paper are a compilation of constraints on sustainability pedagogies, demonstration of the relationship between the usually isolated constraints around teaching and learning about sustainability in higher education, and the application of the theory of the ecology of knowledges to the deconstruction of these constraints. These contributions have implications for achieving justice-based sustainability in higher education.

KEYWORDS:

• Environmental sustainability
• higher education
• justice-based
• ecocentric
• sustainability education

Introduction

This paper aims to deconstruct the constraints of justice-based environmental sustainability in higher education institutions, while highlighting the importance of ecocentric values. This is significant because higher education is well placed to spur effective sustainability outcomes, yet there is a significant gap in knowledge and evidence about higher institutions’ contributions to (un)sustainability and the associated challenges. Thus, the state of earth's environment continues to deteriorate (Chankseliani and McCowan 2021). Furthermore, countries of the Global South are consistently found to be struggling with attaining sustainable development (Noble et al. 2014) and although reasons like low income are usually discussed, these constraints have not been sufficiently analysed at the level of complexity and nuance required. Yet, their deconstruction is necessary towards enhanced understanding of how higher education could effectively contribute to the teaching of justice-based environmental sustainability.

Therefore, this paper argues that the omission of epistemologies from the Global South and the current metamorphosed forms of colonialism inhibit holistic curricula and pedagogical approaches for effective sustainability teaching and learning. Employing the theoretical lens of the ecology of knowledges (de Sousa Santos 2014), the structures and dynamics that frame and constrain teaching and learning about sustainability in higher education were critiqued. The paper then identified and deconstructed the major constraints of environmental sustainability pedagogies found in existing literature within a global context. This includes epistemic inequity, globalisation, neoliberalism, pedagogical incompatibility, anthropocentrism, and social inequity. Focus will be on whether higher education teaching of environmental sustainability is just and representative or whether it prioritises and privileges certain environments and people.

By deconstructing these constraints, better conditions for teaching and learning about environmentally just sustainability will be revealed. These conditions include unstructured learning activities, outdoor learning, place-based pedagogy, practical learning for immediate application to solve real-world problems, socialism, decoloniality, ecocentrism, and polycentrism towards ascending the dualisms of Eurocentrism and ethnocentrism (Amin 1990; Gruenewald 2003). Based on the above, a further analysis focused on how the constraints impact the nature of opportunities in the Global South to engage with sustainability teaching and learning, especially towards activism, ecocentrism, and ‘green living’, which appear to be less viable and rare compared to the Global North, due to historical, political, and social factors (de Sousa Santos 2018). For example, considering the disparity in the level of focus on sustainability across higher education institutions in the Global North and the Global South, how does power and privilege shape the ability or choice to focus on sustainability pedagogies?

Original contributions of this paper would be a comprehensive compilation of constraints on sustainability pedagogies, a demonstration of the relationships between the usually isolated constraints around teaching and learning about sustainability in higher education, and the application of the theory of ecology of knowledges to the deconstruction of these constraints. The paper will be an important contribution within teaching in higher education because it critically analyses how the wider context within which higher education operates constrain effective environmentally just sustainability. This could foster a reimagination of the role of higher education institutions in transforming sustainability teaching and learning towards effective pedagogies that could transform the world on local and global scales.

The paper has the following outline: Introduction which provides the background, context, and purpose of the research, an overview of environmental sustainability in higher education and a critical analysis of higher education institutions as sites of un(sustainability), deconstructing the constraints of environmental sustainability pedagogies, positioning higher education teaching for environmental sustainability drawing from earlier deconstructions of constraints, responsibilities of teaching for Justice-Based Environmental Sustainability (JBES), and conclusion. In sum, this paper responds to the questions posed by Misiaszek and Rodrigues (2023): How do higher education instructors teach to define, frame, question, measure, and (de)prioritise sustainability and development? What politics of and upon higher education effects teaching for JBES? What are the dominant epistemological groundings of higher education teaching that align with or oppose JBES? What are the anthropocentric influences on higher education teaching JBES? What should be the responsibilities of teaching for JBES praxis in higher education?

Justice-based environmental sustainability

Sustainability, and related terms like sustainable development, is a highly contested concept that has been understood in various ways. For example, Leal Filho (2000) outlined four different meanings of the term where emphasis was on local policies, country policies, social ramifications of development, and links to economic growth respectively. Seen as both a process and a goal, sustainable development has been defined as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’ (WCED 1987, 43). Three areas of development usually emphasised are economic, social, and environment.

Hummels and Argyrou (2021) analysed the elusiveness of sustainable development due to the unresolved contradictions among its components and they argued that the vagueness of the WCED definition of sustainable development violates planetary boundaries such as climate change, scarcity of natural resources, and social inequalities. Sustainable entrepreneurship was proffered as a revised definition, which allows the pursuit of economic growth while complying with planetary bodies through the creation and distribution of solutions (Kushnir 2022). Furthermore, Sharma (2020) analysed three problematic conceptualisations of education for sustainable development with respect to an equity-approach. These are top-down equity, where global goals and policies are led by non-representative organisations and detached from local realities, economic growth promises equity, where consistent economic growth is an indication of development, and equity as distribution of resources. These are problematic because they result in the neglect of equity from the bottom, exploitative anthropocentrism, and intersectionality is not considered. We need a combination of equity from above (e.g. education for all policies), middle (e.g. investment in teacher training), and especially from below (e.g. student and teachers’ views shaping educational policies, content and practices). Furthermore, equity, in its conceptualisation as top-down, distributive, and economic growth oriented, legitimises an exploitative anthropocentric consumption of the environment and a consumerist attitude. Insufficient consideration of intersectionality also results in the neglect of marginalised groups and cultural diversity.

Thus, due to the perceived competing nature of the three components of economic, environmental, and societal needs, the term environmental sustainability is usually preferred to sustainable development, to highlight the environmental component over the economic and social components (Cheng 2019). The author goes further to emphasise justice-based environmental sustainability because although all three components are important and environmental sustainability should be focused on, the increasing environmental problems are connected to social injustices (Gadotti 2008). Thus, environmental sustainability education needs to be based on achieving justice for marginalised societies especially and all living and non-living components of our planetary ecosystem.

The vague and controversial nature of sustainable development has necessitated suggestions for specific pedagogies to educate for environmental sustainability (Tomas, Girgenti, and Jackson 2017; Menon and Suresh 2020). However, these pedagogical innovations are not currently associated with sustainability education (e.g. Christie et al. 2013). There is also a disparity between education for sustainable development's ideals and academics’ views on teaching for sustainability (Cebrián, Grace, and Humphris 2015). This could be due to the separation of sustainability pedagogies from sustainability practices in higher education, and Menon and Suresh (2020) argued for a comprehensive approach to incorporating sustainability throughout higher education, in curriculum and pedagogy, research, campus operations, and community engagements. This is important because although environmental sustainability has been gaining traction within higher education, many institutions do not fully understand the concept (Leal Filho 2000). Thus, it is necessary to develop approaches to addressing misconceptions and working towards sustainable practices. For example, many buildings and infrastructure still have centrally controlled high-powered heating and air-conditioning throughout and there are limited facilities for transportation and recycling on and around university campuses. Members of HEIs also travel frequently, especially by air and the high rate of travel contributes to the unsustainability practices across HEIs. Furthermore, high volumes of printing still exist, and this may be difficult to change because many people still prefer printed materials, there are limited sustainability options, and recycled paper is perceived to be more expensive (Leal Filho 2000). These constraints have been analysed further in the ensuing section.

Constraints of justice-based environmental sustainability pedagogies in higher education

While there are practices in HE teaching that align with environmental sustainability (e.g. Menon and Suresh 2020), these are inadequate and so this article focuses on the constraints of justice-based environmental sustainability pedagogies in higher education. Based on the author's experience and existing literature, six of these constraints are discussed here. These are epistemic inequity, globalisation, neoliberalism, pedagogical incompatibility, anthropocentrism, and social inequity.

Epistemic inequity

The first is epistemic inequity due to Eurocentrism, where knowledge from Europe and America, usually referred to as the Western world, are centred and revered as objective and universal (Cupples and Grosfoguel 2019). Despite ongoing efforts to decolonise sustainability education (Eten 2015; Ajaps 2021), much of its pedagogies are still grounded in Western epistemologies. de Sousa Santos’ (2009) ecology of knowledges provides a guide to tackling the structures and dynamics that frame and constrain teaching and learning about sustainability. Omitting epistemologies of the Global South inhibits holistic pedagogical approaches and the superiority status granted to epistemologies of the Global North contribute to ineffective environmental sustainability pedagogies on a global scale.

Epistemologies of the Global South, including Indigenous knowledge systems and practices, usually have environmental sustainability at the core (Ciofalo 2022). This is because Indigenous peoples have a very close relationship with their lands and understand the mutual benefits involved, and thus the need to prioritise its sustainability (Mbah, Ajaps, and Molthan-Hill 2021). Yet, sustainability education is based on the epistemologies of the Global North. For example, findings from two studies in India (SELA 2022) and Nigeria (Ajaps 2021) revealed that the language in learning materials used are inappropriate and difficult for students to understand; the content in the textbooks comprises of themes that are unrelated to the learners’ familiar environment, and they are largely urban and colonial centric. These studies highlight the inequity arising from the disparity between the students’ diverse cultural and linguistic backgrounds and the textbooks they use. On the one hand, to ensure equal opportunity, the same input, that is the materials, is provided to every student; on the other hand, it is inequitable when learners cannot relate to the text they are expected to learn and so do not have what they need to understand and transform their environment. Therefore, integration of the epistemologies of the Global South throughout higher education pedagogy is needed for a more holistic understanding of our world and justice-based environmental sustainability.

Achieving a more inclusive epistemological grounding for environmental sustainability is an ongoing project across several higher education institutions around the world and there are many studies that show how these have been conceptualised and implemented (e.g. Mbah et al. 2022). McCowan (2023) argued for epistemological paradigm shifts that provide possibilities for deepening critical reflection, pushing boundaries, and opening imagination based on the climate crisis. I agree with McCowan that these shifts require working within the established courses of a discipline, not conforming to them but challenging them and pushing the boundaries from within. Similarly, Kinchin (2023) argued for five moves towards an ecological university, which are necessary to achieve greater levels of social justice within higher education. These moves are construct and institutional natural history to understand the university's network of interactions, explore narrative ecologies, value post-abyssal thinking that includes cultural and academic knowledge, develop ecological leadership, and consider how we can develop sustainable pedagogies that can withstand disturbances to the ecosystem. Although these are considerable challenges to university managers, these moves need to be made because of their implications for social and environmental justice.

In addition, the ways in which Western epistemologies are perceived and acted on, with respect to being a constraint, varies across the Global North and the Global South. For example, while there are efforts to integrate Indigenous peoples and centre their knowledge systems in both the Global North and south (e.g. Tom, Sumida Huaman, and McCarty 2019; Zidny, Sjöström, and Eilks 2020), there are also situations whereby the Indigenous peoples do not want to draw from their knowledge systems due to reasons that include lack of trust and the belief that their own ways of knowing are inferior (Ajaps 2021; Mbah et al. 2022). Some researchers have also critiqued the notion of integrating epistemologies of the Global South into those of the Global North, because of the perceived supplemental value of knowledge from the south and the implied superiority or universality of knowledge from the north (Latulippe and Klenk 2020). This means that any integration of epistemologies from the Global South with mainstream or Western knowledge systems should be implemented in ways that do not present it as a supplement or footnote, but as an equal albeit different way of knowing.

There is also inequity in the ways sustainability pedagogies are implemented in the Global North and the Global South. For example, many pedagogies are West-centric and do not focus on the environments of the people from the Global South; therefore, their ability to take the right actions and contribute to sustainability is limited (Ajaps 2021). On the other hand, while some pedagogies in the Global North focus on the learners’ environment, such as place-based education (Gruenewald 2003), which equips them with the knowledge and skills needed for environmental sustainability, Bills and Klinsky (2023) argued that Western academia as a colonial system, upholds and reproduces settler colonialism. This, they argued, is adverse to sustainability goals because it furthers Indigenous erasure and extractive relationships with the land. Similarly, Stein et al. (2023) rightly explained that many current pedagogies are rooted in the same colonial system that created climate change and other socioecological problems and are inadequate for preparing students to navigate these problems in meaningful and responsible ways. They argued for a disruptive education, education otherwise, to deepen intellectual, affective, and relational capacities towards being prepared to collectively face current and future challenges.

Spivak’s (1988) theory of epistemic violence explains the history of the colonial education system, which was the result of the silencing of the colonial subject, who was regarded as ‘other’ with connotations of being inferior, uncivilised, and ignorant. Thus, the validity and equality of non-Western ways of knowing were not recognised. The importance of engaging with diverse ways of knowing is captured in de Sousa Santo's (2009, 116) theory of the ecology of knowledges, which explains that there is an infinite plurality of knowledge and none of them is able to understand itself without referring to the others because the ‘possibilities and limits of understanding each way of knowing can only be grasped to the extent that each way of knowing offers a comparison with other ways of knowing’. For epistemic equity or justice, there should be no perceived hierarchy in the ecology of knowledges since all knowledge systems are equally valid. Sustainability pedagogies in higher education should actively seek out and engage with as many diverse knowledge systems as possible.

Globalisation

The second constraint of justice-based environmental sustainability pedagogies in higher education is globalisation – the process of integration among people worldwide. Despite some benefits of globalisation for environmental sustainability, these benefits are not always universal and consistent (Collier 2018). For example, using a sample of 32 developed and 26 developing economies from 1995 to 2017, Leal, Marques, and Shahbaz (2021) found that although globalisation had a mostly positive effect on the environment in developed countries, the reverse was the case in developing countries. Furthermore, globalisation tends to be imbalanced with more focus on the Global North. This point is clarified by Andreotti’s (2014, 24) assertion that ‘the global does not represent the universal human interest; the seven most powerful countries, the G7, dictate global affairs, but the interests that guide them remain narrow, local, and parochial. Only certain countries have globalising powers – others are globalised’.

Thus, as globalisation increases, there is more focus on the universal than on the local, which is antithetical to justice-based environmental sustainability. Globalisation also exacerbates more focus on the globalising countries than on the globalised countries, which results in sustainability pedagogies from the Global North being exported to the Global South where contextual factors like environment and culture could impact its suitability. Considering the benefits of globalisation for justice-based environmental sustainability, as highlighted above, higher education stakeholders need to continue to explore ways of maximising these benefits while minimising the negative effects. Koyama and Watanabe (2023) suggested that educators develop a dispositional view of ecological literacy especially because dispositions are what people are disposed to do. So, if ecological literacy is seen as residing in the learner, its teaching emerges as something like the education of moral character (Koyama and Watanabe 2023). The adoption of a critical lens to global citizenship education is another avenue through which higher education institutions can leverage on globalisation to achieve justice-based environmental sustainability education (Andreotti 2014). Byker (2013) advocated for the development of global citizenship competencies through investigating the world, recognising perspectives, communicating ideas, and taking action.

Neoliberalism

The third constraint is neoliberalism, whereby economic growth and minimal government intervention are prioritised due to a belief in the productivity of market competition and free trade, which negatively impacts the sustainable development agenda of higher education (Bessant, Robinson, and Ormerod 2015). Furthermore, the commodification and commercialisation of higher education (Mbah and Fonchingong 2019) means that the focus on profits will impede on sustainability practices, to the detriment of people and the planet. In addition, Sharma (2020) showed that education for sustainable development is a concept embedded in neo-liberalism. Thus, sustainability in higher education pedagogy and practices is fraught with contradictory agenda around economic growth, environmental conservation, and justice for people. It is important for higher education institutions to prioritise sustainable pedagogies that can withstand disturbances to the ecosystem, even if this means less economic growth. Espinet and Llerena (2023) argued that for a fair and sustainable future, higher education should include non-hegemonic and dialectical views of sustainability based on degrowth socioeconomic models and socioenvironmental problems as learning contexts.

Pedagogical incompatibility

The fourth is pedagogical incompatibility, which refers to the mismatch of sustainability education and some pedagogical approaches. Sustainability education is incompatible with pedagogies primarily based on structured or formal education, including structured indoor or classroom activities, place-detached learning, universal or context-free perspectives, and abstract learning. This is because unlike many school disciplines, sustainability education has an urgent agenda, which is to provide sufficient opportunities for knowledge acquisition and attitude change, towards behaviour changes and positive actions for sustainability. Hence, many sustainability education researchers and practitioners call for certain pedagogies to be employed (Tomas, Girgenti, and Jackson 2017; Menon and Suresh 2020). Lin et al. (2023) rightly argued for storytelling as a pedagogy for ecojustice education because if its potential to open students’ hearts to feel for and connect with nature. Such pedagogies with less structure and indirect activities have been found to be more effective for sustainability education objectives (Duerden and Witt 2010). Other pedagogies found to be consistent or aligned with sustainability goals are outdoor learning (Truong et al. 2018), place-based activities (Gruenewald 2003), localised learning (Druker-Ibáñez and Cáceres-Jensen 2022), practical or problem-based learning (Thomas 2009; Evans 2011), and critical dialogue (Jickling and Wals 2008). However, despite the evidence of the effectiveness of these more innovative pedagogical approaches, they are not always employed in sustainability education across higher education institutions (Christie et al. 2013).

Anthropocentrism

The fifth constraint of justice-based environmental sustainability pedagogies in higher education is anthropocentrism or human-centredness. Environmental problems and solutions are usually framed by anthropocentric interests, to the detriment of ecocentric interests (Kopnina 2014). This is an injustice to non-human nature. Higher education institutions can be sites for mitigating the causes of climate change through holistic education that critiques anthropocentrism while fostering love and respect for nature (Lin et al. 2023). It is important for higher education to transform its sustainability education and practices from anthropocentrism to ecocentrism or earth-centredness because many researchers have found that the latter is more likely to spur people to act to protect the environment (Kortenkamp and Moore 2001). Three value bases for environmental concern have been identified: self-interest, humanistic altruism, and biospheric altruism (Stern 2000). The first two value bases are anthropocentric. Self-interested people are concerned about the threats to themselves posed by environmental problems like natural catastrophes and pollution. Humanistic altruists extend concern beyond themselves to other humans, for example, caring about poor people in their community or people in developing counties, and this could be counterproductive to environmental sustainability efforts where economic sustainability is prioritised (Kopnina and Keune 2010). Biospheric or ecocentric altruists are concerned about all living beings and their relationship within earth's ecosystems; they recognise the intrinsic value of other species and do not believe humans are superior.

Environmental sustainability pedagogies in higher education should be framed by ecocentric interests to achieve justice for all species and increase the chances that people will engage with actions to protect the environment. Young and Malone (2023) argued for the unsettling of rational, humanist ways of thinking because this is critical for progressing beyond self-interest and humanistic altruism towards critical post-humanity and relationality that can result in new modes of being in the world, including ecocentrism. Furthermore, in their argument about impact being a slippery cousin to development, in the sense that both terms can be appropriated to suit contradictory goals, Meth, Brophy, and Thomson (2023) emphasised the need for any consideration of the impact of sustainability education and programmes to be grounded in justice-based environmental sustainability. The focus on justice is what would help transcend anthropocentric interests, towards ecojustice or justice for all ecosystems.

Social inequity

The sixth constraint of justice-based sustainability education in higher education is social inequity, which includes inequities in the availability of resources and opportunities to engage with environmental sustainability pedagogies and practices. Knowledge, time, and money are resources that have been shown to be valuable for sustainability engagement, where available (Kollmuss and Agyeman 2002). Ajaps and McLellan (2015) found that although a few of the 88 university students in their mixed-methods study had significantly high environmental knowledge, most participants had insufficient knowledge. Furthermore, participants with more knowledge were more likely to report positive attitudes and actions for environmental sustainability. There was also a disparity, with the UK participants more likely to have higher environmental knowledge than the Nigerian participants. Epistemic inequity, as analysed above, contributes to this disparity.

Sustainability education cannot be justice-based if it does not equip all learners with the knowledge that they need to understand and transform their environment, from their local places to global contexts. Insufficient time and money could also constrain higher education's integration of sustainability education across disciplines, budgetary allocations, and so on. This is particularly important for institutions that are not wealthy, especially those in the Global South. Limited opportunities to engage with justice-based environmental sustainability could be systemic or personal. Examples of systemic barriers include high-energy-guzzling facilities and absence of recycling bins, while examples of personal barriers include insufficient intrinsic or extrinsic motivation.

It is important for higher education institutions to reflect their commitment to sustainability education through visible and accessible provisions for engagement with environmental protection throughout their campuses. The University of Manchester's living lab (Evans et al. 2015) is an example of such provisions. Among other things, the living lab is a depository for available sustainability-related projects that students can choose to work on, which would respond directly to organisations who have identified a need for the findings of those research projects. Another example is The University of The Gambia's Sustainable Development Goal Challenge in 2021 where teams of students pitched ideas oriented towards the United Nation's sustainable development goals. This created awareness of the goals among members of the institution and spurred conversations and actions around how the university can work with local communities to attain the goals (Mbah et al. 2022).

The six constraints discussed above impact the nature of opportunities to engage with sustainability teaching and learning, especially in the Global South, due to historical, political, and social factors (de Sousa Santos 2018). For example, the disparity in the level of focus on sustainability across higher education institutions in the Global North and the Global South is shaped by power and privilege. Due to epistemic inequity arising from epistemic violence in the colonial era (Spivak 1988), the universal Eurocentric sustainability pedagogies and practices favour the Global North. This restrains the ability or choice of people in the Global South to focus on sustainability, especially due to the unresolved contradictions between formal or Western education systems and their education systems, including their sustainability worldviews and practices.

Positioning higher education for justice-based environmental sustainability

Higher education institutions have a duty of care to promote environmental sustainability, especially because they usually comprise people and resources that are capable of understanding and interpreting climate change science and reports for the staff and students, and the public. Emphasis should be on justice to begin to undo the marginalisation of Indigenous communities in places like North America and countries of the Global South. There should be justice for non-human species through an ecocentric focus. Higher institutions need to work with communities for environmental sustainability, for example in community-based research where academics and community members learn from each other (Ajaps and Mbah 2022). Institutions also need to lead by example, practicing what they preach.

Furthermore, higher education institutions need to embed ecocentric sustainability in all disciplines and endeavours; for example, statements in course outlines about contributions to socio-environmental transformation, sustainability considerations in travel applications, poster prompts about using stairs instead of lifts, shutting faucets completely, turning off all appliances when leaving offices and classrooms, and so on. It will also be beneficial for higher education institutions to positively reinforce engagement with justice-based sustainability education, especially where it allows people to see that their actions make a difference. Honest and critical conversations about how power and privilege shape the ability or choice to focus on sustainability pedagogies and practices, both for individuals and the institution, is also important.

Justice-based environmental sustainability requires the inclusion of missing voices and consideration of other living species in higher education. Voices or perspectives to be included comprise those of Indigenous or non-Western people, women, low-income earners, and disabled people. Many of the efforts towards justice-based environmental sustainability education appear to be anthropocentric; for example, Eten (2015) reflected on ways of indigenising Africa's environmental education through a development education discourse while Sterling (2013) focused on the transformative potential of sustainability education internationally. Mbah et al. (2021) reviewed the deployment of Indigenous knowledge systems towards climate change adaptation in the Global South. Therefore, more ecocentric-focused initiatives and pedagogies for understanding and resolving environmental sustainability issues are needed.

Responsibilities of teaching for JBES praxis in HE

Justice for marginalised groups and for non-human nature should be prioritised in teaching for justice-based environmental sustainability. Preceding discussions revealed that higher education's environmental sustainability pedagogies are insufficiently just or representative. Certain environments and people, as well as the human species, are prioritised and privileged over others. To prioritise and achieve these justices, ‘othering’ or Eurocentrism must be avoided. An ecology of knowledge (de Sousa Santos 2009) standpoint could promote epistemic justice and foster the holistic knowledge and global cooperation required to deliver effective sustainability education. Education stakeholders also need to engage in constant self-examination to check their biases. Teaching should involve collaboration, accountability, and opportunities to care for both human and non-human species. By embracing the ecology of knowledges, higher education institutions position themselves to access more ways of knowing, including Indigenous epistemologies that emphasise justice for non-humans and non-living things.

Furthermore, sustainability education should be relevant, relatable, critical, holistic, inclusive, and transformational. Relevant education refers to a focus on important and current issues from an ecocentric perspective while relatable means that the people involved in the education activities can see how what they are learning apply to their lives and places. Being critical involves analytical questions and discourse that transcend surface appearances and prioritises equity, including analysis of structural relationships as manifested in language. A holistic sustainability education takes systems view approach (Bastianoni et al. 2019), recognising the interlinkages of earth's ecosystems and embracing interdisciplinary understandings of environmental sustainability. Inclusivity refers to the centreing of all knowledge systems because since none is superior to the other, solutions to complex environmental issues could be drawn from any or a combination of some knowledge systems. For example, some studies show significant benefits of integrating Western and Indigenous knowledge systems in higher education, including for climate change adaptation (Makondo and Thomas 2018; Demssie et al. 2020). Finally, transformational sustainability education (Leal Filho et al. 2018; Gal and Gan 2020) fosters recognition of contradictions inherent in unsustainable lifestyles and anthropocentric worldviews, which could spur perspective changes that tend towards ecocentric worldviews and more sustainable lifestyles. Creative and innovative pedagogical approaches, especially drawing from the arts and technology, could also contribute to transformational education. It is higher education's responsibility to engage with pedagogies and practices that promote justice-based environmental sustainability.

Conclusion

This paper explicated six constraints of justice-based environmental sustainability in higher education drawing from the theoretical lens of ecology of knowledge. These constraints are epistemic inequity, globalisation, neoliberalism, pedagogical incompatibility, anthropocentrism, and social inequity. Emphasis was on the importance of an ecocentric focus for environmental sustainability pedagogies and practices of higher education, towards achieving justice for all living and non-living things. The need for sustainability education to be relevant, relatable, critical, holistic, inclusive, and transformational was also argued. It is important for higher education stakeholders to continue engaging with these constraints to enhance our understanding of their history and ongoing impact, as this could lead us towards alleviating them. The difficult conversations about epistemic and social inequities, as well as overcoming the anthropocentric focus of higher education institutions, also requires focus.

Some of the constraints are more complex and nuanced than presented here, and there are also other constraints not mentioned in this paper. Yet, initial understandings of the six constraints discussed here can begin to contribute to transformations in higher education towards justice-based environmental sustainability teaching and learning. Taking a whole view approach to these constraints is also necessary to prevent the exacerbation of a constraint when other constraints are addressed in isolation. For example, focusing solely on overcoming social inequity by providing more funding to underprivileged institutions could worsen the impacts of neoliberalism and anthropocentrism if economic growth and human interests are prioritised. To achieve justice-based sustainability goals in higher education, continuous engagement with these constraints is imperative.

Disclosure statement

No potential conflict of interest was reported by the author(s).