Complex Systems Regime Shift Complex Systems, Systems Regime, Socio-ecological Systems, Transitions, Tipping Points, Resilience, Governance, Sustainability Readings I Oct, 2014

Giorgio Bertini

Towards sustainability, it is important to understand the dynamics of socio-ecological systems, as complex adaptive systems. An essential aspect of such complex systems is nonlinearity, leading to historical dependency and multiple possible outcomes of dynamics. Regime shifts, the reorganization of the structure and processes shaping a complex adaptive system, are large, abrupt with persistent changes. Regime shifts in socio-ecological systems have large impacts on ecosystem services, and therefore on human well-being, as they can substantially affect the flow of ecosystem services that societies rely upon, such as the provision of food, clean water or climate regulation. Resilience is the ability to absorb disturbances, to be changed and then to re-organise and still have the same identity (retain the same basic structure and ways of functioning). It includes the ability to learn from the disturbance. Resilience shifts attention from purely growth and efficiency to needed recovery and flexibility. Growth and efficiency alone can often lead ecological systems, businesses and societies into fragile rigidities, exposing them to turbulent transformations. The aim of resilience management and governance is to keep the complex system within a particular configuration of states (system 'regime') that will continue to deliver desired ecosystem goods and services. The adaptive capacity in social systems, the existence of institutions and networks that learn and store knowledge and experience, create flexibility in problem solving and balance power among interest groups, play an important role. Complex systems with high adaptive capacity are able to re-configure themselves without significant declines in crucial functions. A consequence of a loss of resilience, and therefore of adaptive capacity, is loss of opportunity. Resilience is key to enhancing adaptive capacity: learning to live with change and uncertainty; nurturing diversity for resilience; combining different types of knowledge for learning; and creating opportunity for self-organization towards socio-ecological systems sustainability. This Readings it is not a linear course list, rather for dialogical rhizomatic learning; will be followed by others on related topics. To access the paper, follow the link.

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Navigating Social-Ecological Systems - Building Resilience for Complexity and Change Resilience, Adaptability and Transformability in Social–ecological Systems Resilience Thinking - Integrating Resilience, Adaptability and Transformability Learning for resilience? - Exploring learning opportunities in Biosphere Reserves Social Learning and Sustainability - Exploring Critical Issues in Relation to Environmental Change and Governance 6. Resilience Management in Social-ecological Systems - a Working Hypothesis for a Participatory Approach 7. Are We Entering an Era of Concatenated Global Crises 8. Ecosystems and the Biosphere as Complex Adaptive Systems 9. Ecological Systems as Complex Systems: Challenges for an Emerging Science 10. Resilience and Sustainable Development - Theory of Resilience, Systems Thinking and Adaptive Governance 11. Community Resilience and Contemporary Agri-Ecological Systems - Reconnecting People and Food, and People with People 12. The Politics of Social-ecological Resilience and Sustainable Socio-technical Transitions 13. Approaching a state shift in Earth’s biosphere 14. Understanding Phase Transitions for Social Change 15. Evolutionary Transitions – How do levels of Complexity Emerge? 16. Critical Transitions in Nature and Society 17. A Framework for Resilience-based Governance of Social-Ecological Systems 18. Resilience and the Behavior of Large-Scale Systems 19. Adaptive Governance of Interdependent Social and Ecological Systems 20. Social-ecological Systems contain various Tipping Points or Thresholds that can Trigger Large-scale Reorganization 21. Anticipating Critical Transitions 22. Early-warning signals for Critical Transitions 23. Complex Dynamical Systems Theory 24. Resilience thinking and Large-scale Transformations in Social-ecological Systems 25. Critical Transtions in Ecology 26. Phase Transitions 27. Tipping Points 28. Early Warning of Climate Tipping Points. Read also: Earth System Tipping Points 29. The Complexity of Transitions 30. On the Sensitivity of Collective Action to Uncertainty about Climate Tipping Points 31. Living dangerously on borrowed time during Slow, Unrecognized Regime Shifts 32. Social Tipping Points and Earth Systems Dynamics 33. Social-ecological Resilience and Socio-technical Transitions - Critical issues for Sustainability Governance 34. Tipping Points among Social Learners - Tools from varied Disciplines 35. Turning back from the brink - Detecting an impending Regime Shift in time to Avert it 36. Are we now living in the Anthropocene? 37. Planetary Boundaries: Exploring the Safe Operating Space for Humanity

1. Navigating Social-Ecological Systems - Building Resilience for Complexity and Change In the effort towards sustainability, it has become increasingly important to develop new conceptual frames to understand the dynamics of social and ecological systems. Drawing on complex systems theory, this book investigates how human societies deal with change in linked social–ecological systems, and build capacity to adapt to change. The concept of resilience is central in this context. Resilient social–ecological systems have the potential to sustain development by responding to and shaping change in a manner that does not lead to loss of future options. Resilient systems also provide capacity for renewal and innovation in the face of rapid transformation and crisis. The term navigating in the title is meant to capture this dynamic process. Navigating Social–Ecological Systems deliberately transcends academic disciplines, because the issues in focus require collaboration over the boundaries of the natural sciences, social sciences, and the humanities. Case studies and examples from several geographic areas, cultures, and resource types are included, merging forefront research from different disciplines into a common framework for new insights into sustainability.

2. Resilience, Adaptability and Transformability in Social–ecological Systems The concept of resilience has evolved considerably since Holling’s (1973) seminal paper. Different interpretations of what is meant by resilience, however, cause confusion. Resilience of a system needs to be considered in terms of the attributes that govern the system’s dynamics. Three related attributes of social–ecological systems (SESs) determine their future trajectories: resilience, adaptability, and transformability. Resilience (the capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain essentially the same function, structure, identity, and feedbacks) has four components—latitude, resistance, precariousness, and panarchy—most readily portrayed using the metaphor of a stability landscape. Adaptability is the capacity of actors in the system to influence resilience (in a SES, essentially to manage it). There are four general ways in which this can be done, corresponding to the four aspects of resilience. Transformability is the capacity to create a fundamentally new system when ecological, economic, or social structures make the existing system untenable.

3. Resilience Thinking - Integrating Resilience, Adaptability and Transformability Resilience thinking addresses the dynamics and development of complex social–ecological systems (SES). Three aspects are central: resilience, adaptability and transformability. These aspects interrelate across multiple scales. Resilience in this context is the capacity of a SES to continually change and adapt yet remain within critical thresholds. Adaptability is part of resilience. It represents the capacity to adjust responses to changing external drivers and internal processes and thereby allow for development along the current trajectory (stability domain). Transformability is the capacity to cross thresholds into new development trajectories. Transformational change at smaller scales enables resilience at larger scales. The capacity to transform at smaller scales draws on resilience from multiple scales, making use of crises as windows of opportunity for novelty and innovation, and recombining sources of experience and knowledge to navigate social–ecological transitions. Society must seriously consider ways to

foster resilience of smaller more manageable SESs that contribute to Earth System resilience and to explore options for deliberate transformation of SESs that threaten Earth System resilience.

4. Learning for Resilience? – Exploring Learning Opportunities in Biosphere Reserves The interdependence of society and nature, the inherent complexity of social–ecological systems, and the global deterioration of ecosystem services provide the rationale for a growing body of literature focusing on social–ecological resilience – the capacity to cope with, adapt to and shape change – for sustainable development. Processes of learning-by-doing and multipleloop social learning across knowledge systems and different levels of decision-making are envisioned to strengthen this capacity, combined in the concept of adaptive governance. This study explores how learning for resilience is stimulated in practice; investigating learning opportunities provided in UNESCO-designated biosphere reserves (BRs). A global survey and qualitative interviews with key informants of selected BRs reveal that a subset of the BRs serve as ‘potential learning sites’ and: (1) provide platforms for mutual and collective learning through face-to-face interactions; (2) coordinate and support the generation of new social– ecological knowledge through research, monitoring and experimentation; and (3) frame information and education to local stewards, resource-based businesses, policy-makers, disadvantaged groups, students and the public. We identify three BRs that seem to combine, in practice, the theoretically parallel research areas of environmental education and adaptive governance. We conclude that BRs have the potential to provide insights on the practical dimension of nurturing learning for social–ecological resilience. However, for their full potential as learning sites for sustainability to be realized, both capacity and incentives for evaluation and communication of lessons learned need to be strengthened.

5. Social Learning and Sustainability – Exploring Critical Issues in Relation to Environmental Change and Governance This report addresses a critical part of the very front of social-ecological systems research. Learning can be seen as a process of change in the way we look upon the world — our thoughts, feelings and actions — which is dependent on the learner, the object of learning, and the physical, biological, social, cultural, and economic situation and setting. A key feature of resilience thinking is that changes, sometimes abrupt, often interpreted as crises, perceived or real, can trigger renewal and innovation if there is resilience. Learning plays a central role in resilience of social-ecological systems, in particular the recombination of experiences from different areas and diverse fields that may lead to new insights and pathways for development. Gathering around ideas and theories on complex adaptive systems and resilience, the qualified authors of the report, actively discuss, connect and combine research perspectives that otherwise tend to focus solely on the individual, the community or society, and in relation to improved environmental stewardship. In an exciting and novel fashion, they contemplate upon and analyze the role of learning for finding pathways that make it possible to navigate socialecological development toward sustainability, not for the sake of the environment but for our own sake in the new era of global social-ecological change.

6. Resilience Management in Social-ecological Systems: A working hypothesis for a Participatory Approach Approaches to natural resource management are often based on a presumed ability to predict

probabilistic responses to management and external drivers such as climate. They also tend to assume that the manager is outside the system being managed. However, where the objectives include long-term sustainability, linked social-ecological systems (SESs) behave as complex adaptive systems, with the managers as integral components of the system. Moreover, uncertainties are large and it may be difficult to reduce them as fast as the system changes. Sustainability involves maintaining the functionality of a system when it is perturbed, or maintaining the elements needed to renew or reorganize if a large perturbation radically alters structure and function. The ability to do this is termed “resilience.” This paper presents an evolving approach to analyzing resilience in SESs, as a basis for managing resilience. We propose a framework with four steps, involving close involvement of SES stakeholders. It begins with a stakeholder-led development of a conceptual model of the system, including its historical profile (how it got to be what it is) and preliminary assessments of the drivers of the supply of key ecosystem goods and services. Step 2 deals with identifying the range of unpredictable and uncontrollable drivers, stakeholder visions for the future, and contrasting possible future policies, weaving these three factors into a limited set of future scenarios. Step 3 uses the outputs from steps 1 and 2 to explore the SES for resilience in an iterative way. It generally includes the development of simple models of the system’s dynamics for exploring attributes that affect resilience. Step 4 is a stakeholder evaluation of the process and outcomes in terms of policy and management implications. This approach to resilience analysis is illustrated using two stylized examples.

7. Are We Entering an Era of Concatenated Global Crises An increase in the frequency and intensity of environmental crises associated with accelerating human-induced global change is of substantial concern to policy makers. The potential impacts, especially on the poor, are exacerbated in an increasingly connected world that enables the emergence of crises that are coupled in time and space. We discuss two factors that can interact to contribute to such an increased concatenation of crises: (1) the increasing strength of global vs. local drivers of change, so that changes become increasingly synchronized; and (2) unprecedented potential for the propagation of crises, and an enhanced risk of management interventions in one region becoming drivers elsewhere, because of increased connectivity. We discuss the oil-food-financial crisis of 2007 to 2008 as an example of a concatenated crisis with origin and ultimate impacts in far removed parts of the globe. The potential for a future of concatenated shocks requires adaptations in science and governance including (a) an increased tolerance of uncertainty and surprise, (b) strengthening capacity for early detection and response to shocks, and (c) flexibility in response to enable adaptation and learning.

8. Ecosystems and the Biosphere as Complex Adaptive Systems Ecosystems are prototypical examples of complex adaptive systems, in which patterns at higher levels emerge from localized interactions and selection processes acting at lower levels. An essential aspect of such systems is nonlinearity, leading to historical dependency and multiple possible outcomes of dynamics. Given this, it is essential to determine the degree to which system features are determined by environmental conditions, and the degree to which they are the result of self-organization. Furthermore, given the multiple levels at which dynamics become apparent and at which selection can act, central issues relate to how evolution shapes ecosystems properties, and whether ecosystems become buffered to changes (more resilient) over their ecological and evolutionary development or proceed to critical states and the edge of chaos.

9. Ecological Systems as Complex Systems - Challenges for an Emerging Science Complex systems science has contributed to our understanding of ecology in important areas such as food webs, patch dynamics and population fluctuations. This has been achieved through the use of simple measures that can capture the difference between order and disorder and simple models with local interactions that can generate surprising behaviour at larger scales. However, close examination reveals that commonly applied definitions of complexity fail to accommodate some key features of ecological systems, a fact that will limit the contribution of complex systems science to ecology. We highlight these features of ecological complexity— such as diversity, cross-scale interactions, memory and environmental variability—that continue to challenge classical complex systems science. Further advances in these areas will be necessary before complex systems science can be widely applied to understand the dynamics of ecological systems.

10. Resilience and Sustainable Development - Theory of Resilience, Systems Thinking and Adaptive Governance Resilience thinking is inevitably systems thinking at least as much as sustainable development is. In fact, “when considering systems of humans and nature (social-ecological systems) it is important to consider the system as a whole. The human domain and the biophysical domain are interdependent”. In this framework where resilience is aligned with systems thinking, three concepts are crucial to grasp: (1) humans live and operate in social systems that are inextricably linked with the ecological systems in which they are embedded; (2) socialecological systems are complex adaptive systems that do not change in a predictable, linear, incremental fashion; and (3) resilience thinking provides a framework for viewing a social-ecological system as one system operating over many linked scales of time and space. Its focus is on how the system changes and copes with disturbance. To fully understand the resilience theory, the report focuses therefore on the explanation of a number of crucial concepts: thresholds, the adaptive cycle, panarchy, resilience, adaptability, and transformability. As shown, humanity and ecosystems are deeply linked. This is also the fundamental reason why to adopt the resilience-thinking framework is a necessity for governance.

11. Community Resilience and Contemporary Agri-Ecological Systems Reconnecting People and Food, and People with People Alternative agricultural systems that emphasize ecological and community resilience provide a bridge between traditional agriculture and natural resource management. These can be referred to as agri-ecological systems and include systems such as Organic Agriculture, Biodynamics, Community Supported Agriculture (CSA), Permaculture, Farmers Markets and Community Gardens. This paper reports on current research by the author to explore a range of these systems and how they contribute to agri-ecological and community resilience. For example, resiliency can be seen as a system’s ability to adapt and respond to external impacts on a system, and farmers markets show resiliency to sudden market changes (such as price or consumer preferences toward organics, through direct sale and the involvement of a range of consumers and producers offering a broad range of organic produce). That is, this paper reviews these alternative approaches to food production in relation to key concepts from ecological systems thinking, such as ecological resilience, biodiversity and holism. More specifically, the paper explores how agri-ecological systems contribute to more sustainable and resilient communities, through community development processes such as relationship

building, genuine participation, inclusiveness, resource mobilization and creating space for knowledge sharing. The paper concludes by comparing ecological systems models to agriecological systems, and suggests how ecological systems theories and concepts might contribute to thinking about the future of community-based agri-ecological resilience.

12. The Politics of Social-ecological Resilience and Sustainable Sociotechnical Transitions Technology-focused literature on socio-technical transitions shares some of the complex systems sensibilities of social-ecological systems research. We contend that the sharing of lessons between these areas of study must attend particularly to the common governance challenges that confront both approaches. Here, we focus on critical experience arising from reactions to a transition management approach to governing sustainable socio-technical transformations. Questions over who governs, whose system framings count, and whose sustainability gets prioritized are all pertinent to social-ecological systems research. We conclude that future research in both areas should deal more centrally and explicitly with these inherently political dimensions of sustainability.

13.

Approaching a State Shift in Earth’s Biosphere

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. The plausibility of a planetary-scale ‘tipping point’ highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions. It is also necessary to address root causes of how humans are forcing biological changes.

14. Understanding Phase Transitions for Social Change The great challenges of the 21st Century are systemic in nature. From ecological decline to cybersecurity in a digital age, the patterns of change we must grapple with are profoundly complex. Change agents will need to understand how change unfolds in complex systems in order to promote political and economic stability during these turbulent times. A phase transition is simply the change of a substance from one phase to another. It’s most common usage refers to changes between solid, liquid, gaseous, and plasma states for physical materials — an example being the stages involved in transforming the surface of a lake from flowing waves of water to a frozen plateau of ice.

15. Evolutionary Transitions – How do levels of complexity emerge? It is a common observation that complex systems have a nested or hierarchical structure: they consist of subsystems, which themselves consist of subsystems, and so on, until the simplest components we know, elementary particles. It is also generally accepted that the simpler, smaller components appeared before the more complex, composite systems. Thus, evolution tends to produce more complex systems, gradually adding more levels to the hierarchy. For example, elementary particles evolved subsequently into atoms, molecules, cells, multicellular organisms, and societies of organisms. These discrete steps, characterized by the emergence

of a higher level of complexity, may be called “evolutionary transitions“. The logic behind this sequential complexification appears obvious: you can only build a higher order system from simpler systems after these building blocks have evolved themselves. The issue becomes more complicated when you start looking for the precise mechanisms behind these evolutionary transitions, and try to understand which levels have appeared at what moment, and why.

16. Critical Transitions in Nature and Society How do we explain the remarkably abrupt changes that sometimes occur in nature and society– and can we predict why and when they happen? This book offers a comprehensive introduction to critical transitions in complex systems–the radical changes that happen at tipping points when thresholds are passed. Marten Scheffer accessibly describes the dynamical systems theory behind critical transitions, covering catastrophe theory, bifurcations, chaos, and more. He gives examples of critical transitions in lakes, oceans, terrestrial ecosystems, the climate, evolution, and human societies. And he demonstrates how to deal with these transitions, offering practical guidance on how to predict tipping points, how to prevent “bad” transitions, and how to promote critical transitions that work for us and not against us. Scheffer shows the time is ripe for understanding and managing critical transitions in the vast and complex systems in which we live. This book can also serve as a textbook and includes a detailed appendix with equations. Provides an accessible introduction to dynamical systems theory. Covers critical transitions in lakes, oceans, terrestrial ecosystems, the climate, evolution, and human societies. Explains how to predict tipping points. Offers strategies for preventing “bad” transitions and triggering “good” ones. Features an appendix with equations.

17. A Framework for Resilience-based Governance of Social-Ecological Systems Panarchy provides a heuristic to characterize the cross-scale dynamics of social-ecological systems and a framework for how governance institutions should behave to be compatible with the ecosystems they manage. Managing for resilience will likely require reform of law to account for the dynamics of social-ecological systems and achieve a substantive mandate that accommodates the need for adaptation. In this paper, we suggest expansive legal reform by identifying the principles of reflexive law as a possible mechanism for achieving a shift to resilience-based governance and leveraging cross-scale dynamics to provide resilience-based responses to increasingly challenging environmental conditions.

18. Resilience and the Behavior of Large-Scale Systems Scientists and researchers concerned with the behavior of large ecosystems have focused in recent years on the concept of “resilience.” Traditional perspectives held that ecological systems exist close to a steady state and resilience is the ability of the system to return rapidly to that state following perturbation. However beginning with the work of C. S. Holling in the early 1970s, researchers began to look at conditions far from the steady state where instabilities can cause a system to shift into an entirely different regime of behavior, and where resilience is measured by the magnitude of disturbance that can be absorbed before the system is restructured. Resilience and the Behavior of Large-Scale Systems examines theories of resilience and change, offering readers a thorough understanding of how the properties of ecological resilience and human adaptability interact in complex, regional-scale systems. The book addresses the theoretical concepts of resilience and stability in large-scale ecosystems as well as the empirical application of those concepts in a diverse set of cases. In addition, it

discusses the practical implications of the new theoretical approaches and their role in the sustainability of human-modified ecosystems. The book begins with a review of key properties of complex adaptive systems that contribute to overall resilience, including multiple equlibria, complexity, self-organization at multiple scales, and order.

19. Adaptive Governance of Interdependent Social and Ecological Systems Adaptive governance of interdependent social ecological systems is key to address complex interactions and to manage uncertainty and periods of change. A central characteristic of such adaptive governance is collaborative, flexible and learning-based issue management across different scales. Adaptive governance of social-ecological systems is about connecting actors and institutions at multiple organizational levels to enable ecosystem stewardship in the face of uncertainty and surprise. These actors tend to be connected in social networks and can provide leadership, trust, vision, and meaning in ways that help manage conflicts, anticipate and prepare for uncertainty and change or transform management organizations toward a learning environment.

20. Social-ecological Systems contain various Tipping Points or Thresholds that can Trigger Large-scale Reorganization Understanding of regime shifts is important for ecosystem governance as they often have substantial impacts on human economies and societies, tend to occur unexpectedly, and are difficult, expensive and sometimes impossible to reverse. Sudden, large, long-lasting shifts in system structure and function as a consequence of human actions have been documented in a variety of ecosystems, including coral reefs, freshwater lakes, marine systems and savanna rangelands. Similar shifts linked to ecosystems have been documented in social, political and economic spheres. Understanding of regime shifts derives from these empirical observations as well as from dynamical systems theory, a branch of mathematics that studies the behavior of complex systems. Mathematical models show that complex systems such as social-ecological systems (SES) can self-organize around different equilibrium points or attractors. This is because complex systems consist of many components linked by feedback loops, which can be configured in a limited number of different ways.

21. Anticipating Critical Transitions Tipping points in complex systems may imply risks of unwanted collapse, but also opportunities for positive change. Our capacity to navigate such risks and opportunities can be boosted by combining emerging insights from two unconnected fields of research. One line of work is revealing fundamental architectural features that may cause ecological networks, financial markets, and other complex systems to have tipping points. Another field of research is uncovering generic empirical indicators of the proximity to such critical thresholds. Although sudden shifts in complex systems will inevitably continue to surprise us, work at the crossroads of these emerging fields offers new approaches for anticipating critical transitions.

22. Early-warning signals for Critical Transitions Complex dynamical systems, ranging from ecosystems to financial markets and the climate, can have tipping points at which a sudden shift to a contrasting dynamical regime may occur.

Although predicting such critical points before they are reached is extremely difficult, work in different scientific fields is now suggesting the existence of generic early-warning signals that may indicate for a wide class of systems if a critical threshold is approaching. It is becoming increasingly clear that many complex systems have critical thresholds—so-called tipping points —at which the system shifts abruptly from one state to another. In medicine, we have spontaneous systemic failures such as asthma attacks or epileptic seizures; in global finance, there is concern about systemic market crashes; in the Earth system, abrupt shifts in ocean circulation or climate may occur; and catastrophic shifts in rangelands, fish populations or wildlife populations may threaten ecosystem services.

23. Complex Dynamical Systems Theory Complexity is a systemic property. Whether in the physical or social realms, if individuals are independent or even weakly interdependent no complex physical or social structure will emerge; connectivity and interaction are necessary conditions for the emergence of complexity. The rich interactions between real complex adaptive systems and their environment also mean that because a given domain “is connected to other domains in various ways, the effects of those changes might propagate through the system and out into other domains in the world, inducing changes of various degrees on all scales. Those effects might eventually travel back and lead to the disappearance of the original domain or transform its dynamics” Therefore only complex dynamical systems theory and its related disciplines and tools - network theory, agent-based modeling - provide the appropriate prism through which interdependent systems such as social groups can be understood, and coherent, integrated policy recommended.

24. Resilience thinking and Large-scale Transformations in Socialecological Systems Despite pleas for major change, there is still a lack of understanding of the mechanisms and patterns involved, and of the conditions under which critical transformations can emerge. This lack of understanding greatly decreases the chances for successfully navigating transformation and embarking upon sustainable trajectories. Transformation involves the ability to steer away from undesired regimes and shift social-ecological systems into new improved trajectories that sustain and enhance ecosystem services and human wellbeing. Transformations involve incremental as well as abrupt change at many different scales There are no blueprints or recipes for sustainability transitions. Empirical studies show that transformations that reconnect people to the Biosphere are multi-level and multi-phase processes that involve incremental as well as abrupt change. Transformational change is needed for moving out of “bad states” (social-ecological traps) or steering away from potential critical thresholds.

25. Critical Transtions in Ecology In complex systems the degree of homogeneity (vs. Heterogeneity) and connectivity (vs. Modularity) determines whether or not there is a phase transition from one state to another. These are called critical transitions, and there are current efforts to understand both what factors are signicant in causing these transitions and what factors are significant in predicting the fragility of these systems, or the susceptibility to the induction of a phase transition by some external shock. Complex phenomena in a wide range of fields can be studied using these ideas combined with the idea of critical slowing down. Approaches to complex systems in several examples will be discussed, with a focus on living systems.

26. Phase Transitions (Chapters 9, 12, 13, 14 & 16) Ecosystems are complex and adaptive, displaying nontrivial forms of organization in both space and time. An important component of change in ecological systems involves the rapid response of some communities to slow changes in external variables. It has been shown in different contexts that constant changes in water availability, decline of some plant or fish species or increasing temperatures can trigger sudden changes in ecosystem organization. The outcome of such changes is often a shift from one stable state to another. This can affect a large geographic area, as happened with the transition from green to desert in the Sahara, and discussed in chapter 3. Such changes are the result of nonlinearities coupling external inputs and internal responses. In terms of dynamical systems, populations can shift suddenly from one state to another as a limiting input parameter changes beyond some given threshold. A perfect illustration of the type of sudden changes that can occur in complex ecosystems is provided by the dynamics of semiarid vegetation.

27. Tipping Points This paper formally defines tipping points as a discontinuity between current and future states of a system and introduces candidate measures of when a system tips based on changes in the probability distribution over future states. We make two categorical distinctions between types of tips relevant in social contexts: The first differentiates between direct tips and contextual tips. A direct tip occurs when a gradual change in the value of a variable leads to a large, i.e. discontinuous, jump in that same variable in the future. A contextual tip occurs when a gradual change in the value of one variable leads to a discontinuous jump in some other variable of interest. We argue that while scholars and writers often focus on direct tips, contextual tips often make direct tips possible, such as when human rights conditions in a state deteriorate creating the potential for an uprising. The second differentiates tips between outcomes that belong to the same class - such as tips from one equilibrium to another - from tips that result in a change in the outcome class, such as tips that occur when an equilibrium system becomes chaotic or complex.

28. Early warning of climate tipping points A climate ‘tipping point’ occurs when a small change in forcing triggers a strongly nonlinear response in the internal dynamics of part of the climate system, qualitatively changing its future state. Human-induced climate change could push several large-scale ‘tipping elements’ past a tipping point. Candidates include irreversible melt of the Greenland ice sheet, dieback of the Amazon rainforest and shift of the West African monsoon. Recent assessments give an increased probability of future tipping events, and the corresponding impacts are estimated to be large, making them significant risks. Recent work shows that early warning of an approaching climate tipping point is possible in principle, and could have considerable value in reducing the risk that they pose. Read also:

Earth System Tipping Points

A tipping point is a critical threshold at which the future state of a system can be qualitatively altered by a small change in forcing. A tipping element is a part of the Earth system (at least sub-continental in scale) that has a tipping point. Previous work identified a shortlist of nine potential policy-relevant tipping elements in the climate system that could pass a tipping point this century and undergo a transition this

millennium under projected climate change. We should be most concerned about those tipping points that are nearest (least avoidable) and those that have the largest negative impacts. Generally, the more rapid and less reversible a transition is, the greater its impacts. Additionally, any positive feedback to global climate change may increase concern, as can interactions whereby tipping one element encourages tipping another.

29. The Complexity of Transitions Complexity approaches to socio-economic systems have mostly involved financial markets. Here we claim that technological change is another promising field for complexity theories, and that technological transitions in particular have a large potential of new insights that complexity thinking can offer. In this paper we review a number of concepts and modelling approaches that we believe are particularly interesting in attacking technological transitions. It is not our aim to be exhaustive in this review, but only to propose the approaches that we believe were most significant and that we think are most promising for future research. In a number of cases, we explicitly indicate direction for further research. The article is organized as follows. Section 2 addresses multiple equilibria, network externalities and positive feedback. Section 3 shows how game theory and evolutionary game theory are insightful for transitions in a strategic context. Section 4 presents diffusion on networks, with an accent on phase transitions. Section 5 reviews models of cascades and herding behavior. Section 6 is totally dedicated to a model of network formation based on the concept of catalytic processes. Section 7 is about the complexity of modular technologies, and Section 8 considers the case of niche technologies. Finally, Section 9 concludes.

30. On the Sensitivity of Collective Action to Uncertainty about Climate Tipping Points Previous research shows that collective action to avoid a catastrophic threshold, such as a climate “tipping point,” is unaffected by uncertainty about the impact of crossing the threshold but that collective action collapses if the location of the threshold is uncertain. Theory suggests that behavior should differ dramatically either side of a dividing line for threshold uncertainty. Inside the dividing line, where uncertainty is small, collective action should succeed. Outside the dividing line, where uncertainty is large, collective action should fail. We test this prediction in the experimental lab. Our results strongly support the prediction: behavior is highly sensitive to uncertainty around the dividing line.

31. Living dangerously on borrowed time during slow, unrecognized Regime Shifts Regime shifts from one ecological state to another are often portrayed as sudden, dramatic, and difficult to reverse. Yet many regime shifts unfold slowly and imperceptibly after a tipping point has been exceeded, especially at regional and global scales. These long, smooth transitions between equilibrium states are easy to miss, ignore, or deny, confounding management and governance. However, slow responses by ecosystems after transgressing a dangerous threshold also affords borrowed time – a window of opportunity to return to safer conditions before the new state eventually locks in and equilibrates. In this context, the most important challenge is a social one: convincing enough people to confront business-as-usual before time runs out to reverse unwanted regime shifts even after they have already begun.

32. Social Tipping Points and Earth Systems Dynamics Recently, Early Warning Signals (EWS) have been developed to predict tipping points in Earth Systems. This discussion highlights the potential to apply EWS to human social and economic systems, which may also undergo similar critical transitions. Social tipping points are particularly difficult to predict, however, and the current formulation of EWS, based on a physical system analogy, may be insufficient. As an alternative set of EWS for social systems, we join with other authors encouraging a focus on heterogeneity, connectivity through social networks and individual thresholds to change.

33. Social-ecological Resilience and Socio-technical Transitions Critical issues for Sustainability Governance Technology contributes both positively and negatively to the resilience of ‘social-ecological systems’, but is not considered in depth in that literature. A technology-focused literature on sociotechnical transitions shares some of the complex adaptive systems sensibilities of socialecological systems research. It is considered by others to provide a bridging opportunity to share lessons concerning the governance of both. We contend that lessons must not be restricted to advocacy of flexible, learning-oriented approaches, but must also be open to the critical challenges that confront these approaches. Here, we focus on the critical lessons arising from reactions to a ‘transition management’ approach to governing transitions to sustainable socio-technical regimes. Moreover, we suggest it is important to bear in mind the different problems each literature addresses, and be cautious about transposing lessons between the two. Nevertheless, questions for transition management about who governs, whose system framings count, and whose sustainability gets prioritised are pertinent to social-ecological systems research. They suggest an agenda that explores critically the kinds of resilience that are helpful or unhelpful, and for whom, and with what social purposes in mind.

34. Tipping Points among Social Learners - Tools from varied Disciplines There is a long and rich tradition in the social sciences of using models of collective behavior in animals as jumping-off points for the study of human behavior, including collective human behavior. Here, we come at the problem in a slightly different fashion. We ask whether models of collective human behavior have anything to offer those who study animal behavior. Our brief example of tipping points, a model first developed in the physical sciences and later used in the social sciences, suggests that the analysis of human collective behavior does indeed have considerable to offer.

35. Turning back from the brink - Detecting an impending Regime Shift in time to avert it Ecological regime shifts are large, abrupt, long-lasting changes in ecosystems that often have considerable impacts on human economies and societies. Avoiding unintentional regime shifts is widely regarded as desirable, but prediction of ecological regime shifts is notoriously difficult. Recent research indicates that changes in ecological time series (e.g., increased variability and autocorrelation) could potentially serve as early warning indicators of impending shifts. A critical question, however, is whether such indicators provide sufficient warning to adapt management to avert regime shifts. We examine this question using a fisheries model, with

regime shifts driven by angling (amenable to rapid reduction) or shoreline development (only gradual restoration is possible). The model represents key features of a broad class of ecological regime shifts. We find that if drivers can only be manipulated gradually management action is needed substantially before a regime shift to avert it; if drivers can be rapidly altered aversive action may be delayed until a shift is underway. Large increases in the indicators only occur once a regime shift is initiated, often too late for management to avert a shift. To improve usefulness in averting regime shifts, we suggest that research focus on defining critical indicator levels rather than detecting change in the indicators. Ideally, critical indicator levels should be related to switches in ecosystem attractors; we present a new spectral density ratio indicator to this end. Averting ecological regime shifts is also dependent on developing policy processes that enable society to respond more rapidly to information about impending regime shifts.

36. Are we now living in the Anthropocene? The term Anthropocene, proposed and increasingly employed to denote the current interval of anthropogenic global environmental change, may be discussed on stratigraphic grounds. A case can be made for its consideration as a formal epoch in that, since the start of the Industrial Revolution, Earth has endured changes sufficient to leave a global stratigraphic signature distinct from that of the Holocene or of previous Pleistocene interglacial phases, encompassing novel biotic, sedimentary, and geochemical change. These changes, although likely only in their initial phases, are sufficiently distinct and robustly established for suggestions of a Holocene– Anthropocene boundary in the recent historical past to be geologically reasonable. The boundary may be defined either via Global Stratigraphic Section and Point (“golden spike”) locations or by adopting a numerical date. Formal adoption of this term in the near future will largely depend on its utility, particularly to earth scientists working on late Holocene successions. This datum, from the perspective of the far future, will most probably approximate a distinctive stratigraphic boundary.

37. Planetary Boundaries: Exploring the Safe Operating Space for Humanity Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them. These seven are climate change; ocean acidification; stratospheric ozone; biogeochemical nitrogen (N) cycle and phosphorus (P) cycle; global freshwater use; land system change; and the rate at which biological diversity is lost. The two additional planetary boundaries for which we have not yet been able to determine a boundary level are chemical pollution and atmospheric aerosol loading. We estimate that humanity has already transgressed three planetary boundaries: for climate change, rate of biodiversity loss, and changes to the global nitrogen cycle. Planetary boundaries are interdependent, because transgressing one may both shift the position of other boundaries or cause them to be transgressed. The social impacts of transgressing boundaries will be a function of the social– ecological resilience of the affected societies. Our proposed boundaries are rough, first estimates only, surrounded by large uncertainties and knowledge gaps. Filling these gaps will require major advancements in Earth System and resilience science. The proposed concept of “planetary boundaries” lays the groundwork for shifting our approach to governance and

management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries define, as it were, the boundaries of the “planetary playing field” for humanity if we want to be sure of avoiding major human-induced environmental change on a global scale.