Rethinking adult learning and education as global citizenship education: A conceptual model with implications for policy, practice and further research

This article provides a conceptual analysis of the two domains of global citizenship education and adult education and learning, along with their similarities and differences. It begins by unpacking the ambiguous and contested concept of global citizenship education and proposing a critical vision of it, within a global social justice framework. Against this backdrop, the article argues for reconceptualizing adult education and learning as global citizenship education, instead of considering the latter to be one of the key issues of the former. Their structural link is grounded in their common epistemological nature. The domains are interlocked to the extent that both (1) promote active citizenship skills, (2) strive towards equality and social justice on a global level and (3) adopt a valuesbased approach and promote transformative learning. In conclusion, an original ‘Four-dimensions approach to adult education and learning as global citizenship education’ conceptual model is advanced potentially to inform policymakers, practitioners and researchers. The model is made up of four basic components of adult education and learning as global citizenship education, namely: aims and scope (what for), contents and skills (what), processes and pedagogies (how), actors and learning environments (who).


Introduction
Global citizenship education and adult learning and education refer respectively to widely recognized domains of political and professional concerns. However, researchers, policymakers or practitioners have not to date adequately addressed the strong ties between these domains. The academic literature tends to focus on either global citizenship education or on adult learning and education. With few exceptions (Nikolitsa-Winter et al., 2019), consideration of global citizenship education is for the most part given in relation to its implementation in school curricula in higher education (Horey et al., 2018) and in the schooling of children and young people rather than adults. Despite an increasing volume of literature that addresses adult learning and education in the frame of Sustainable Development Goal (SDG) 4 (Benavot and Stepanek Lockhart, 2016;Elfert, 2019;Boeren, 2019), studies that connect adult learning and education to global citizenship education are still rare (Larjanko, 2015;Dorio, 2017;Schreiber-Barsch, 2018).
The separation between global citizenship education and adult learning and education as different policy domains is also evident in international cooperation, where UNESCO (n.d.) standard-setting mechanisms that fix common rules for states differentiate between the two. Accordingly, the monitoring of global citizenship education and of adult learning and education developments in UNESCO member states is done separately.
On that premise, this article provides a conceptual analysis of the two domains and teases out forms and modes of interconnections between them. Accordingly, we argue for the need not to consider global citizenship education as an issue of concern for adult learning and education, nor the latter as a sub-topic of the former. Rather, we argue for re-conceptualizing adult learning and education as global citizenship education, and we explain the circumstances under which this is made possible. Against this background, a conceptual model of adult learning and education as global citizenship education is presented. This holistic model builds on four interrelated dimensions: aims and scope (what for), contents and skills (what), processes and pedagogies (how) and actors and learning environments (who). In the concluding section, we elaborate on possible implications of this model for both policy and practice and for further research.

the ambitions of global citizenship education and adult learning and education adult learning and education
Adult learning and education are non-univocal terms that address a constellation of practices with diverse embedded ideologies (see Milana et al., 2018). For the purposes of this article, we define adult learning and education as 'all forms of education and learning that aim to ensure that all adults participate in their societies and the world of work' (UIL, 2016: 5-6). Accordingly, adult learning and education aspire 'to equip people with the necessary capabilities to exercise and realize their rights and take control of their destinies' (UIL, 2016: 8).
Excluding incidental learning that occurs unintentionally, multiple contexts (i.e. the school, the workplace and the community) intentionally support adult learning and education, each incorporating different forms and approaches (Milana, 2018).
First, there is the context of different kinds of schools, training or learning centres in which adults learn basic literacy, gain up to secondary school degrees and train for different professions. These types of educational institutions have increasingly attracted not only the illiterate population, but also early school leavers, young people not in education, employment or training (so-called NEETs), long-term unemployed, migrants, refugees, among others (Milana, 2017). Second, universities and other higher education institutions have also increased their provision for the targeting of 'non-traditional' students such as adults (Finnegan et al., 2014), thanks to part-time programmes, professional degrees, non-credit courses and massive open online courses.
Third, the workplace constitutes an important context in which adults learn and at times engage in hybrid forms bridging the workplace and school -for instance through apprenticeships, with their different 'models of learning' (Fuller and Unwin, 2009). Apprenticeships involve a pedagogical as much as an occupational dimension (Fuller and Unwin, 2013); they can lead to a more expansive or restrictive learning practice (Fuller and Unwin, 2009), which is not free from possible forms of exploitation (e.g. cheap labour).
Fourth, the immediate as well as more distant communities in which adults live and/or connect are also contexts in which adults learn -for instance, through career guidance by public and private employment agencies or community-based services, or through the use of information and communication technologies. Popular culture and media, of which adults are active consumers, also 'operate pedagogically with and for their adult audiences' (Jubas et al., 2015: 2).
In sum, adult learning and education take place in a variety of contexts in which adults are also called to exert rights and make choices for themselves and others.

Global citizenship education
Following the 2012 United Nations Global Education First Initiative, the notion of global citizenship education has gained momentum and become popular. Despite the term's increasing political prominence, many scholars stress its polysemic conceptual ambiguities (Mannion et al., 2011;Hartung, 2017;Bourn, 2020;Davies et al., 2018;Pashby et al., 2020). In particular, contrasting ideologies underpinning global citizenship as a new educational framework are outlined (Abdi et al., 2015;Andreotti, 2006Andreotti, , 2011Andreotti, , 2015Pashby et al., 2020). These range from a neoliberal entrepreneurial view (Stein, 2015;Pais and Costa, 2020) of educating global elites for the global free market (Hartung, 2017) to a critical and decolonial perspective emphasizing equality and social justice as fundamental educational goals (Bourn, 2015;Davies, 2006;Shultz, 2007). While the former promotes from a market-oriented perspective a new type of entrepreneurial citizen, able to enjoy the opportunities provided by economic globalization, the latter perspective, being an ethical vision, aspires to prepare people 'to become proactive contributors to a more just, peaceful, tolerant, inclusive, secure and sustainable world' (UNESCO, 2014: 15). This aspiration, however, can be twofold. On the one hand, it tends to endorse a superficial sense of naive internationalism, aimed at pursuing a controversial international awareness, which can be condemned as an expression of a masked colonialism (Abdi et al., 2015;Andreotti and de Souza, 2012). On the other hand, a more critical vision of global citizenship education emphasizes equality and social justice as fundamental educational goals (Bourn, 2015;Davies, 2006;Jefferess, 2008;Tarozzi and Torres, 2016).
As Tarozzi (2021) argued, we position ourselves within a global social justice conceptual framework, combining individual global mindedness, subjective responsibility and behaviour towards the social and environmental sphere in which adjectival educations -such as intercultural education, education for sustainable development and social justice education -are reframed from a global holistic angle.
At the same time, the global education perspective is effective only if it combines the interventions at local level with a global ethos. This is because rights do not only depend on national citizenship, as is clearly shown by international migrations which demonstrate that the impact of human rights on national legislations and individual destinies are often determined by global challenges (i.e. war and conflicts, climate change or natural resources exploitation). In other words, as suggested by Edgar Morin (1999) more than two decades ago, beyond local, national and international communities a further space of people's belonging and identity recognition can be found at global level; here citizenship also entitles an earth identity, or awareness of belonging to a worldwide community of destiny or common earthly fate. Nowadays a shared sense of belonging to a common destiny at global level is emerging, generated by events and threats that affect humanity in its entirety. These include economic and market interconnections, environmental risks, the global consequences of local conflicts or the dangers of nuclear war (Milana and Tarozzi, 2013) -not to mention the global impact of the spread of infectious diseases that threaten populations across countries and continents, such as the COVID-19 pandemic.
Global citizenship education cannot be understood merely as an abstract ethical attitude. A de-localized global citizenship education risks becoming a naive form of superficial internationalism, abstract and unable to generate concrete and fruitful educational practices. Albeit we are world citizens because we belong to the human community and live in an interlocked, globalized world, some economists criticize globalization as not inevitable or advantageous to all (Rodrik, 2011). We witness the emergence of right-wing populism, conservative communitarianism and radical nationalism in many parts of the word, all running counter to the values of global citizenship. There is thus an emerging discourse that tends to contrast globalization in its various forms by creating artificial and unfounded tensions between globalization vs. identity, globalists vs. patriots, global vs. local. All of this has raised questions and posed serious challenges to the global dimension of education (UNESCO, 2018), emphasizing the role of national citizenship, local communities and identities in contrast to the educational significance of a global mindedness.

conflating ambitions
Global citizenship education and adult education are non-univocal terms addressing a constellation of practices with diverse embedded ideologies . The aspirations of global citizenship education and adult learning and education seem at first to differ remarkably. Global citizenship education, from our viewpoint, is an ethical vision that seeks to prepare people 'to become proactive contributors to a more just, peaceful, tolerant, inclusive, secure and sustainable world' (UNESCO, 2014: 15). Adult learning and education more concretely aspire to provide learners with the knowledge and skills needed to exercise their rights, and this predominantly happens in national and local communities.
On closer inspection, the aspirations of both adult learning and education and global citizenship -to make people proactive contributors to a better world and to realize their own rights and destinies -can be better achieved through a global education perspective. Yet the objectives of adult learning and education encompass the capacity for people to: fully participate in sustainable development processes and to enhance solidarity among people and communities; … promote peaceful coexistence and human rights; and … enhance awareness for the protection of the environment. (UIL, 2016: 8) Complementing these objectives are broader ones, such as to think critically, act autonomously and responsibly, deal with the economy and the world of work and foster resilience in young people and older adults (UIL, 2016).
In sum, while it is crucial to translate global education locally to make it more viable, concrete and fruitful, as suggested by adult education, the aspirations of both global citizenship education and adult learning and education correspondingly point at education and learning as the means to foster sustainable development processes and peaceful coexistence. These are precisely the aspirations of the global dimension of education. Correspondingly: A global citizenship education approach to adult education intersects individual development as a participatory process with sustainable development and peace education fostered by a model of global commons. (Torres and Dorio, 2015: 5) In the next section, the conditions under which the alliance between adult learning and education and global citizenship education is made possible within a common global aspiration will be further explored by examining three main dimensions.

Interlocking global citizenship education and adult learning and education
Having pointed at essential convergences between their aspirations, we now consider how global citizenship education and adult learning and education, under certain conditions, also share a number of aims, approaches and fields of applications that are values-based (Dorio, 2017). Accordingly, as we further clarify below, global citizenship education and adult learning and education may share a common epistemological nature, and thus be seen as interlocked conceptions, on the condition that both (1) promote active citizenship skills to enhance participation, (2) aim at equality and social justice at global level and (3) adopt a values-based approach and promote transformative learning. In the following section these three conditions are illustrated further.

active citizenship and participation
Recognizing a global perspective on citizenship is crucial in addressing people's participation in social and political life. In recent years, in fact, we observe the exacerbation of social and economic crises, both within and across nations, independently from the growth model behind a country's development. Under these circumstances, many countries around the world have experienced the long-term evolution of inequalities, a concentration of wealth, the limits of social solidarity and the fragility of social cohesion. Current disputes consequently call for new ways to reconcile economic growth, equity and social justice.
One way to do so is 'to reclaim the notion, the idea and the concept of citizenship', not least as 'global challenges care little about national borders' (Larjanko, 2015: 1). In fact, some suggest that Marshall's (1992) classical conception of national citizenship might be obsolete in modern times and in post-national societies (Soysal, 1994;Cohen, 1999;Tambini, 2001) because it does not take into account the transnational dimension of today's citizenship. Moreover, participation rights, despite their growing entitlement, are exerted less and less. In addition, the role and power of nation-states have considerably decreased, and new forms of global powers govern national policies. This has weakened the possibilities for citizens' participation in political decisionmaking processes, which are spread to a far-off and indefinite supranational space (Sassen, 2002). As we have noted, acknowledging a global perspective on citizenship is therefore crucial in addressing participation needs and global challenges. Unlike its twin concepts such as global education or global learning, global citizenship education emphasizes the idea of citizenship as a form of participation in society. This makes the idea of a global dimension in education not only more concrete, but also closely related to equity, social justice, human rights and the rule of law by fostering people's agency for a common good. Significantly, adult educators and researchers such as Torres and Dorio (2015: 5) claim that: A participatory educational approach focusing on the individual as a decision maker interconnected to a wider local and global community concerning virtues of the environment and cultural diversity is greatly overlooked.
Since global citizenship does not provide individuals with a legal or political status, it is possible to regard it as just an ideal abstraction. But global citizenship education advocates a condition of participation that presupposes individual rights at global level; these, though not formally recognized, retain a symbolic value. Global citizenship can therefore be regarded as an ethos that informs practice and enhances new meanings for education. For this reason, while educating global citizens is crucial for every educational level and age group, it seems especially appropriate and meaningful for adults who experience multiple opportunities and threads of participation in society in their everyday lives. equity and social justice at global level As noted above, active citizenship and participation, both nationally and globally, can be regarded as a way to reconcile economic growth and social justice at a global level. Both global citizenship education and adult learning and education could root their ideas of citizenship in these basic principles. However, the relevance of global citizenship education in challenging environments is non-univocal. Some perceive global citizenship education to be a luxury disconnected from the basic needs of the learners. Such a view sees it as a form of human capital that demands a very selective education of the new global elite, producing privileged people capable of benefiting from the global economy (Gardner-McTaggart, 2016). Others believe that global citizenship education aims to address global inequalities and promote a social justice education by championing 'the development of skills as a means for the emancipation of the oppressed and marginalized, and thus for ensuring a more equitable and just society where everyone has the same educational, social and political opportunities to develop this potential' (Tarozzi and Torres, 2016: 13). Following this line of reasoning, it can be argued that social justice and social justice education are viewed as basic principles and fundamental aims by both adult learning and education and global citizenship education. However, combining economic development with equality (as well as environmental sustainability) embraced by adult learning and education, and by global citizenship education, is not a neutral option. It requires a precise commitment towards social justice and equity which is not universally accepted -as exemplified by the 'entrepreneurial' global citizenship education model (Stein, 2015).
On the one hand, despite the growing, economic-driven proposals for adult learning and education put forward by some international organizations, in contrast to UNESCO's 'utopian and citizenship-oriented version of lifelong learning' (Elfert, 2019: 540), we claim that inclusive education and equity remain basic principles for adult learning and education. On the other hand, while different ideologies and contrasting visions underpin global citizenship education, which can be regarded as an approach either enhancing global competition for global elites or a means of challenging global inequality, we endorse a critical vision on global citizenship education. This critical vision emphasizes equality and social justice as fundamental educational goals (Shultz, 2007(Shultz, , 2015Tarozzi and Torres, 2016) within a global social justice framework (Tarozzi, 2021). Such an agenda is also very much in line with the Belém Framework for Action (UIL, 2009) towards an inclusive and equitable access and participation in adult learning and education activities.

values-based approaches and transformative learning
Neither global citizenship education nor adult learning and education are neutral concepts. Whatever the setting and the educational environment, these two educational perspectives are grounded in an ethical or political view and cannot even be understood from a value-free standpoint.
No matter the context in which adults learn or education takes place, and in which the forms and the approach are adopted, adult learning does not happen in a social vacuum nor is it value-free. This implies that adult learning always builds on some sort of political and ethical commitment, reflecting the values pursued by those providing education and learning opportunities to adults. This is also the case for global citizenship education, revealing its adaptability to different educational environments in a vertical (lifelong) and a horizontal (lifewide) perspective. This flexibility is due especially to its ethical underpinnings. Global citizenship education can be seen as a values-based approach (Sharma, 2018(Sharma, , 2020. As Tarozzi and Torres (2016) argue, global citizenship education is an ethos, an educational paideia, a framing paradigm which embodies new meaning for education and its role in developing knowledge, values, attitudes for securing tolerance, diversity recognition, inclusion, justice and sustainability across the world.
As a values-based approach, global citizenship education's main goal appears to be fostering change in people's attitudes and behaviours. Here values, beliefs or an ethos are important aspects to be developed throughout educational practices and transformative learning. Such an approach is aimed at engaging people, namely adults, to embrace values or to activate them to promote change in the community. Global citizenship education as a form of values-based adult learning and education is therefore highly valuable in developing transformative processes and engaging learners to achieve positive agency towards societal change.
In fact both global citizenship education and adult learning and education also promote transformative learning. This means that people involved in activities that produce a disorienting dilemma are stimulated towards a revision of their meaning schemas or meaning perspectives that constitute their frame of reference to make sense of, and act into, the world (Mezirow, 1991). Transformation of people's meaning perspectives can be within either the instrumental or the communicative domain of learning. The former involves understanding how things work, the latter understanding people's relationships and how they comprehend each other. Whichever domain is used, however, transformative learning involves the learner's critical reflection on their own (previous) assumptions and engagement with others. As a result individual, interpersonal and collective actions are also inextricably bound to transformative learning (Moyer et al., 2016). For instance, dialogic interactions of values, beliefs and experiences that occur through dialogue and the deep sharing of meanings among people may therefore serve 'as a foundation, a catalyst, and culmination of transformative learning processes' (Pope and Nicolaides, 2021: 1). In other words, 'learning can be seen to have a transformative effect on the learner and on the learner's life and, likewise, transformation can be said to create, amongst other effects, learning' (Howie and Bagnall, 2013: 482).
However, no transformative learning that fosters change in people's attitudes and behaviours can be achieved when educators are required to set aside personal beliefs and commitments (Ball, 2003) within prevailing regimes of testing and accountability (Biesta, 2016).
adult learning and education as global citizenship education: a fourdimensional conceptual model Thus far we have explained the reasons for addressing global citizenship education in adult learning and education and considered forms and modes of interconnections between the two concepts. On this basis, instead of regarding global citizenship education as a key topic in adult learning and education, or asking what adult learning and education can do for global citizenship education, paraphrasing Schreiber-Barsch and Mauch (2019), we advance a perspective of adult learning and education as global citizenship education. This means that, when interpreted in a particular and non-neutral way (i.e. addressing social transformation, equity and social justice from a non-Western-centred perspective), adult learning and education can be regarded as global citizenship education; this provides a comprehensive view that encompasses a vertical (lifelong), a horizontal (lifewide) and a methodological sphere.
A vertical sphere includes cultural, social and political commitments and responsibilities that apply to everyone, of all ages and from all backgrounds, along their life span. A horizontal sphere embodies various learning forms that happen in multiple environments beyond formal education. Accordingly, adult learning and education contribute to expanding the scope of global citizenship education by stressing the lifelong and lifewide learning dimensions and not limiting global citizenship education to formal education, taking place in the early stages of life. In addition, adult learning and education and global citizenship education share a common methodological sphere and theoretical framework: both are holistic in nature and accept complexities and contradictions, while any reductionist attempt to simplify them or trap them into rigid boxes contradicts their essence.
Against this backdrop, in order to suggest a holistic conceptual approach to adult learning and education as global citizenship education, we follow Schreiber-Barsch and Mauch (2019), who propose an all-encompassing approach to systematizing and connecting different views to sustainability in adult learning and education. This approach is based on three dimensions: contents, processes and structures. It considers learning to be 'a phenomenon that addresses contents, processes and structures in a non-linear, cumulative and recursive-way' (Schreiber-Barsch and Mauch, 2019: 532, emphasis in original), and echoes the fields of learning, policy devices and appropriate learning environments identified by the Recommendation on Adult Learning and Education (UIL, 2016) adopted by UNESCO in 2015.
Schreiber-Barsch and Mauch's (2019) approach resonates with the conditions addressed above, under which global citizenship education and adult learning and education share a common epistemological nature. Both seek to promote active citizenship skills to enhance participation, aim at equality and social justice at global level and adopt a transformative and values-based approach.
We suggest therefore that a similar approach could be applied to implement adult learning and education as a form of global citizenship education in practice, yet with an important addition to Schreiber-Barsch and Mauch's (2019) model. Such an addition constitutes a key overlapping dimension between adult learning and education and global citizenship education: aims and scope. These are pivotal factors in understanding educational policy and practice. Beyond their instrumental value of effectiveness, all educational systems and institutions should deal with what is educationally desirable or the values of the aims and purposes of education (Biesta, 2007(Biesta, , 2016. Following this way of thinking, we propose a conceptual model composed of four specific dimensions. These, shared between adult learning and education and global citizenship education, serve to reflect the four basic dimensions of education: aims and scope (what for), contents and skills (what), processes and pedagogies (how), actors and learning environments (who). Due to limitations of space, we briefly illustrate the model's different dimensions (more information on the conceptual background on which these dimensions build can be found elsewhere; see Milana and Tarozzi, 2019): • Aims and scope (what for) have to do with adult learning and education's purposes, or what constitutes the educationally desirable in terms of global social justice. Adult learning and education as global citizenship education fundamentally aims to empower youth and adult learners to engage and assume active roles, both locally and globally, to face global challenges and ultimately to become proactive contributors to a more just, tolerant, inclusive, secure and sustainable world. This goal makes sense in a social justice education framework. • Contents and skills (what) refer to the cognitive, socio-emotional and behavioural learning domains of global citizenship education that can be transformed in key learning outcomes and skills (UNESCO, 2015). This taxonomy of global citizenship education topics and learning objectives for primary and secondary schools should be adapted for adult learning and education in a flexible way and also incorporate active citizenship skills to foster participation and public engagement. • Processes and pedagogies (how) have to do with the political and practical processes that transform abstract statements of principle and/or adult learning and education recommendations into actual global citizenship education learning activities, pedagogies and learning methods. Both in global citizenship education and in adult learning and education, transformative pedagogy has been regarded as an appropriate device to 'bring about changes and personal transformations in the process through the experience of action and practice' (UNESCO Bangkok, 2018: 7). • Actors and learning environments (who) refer to the active engagement of various stakeholders in fostering global citizenship education in different environments for adult learning and education. Key stakeholders include national and international non-governmental organizations (NGOs) and civil society organizations, local authorities, governmental organizations (Ministry of Education and Ministry of Foreign Affairs), researchers and educators of teachers/ educators, funding bodies, teachers' unions, higher education institutions, etc. In particular, it has been argued that NGOs and civil society organizations are major drivers in promoting global citizenship education (Tarozzi, 2019(Tarozzi, , 2021Gene, 2017;Bourn, 2015).
Yet the question of how adult learning and education as global citizenship education can be addressed beyond statements of principle remains. This requires both policymakers and practitioners to give full recognition to the fact that global citizenship education and adult learning and education are interconnected, and that adult learning and education play an important role in global citizenship. Consequent to this is also that, in the pursuit of target 4.7 of the Sustainable Development Goals Agenda, adult learning and education shall be given reasonable attention in global citizenship education's policy and practice, while global citizenship education shall be well attended in adult learning and education policy, research and practice. In fact, while adult learning and education's contribution to SDG 4 and across SDGs has been addressed (Benavot and Stepanek Lockhart, 2016;Elfert, 2019;Boeren, 2019), its specific contribution to target 4.7 has not yet received sufficient attention. By contrast, target 4.7 explicitly mentions global citizenship education as one of the educational goals to be achieved by 2030 (UNESCO, 2016). Beyond this focused target at the heart of the SDGs (Bamber, 2019) are incorporated several diverse goals and approaches, from environmental issues to human rights, from poverty to gender issues. In short, global citizenship education and its complementary approach (i.e. Education for Sustainable Development) embody holistic and transformational education across a wide range of institutions and learning environments, thus including adult learning and education's institutions and learning environments. Accordingly, we claim that both global citizenship education and adult learning and education share the Sustainable Development Goals Agenda as a top priority and focus on a common goal, particularly in target 4.7.

Implications for policy, practice and further research
In this final section we suggest some possible implications of rethinking adult learning and education as global citizenship education. In particular, using the conceptual model advanced in the previous section, for each of its four dimensions we point out below some practical implications for both policymakers and practitioners, as well as topics for further research. This discussion is crucial: a model's key implication is that it calls for closer cooperation among these groups and a multi-stakeholder approach is a fundamental feature for effectively informing policy and practice: • What for (aims and scope): Different interpretations of global citizenship education coexist; rooted in contrasting visions and political assumptions, they address different goals. Likewise different motives and preoccupations with adult learning and education coexist; these do not necessarily redress social injustices, and can even reinforce or create new social injustices (Milana, 2018). Global citizenship education for social justice is a framing paradigm that invests well-established concepts and approaches with new significance. It is a new topic, offering above all a lens through which to review one's own work and to provide a framework for guiding teachers and educators' activities, or a perspective that they can adopt (Wintersteiner et al., 2015). Supporting global citizenship education for social justice across adult learning and education's learning environments implies advancing a transformational agenda, and engaging in the pursuit of global social justice that reconciles local aspirations with global concerns. This calls for policymakers to engage in inter-ministerial collaborations, encourage multistakeholder approaches, secure coherence among different levels of governance and promote national curriculum reforms in public and private schools and in education, training or learning centres for young people and adults. At the same time, it calls for practitioners actively to engage in international partnerships and transnational informal adult learning and education projects. • Who (actors and learning environments): Independently from the growth model behind a country's development, issues such as religious conflict, ethnonationalism, violent extremism and warfare, as well as growing evidence of climate change, have exacerbated social and economic crises at local, national and international level. Being a values-based approach, global citizenship education can foster change in people's attitudes and engage young people and adults in transformative processes and positive agency towards changes in society. However, changes in society are rooted in the alteration of citizens' everyday practices, and in their awareness of, and connections to, their immediate as well as global communities. Policymakers are thus expected to promote whole institution approaches (e.g. SDGs' Global schools, UNESCO Learning cities). At the same time practitioners are expected to engage themselves and learners actively in international partnerships and exchange programmes, as well as in local collaborative projects (e.g. community-based programmes, service learning, and so on). • What (contents) and How (processes and pedagogies): Here we purposely combine these two dimensions to prevent a functionalist delivering of global citizenship education in adult learning and education. In fact, as our model contends, the contents of both global citizenship education and adult learning and education cannot be separated from the processes through which learners acquire knowledge, skills, abilities and behaviours. UNESCO and other international institutions have developed useful documents on global citizenship education such as Global Citizenship Education: Topics and learning objectives (UNESCO, 2015) -a pedagogical guide that contains suggestions for translating global citizenship education concepts into practical and agespecific topics and learning objectives. This pedagogical guide can serve as the basis around which both policymakers and practitioners could reflect, debate and agree on useful adaptations to local contexts and target groups. At the same time, teacher education is a key indicator for global citizenship education policy implementation (Tarozzi and Inguaggiato, 2018;Tarozzi and Mallon, 2019).
Values-based approaches that foster transformative learning can be regarded both as a tool to equip young people and adult teachers, trainers and educators with the knowledge, skills and abilities required to improve learning experiences and as a political apparatus for achieving curriculum change.
All this analysis calls for policymakers to identify relevant ministries to coordinate multi-stakeholder' global citizenship education platforms at national and local levels, thus involving all interested parties across adult learning and education's learning environments (formal, non-informal, informal). However, it also calls for practitioners to learn about, and consider how, the cognitive, emotional and behavioural dimensions of global citizenship education can be adapted, and then promoted through the adult learning and education practices in which they are involved. In concluding this section, it is worth highlighting the need to engage all the relevant stakeholders in the process of researching, agreeing and applying sound and reliable -but also flexible, holistic and not standardized -criteria for monitoring and evaluating the achievement of SDGs involving education. This is specifically the case with target 4.7, whose indicators are particularly difficult to acknowledge and require a participatory and comprehensive process. What is imperative is to ensure that adult learning and education is included in this discussion; it can significantly enrich the discussion on measuring the Agenda progress with its well-established tradition of formative, local and non-standard learning assessment.

conclusion
In this article we have engaged in a conceptual analysis of what is usually seen as two distinct domains for policy and practice: global citizenship education and adult learning and education. In so doing we have developed an argument that overcomes the functionalist view that considers global citizenship education as a key issue or one of the domains of adult learning and education. On the contrary, we have endorsed a perspective of adult learning and education as global citizenship education. This means that the two domains are interconnected and share some key constitutive elements when interpreted in a particular and non-neutral way (i.e. addressing social transformation, equity and social justice from a non-Western-centric perspective). On this ground, we presented an interpretative model that builds on four conceptual dimensions: aims and scope (what for), contents and skills (what), processes and pedagogies (how) and actors and learning environments (who). We discussed how these could inform both policy and practice, and pointed at some of their implications.
Further research is also needed to better elaborate the structural links between adult learning and education and global citizenship education, and how coherently to inform policy and practice. Comparative research is required to examine education policy developments and their impact on adult learning and education practices, as well as to examine what type of global citizenship education is promoted and/or hampered by different adult learning and education practices. Further research is also needed outside the formal education system, for instance in professional education, programme development and learning assessment at post-compulsory level.
Despite the interconnectedness of global citizenship education and adult learning and education at conceptual and definitional level, we have shown in this article how, in mainstream education policy and practice, they are still considered as separate areas of intervention. The former is regarded as a key issue of the latter, or the latter as a field of application of the former. Here, on the contrary, we have attempted to demonstrate that stronger links between these two policy and practice domains are possible, due to their similar epistemological nature. Moreover, as interlocked conceptions, they can magnify their transformative power and social commitment.
Following Freire, we note that adult learning and education are integrally linked with participation in the political process through knowledge achievement; they do not just involve a de-contextualized and functional cognitive process of skills acquisition. The same is true of citizenship which underpins a critical social justice global citizenship education.

Declarations and conflict of interests
The authors declare no conflicts of interest with this work.
notes on the contributors marcella milana is Associate Professor at the University of Verona, Italy, where she directs the International Research Centre for Global and Comparative Policy Studies on the Education and Learning of Adults (IRC-GloCoPoS). She is also Honorary Professor of Adult Education at the University of Nottingham, UK. She researches the politics, policy and governance of adult education and learning from comparative and global perspectives.