The structuring of the research field of sustainability science must draw upon scholarly work from a range of disciplines. Such a broad basis provides a crucial starting point for understanding theoretical and empirical multiplicities and addressing the urgency of sustainability challenges. This section describes the scientific connectivity. We proceed from the assumption that social and natural systems are characterised by complexity, non-linearity, self-organisation and strong interlinkages. Yet, there are fundamental differences between the systems. Natural systems are driven by a set of fundamental natural principles, such as gravity, thermodynamics and natural selection, while social systems are driven by totally different dynamics, such as demography, ideology, inequality and power struggles, as well as rationalisation, specialisation, institutionalisation, competition, capital accumulation, efficiency and technological change. From an anthropocentric perspective, natural systems have no purpose, while social systems may be goal-oriented and politicised. Intentionality may, thus, distinguish social from natural systems. The debate on linked social and natural systems often downplays this crucial difference, perhaps because it is still largely dominated by the natural sciences. We, therefore, need to consider the very foundation of sustainability and proceed from basic ontological and epistemological questions: what exists? What and how can we know about it? And what is the nature of that knowledge?
Our integrated approach to sustainability science is structured in accordance with the three-dimensional matrix in Fig. 2. In its present form, the matrix addresses only four sustainability challenges but we see it as a generic research platform to be applied to a range of sustainability issues. The matrix illustrates how research themes and questions in sustainability science can be conceptualised and organised in principle. It can also stimulate further analytical thought and insights into previously unknown or neglected aspects. The matrix comprises the following components:
Four sustainability challenges
The research platform is applied here to four interrelated sustainability challenges in order to identify, explore and scrutinise the drivers of social and scientific change, be they social, economic, political, natural or technological.
Global climate change is a reality confirmed by the 0.74°C increase in the global average temperature over the past century and the impacts are already evident (IPCC 2007c; Richardson et al. 2009). Changes in water availability, decreased food security, sea level rise, reduction in ice cover and increasing frequency and intensity of heat waves, storms, floods and droughts are projected to dramatically affect many millions of people. The likely range of human-induced warming over the current century is between 1.4 and 6.4°C (IPCC 2007b). Moreover, climate change exacerbates the loss of biodiversity and degradation of land, soil, forest and water.
The rate of species extinction is believed to be between one hundred and one thousand times faster than before the Industrial Revolution (Dirzo and Raven 2003; Reid et al. 2005). Recent estimates, however, indicate that it is expected to increase to as much as ten thousand times in coming decades (Chivian and Bernstein 2008), having disastrous consequences because biological diversity is a precondition for human well-being in terms of food, health and medicine, as well as immaterial values such as aesthetics, recreation and spiritual activities. A majority of all medicines used in the US and as much as 80% of medicines used in developing countries originate from biological organisms (Mindell 2009), while only a fraction of all species have been scientifically described and an even smaller fraction of identified species have been screened for useable substances (Beloqui et al. 2008). It is estimated that 15,000 out of 50,000–70,000 known medicinal plants are threatened by extinction (Li and Vederas 2009).
Land use change and food production
The global demand for food is expected to rise steeply as a result of burgeoning population, shifting dietary preferences and increasing demands for renewable energy (Hubert et al. 2010). In 2009, the FAO estimated that we must increase the global food production by 70% by 2050 in order to meet demands and needs (Schmidhuber and Tubiello 2007). This estimate was more recently challenged as an underestimation, thereby, further underlining the importance of the food problem (Tilman et al. 2002, 2010). At the same time, climate change, water scarcity and land use change are expected to jeopardise continued increases in agricultural production (Schmidhuber and Tubiello 2007; Battisti and Naylor 2009), thus, making food security a planetary emergency. This calls for a range of policies and creative solutions at the global, regional and local levels. In addition, there is an obvious risk that other important ecosystem services, such as clean water, biodiversity and protection against natural hazards, will be compromised in the search for agricultural land (UNEP 2007). The increasing competition for land to produce bio-energy is also a concern that may further aggravate food production and the international scramble for securing future food supplies. The situation is particularly problematic since the production of cereals per capita peaked in the mid-1980s and has since slowly decreased, despite the increase in average yields (Ramankutty et al. 2008).
It is estimated that over a billion people worldwide lack access to safe drinking water and, if the current trend continues, there will be 1.8 billion people in regions with absolute water scarcity by 2025 (UNEP 2007). In addition, climate change will exacerbate water scarcity in certain regions, such as Northern India, and put another several hundred million people in acute water crisis. Global water and food security may, thus, be in jeopardy towards the middle or the end of the twenty-first century (IPCC 2007c).
Sustainability challenges are often defined and described by the natural sciences, and only later recognised as important for society and the social sciences. In contrast, the strength and innovation of an integrated approach is its ability to draw simultaneously on expertise from the natural sciences, social sciences and humanities to rethink, reconceptualise and reframe those challenges. As an example, we discuss distributional aspects of land, water and biodiversity in terms of access, allocation and agency along the three dimensions of international, intergenerational and intersectional justice. To that end, we borrow from existing theories and perspectives and, thus, expand concepts and analytical frames from classical disciplines into the domain of sustainability. All along, the dual critical and problem-solving research strategy is a frame that stimulates the generation of new theory and approaches for investigating complex issues.
Three core themes
Theme one: scientific understandings of social–ecological systems
Sustainability challenges, be it climate change or biodiversity loss, are normally defined and framed in natural scientific terms. Whereas the cognitive products of the natural sciences often shape how environmental problems are understood and acted upon in society, we know from years of social constructivist scholarship that science is far from autonomous from society, culture or the political. Rather, knowledge and beliefs about the natural world are embedded in the social world (Nowotny et al. 2001; Jasanoff and Martello 2004; Latour 2004). Building upon this insight, the first core theme involves four research efforts where connections between natural and social systems are understood and conceptualised. We, thus, show how research can critically scrutinise existing conceptual models and, on the basis of integrated research efforts, suggest improved understandings for sustainability science.
The research efforts discussed below represent different levels of theoretical ambition. Two grand theories, earth system science and world system dynamics of unequal exchange, aim to describe and explain global processes. Earth system analysis deals with the natural world from a natural scientific perspective (Schellnhuber 1999), whereas world system theory originally dealt with the world system from a sociological perspective (Wallerstein 1974) but more recently also from a ‘green’ political ecology perspective (Hornborg 1998; Wallerstein 2007), indicating that the two schools of thought can benefit from constructive dialogues. The two middle-range theories, resilience (Berkes et al. 2003) and material flow analysis, operate within more specifically defined scales, levels and systems. Resilience theory aims at understanding the dynamics of well-defined coupled social–ecological systems, such as a fishery, a wetland or a forest. Material flow analysis involves detailed mapping and accounting of observable units and processes in well-defined systems spanning local to global levels, such as the flow of metals and nutrients in time and space. Below, we introduce the grand and the middle-range theories, which can be critically and systematically applied.
The Earth system metaphor
This sub-theme deals with emerging attempts to conceptualise and study natural and social systems as a single interrelated Earth system. According to this approach, the Earth system consists of two main components: the ecosphere with four subsystems (atmosphere, biosphere, hydrosphere, lithosphere) and the anthroposphere that accounts for all human activity (Schellnhuber 1999; Steffen et al. 2004). Building upon a view from space provided by remote sensing technology, global databases and sophisticated computer models, the quest of Earth system science is consequently to move beyond the study of each subsystem as a self-contained entity in favour of a holistic and interdisciplinary understanding of how they are connected and interlinked. While this approach acknowledges the complexity, non-linearity and surprise built into ‘the coupled socio-ecological system,’ it may also epitomise modern virtues such as rationality, control and predictability. Hence, this sub-theme can help scrutinise the tensions built into the Earth system metaphor and analyse their implications for the understanding of sustainability (Lövbrand et al. 2009).
The world system dynamics metaphor: theories of unequal exchange
The world system perspective was created by economic historians and sociologists in the field of development theory (Wallerstein 1974), but is now also core to discussions on sustainability and political ecology. Whereas conventional economic science seems unable to accommodate concepts of unequal exchange, except in the sense of monopoly (i.e. market power), several strands of trans-disciplinary ecological economics are developing methodological tools for defining unequal exchange in objective, biophysical terms. Two potentially useful tools for assessing asymmetric resource flows are Ecological Footprints (Wackernagel et al. 2000) and Material Flow Analysis (Weisz 2007), as discussed below. Biophysical accounting tools, measuring the physical volumes exchanged or the land requirements of their production, tend to provide completely different perspectives on international trade than conventional economic statistics based on monetary value (Hornborg 2001; Martinez-Alier 2002). These new approaches to global, societal metabolism are of crucial significance for the topic of sustainability. Climate change, for example, will be one major, to some extent predictable, driver of changes in the global distribution of vital ecosystem services, which can be integrated into existing frameworks for addressing and projecting exchange patterns.
Resilience of coupled social–ecological systems
As an analytical framework, resilience emerged in ecology during the 1970s in reaction to ideas of equilibrium. Resilience depicts incremental changes and capacity to preserve systems within given frames (Holling 1973). However, in its original definition, resilience does not recognise that social change mainly implies transitions to new forms of production, consumption and distribution with new combinations of technology, organisation, institutions and lifestyles (Jerneck and Olsson 2008). The inner logic and utility of the increasingly popular resilience framework (Folke et al. 2002) should, therefore, be scrutinised.
Material flow analysis and various cycles
Modern society is heavily dependent on manipulating a number of bio-geo-chemical cycles, such as: the carbon cycle for the provision of energy; the nitrogen and phosphorous cycles for the provision of food; and the water cycle for the provision of water, food, energy and transport. In the natural sciences, the study of such cycles has resulted in biogeochemistry, an area of scientific inquiry that integrates the disciplines of biology, geosciences and chemistry (Schlesinger 1997; Megonigal 2002). Material flow analysis (MFA) represents a similar development in the social sciences, as mentioned above. To some extent, MFA resembles macro-economic modelling, with the difference that MFA deals with physical units of materials rather than monetary units. The challenge to integrate the complete cycles, both the natural and the social components of these cycles, is at the very heart of sustainability science. But this requires a rethinking of the ontology and epistemology of disciplines. The natural science ontology of the carbon cycle is based on carbon as a bio-physical entity. If the ontology is reframed to incorporate also carbon used in the manufacturing, transporting and consumption of goods, then the cycling of carbon becomes as much a social as a natural cycle. Analogous reasoning of integration can be applied to the water and the nutrient cycles.
Theme two: sustainability goals
This theme explores the process of formulating and establishing various global sustainability goals, including their very content. Since the publication of ‘Our Common Future’ in 1987 (WCED 1987), social goal setting has changed from a broad qualitative vision of a sustainable society to more precise policies, including specific planning instruments and targets of efficiency and effectiveness that are measurable in quantitative terms, such as the Lisbon Agenda in the EU (Gros 2005).
The Brundtland Commission (WCED 1987) defined sustainable development as development that “meets the needs of the present without compromising the ability of future generations to meet their own needs.” The concept, comprising environmental, economic and social pillars, is subject to criticism on many grounds, especially for its ambiguity and the lack of tangible operationalisation. The MDGs formulated in the United Nations Millennium Declaration (UN 2000) serve as an example of social goal-setting linked to a delivery system that attempts to contribute an operationalisation of sustainable development. One criticism against the MDGs is that they emphasise planning in top-down processes rather than the agency and participation of the people who are poor (Banuri 2005). Even more specific goals are set in the contexts of individual sustainability issues, such as the UN conventions (UNFCC, UNCBD etc.). Common to all such goals is that they are formulated through a complex interaction between science, politics, industry, media etc. Goals are also intimately and mutually related to scientific understanding. For example, the formulation of the MDGs has triggered many research initiatives specifically aimed at fostering scientific understandings that support the goals. The millennium development villages initiated and researched by the Earth Institute are an example (Cabral et al. 2006; Sanchez et al. 2007; Carr 2008; Diepeveen 2008). Sustainability goals can be critically examined from the point of view of three pertinent dimensions of justice and fairness, namely, the intergenerational, the international and the intersectional. Below, we list important research topics on this theme in relation to the three dimensions in the matrix as seen in Fig. 3.
Intergenerational justice and fairness
Intergenerational justice is core to sustainability and has been discussed in relation to equity and law (Weiss 1990), energy policy (Barry 1982) and climate policy (Page 1999). The dramatic differences between the conclusions of the Stern Review (Stern 2006) and previous investigations into the costs of climate change stem from differences in normative assumptions underlying the studies. The Review states explicitly that the welfare of future generations is as important as the welfare of the current generation, while most previous studies implicitly assume that the welfare of the current generation is more important than the welfare of future ones. The utilisation of finite resources is another important example. Can it be taken for granted that minerals found in geological deposits belong to the current generation? The problem of one generation reaping the benefits of a technology while leaving waste to future generations should be one of the most burning issues today, with renewed interest in nuclear energy. Should we build intergenerational justice into the exploitation of technology, and how can this be done? In relation to the notion of the cost-effectiveness of climate policies in the UNFCC, we may ask: cost-effective for whom (which generation)? (Hermele et al. 2009). These illustrations reflect theoretical challenges that can be subject to inquiry: in what sense can future agents have moral rights with respect to us and we have obligations with respect to them? How do collective obligations and responsibilities correspond to those of individual agents and how do the values of different aspects add up to values of wholes? An important component of these moral and legal problems is, in fact, descriptive and epistemic. How do we predict present and future needs and states of the world? How is this done in everyday life, in policy-making, in science and in law?
International justice and fairness
Research in this field should deconstruct different aspects of the sustainability discourse in order to reveal biases and constraints. For instance, concern has been raised that climate change might trigger a new kind of world order founded on ‘carbon colonialism’ (Bäckstrand and Lövbrand 2006). Global problems related to climate change are, to a large extent, caused by the industrialised countries, but will have much more severe negative impacts on developing countries (World Bank 2009). In the struggle to reduce the emissions of greenhouse gases, developing countries are increasingly coerced into strategies that contribute to this polarisation rather than alleviating it. In subjecting the globalised discourse on sustainability to critical scrutiny, it could be an aim to uncover such tacit agendas, as it may reflect the perspectives and knowledge interests of affluent sectors of world society. Regarding control over natural resources such as oil, minerals and agricultural land, it may happen that bi-lateral and international policies violate international justice and fairness under the benign guise of development assistance (Lee 2006).
Intersectional justice and fairness
The concept and analytical perspective of intersectionality focuses on “the relationship among multiple dimensions and modalities of social relations and subject formations” (McCall 2005). Intersectionality, thereby, reminds us that life worlds are multi-dimensional and identities entail combinations of age, class, ethnicity, race, religion, gender, sexual orientation etc. Apart from stressing multi-identities, intersectionality brings attention to power and takes into account that individuals may suffer simultaneous and multiple oppressions and inequalities in accordance with their identity. However, while some argue that the advantage of the term intersectionality is its intentional neutrality, others maintain that the political dimensions of inequality are washed away in the use of the concept (Hawthorne 2004). In resource governance, we may add the intersectional category of space such as upstream and downstream in water management or rural and urban in land use. Intersectionality is also used to explore dimensions of human identity in relation to sustainability goals. For instance, the MDGs are sometimes applauded for their gender awareness, while others argue that, by focusing on material and instrumental aspects in relation to gender, many other discriminatory aspects and intrinsic values are downplayed or not understood (Sweetman 2005). In sum, a sort of ‘diversity matrix’ (Hawthorne 2004) can be used to simultaneously scrutinise sustainability goals along several axes of identity.
Theme three: sustainability pathways, strategies and implementation
Science, politics, industry, media and civil society participate in complex multi-level dialogues to formulate strategies and pathways aiming at the fulfilment of sustainability goals. Such strategies are intimately and mutually related to scientific understandings, as well as to the political and economic context in which science is pursued. This is manifested in contesting views resulting in very different pathways, as illustrated by the Stern Review (Stern 2006). This theme serves to scrutinise pathways to sustainability by critically analysing proposed mechanisms for and pathways to sustainable societies. The broad domains of options available for the state are marketisation, regulation and democratisation (see Fig. 4).
The public sector increasingly adopts values and practices from the private sector in fields such as health, education and environmental management. This marketisation trend is ubiquitous but particularly strong in transitionary economies with rapid industrialisation (Rigg 2006). As a response to the threat of global climate change, we see the emergence of a global carbon market and a new ‘carbon economy.’ The current global climate policy regime relies, to a large extent, on market mechanisms such as emissions trading, joint implementation and the Clean Development Mechanism. Regarding adaptation to climate change, insurance as an adaptation strategy represents a rapidly growing market where major financial players are increasingly active. Payments for environmental services (PES) is emerging as a universal tool for the integrated management of natural resources, such as biodiversity, water and soils (Pagiola et al. 2005). In the development debate, market integration is often described as a panacea (Sachs 2005). Proponents of marketisation argue that markets are most effective for dealing with problems, while opponents fear that this will compromise values related to democracy, citizenship (Eikenberry and Kluver 2004) and equity (Rigg 2006). In the context of this research agenda on sustainability challenges, marketisation can, thus, be scrutinised for its effectiveness and its impact on social justice.
There are profound challenges regarding legal regulations of sustainability. While environmental problems are often transboundary, much regulation is based on national law. New forms of regulative bodies transcending the nation state are, therefore, needed. Since there is no legal bearer of a right belonging to future generations, contemporary law is challenged by the intergenerational approach to sustainability. We, therefore, need more emphasis on both regulatory techniques and ethical principles (Gunningham et al. 2003). One initiative in this direction is seen in climate politics with the concept of the ‘ensuring state’ that serves as the catalyst, facilitator and provider of guarantees in relation to both citizens and other states; this would imply a new form of strong state (Giddens 2009). The new global research programme Earth System Governance aims to contribute to new forms of governance at the planetary (and local) level (Biermann et al. 2009). A suggested task here is to critically rethink contemporary regulative processes from a normative perspective.
Democratisation through deliberation
The strong deliberative turn in democratic theory during recent decades speaks to an emerging concern with the distance between the interests and motives of citizens and the decisions made in their name (Smith 2003). A growing scholarship today questions liberal democratic institutions by pointing at the lack of voice of citizens and the poor representation of ecological values in decision-making processes (Dryzek 1997; Eckersley 2004). Deliberative democratic theory has evolved as a response to this perceived weakness of liberal democracy. It seeks to both democratise and to ‘green’ policy discourses by increasing the opportunities for citizens to engage in decisions that affect their lives and surrounding environment (Dobson 2003). The deliberative project also extends to the international arena and has been forwarded as a strategy that can bridge the democracy deficit in governance arrangements beyond the state (Nanz and Steffek 2005) and foster a trans-national green public sphere (Dryzek 1997). Research in this sub-theme should seek to examine how ‘democratisation through deliberation’ plays out in the environmental domain. We are particularly concerned with the potential synergies and tensions between the substantive and procedural aspects built into the deliberative project. As Goodin (1992) famously claimed, “(t)o advocate democracy is to advocate procedures, to advocate environmentalism is to advocate substantive outcomes.” Hence, how and to what extent can a deliberative model of democracy represent a pathway towards sustainability?
Two cross-cutting approaches
Problem-solving and critical theories
In 1981, Robert Cox (1981) made a seminal distinction between theories that seek to solve the problems posed within a particular perspective and critical theories that are more reflective upon the process of theorising itself. Problem-solving theory takes the world ‘as it finds it,’ with prevailing social and power relationships and the institutions into which they are organised as the given framework for action. The general aim within this school of thought is, according to Cox, to reduce a particular problem into a limited number of variables that can be studied with such precision that regularities of general validity can be identified. While problem-solving theory seeks to guide tactical actions and increase the efficiency of the existing institutional framework, critical theory stands apart from the prevailing order of the world and asks ‘how it came about.’ Unlike problem-solving theory, critical theory calls contemporary institutions and power relations into question and allows for a normative choice in favour of alternative social and political orders. With an example from climate change research, problem-solving research could deal with how to optimise an emissions trading scheme, while critical research would question the very existence of market-based mechanisms such as trading schemes as solutions to climate change. While acknowledging that each school of thought has its strengths and weaknesses, Cox (1981) affirmed that there is no such thing as a theory in itself divorced from a standpoint in time and space; theory is always for someone and for some purpose.
This epistemological claim functions as an organising principle in the matrix described in Fig. 2. The integrated research proceeds from different disciplinary perspectives and is grounded in both problem-solving and critical approaches, wherein epistemological reflexivity is a necessary prerequisite for successful interdisciplinary dialogue and integration to be discussed below.