Growing number of policy documents that regulate the direction of formal education development worldwide focus on sustainable development (SD) as a crucial issue(s) to be addressed in the next decade. As part of this global goal, the notion of education for SD is explicitly emphasized in many of those documents, as for example: "By 2030 ensure all learners acquire knowledge and skills needed to promote SD, including among others through education for SD and sustainable lifestyles, human rights, gender equality, promotion of a culture of peace and nonviolence, global citizenship, and appreciation of cultural diversity and of culture’s contribution to SD." (UN, 2015, p. 21).  

Such ‘evolution’ and increasing importance is leaving traces on academic debate in terms of (re)conceptualising citizenship constructs. Sustainability citizenship (SC), is being ‘pushed’ on the forefront, replacing or ‘upgrading’ already known constructs such as ecological, environmental, and socially responsible and active citizenship. SC implies interdependence of all dimensions of SD – ecological, social, economic and political. The need to upgrade existing citizenship concepts stems from the fact that young people today are facing global sustainability challenges and will cope with them much longer than older members of their families (Wals, 2015).

For a citizen to cope constructively with the sustainability challenges, one needs to possess certain attributes that represent the interrelation of cognitive, affective and behavioural dimension. Cognitive dimension implies being knowledgeable about SD and having critical thinking skills, while affective dimension includes ability to cooperate and communicate for the purpose of promoting SD goals. As Littledyke (2008, p. 3) argues, both dimensions are necessary for “developing a positive relationship with the environment that is based on informed motivation for action”. Finally, citizens have to have the ability to act according to the SD goals (UNESCO, 2017), which stipulates the behavioural dimension. It is necessary to cultivate reason and emotions for socially or ecologically beneficial behaviour on different levels - individual, societal and political (Littledyke, 2008) - all equally important for becoming a true sustainability citizen.

Being of a new date construct, SC is discussed in fast growing academic and professional literature, as well as in numerous policy documents, but still in a more descriptive than analytical manner. Some of the authors therefore describe sustainability citizens as those who reflect upon their own actions and effects such have for the environment, society and economy, while being self-reflecting and critical of their own lifestyle, as well as willing to change a system that perpetuates unsustainable behaviour (Banks, 2016). Dobson (2011) argues that sustainability issues cannot be effectively addressed in a long-term way by punishing unsustainable behaviour and thus advocates cultivating sustainability citizens as a long-term solution. SC further broadens the concept of citizenship as the scope of citizenship extends beyond mere obedience to laws and norms , by respectively including the care of global well-being and the environment (Micheletti & Stolle, 2012).

Being recognised as an important new construct in multiple arenas (e.g. educational, academic, policy) but still without consensus upon its definition, it is of vital importance to develop a more explicit definition of SC thus aiming to surpass its dominant descriptive notion(s) that usually prevails in existing definitions. We argue that such an explicit definition of SC represents necessity for several key reasons: (I) for HEIs to integrate SC as a learning outcome of their study programmes, as well as within teaching and learning pedagogies in a more constructive manner, (II) for educators to better navigate the expected outcomes of contemporary education (and ESD), and (III) for (educational) policy makers to effectively address various relevant factors related with SC being an educational ideal.

This study therefore investigates current conceptualisation(s) of SC in related educational and social research, as well as in (selected) strategic documents, by a systematic review of the relevant academic and policy literature. The study is guided by the following research question: How is sustainability citizenship conceptualised within existing recent studies and policy documents, what are its main descriptive attributes and how can those be (de)constructed in explicit definition? Since it allows researchers to “reduce data to concepts that describe the research phenomenon by creating categories, concepts, a model, conceptual system or conceptual map” (Elo et al., 2014, p. 1), qualitative content analysis on key literature and policy documents in the field of education for SD was conducted. We decided to use qualitative content analysis because it includes latent content analysis and not mere word counting (Hsieh and Shannon, 2005). The sources used to inform this literature review include books, academic journal articles, and policy documents. Some of the main keywords in the first phase of the systematic search were “sustainability citizenship”, “sustainability citizen”, “global citizenship” and “citizenship education”. Research has been organised in several phases. First phase consisted of gathering relevant literature and policy documents, reading full texts, and placing relevant notes. The search was restricted to books, academic journal articles and policy documents published in English from 2005 to 2020, and each document was a separate unit of analysis. Second, developing an organization and management scheme. Third phase was focused on asking questions about documents and literature (who produces it, for what purpose, what is the type of the data). Final phase is related to exploring and analysing the content with several steps developed: (I) open coding and category construction, (II) fragmenting the data into smaller units/codes and comparing them, (III) grouping/synthesising codes, and (IV) naming the categories with basic analytical attributes.

Results from this research indicate that “sustainability citizenship”, as expected, has various conceptualisations depending on both author(s) and the nature of documents. There seem to be three general categories of definitions of sustainability citizenship in books and academic journals: I) competence-oriented; (II) value-oriented, and (III) behaviour-oriented definition of SC. First category contains subcategories such as system thinking and critical thinking competencies. Second one, indicates focus on securing human rights and fairness of the distribution. The last category focuses on active participation in community and pro-sustainability behaviour. Usually one of the categories prevails in the definitions, while we argue that there is a need for the whole-approach that will synthesise all of the categories. Content analysis of policy documents, unexpectedly, reveals complete absence of the sustainability citizenship construct, as such. There are alternative constructs 'engraved' in those documents, namely - global citizenship, democratic and active citizenship. We conclude that even in the context of those alternative constructs, the analysis proves the dominance of the descriptive manner of defining. Due to various descriptive nuances there is a lack of understanding what this construct entails all together. Considering the analysed categories of descriptive definitions, we propose the working definition of SC leaning on the whole-approach: Sustainability citizens (SC) possess knowledge in sustainable development and understand the importance and interconnectedness of all sustainable development dimensions – ecological, social, economical and political. SC have a strong sense of interdependence and shared responsibility for the well-being of all humans and the entire ecosystem. SC are reflexive, critical toward their own behaviour and prone to take responsibility for own actions. They act proactively and contribute to altering the unsustainable system by engaging in actions for the well-being of others as well as in decision-making processes.

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