2.1. Sustainability

The terms ‘sustainability’ and ‘sustainable development’ have been in use since the 1970s [Reference Meadows, Meadows, Randers and Behrens20] with increasing focus in policy circles since the Brundtland Commission [21] and the World Summit on Sustainable Development [22], recently becoming recognized as an interdisciplinary research discipline: Sustainability Science [Reference Kates23]. Despite, or perhaps because of, this long interdisciplinary history, the terms are interpreted in diverse ways by different groups.

We find it useful here to differentiate between ‘sustainable development’ as a process and ‘sustainability’ as an outcome or property. We further highlight that sustainability is a wider concept than environmental sustainability, recognizing that the term ‘sustainability’ has evolved from its earlier focus on environmental or natural resource limits on growth or development, to a broader vision of sustainability as three interdependent pillars of environmental, social and economic dimensions [22,24].

A social–ecological systems perspective on sustainability would suggest an even more integrated and dynamic vision of these three dimensions, moving towards the notion of society (including the economy) and ecosystems as inseparable and co-evolving (e.g. [Reference Leach, Raworth and Rockström2,Reference Kallis and Norgaard9,Reference Folke, Biggs, Norstrom, Reyers and Rockstrom11]). Recognizing that social–ecological systems act as strongly coupled, complex and integrated [Reference Liu, Dietz, Carpenter, Alberti, Folke, Moran, Pell, Deadman, Kratz, Lubchenco, Ostrom, Ouyang, Provencher, Redman, Schneider and Taylor25], this perspective focuses on sustainability of the whole dynamic social–ecological system over time [Reference Ostrom26].

Beyond acknowledging social, ecological and social–ecological dimensions of sustainability, such a SES perspective also makes clear a shift away from the notion of sustainability as an equilibrium state or an environmental/social end point to an acknowledgement of variability and system dynamics. In this SES perspective, sustainability is not achieved through interventions which aim to decrease variance in order to achieve system stability and predictability; in fact, research has shown that variance, within certain bounds, can prevent systems moving out of the desired system configuration in the long term [Reference Carpenter, Brock, Folke, van Nes and Scheffer27]. The concept of dynamic sustainability suggests the management of the whole system, its elements and their relationships with one another, within a specified range of variability – a multi-dimensional envelope of acceptable variation. This specified or desired range is bounded by multiple social, ecological and social–ecological thresholds beyond which the system would risk undesirable and often irreversible change (Figure 1). This is similar to the notion of planetary boundaries, social foundations or safe and just operating spaces [Reference Steffen, Richardson, Rockstrom, Cornell, Fetzer, Bennett, Biggs, Carpenter, de Vries, de Wit, Folke, Gerten, Heinke, Mace, Persson, Ramanathan, Reyers and Sörlin1,Reference Carpenter, Brock, Folke, van Nes and Scheffer27,Reference Raworth28], but offers a more coupled and context-specific perspective on systems and thresholds.

Fig. 1. A schematic representation of a social–ecological systems perspective on sustainability showing systems variation across multiple social and ecological dimensions, but staying within a desirable and meaningful life support zone. In this figure, the dimensions are notional and situational, to be determined by scale or context. The set of sustainable development goals can be seen as an example of a possible set of dimensions at a global scale with which to define such a multidimensional social–ecological space, where the targets reflect positions along those dimensions which define the acceptable zone within which system states can vary. Adapted from Biggs and Rogers [Reference Biggs, Rogers, Du Toit, Rogers and Biggs30].

The SES perspective on sustainability proposes the bringing together of the sustainability of biophysical life support systems with the recognition that these support systems are not just biophysical, but are in fact coupled systems of local and cross-scale interconnections of people, place and environment. Such recognition broadens sustainability to focus on the long-term maintenance of desirable and meaningful life support systems which are biophysically, culturally and socially determined. Hereafter in this paper such a SES perspective on sustainability is adopted and thus references to sustainability imply this perspective. Often conflated with sustainability, resilience is, instead, key to helping the system stay in this desirable ‘zone of sustainability’ through the cultivation of social and ecological capacities needed to absorb or adapt to shocks and stressors to stay in the zone, as well as capacities needed to transform or reconfigure the system into a new desirable zone should social, ecological or economic circumstances become unsustainable [Reference Folke, Carpenter, Walker, Scheffer, Chapin and Rockstrom29].

While intuitively compelling, adopting this dynamic perspective on sustainability as a desirable zone or range of variation brings with it enormous challenges for implementation. While certain thresholds may be universal (e.g. basic income, air pollution standards) or global (e.g. climate or biodiversity status), others are often context and value specific, and may be contested (e.g., dietary needs, species numbers or education levels). Thus, we need to ask – desirability of what for whom? And who decides? – recognizing sustainability as a plural and politicized concept [Reference Leach, Scoones, Leach and Newell31,Reference Leach, Scoones and Stirling32]. Furthermore, many of the thresholds themselves are dynamic and linked through feedbacks across scales of space and time. The SDGs provide an approach to this through goals and targets which can be seen as a set of politically-negotiated thresholds outlining the desirable and meaningful life support zone to be sustained, at least at the global level (Figure 1). SDG implementation must, however, address both the interlinkages amongst the various goals and targets, and the challenges of grounding internationally-negotiated thresholds in diverse national and local contexts. Previous work on thresholds of desirable life support systems have not explored the social processes of defining desirability in depth. While ‘social equity’ (and gender equality) figure as part of the social foundations for a safe and just operating space [Reference Raworth28], there has been little attempt to unpack the various dimensions of equity, nor to relate them systematically to sustainability. Our next two sections lay out key elements of a framework for doing this.

2.2. Equity

Like sustainability, equity is a plural and politicized concept. Envisaging an equitable Anthropocene requires that the desirable zone or range of variation in which SES move over time is also bounded by acceptable notions of equity. Defining such zones requires attention to equity as a moral and political concept, recognizing that what is acceptable will vary between societies and over time. Integrating equity with sustainability requires attention to multiple forms of equity, asking ‘equity of what’ and ‘equity between whom’. It then requires consideration of how changes in SES are shaped by different forms of equity or inequity, both as inputs to a particular system intervention or change, and as emergent outcomes from the system which then provide the conditions for subsequent changes.

The concept of equity has a long and deep history in social science literature, addressed through numerous disciplinary and philosophical traditions rooted in the common dignity and transcendence of the human person and associated human rights. Looking across these, some key distinctions emerge. First is that between equity and equality. While often treated as synonyms, equality strictly refers to treating everyone in the same way, or evenly distributing a given ‘pie’. By contrast, equity refers to ensuring that everyone has what they need for wellbeing in a given context, implying ‘more for those who need it’. Equity is our preferred term in this paper. It refers more fully to fairness and justice, acknowledging that these have both material dimensions – fairness in means and capabilities for a worthwhile life – and moral ones – treating or representing someone or something with due fairness, respect or appreciation [Reference Sen33]. What is deemed equitable or fair is shaped by what is seen to be a ‘good society’, and this can vary across cultures and over time. We need to appreciate this variability in what is acceptable, while also acknowledging in a globally-collective sense (perhaps as currently and normatively defined in part by Agenda 2030) that extreme forms of inequity are intolerable, and incompatible with a fair and sustainable Anthropocene.

Recently, wide-ranging surveys of literature and examples from multiple disciplines and countries have been brought together in the World Social Science Report ‘Challenging inequalities: pathways to a just world’ [6]. The report uses the term ‘inequality’ broadly to cover dimensions of both inequity and inequality, as defined more specifically in the report's particular contributions. Economic inequalities have dominated most analyses past and present, and important recent works address the dimensions, trends, causes and consequences of economic inequalities, both globally (e.g. [Reference Milanovic34,Reference Bourguignon35]) and within countries (e.g. [Reference Deaton36,Reference Piketty37]), addressing why they have in most cases been rising over recent decades. Yet, as traditions of work in sociology, philosophy, anthropology, political science, environmental justice, feminist analysis and diverse applied fields have long argued, the forms of inequality and inequity that matter are not just economic; multiple forms need to be considered. All are relevant to conceptualizing a fair and sustainable Anthropocene. Indeed, we can argue that acceptable SES change (e.g. Figure 1) needs to be bounded by acceptable standards of the multiple forms of equity.

Figure 2 offers a summary of the multiple forms of equity. First, this addresses ‘equity of what’. Building on analysis in the World Social Science Report, and referencing only key examples from much larger literatures, the ‘what’ includes: economic incomes, assets, wealth and capital, living standards and employment [Reference Piketty37,Reference Belser38]; social status, rights, and experiences with respect to education, health, justice and social protection systems [Reference Starfield39]; cultural freedoms and abilities to hold and practise beliefs and identities [Reference Almeida, Hernandez-Wolfe and Tubbs40]; political capacities to influence decision-making processes and to benefit from those decisions, and to enter into political action [Reference Gaventa and Martorano41]; spatial attributes of where people live, and how different places and geographies are accorded status, value and attention [Reference Knight and Song42]; environmental endowments and entitlements, including access to natural resources and benefits from their exploitation, exposure to pollution and risks, and agency to adapt to such threats [Reference Leach, Mearns and Scoones43–Reference Agyeman, Bullard and Evans45]; and, knowledge – referring to access and contribution to different sources and types of knowledge, and the extent to which people's knowledge and cognitive systems have value and legitimacy [Reference Visvanathan, Leach, Scoones and Wynne46].

Fig. 2. A schematic summary of different forms of equity, distinguishing between ‘equity of what’ and ‘equity between whom’, within an overarching typology of distributional, recognitional and procedural equity.

Second, our summary addresses ‘equity between whom’. This refers to how disparities (with respect to any of the ‘whats’ considered above) are distributed and experienced between individuals and groups, according to various dimensions of difference. These include class, occupation, gender, ethnicity, space/place, and other contextual aspects of status and identity (e.g. related to ability/disability; language; educational achievement; sexual identity). Such disparities might apply both in the present (intragenerational equity) and between social groups living in the present and those in the future, including as yet unborn (intergenerational equity).

Questions of ‘equity between whom’ also apply at different scales, according to differences amongst individuals or groups within a community, a locality, country or globally. Thus, disparities relating to space/place might pertain, for instance, to groups living in different parts of a city, relatively better or worse endowed with infrastructure or services [Reference Bai, Brondizio, Bullard, Edwards, Grimm, Lora-Wainwright, Özkaynak, Schindler, Lele, Brondizio, Byrne, Mace and Martinez-Alier44,Reference Bullard and Johnson47]. Within a country, they might relate to disparities between urban and rural areas, or those with different geographical conditions (coastal or mountainous areas, or rainfall or agro-ecological zones) [Reference Knight and Song42,Reference Deng and Bai48]. Globally, they might be linked to position in global geo-political orders, relative national resource endowments, or experience of global processes and risks such as climate change.

Importantly, these various forms of inequity (of what and between whom) intersect with one another, creating disadvantage or privilege in complex ways – as for instance economic, ethnic, spatial and gender inequities interact to affect people's experiences [Reference Kabeer49]. Downward spirals of intersecting inequities can, in turn, affect people's self perceptions, limiting their capacities to aspire to a different way of life [Reference Appadurai50,Reference Baillergeau and Duyvendak51]. And, indeed, all of the inequities in one generation can shape those in subsequent generations, as parental and community experiences affect the next generation's access to resources, status and aspirations. The literature on intersecting inequalities to date has generally had a local focus, but inequities can also be envisaged to intersect at an international scale. Thus, a developing small island state might experience a combination of global economic inequity and environmental inequity linked to vulnerability to extreme climatic events and sea level rise, as well as political inequity as its national political agendas are shaped by global decision making [Reference Scobie52].

The arrows forming the outer ring of Figure 2 provide an overarching typology that distinguishes between distributional, recognitional and procedural equity. This categorization, rooted in diverse theories of justice, has been articulated most clearly by Fraser [Reference Fraser53,Reference Fraser54]. Distributional equity refers to how resources, costs and benefits are allocated or shared amongst people and groups. While this was the dominant mode of thinking about and mobilizing for justice during much of the twentieth century, Fraser [Reference Fraser53] observed a rise in what she termed the ‘struggle for recognition’ as groups mobilized under the banners of nationality, ethnicity, ‘race’, gender, and sexuality. Recognitional equity thus refers to acknowledgement of and respect for identity, values and associated rights. Recognitional equity especially emphasizes cultural and political domination and discrimination as forms of inequity and injustice. Procedural equity, a third category, draws on literatures on institutions, governance and participation to highlight how decisions are made, and the extent to which different people and groups are able to influence these or have their perspectives represented or incorporated. It relates closely to political inequity and to broader debates on power and voice, and the ways these operate through both formal and informal institutions and spaces at local, national and international scales [Reference Gaventa and Martorano41]. Knowledge inequities are a crucial aspect of procedural equity, given the ways that groups can be included or excluded from decisions based on what they know, or the extent to which their knowledge and perspectives are deemed valid or legitimate, as works on cognitive justice and knowledge democracy have explored [Reference Leach, Scoones and Wynne55].

The tripartite typology of distributional, recognitional and procedural equity has recently been applied to protected area schemes – an application that gives some insights into its possible application to wider areas of sustainable development [Reference McDermott, Mahanty and Schreckenberg56–Reference Zafra-Calvo, Pascual, Brockington, Coolsaet, Cortes-Vazquez, Gross-Camp, Palomo and Burgess59]. As these examples illustrate, distributional, recognitional and procedural inequities interact with each other as feedbacks of a given intervention. Recognitional equity (identity, values, rights) is usually best understood as an input to a given intervention; this helps set up the context in which procedural equity emerges through governance and decision making, with feedbacks to particular distributional outputs (resources, costs and benefits). In turn, distributional outputs help shape the subsequent processes of recognitional equity, and further procedural equity, and so on through successive cycles of intervention and change.

As Figure 2 suggests, our summary integrates this typology with a more discriminating consideration of ‘equity of what’ and ‘equity between whom’, acknowledging that recognition, procedure and distribution may refer to particular forms of ‘what’ and ‘whom’, or bundles of these forms, depending on the issue and context. When taken together with the potential interactions and intersections between equity and sustainability, the complex systems nature of equity and sustainability outcomes become apparent.

In the next section, we integrate this equity typology, together with our SES perspective on sustainability (Figure 1), into a framework for understanding the relationships between equity and sustainability, by considering a variety of specific ‘interaction dynamics’. To frame this discussion, however, it is also important to address broader conceptualizations of the overlap or linkages between equity and sustainability, including in the SDGs.

2.3. Sustainability and equity: exploring the overlap

Equity and equality are mentioned explicitly in two of the SDGs – Goal 10, ‘Reduce inequality in and among countries’ and Goal 5, ‘Achieve gender equality’, and in around 18 of the 169 SDG targets (Table 1), broadly in three ways:

• • Equitable recognition, rights and access expressed as inputs (to economic conditions, physical conditions, such as water, sanitation, energy, infrastructure and land, and processes such as education and justice)

• • Procedural aspects of equitable participation and opportunity (across gender, in law and policy, and the international trading system)

• • As distributional outcomes expressed as fair sharing of benefits (of use of genetic resources, and in wages or pay)

Table 1. Equity as referenced in the Sustainable Development Goals/Agenda 2030.

This table includes all references in the goals and targets to equal*, equit*, fair* (omitting uses not related to equality, and deliberately abbreviating to emphasize primary meaning where sensible; ‘fair’ actually only appears twice, both times in conjunction with ‘equitable’, and both times related to genetic resources). It is interesting to note that goals 11–14 have no mention of equity or ‘for all’.

NB. ‘for all’, and ‘paying special attention to needs of vulnerable, and women and children’ are common additional phrases that also hint at equality/equity, depending on context.

SDG, Sustainable Development Goal.

Whilst these goals and targets provide the explicit focus on equity in the SDGs, the language of inclusivity, non-discrimination, ‘leave no-one behind’ and universality (‘for all’) implies a much wider intent to achieve equitable development outcomes. Of course, the SDGs also make explicit the need for sustainability outcomes, in both the goals and targets, and in the more general aspirations of Agenda 2030. However, here we contend that this is not enough, as social–ecological system feedbacks mean that many targets will not be achieved without attention to equity and sustainability dimensions that include/overlap with but go beyond those made explicit in specific SDG targets; it is these effects with high systems influence that we argue require greater attention, assisted by a more systemic framework for understanding, identifying and addressing critical interactions.

More broadly, recognizing sustainability and equity as dual aspects of SES change raises many questions about the similarities and differences between these concepts and how much they overlap. Diverse conceptualizations are visible in different literatures, ranging along an axis where at one extreme sustainability is mostly focused on biophysical life support systems with no reference to equity, other than protecting life support systems for future generations. At the other extreme, there is total overlap: equity is conceptualized as an intrinsic part of sustainability, implying that sustainability is defined as achieving equity outcomes and vice versa. Neither of these views, we suggest, is useful: the former is normatively incompatible with the notion of a sustainable and fair Anthropocene, does not adopt a SES perspective on sustainability, and analytically misses key aspects of equity which will critically influence the biophysical life support system. The latter is normatively attractive, and aligns with broad understandings of sustainable development, including as embodied in Agenda 2030. However, when the concepts of equity and sustainability are collapsed into each other, there is little analytical space to address which aspects of equity and sustainability interact in which ways and with what outcomes, and, indeed, what interactions do not matter. Thus, our approach occupies a middle ground of substantial overlap but some separation, matching our framing of sustainability as ‘the long-term maintenance of desirable and meaningful life support systems which are biophysically, culturally and socially determined’. Thus, equity is seen as a part of defining acceptable levels of sustainability (as above), as well as equity forming a key part of achieving aspects of sustainability and vice versa. However, there may remain aspects of equity and sustainability which are not critical to each other.

In the context of this broader framing, and through our SES perspective on sustainability and multi-faceted equity typology, we now go on to explore a variety of specific ways in which sustainability and equity interact using a complex systems perspective.

3.1. Interaction dynamics

To demonstrate and explore this conceptual perspective, a Future Earth workshop with experts from social and natural science disciplines and practitioner backgrounds in March 2017 built on an analysis of previous reviews, the 2016 World Social Science Report [6], and individuals’ own knowledge and experience, to identify a variety of ways in which equity and sustainability could be interlinked in the context of the Anthropocene. From the workshop discussion we identified an illustrative suite of what we term ‘interaction dynamics’ in SES, which shape emergent equity and sustainability outcomes. These take a SES perspective on sustainability as a multidimensional zone and attend to the multiple forms of equity ‘of what’ and ‘between whom’, and the recognitional, procedural and distributional equity typology we outline above.

Provisionally, we identified ten different but overlapping forms of interaction dynamics to illustrate our approach and perspective. These reflect a range of empirically-observable situations, and interactions between particular (differentiated) social groups and dimensions of sustainability. The interaction dynamics involve different system structures and processes, operate at and across different levels, scales and modes of human organization and governance, and are more or less amenable to different types of intervention; our set of ten attempts to exemplify this diversity.

3.2. Towards transformational pathways

The interaction dynamics provide a useful lens on the central practical challenge of our time: how to reorient human–nature relations so as to enable a shift to more sustainable and equitable trajectories (Figure 3). It provides a basis from which we can start to develop a systematic approach to identifying interventions that can address the dynamics that threaten to move development outside the equitable sustainability space, and are thus less compatible with societal goals as embodied in Agenda 2030. We argue that, whilst the overall framing of Agenda 2030 certainly aims at shifting global design and intent leverage points, the SDG targets themselves are largely focused on parameters or feedbacks (sensu [Reference Abson, Fischer, Leventon, Newig, Schomerus, Vilsmaier, von Wehrden, Abernethy, Ives, Jager and Lang85]). These now need to be complemented by other entry points and approaches for influencing co-evolving systems. The analysis of these dynamics makes it clear that there is already a powerful design role in market capitalism. The environmental intervention dynamic needs to drive positive actions targeted at reducing the severity of many of the other feedbacks, at local to global scales. Both of these then require support from the collective action dynamic, which allows approaches to be tested locally but then scaled or remodelled and replicated to have global impact. Again, the design of appropriate institutions and multi-level governance regimes will be an important focus of these interventions. However, broader intent – political and societal – is also needed to enable effective design to operate and take root, especially for the market capitalism and collective action dynamics. Behind all of these actions, a shift in intent through the morality–power–knowledge dynamic is the hardest but most effective intervention to ensure the other desirable changes are deeply embedded.

Building on analysis in Part IV of the World Social Science Report [6] and on research on transformations to sustainability (e.g. [Reference Scoones, Leach and Newell86]), we can envisage such interventions contributing to ‘transformative pathways’ towards a fairer and more sustainable world. These must address the challenge of solving sustainability problems and creating conditions for good and just lives for people, today and in the future, creating the conditions to support 7.5 billion lives on Earth equitably, while strengthening the desirable and meaningful life support system. Such transformative pathways will often involve transformative alliances between different actors – governments, businesses, academia, and citizens – and new modes of governance of and by groups and regimes affecting multiple parts of the SES in dynamically evolving ways [Reference Biermann, Bai, Bondre, Broadgate, Chen, Dube, Erisman, Glaser, van der Hel, Lemos, Seitzingerm and Seton87,Reference Boas, Biermann and Kanie88].

Some approaches may be ‘top down’, involving changes in the rules of the economy, or new policy packages, that alter the market capitalism design dynamic, thus changing the outcomes of the various feedback dynamics (e.g. elite, status and consumption, and marginalization dynamics). ISSC et al. [6] document a range of measures that have proved effective in reducing inequities from local to global scales, ranging from macro-economic measures, labour and market regulation, and progressive tax regimes, to land and resource redistribution, universal health and education access, social protection measures and more accessible and effective systems of environmental justice. Further work is needed to explore the effects of such policy measures that have proven potential to reduce inequities on coupled equity–sustainability outcomes. Likewise, building on Steffen and Stafford Smith [Reference Steffen and Stafford Smith69], we might explore how policy and regulatory measures in the sustainability arena – such as those intended to address various planetary boundaries – could be shaped to bring synergies with various equity considerations through positive environmental intervention design dynamics.

‘Bottom-up’ experiments and small forms of innovation and action by citizens, businesses and local governments also have the potential to contribute to transformative pathways [Reference Bai, Roberts and Chen89–92]. These may, for instance, operate through the collective action design dynamic, or help to alter the feedbacks of the environmental disconnection dynamic. Many examples are emerging around the world of such alternatives that deliver simultaneously on greater equity and sustainability, ranging from community-based management of land, forests, fisheries or waste to collective, solidarity-based forms of economic management and sharing. Such ‘seeds’ of a more equitable and sustainable Anthropocene offer the potential to scale up and spread through networking, movements and learning [Reference Bennett, Solan, Biggs, McPhearson, Norström, Olsson, Pereira, Peterson, Raudsepp-Hearne, Biermann, Carpenter, Ellis, Hichert, Galaz, Lahsen, Milkoreit, Martin López, Nicholas, Preiser, Vince, Vervoort and Xu93].

We can therefore envisage a range of transformational pathways which offer the potential to (re-)orient within an equitable sustainability space (cf. Figure 3). These may play out in specific sectors and contexts, and will involve varying combinations of parameter, feedback, design and intent interventions, and of ‘bottom-up’ action and initiatives, with ‘top-down’ action to achieve and sustain larger impact. For change to be truly transformative, these pathways cannot simply involve ‘tweaks’ to the status quo through a new technology, or a changed market arrangement. Systemic challenges generally demand systemic responses. So they must involve changes that lead to more radical shifts in power relations, both to challenge dominant pathways and the political economies and power–knowledge relations that support them, and to appreciate and support alternatives [Reference Scoones, Leach and Newell86].

The following examples indicate the potential for such transformative change, especially arising from localized responses and alternatives in the face of equity, sustainability and development challenges. Each exemplifies a topic that could be elaborated and enriched in relation to our framework. Many further examples could be identified, in domains that relate to different SDGs and interactions between them; collecting and documenting these represents an important future research frontier.