This theme focuses on operationalizing the regime shifts theory to explain important mechanisms in social-ecological systems
Regime shifts are persistent change in systems structure and function, which can be abrupt and difficult to reverse. The focus here is on regime shifts in social-ecological systems that have substantial impacts on ecosystem services.
The aim is to develop regime shift theory through case study development, comparison, and analysis of regime shifts in social-ecological systems. It connects to other themes at the Centre by addressing regime shifts in: the Baltic Sea, the Sahel, the Arctic, Southern Africa, and coral reefs.
The theme has five organizing questions:
1. How can regime shifts concepts be best operationally defined, identified and detected?
2. What are the main drivers of regime shifts, and how are different regime shifts interconnected?
3. Which locations are most likely to experience regime shifts?
4. How do regime shifts impact ecosystem services?
5. How can we most efficiently modify resilience to regime shifts?
Research news | 2016-04-19
Announcing Global Sustainability, a new Open Access launch from Cambridge
Research news | 2016-02-25
Even in a reported Baltic Sea regime shift, not all parts of the system are affected
Research news | 2016-01-18
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Reducing resilience to a few measurements can block deeper understanding
Research news | 2015-11-18
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Research news | 2015-10-12
Recent crises are increasingly global and follow new kinds of patterns
2015 - Journal / article
Abrupt systemic changes in ecological and socio-economic systems are a regular occurrence. While there has been much attention to studying systemic changes primarily in ecology as well as in economics, the attempts to do so for coupled socio-environmental systems are rarer. This paper bridges the gap by reviewing how models can be instrumental in exploring significant, fundamental changes in such systems. The history of modelling systemic change in various disciplines contains a range of definitions and approaches. Even so, most of these efforts share some common challenges within the modelling context. We propose a framework drawing these challenges together, and use it to discuss the articles in this thematic issue on modelling systemic change in coupled social and environmental systems. The differing approaches used highlight that modelling systemic change is an area of endeavour that would benefit from greater synergies between the various disciplines concerned with systemic change.
2015 - Journal / article
A prominent characteristic of the reconstructed Northern Hemisphere temperature signal over the last millennium is the transition from the Medieval Climate Anomaly to the Little Ice Age (LIA). Here we report indications for a non-linear regime shift in the North Atlantic ocean circulation at the onset of the LIA. Specifically, we apply a novel statistical test based on horizontal visibility graphs to two ocean sediment August sea-surface temperature records from the Norwegian Sea and the central subpolar basin and find robust indications of time-irreversibility in both records during the LIA onset. Despite a basin-wide cooling trend, we report an anomalous warming in the central subpolar basin during the LIA that is reproduced in ensemble simulations with the climate model of intermediate complexity CLIMBER-3αα as a result of a non-linear regime shift in the subpolar North Atlantic ocean circulation. The identified volcanically triggered non-linear transition in the model simulations provides a plausible explanation for the signatures of time-irreversibility found in the ocean sediment records. Our findings indicate a potential multi-stability of the North Atlantic ocean circulation and its importance for regional climate change on centennial time scales.
2015 - Journal / article
Ecosystems can undergo regime shifts that potentially lead to a substantial decrease in the availability of provisioning ecosystem services. Recent research suggests that the frequency and intensity of regime shifts increase with growing anthropogenic pressure, so understanding the underlying social-ecological dynamics is crucial, particularly in contexts where livelihoods depend heavily on local ecosystem services. In such settings, ecosystem services are often derived from common-pool resources. The limited capacity to predict regime shifts is a major challenge for common-pool resource management, as well as for systematic empirical analysis of individual and group behavior, because of the need for extensive preshift and postshift data. Unsurprisingly, current knowledge is mostly based on theoretical models. We examine behavioral group responses to a latent endogenously driven regime shift in a laboratory experiment. If the group exploited the common-pool resource beyond a certain threshold level, its renewal rate dropped drastically. To determine how the risk of such a latent shift affects resource management and collective action, we compared four experimental treatments in which groups were faced with a latent shift with different probability levels (0.1, 0.5, 0.9, 1.0). Our results suggest that different probability levels do not make people more or less likely to exploit the resource beyond its critical potential threshold. However, when the likelihood of the latent shift is certain or high, people appear more prone to agree initially on a common exploitation strategy, which in turn is a predictor for averting the latent shift. Moreover, risk appears to have a positive effect on collective action, but the magnitude of this effect is influenced by how risk and probabilities are communicated and perceived.
2015 - Journal / article
Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers.