Showing papers on "Tipping point (climatology) published in 2020"

Abrupt shift to hotter and drier climate over inner East Asia beyond the tipping point

Abstract: Unprecedented heatwave-drought concurrences in the past two decades have been reported over inner East Asia. Tree-ring-based reconstructions of heatwaves and soil moisture for the past 260 years reveal an abrupt shift to hotter and drier climate over this region. Enhanced land-atmosphere coupling, associated with persistent soil moisture deficit, appears to intensify surface warming and anticyclonic circulation anomalies, fueling heatwaves that exacerbate soil drying. Our analysis demonstrates that the magnitude of the warm and dry anomalies compounding in the recent two decades is unprecedented over the quarter of a millennium, and this trend clearly exceeds the natural variability range. The "hockey stick"-like change warns that the warming and drying concurrence is potentially irreversible beyond a tipping point in the East Asian climate system.

Ecosystem-based fisheries management forestalls climate-driven collapse

Abstract: Climate change is impacting fisheries worldwide with uncertain outcomes for food and nutritional security. Using management strategy evaluations for key US fisheries in the eastern Bering Sea we find that Ecosystem Based Fisheries Management (EBFM) measures forestall future declines under climate change over non-EBFM approaches. Yet, benefits are species-specific and decrease markedly after 2050. Under high-baseline carbon emission scenarios (RCP 8.5), end-of-century (2075–2100) pollock and Pacific cod fisheries collapse in >70% and >35% of all simulations, respectively. Our analysis suggests that 2.1–2.3 °C (modeled summer bottom temperature) is a tipping point of rapid decline in gadid biomass and catch. Multiyear stanzas above 2.1 °C become commonplace in projections from ~2030 onward, with higher agreement under RCP 8.5 than simulations with moderate carbon mitigation (i.e., RCP 4.5). We find that EBFM ameliorates climate change impacts on fisheries in the near-term, but long-term EBFM benefits are limited by the magnitude of anticipated change. Ecosystem Based Management measures developed to prevent overfishing could be particularly important under climate change. Here the authors combine climate and fish stock modelling to show that EBM cap implementation reduces climate-driven fishery declines under RCP 4.5 and 8.5 before midcentury. However, there are thermal tipping points beyond which potential collapses are predicted.

Climate change causes critical transitions and irreversible alterations of mountain forests

Abstract: Mountain forests are at particular risk of climate change impacts due to their temperature limitation and high exposure to warming. At the same time, their complex topography may help to buffer the effects of climate change and create climate refugia. Whether climate change can lead to critical transitions of mountain forest ecosystems and whether such transitions are reversible remain incompletely understood. We investigated the resilience of forest composition and size structure to climate change, focusing on a mountain forest landscape in the Eastern Alps. Using the individual-based forest landscape model iLand, we simulated ecosystem responses to a wide range of climatic changes (up to a 6°C increase in mean annual temperature and a 30% reduction in mean annual precipitation), testing for tipping points in vegetation size structure and composition under different topography scenarios. We found that at warming levels above +2°C a threshold was crossed, with the system tipping into an alternative state. The system shifted from a conifer-dominated landscape characterized by large trees to a landscape dominated by smaller, predominantly broadleaved trees. Topographic complexity moderated climate change impacts, smoothing and delaying the transitions between alternative vegetation states. We subsequently reversed the simulated climate forcing to assess the ability of the landscape to recover from climate change impacts. The forest landscape showed hysteresis, particularly in scenarios with lower precipitation. At the same mean annual temperature, equilibrium vegetation size structure and species composition differed between warming and cooling trajectories. Here we show that even moderate warming corresponding to current policy targets could result in critical transitions of forest ecosystems and highlight the importance of topographic complexity as a buffering agent. Furthermore, our results show that overshooting ambitious climate mitigation targets could be dangerous, as ecological impacts can be irreversible at millennial time scales once a tipping point has been crossed.

The uncertain future of the Antarctic Ice Sheet.

Abstract: The Antarctic Ice Sheet is losing mass at an accelerating pace, and ice loss will likely continue over the coming decades and centuries. Some regions of the ice sheet may reach a tipping point, potentially leading to rates of sea level rise at least an order of magnitude larger than those observed now, owing to strong positive feedbacks in the ice-climate system. How fast and how much Antarctica will contribute to sea level remains uncertain, but multimeter sea level rise is likely for a mean global temperature increase of around 2°C above preindustrial levels on multicentennial time scales, or sooner for unmitigated scenarios.

When will the Amazon hit a tipping point

Abstract: Scientists say climate change, deforestation and fires could cause the world’s largest rainforest to dry out. The big question is how soon that might happen. Scientists say climate change, deforestation and fires could cause the world’s largest rainforest to dry out. The big question is how soon that might happen.

Climate change induced socio-economic tipping points: Review and stakeholder consultation for policy relevant research

Abstract: Tipping points have become a key concept in research on climate change, indicating points of abrupt transition in biophysical systems as well as transformative changes in adaptation and mitigation strategies. However, the potential existence of tipping points in socio-economic systems has remained underexplored, whereas they might be highly policy relevant. This paper describes characteristics of climate change induced socio-economic tipping points (SETPs) to guide future research on SETPS to inform climate policy. We review existing literature to create a tipping point typology and to derive the following SETP definition: a climate change induced, abrupt change of a socio-economic system, into a new, fundamentally different state. Through stakeholder consultation, we identify 22 candidate SETP examples with policy relevance for Europe. Three of these are described in higher detail to identify their tipping point characteristics (stable states, mechanisms and abrupt change): the collapse of winter sports tourism, farmland abandonment and sea-level rise-induced migration. We find that stakeholder perceptions play an important role in describing SETPs. The role of climate drivers is difficult to isolate from other drivers because of complex interplays with socio-economic factors. In some cases, the rate of change rather than the magnitude of change causes a tipping point. The clearest SETPs are found on small system scales. On a national to continental scale, SETPs are less obvious because they are difficult to separate from their associated economic substitution effects and policy response. Some proposed adaptation measures are so transformative that their implementations can be considered an SETP in terms of 'response to climate change'. Future research can focus on identification and impact analysis of tipping points using stylized models, on the exceedance of stakeholder-defined critical thresholds in the RCP/SSP space and on the macro-economic impacts of new system states.

Towards the Tipping Point for FAIR Implementation

Abstract: This article explores the global implementation of the FAIR Guiding Principles for scientific management and data stewardship, which provide that data should be findable, accessible, interoperable and reusable. The implementation of these principles is designed to lead to the stewardship of data as FAIR digital objects and the establishment of the Internet of FAIR Data and Services (IFDS). If implementation reaches a tipping point, IFDS has the potential to revolutionize how data is managed by making machine and human readable data discoverable for reuse. Accordingly, this article examines the expansion of the implementation of FAIR Guiding Principles, especially how and in which geographies (locations) and areas (topic domains) implementation is taking place. A literature review of academic articles published between 2016 and 2019 on the use of FAIR Guiding Principles is presented. The investigation also includes an analysis of the domains in the IFDS Implementation Networks (INs). Its uptake has been mainly in the Western hemisphere. The investigation found that implementation of FAIR Guiding Principles has taken firm hold in the domain of bio and natural sciences. To achieve a tipping point for FAIR implementation, is now time to ensure the inclusion of non-European ascendants and of other scientific domains. Apart from equal opportunity and genuine global partnership issues, a permanent European bias poses challenges with regard to the representativeness and validity of data and could limit the potential of IFDS to reach across continental boundaries. The article concludes that, despite efforts to be inclusive, acceptance of the FAIR Guiding Principles and IFDS in different scientific communities is limited and there is a need to act now to prevent dampening of the momentum in the development and implementation of the IFDS. It is further concluded that policy entrepreneurs and the GO FAIR INs may contribute to making the FAIR Guiding Principles more flexible in including different research epistemologies, especially through its GO CHANGE pillar.

Cultural Evolution of Sustainable Behaviors: Pro-Environmental Tipping Points in an Agent-Based Model

Abstract: Summary To reach sustainability transitions, we must learn to leverage social systems into tipping points, where societies exhibit positive-feedback loops in the adoption of sustainable behavioral and cultural traits. However, much less is known about the most efficient ways to reach such transitions or how self-reinforcing systemic transformations might be instigated through policy. We employ an agent-based model to study the emergence of social tipping points through various feedback loops that have been previously identified to constitute an ecological approach to human behavior. Our model suggests that even a linear introduction of pro-environmental affordances (action opportunities) to a social system can have non-linear positive effects on the emergence of collective pro-environmental behavior patterns. We validate the model against data on the evolution of cycling and driving behaviors in Copenhagen. Our model gives further evidence and justification for policies that make pro-environmental behavior psychologically salient, easy, and the path of least resistance.

Fiddling while the planet burns? COP25 in perspective

Abstract: With fires, storms, social protests, and climate strikes sweeping the world, 2019 should have been a tipping point in how the world responds to global heating. This was the backdrop to the COP25 cl...

Emergence of cascading dynamics in interacting tipping elements of ecology and climate.

Abstract: In ecology, climate and other fields, (sub)systems have been identified that can transition into a qualitatively different state when a critical threshold or tipping point in a driving process is crossed An understanding of those tipping elements is of great interest given the increasing influence of humans on the biophysical Earth system Complex interactions exist between tipping elements, eg physical mechanisms connect subsystems of the climate system Based on earlier work on such coupled nonlinear systems, we systematically assessed the qualitative long-term behaviour of interacting tipping elements We developed an understanding of the consequences of interactions on the tipping behaviour allowing for tipping cascades to emerge under certain conditions The (narrative) application of these qualitative results to real-world examples of interacting tipping elements indicates that tipping cascades with profound consequences may occur: the interacting Greenland ice sheet and thermohaline ocean circulation might tip before the tipping points of the isolated subsystems are crossed The eutrophication of the first lake in a lake chain might propagate through the following lakes without a crossing of their individual critical nutrient input levels The possibility of emerging cascading tipping dynamics calls for the development of a unified theory of interacting tipping elements and the quantitative analysis of interacting real-world tipping elements

Tipping to Staying on the Ground: Internalized Knowledge of Climate Change Crucial for Transformed Air Travel Behavior

Abstract: Air travel accounts for a major share of individual greenhouse gas emissions, particularly for people in high-income countries. Until recently, few have reduced flying because of climate concerns, but currently, a movement for staying on the ground is rising. Sweden has been a focal point for this movement, particularly during 2018–2019, when a flight tax was introduced, and air travel reduction was intensely discussed in the media. We performed semi-structured interviews with Swedish residents, focusing primarily on individuals who have reduced flying because of its climate impact. We explore how such individual transformation of air travel behavior comes about, and the phases and components of this process. Applying a framework of sustainability transformation, we identify incentives and barriers in personal and political spheres. We show that internalized knowledge about climate change and the impact of air travel is crucial for instigating behavioral change. Awareness evokes negative emotions leading to a personal tipping point where a decision to reduce or quit flying is made. However, the process is often counteracted by both personal values and political structures promoting air travel. Even individuals with a strong drive to reduce flying feel trapped in social practices, norms and infrastructures. Hence, we argue that personal and political spheres interact complexly and to reduce flying at larger scales, interventions are needed across spheres, e.g., change of norms, effective policy instruments and better alternatives to air travel.

Why telemedicine is here to stay.

Abstract: Virtual consultations and triaging have reached a tipping point, pushed on by the covid-19 pandemic. Chris Stokel-Walker reports on what a market worth at least $250bn means for doctors

Exploring non-linear transition pathways in social-ecological systems.

Abstract: Tipping point dynamics are fundamental drivers for sustainable transition pathways of social-ecological systems (SES). Current research predominantly analyzes how crossing tipping points causes regime shifts, however, the analysis of potential transition pathways from these social and ecological tipping points is often overlooked. In this paper, we analyze transition pathways and the potential outcomes that these may lead to via a stylized model of a system composed of interacting agents exploiting resources and, by extension, the overall ecosystem. Interactions between the social and the ecological system are based on a perception-exploitation framework. We show that the presence of tipping points in SES may yield counter-intuitive social-ecological transition pathways. For example, the high perception of an alarming ecological state among agents can provide short-term ecological benefits, but can be less effective in the long term, compared to a low-perception condition. This work also highlights how understanding non-linear interactions is critical for defining suitable transition pathways of any SES.

Shifts in national land use and food production in Great Britain after a climate tipping point

Abstract: Climate change is expected to impact agricultural land use. Steadily accumulating changes in temperature and water availability can alter the relative profitability of different farming activities and promote land-use changes. There is also potential for high-impact ‘climate tipping points’, where abrupt, nonlinear change in climate occurs, such as the potential collapse of the Atlantic Meridional Overturning Circulation (AMOC). Here, using data from Great Britain, we develop a methodology to analyse the impacts of a climate tipping point on land use and economic outcomes for agriculture. We show that economic and land-use impacts of such a tipping point are likely to include widespread cessation of arable farming with losses of agricultural output that are an order of magnitude larger than the impacts of climate change without an AMOC collapse. The agricultural effects of AMOC collapse could be ameliorated by technological adaptations such as widespread irrigation, but the amount of water required and the costs appear to be prohibitive in this instance.

The Quiet Crisis of PhDs and COVID-19: Reaching the financial tipping point.

Abstract: Before the COVID-19 crisis, existing high levels of financial concerns amongst PhD students increased their vulnerability to disruptive events. Impacts from the pandemic have increased their financial stress to the point that may result in many being forced to exit research studies. An exodus of doctoral students now would impact our future research capacity. The effects of the unfolding crisis on research students at a research-intensive Australian university was documented by a group of doctoral candidates who received 1,020 survey responses from their cohort. Here we show that the pandemic has severely affected research candidates and argue that these results have notable implications for a future research workforce. We found that 75% of students expect to experience financial hardship as a result of the pandemic. Consequently, 45% report being pushed beyond their financial capacities and expect to be forced to disengage from their research within six months. Comparative pre-COVID data from an Australian national survey, reports research student disengagement of 20% over four years. The 25% increase of expected disengagement, in a much-reduced period, signals a deeper PhD crisis. Swift intervention is required to avert substantial impacts to the pipeline of research talent.

Early-Warning Signals for Marine Anoxic Events

Abstract: Predicting which marine systems are close to abrupt transitions into oxygen-deficient conditions (“anoxia”) is notoriously hard but important—as rising temperatures and coastal eutrophication drive many marine systems toward such tipping points. Rapid oxic-to-anoxic transitions occurred regularly within the eastern Mediterranean Sea on (multi)centennial time scales, and hence, its sedimentary archive allows exploring statistical methods that can indicate approaching tipping points. The here presented high-resolution reconstructions of past oxygen dynamics in the Mediterranean Sea reveal that early-warning signals in these deoxygenation time series occurred long before fast transitions to anoxia. These statistical indicators (i.e., rise in autocorrelation and variance) are hallmarks of so-called critical slowing down, signaling a steady loss of resilience of the oxygenated state as the system approaches a tipping point. Hence, even without precise knowledge of the mechanisms involved, early-warning signals for widespread anoxia in marine systems are recognizable using an appropriate statistical approach.

The importance of transient social dynamics for restoring ecosystems beyond ecological tipping points.

Abstract: Regime shift modeling and management generally focus on tipping points, early warning indicators, and the prevention of abrupt shifts to undesirable states. Few studies assess the potential for restoring a deteriorating ecosystem that is on a transition pathway toward an undesirable state. During the transition, feedbacks that stabilize the new regime are still weak, providing an opportunity to reverse the ongoing shift. Here, we present a social-ecological model that explores both how transient social processes affect ecological dynamics in the vicinity of a tipping point to reinforce the desired state and how social mechanisms of policy implementation affect restoration time. We simulate transitions of a lake, policy making, and behavioral change by lake polluters to study the time lags that emerge as a response to the transient, deteriorating lake state. We found that restoration time is most sensitive to the timing of policy making, but that the transient dynamics of the social processes determined outcomes in nontrivial ways. Social pressure to adopt costly technology, in our case on-site sewage treatment, was up to a degree capable of compensating for delays in municipal policy making. Our analysis of interacting social and ecological time lags in the transient phase of a shallow lake highlights opportunities for restoration that a stable state analysis would miss. We discuss management perspectives for navigating critical feedbacks in a transitioning social-ecological system. The understanding of transient dynamics and the interaction with social time lags can be more relevant than solely stable states and tipping points.

Tipping point and noise-induced transients in ecological networks.

Abstract: A challenging and outstanding problem in interdisciplinary research is to understand the interplay between transients and stochasticity in high-dimensional dynamical systems. Focusing on the tipping-point dynamics in complex mutualistic networks in ecology constructed from empirical data, we investigate the phenomena of noise-induced collapse and noise-induced recovery. Two types of noise are studied: environmental (Gaussian white) noise and state-dependent demographic noise. The dynamical mechanism responsible for both phenomena is a transition from one stable steady state to another driven by stochastic forcing, mediated by an unstable steady state. Exploiting a generic and effective two-dimensional reduced model for real-world mutualistic networks, we find that the average transient lifetime scales algebraically with the noise amplitude, for both environmental and demographic noise. We develop a physical understanding of the scaling laws through an analysis of the mean first passage time from one steady state to another. The phenomena of noise-induced collapse and recovery and the associated scaling laws have implications for managing high-dimensional ecological systems.

Critical slowing down indicators

Abstract: Critical slowing down is considered to be an important indicator for predicting critical transitions in dynamical systems. Researchers have used it prolifically in the fields of ecology, biology, sociology, and finance. When a system approaches a critical transition or a tipping point, it returns more slowly to its stable attractor under small perturbations. The return time to the stable state can thus be used as an index, which shows whether a critical change is near or not. Based on this phenomenon, many methods have been proposed to determine tipping points, especially in biological and social systems, for example, related to epidemic spreading, cardiac arrhythmias, or even population collapse. In this perspective, we briefly review past research dedicated to critical slowing down indicators and associated tipping points, and we outline promising directions for future research.

Early Warning from Space for a Few Key Tipping Points in Physical, Biological, and Social-Ecological Systems

Abstract: In this review paper, we explore latest results concerning a few key tipping elements of the Earth system in the ocean, cryosphere, and land realms, namely the Atlantic overturning circulation and the subpolar gyre system, the marine ecosystems, the permafrost, the Greenland and Antarctic ice sheets, and in terrestrial resource use systems. All these different tipping elements share common characteristics related to their nonlinear nature. They can also interact with each other leading to synergies that can lead to cascading tipping points. Even if the probability of each tipping event is low, they can happen relatively rapidly, involve multiple variables, and have large societal impacts. Therefore, adaptation measures and management in general should extend their focus beyond slow and continuous changes, into abrupt, nonlinear, possibly cascading, high impact phenomena. Remote sensing observations are found to be decisive in the understanding and determination of early warning signals of many tipping elements. Nevertheless, considerable research still remains to properly incorporate these data in the current generation of coupled Earth system models. This is a key prerequisite to correctly develop robust decadal prediction systems that may help to assess the risk of crossing thresholds potentially crucial for society. The prediction of tipping points remains difficult, notably due to stochastic resonance, i.e. the interaction between natural variability and anthropogenic forcing, asking for large ensembles of predictions to correctly assess the risks. Furthermore, evaluating the proximity to crucial thresholds using process-based understanding of each system remains a key aspect to be developed for an improved assessment of such risks. This paper finally proposes a few research avenues concerning the use of remote sensing data and the need for combining different sources of data, and having long and precise-enough time series of the key variables needed to monitor Earth system tipping elements.

Critical mass effect in evolutionary games triggered by zealots

Abstract: The authors use evolutionary game theory to examine whether a finite fraction of zealots can drive the system to large-scale cooperation. The paper finds that such a tipping point exists in coordination games, whereas its existence depends on the selection pressure, update rule, and network structure in other types of games.

Extreme Sensitivity and Climate Tipping Points

Abstract: A climate state close to a tipping point will have a degenerate linear response to perturbations, which can be associated with extreme values of the equilibrium climate sensitivity (ECS). In this paper we contrast linearized (‘instantaneous’) with fully nonlinear geometric (‘two-point’) notions of ECS, in both presence and absence of tipping points. For a stochastic energy balance model of the global mean surface temperature with two stable regimes, we confirm that tipping events cause the appearance of extremes in both notions of ECS. Moreover, multiple regimes with different mean sensitivities are visible in the two-point ECS. We confirm some of our findings in a physics-based multi-box model of the climate system.

Beyond the tipping point: the curvilinear relationships of transformational leadership, leader–member exchange, and emotional exhaustion in the French police

Abstract: As one promise of transformational leadership (TFL), it inspires public servants to perform beyond expectations and embrace needed change. However, it remains unclear whether TFL is linked to reduc...