Given the complexity deriving from the multidimensionality of environmental-sustainability issues (Capra and Luigi Luisi, 2014) and the huge challenges and gaps in achieving pro-environmental behavior (PEB) or behavioral change towards sustainability (MEA, 2005; UNESCO, 2017; UN, 2013), a significant body of literature is devoted to the question of how to promote PEB.The value-belief-norm theory posits that in the causal chain of factors that influence the individual’s behavioral decisions, personal values are fundamental determinants of environmental concern, and are therefore, a strong leverage-point in changing environmental decisions (Dietz et al., 2005). Values are especially triggered in decision-making that involves trade-offs among preferences, which are common in the context of environmental behavior. In light of this role of values and the complexity of understanding what may bring about change in personal values, alongside evidence that individual behavior does not always align with personal values (Engqvist Jonsson and Nilsson, 2014), some scholars argue that leadership plays a central role in changing values and mindsets and constructing appropriate strategies for promoting PEB and sustainability (Hargreaves and Fink, 2006; Quinn and Dalton, 2009).

The current state of social-ecological unsustainability and recognition of the necessity of reexamining basic assumptions and values (Capra and Luigi Luisi, 2014) has led to increased acknowledgement of the idea of transformative learning (Sterling, 2010): effecting a qualitative shift in perception such that the individual reframes personal assumptions and habits-of-thought. Thus, this paper ties together, in the context of sustainability, three areas of thought: leadership, transformative change and values. All these areas are central elements of environmental sustainability education (ESE). Since a major challenge of ESE (formal and non-formal, addressing all educational stakeholders) is to develop sustainability citizens who are capable and active in leading the social change required to achieve a society that embraces sustainability.

Despite the paucity of literature on environmental or sustainability leadership (Quinn and Dalton, 2009; Redekop, 2010), recent attempts have been made to connect ‘leadership’ to ‘environmental sustainability’ in various arenas including education (Bottery, 2016; Hargreaves and Fink, 2006) and civil society (Doppelt, 2017). Often the connection is made by reference to ‘transformational leadership’ (Bass, 1999). Since organizational and attitudinal change is a recurrent theme in sustainability leadership discourse, change-driven transformational theories of leadership, principally those that encourage change in followers' values and attitudes, are seen to provide a common framework for connecting leadership scholarship to sustainability discourse (Bottery, 2016). However, despite productive models (Kose and Shields, 2010), to date no framework has been offered that conceptually links the two literatures together at the most basic level of motivationalvalues and attitudes, which serve as guiding principles for people (Dietz et al., 2005; Schwartz, 2012).

This study offers a conceptually grounded methodological framework for connecting leadership to sustainability, which may provide important insights for understanding educational processes of change toward PEB. The proposed framework corresponds with contemporary developments in two bodies of literature: (1) An emerging concept in sustainability discourse is 'sustainability citizenship' (SC) (Bell, 2005; Dobson, 2007; ENEC, 2018). SC inherently links socioeconomic and environmental-ecological aspects. SC reflects a comprehensive mode of thinking and behavior concerning sustainability issues, which originates from the individual’s mindset rather than external means, such as economic incentives (Dobson, 2007). (2) In the area of leadership, following the distinction drawn between transformational and transformative leadership (Shields, 2010, 2013), transformative leadership (TL) is most suitable for linking leadership to SC. TL constitutes a comprehensive model of leadership that corresponds to a VUCA (volatility, uncertainty, complexity, ambiguity) world: "…a VUCA world argues for a form of leadership known increasingly as transformative leadership because its focus is not 'business as usual'" (Shields, 2013).

Building on previous research (e.g. de Groot and Steg, 2008), this study engages in constructing a conceptual-methodological framework that links TL to SC using Schwartz’s theory of motivational values (2012). This three-level SC-TL framework applies Schwartz's bi-dimensional organization of motivational values; each level is described in relation to Schwartz’s higher-order values: Self-enhancement–Self-transcendence (SE-ST) and Conservation–Openness-to-change (CONS-OC). Level One SC – Regarding the SE-ST dimension, individuals are aware that their personal lifestyle impacts others' well-being and welfare. Individuals comprehend that decisions made in one's personal life connect to questions of the 'common good', but the extent to which individuals are willing to act for others’ benefit is limited to actions that do not entail taxing personal tradeoffs. While individuals at this SC-level may exhibit higher commitment to OC (self-directed behavior, stimulation, risk-taking), this commitment is restricted to ‘change’ promoting their own self-enhancement. Since TL involves acting for and activation of others, at this SC-level TL is minimal or non-existent. Level Two SC - Individuals are characterized by increased importance of self-transcendence values in relation to self-enhancement values: focus broadens beyond the individual to encompass one’s ‘identity group’/social community/affiliations. This is expressed by greater propensity for enhancing and protecting the welfare of those belonging to one's in-group. Regarding the CONS-OC dimension, motivation for adopting a change-oriented mindset is enhanced and directed not only to oneself but also to changing individuals belonging to one’s in-group. The combination of these attributes (in both dimensions) at this level reflects moderate TL. Level Three SC - At this level self-transcendence values outweigh self-enhancement values: the individual is characterized by an increasingly universal-cosmopolitan perspective (Dobson, 2007). The focus-of-concern is society-at-large and expands beyond an intragenerational to include an intergenerational perspective. The person is willing to make more taxing tradeoffs in terms of time and efforts directed towards promoting the welfare of humanity and the environment. Regarding the CONS-OC dimension, change is deep in the mindset of the individual; the individual change-agent is not satisfied only with effecting change in others, but also aspires for changing the 'rules-of-the-game', namely, changing existing norms, socioeconomic infrastructures and political decision-making processes. Relating to sustainability discourse, this perspective reflects the 'deep ecology' philosophy (Naess, 1973) and cradle-to-cradle (McDonough and Braungart, 2002) approach. This SC-level reflects high-level TL, since individuals’ motivation and behavior reflect a change-agentry that combines high commitment to democratic citizenship (e.g. social equity, diversity) and propensity for 'deep' change.

The proposed framework has various conceptual and methodological implications. From a conceptual perspective, it advances the understanding of the connection between leadership and PEB by relating them to Schwartz's theory of universal values, thus grounding the concept of sustainability leadership in socio-psychological theory. Specifically, understanding sustainability leadership through the two dimensions (SE-ST and CONS-OC) of Schwartz's model better clarifies the kinds of motivations and practical behavioral tendencies that define citizens dedicated to sustainability. Cultivating environmentally-responsible citizenry is uncontested in the aim of realizing SD goals and achieving a socially-environmentally sustainable society. "Individuals must become sustainability change-makers". Therefore, education is crucial. "Education has a responsibility to be in gear with 21st century challenges" (UNESCO, 2017). Connecting SC to TL is relevant to ESE on several fronts – policy, teacher competencies, curriculum and its implementation. Given the expectation that teachers serve as role-models and agents for societal change, and empirical evidence indicating gaps in their proficiencies in fulfilling these roles in relation to ESE (Author 2), connecting sustainability-citizenship to transformative-leadership offers a conceptual and methodological framework for preparing teachers and for their ongoing professional development as effective environmental educators. It provides a basis/outline/guide for adapting and developing ESE contents and pedagogies. From the policy perspective, it offers and ethical and practical guide for cultivating educational leadership at all levels of educational decision-making. Regarding ESE research, from a methodological perspective, given the paucity of empirical research and the lack of validated instruments for measuring both TL and SC, and the absence of instruments to measure sustainability leadership, the proposed connection to Schwartz’s model and tools offers a fruitful methodological ground for future empirical investigations: The three-level SC-framework offers a gauge to investigate more practically different extents of individuals’ PEB/SC.

Bass, B.M. 1999. 'Two decades of research and development in transformational leadership'. European Journal of Work and Organizational Psychology 8: 9-32. Bell, D.R. 2005. 'Liberal environmental citizenship'. Environmental Politics 14: 179–194. Bottery, M. 2016. Educational Leadership for a More Sustainable World. New-York: Bloomsbury. Capra, F., and P. Luigi Luisi. 2014. The Systems View of Life – A Unifying Vision. New York: Cambridge University Press. de Groot, J.M., and L.Steg. 2008. ‘Values orientations to explain beliefs related to environmental significant behavior: How to measure egoistic, altruistic, and biospheric value orientations’. Environment and Behavior 40: 330-354. Dietz, T., A.Fitzgerald, and R.Shwon. 2005. ‘Environmental values’. Annual Review of Environmental Resources 30: 335-372. Dobson, A. 2007. 'Environmental citizenship: towards sustainable development'. Sustainable Development 15: 276-285. Doppelt, B. 2017. Leading Change toward Sustainability: A Change-Management Guide for Business, Government and Civil Society. New York: Routledge. Engqvist-Jonsson, A.K., and A.Nilsson. 2014. ‘Exploring the relationship between values and pro-environmental behaviour: The influence of locus of control’. Environmental Values 23: 297–314. European Network for Environmental Citizenship (ENEC). http://enec-cost.eu/ Hargreaves, A., and D. Fink. 2006. Sustainable leadership. San Francisco: Jossey-Bass. Kose, B.W., and C.Shields. 2010. 'Ecological and social justice: a leadership framework for sustainability'. The International Journal of Environmental, Cultural, Economic and Social Sustainability 6: 275-288. McDonough, W., and M. Braungart. 2002. Cradle-to-Cradle: Remaking the Way We Make Things. New York: North Point Press. Millennium Ecosystem Assessment. 2005. Living Beyond our Means: Natural Assets and Human Well-being. https://www.millenniumassessment.org/documents/document.429.aspx.pdf Naess, A. 1973. 'The shallow and the deep, long-range ecology movements: A summary'. Inquiry 16: 95-100 Quinn, L., and M. Dalton. 2009. 'Leading for sustainability: Implementing the tasks of leadership'. Corporate Governance 9: 21-38. Redekop, B.W. (ed.) 2010. Leadership for Environmental Sustainability. New-York: Routledge. Schwartz, S.H. 2012. 'An overview of the Schwartz theory of basic values'. Online Readings in Psychology and Culture, 2. http://scholarworks.gvsu.edu/cgi/viewcontent.cgi?article=1116&context=orpc Shields, C.M. 2010. 'Transformative leadership: Working for equity in diverse contexts'. Educational Administration Quarterly, 46: 558-589. Shields, C. 2013. Transformative Leadership in Education: Equitable Change in an Uncertain and Complex world. N.Y.: Routledge. Sterling, S. 2010-11. ‘Transformative learning and sustainability: sketching the conceptual ground. Learning and Teaching in Higher Education 5: 17-33 UNESCO. 2017. Educating for Sustainable Development Goals – Learning Objectives. https://unesdoc.unesco.org/ark:/48223/pf0000247444 United Nations Department of Economic and Social Affairs. 2013. World Economic and Social Survey 2013: Sustainable Development Challenges. https://sustainabledevelopment.un.org/content/documents/2843WESS2013.pdf