442 results on '"Donges, Jonathan F."'
Search Results
202. Hierarchical structures in Northern Hemispheric extratropical winter ocean-atmosphere interactions.
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Wiedermann, Marc, Donges, Jonathan F., Handorf, Dörthe, Kurths, Jürgen, and Donner, Reik V.
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CYCLONES , *OCEAN-atmosphere interaction , *SURFACE of the earth , *OCEAN temperature , *STRATOSPHERE - Abstract
ABSTRACT In recent years extensive studies on the Earth's climate system have been carried out by means of advanced complex network statistics. The great majority of these studies, however, have been focusing on investigating correlation structures within single climatic fields directly on or parallel to the Earth's surface. Here, we develop a novel approach of node weighted coupled network measures to study correlations between ocean and atmosphere in the Northern Hemisphere extratropics and construct 18 coupled climate networks, each consisting of two subnetworks. In all cases, one subnetwork represents monthly sea-surface temperature ( SST) anomalies, while the other is based on the monthly geopotential height ( HGT) of isobaric surfaces at different pressure levels covering the troposphere as well as the lower stratosphere. The weighted cross-degree density proves to be consistent with the leading coupled pattern obtained from maximum covariance analysis. Network measures of higher order allow for a further analysis of the correlation structure between the two fields and consistently indicate that in the Northern Hemisphere extratropics the ocean is correlated with the atmosphere in a hierarchical fashion such that large areas of the ocean surface correlate with multiple statistically dissimilar regions in the atmosphere. Ultimately we show that this observed hierarchy is linked to large-scale atmospheric variability patterns, such as the Pacific North American pattern, forcing the ocean on monthly time scales. [ABSTRACT FROM AUTHOR]
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- 2017
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203. Analytically tractable climate-carbon cycle feedbacks under 21st century anthropogenic forcing.
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Lade, Steven J., Donges, Jonathan F., Fetzer, Ingo, Anderies, John M., Beer, Christian, Cornell, Sarah E., Gasser, Thomas, Norberg, Jon, Richardson, Katherine, Rockström, Johan, and Steffen, Will
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CARBON cycle , *EFFECT of human beings on climate change , *CLIMATE change - Abstract
Changes to climate-carbon cycle feedbacks may significantly affect the Earth System's response to greenhouse gas emissions. These feedbacks are usually analysed from numerical output of complex and arguably opaque Earth System Models (ESMs). Here, we construct a stylized global climate-carbon cycle model, test its output against complex ESMs, and investigate the strengths of its climate-carbon cycle feedbacks analytically. The analytical expressions we obtain aid understanding of carbon-cycle feedbacks and the operation of the carbon cycle. We use our results to analytically study the relative strengths of different climate-carbon cycle feedbacks and how they may change in the future, as well as to compare different feedback formalisms. Simple models such as that developed here also provide "workbenches" for simple but mechanistically based explorations of Earth system processes, such as interactions and feedbacks between the Planetary Boundaries, that are currently too uncertain to be included in complex ESMs. [ABSTRACT FROM AUTHOR]
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- 2017
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204. A perturbation-theoretic approach to Lagrangian flow networks.
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Naoya Fujiwara, Kirchen, Kathrin, Donges, Jonathan F., and Donner, Reik V.
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PERTURBATION theory ,LAGRANGIAN functions ,GEOPHYSICS ,FLUID dynamics ,MARKOV processes - Abstract
Complex network approaches have been successfully applied for studying transport processes in complex systems ranging from road, railway, or airline infrastructures over industrial manufacturing to fluid dynamics. Here, we utilize a generic framework for describing the dynamics of geophysical flows such as ocean currents or atmospheric wind fields in terms of Lagrangian flow networks. In this approach, information on the passive advection of particles is transformed into a Markov chain based on transition probabilities of particles between the volume elements of a given partition of space for a fixed time step. We employ perturbation-theoretic methods to investigate the effects of modifications of transport processes in the underlying flow for three different problem classes: efficient absorption (corresponding to particle trapping or leaking), constant input of particles (with additional source terms modeling, e.g., localized contamination), and shifts of the steady state under probability mass conservation (as arising if the background flow is perturbed itself). Our results demonstrate that in all three cases, changes to the steady state solution can be analytically expressed in terms of the eigensystem of the unperturbed flow and the perturbation itself. These results are potentially relevant for developing more efficient strategies for coping with contaminations of fluid or gaseous media such as ocean and atmosphere by oil spills, radioactive substances, non-reactive chemicals, or volcanic aerosols. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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205. Publisher's Note: Disentangling different types of El Niño episodes by evolving climate network analysis [Phys. Rev. E88, 052807 (2013)]
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Radebach, Alexander, primary, Donner, Reik V., additional, Runge, Jakob, additional, Donges, Jonathan F., additional, and Kurths, Jürgen, additional
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- 2014
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206. Complex networks for climate model evaluation with application to statistical versus dynamical modeling of South American climate
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Feldhoff, Jan H., primary, Lange, Stefan, additional, Volkholz, Jan, additional, Donges, Jonathan F., additional, Kurths, Jürgen, additional, and Gerstengarbe, Friedrich-Wilhelm, additional
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- 2014
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207. Detection of coupling directions with intersystem recurrence networks
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Marwan, Norbert, primary, Feldhoff, Jan H., additional, Donner, Reik V., additional, Donges, Jonathan F., additional, and Kurths, Jürgen, additional
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- 2014
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208. Identifying nonlinearities by time-reversal asymmetry of vertex properties in visibility graphs
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Donner, Reik V., primary and Donges, Jonathan F., additional
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- 2014
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209. Disentangling different types of El Niño episodes by evolving climate network analysis
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Radebach, Alexander, primary, Donner, Reik V., additional, Runge, Jakob, additional, Donges, Jonathan F., additional, and Kurths, Jürgen, additional
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- 2013
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210. Complex network approach for recurrence analysis of time series
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Marwan, Norbert, Donges, Jonathan F., Zou, Yong, Donner, Reik V., and Kurths, Jürgen
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- 2009
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211. Testing time series irreversibility using complex network methods
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Donges, Jonathan F., primary, Donner, Reik V., additional, and Kurths, Jürgen, additional
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- 2013
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212. Patterns of land-cover transitions from satellite imagery of the Brazilian Amazon.
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Müller-Hansen, Finn, Cardoso, Manoel F., Dalla-Nora, Eloi L., Donges, Jonathan F., Heitzig, Jobst, Kurths, Jürgen, and Thonicke, Kirsten
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LAND cover ,ATOMIC transition probabilities ,MARKOV processes - Abstract
Changes in land-use systems in tropical regions, including deforestation, are a key challenge for global sustainability because of their huge impacts on green-house gas emissions, local climate and biodiversity. However, the dynamics of land-use and land-cover change in regions of frontier expansion such as the Brazilian Amazon is not yet well understood because of the complex interplay of ecological and socio-economic drivers. In this paper, we combine Markov chain analysis and complex network methods to identify regimes of land-cover dynamics from land-cover maps (TerraClass) derived from high-resolution (30 m) satellite imagery. We estimate regional transition probabilities between different land-cover types and use clustering analysis and community detection algorithms on similarity networks to explore patterns of dominant land-cover transitions. We find that land-cover transition probabilities in the Brazilian Amazon are heterogeneous in space and adjacent subregions tend to be assigned to the same clusters. When focusing on transitions from single land-cover types, we uncover patterns that reflect major regional differences in land-cover dynamics. Our method is able to summarize regional patterns and thus complements studies performed at the local scale. [ABSTRACT FROM AUTHOR]
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- 2016
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213. Analytical framework for recurrence network analysis of time series
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Donges, Jonathan F., primary, Heitzig, Jobst, additional, Donner, Reik V., additional, and Kurths, Jürgen, additional
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- 2012
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214. Information Visualization in Climate Research
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Tominski, Christian, primary, Donges, Jonathan F., additional, and Nocke, Thomas, additional
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- 2011
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215. RECURRENCE-BASED TIME SERIES ANALYSIS BY MEANS OF COMPLEX NETWORK METHODS
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DONNER, REIK V., primary, SMALL, MICHAEL, additional, DONGES, JONATHAN F., additional, MARWAN, NORBERT, additional, ZOU, YONG, additional, XIANG, RUOXI, additional, and KURTHS, JÜRGEN, additional
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- 2011
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216. Identifying complex periodic windows in continuous-time dynamical systems using recurrence-based methods
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Zou, Yong, primary, Donner, Reik V., additional, Donges, Jonathan F., additional, Marwan, Norbert, additional, and Kurths, Jürgen, additional
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- 2010
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217. Recurrence networks—a novel paradigm for nonlinear time series analysis
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Donner, Reik V, primary, Zou, Yong, additional, Donges, Jonathan F, additional, Marwan, Norbert, additional, and Kurths, Jürgen, additional
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- 2010
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218. Ambiguities in recurrence-based complex network representations of time series
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Donner, Reik V., primary, Zou, Yong, additional, Donges, Jonathan F., additional, Marwan, Norbert, additional, and Kurths, Jürgen, additional
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- 2010
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219. Social tipping processes towards climate action: A conceptual framework.
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Winkelmann, Ricarda, Donges, Jonathan F., Smith, E. Keith, Milkoreit, Manjana, Eder, Christina, Heitzig, Jobst, Katsanidou, Alexia, Wiedermann, Marc, Wunderling, Nico, and Lenton, Timothy M.
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SOCIAL processes , *EFFECT of human beings on climate change , *AGENT (Philosophy) , *ECOSYSTEM dynamics , *GOVERNMENT policy on climate change , *CLIMATE change mitigation - Abstract
Societal transformations are necessary to address critical global challenges, such as mitigation of anthropogenic climate change and reaching UN sustainable development goals. Recently, social tipping processes have received increased attention, as they present a form of social change whereby a small change can shift a sensitive social system into a qualitatively different state due to strongly self-amplifying (mathematically positive) feedback mechanisms. Social tipping processes with respect to technological and energy systems, political mobilization, financial markets and sociocultural norms and behaviors have been suggested as potential key drivers towards climate action. Drawing from expert insights and comprehensive literature review, we develop a framework to identify and characterize social tipping processes critical to facilitating rapid social transformations. We find that social tipping processes are distinguishable from those of already more widely studied climate and ecological tipping dynamics. In particular, we identify human agency, social-institutional network structures, different spatial and temporal scales and increased complexity as key distinctive features underlying social tipping processes. Building on these characteristics, we propose a formal definition for social tipping processes and filtering criteria for those processes that could be decisive for future trajectories towards climate action. We illustrate this definition with the European political system as an example of potential social tipping processes, highlighting the prospective role of the FridaysForFuture movement. Accordingly, this conceptual framework for social tipping processes can be utilized to illuminate mechanisms for necessary transformative climate change mitigation policies and actions. [ABSTRACT FROM AUTHOR]
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- 2022
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220. Nonlinear detection of paleoclimate-variability transitions possibly related to human evolution.
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Donges, Jonathan F., Donner, Reik V., Trauth, Martin H., Marwan, Norbert, Schellnhuber, Hans-Joachim, and Kurths, Jürgen
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PLEISTOCENE paleoclimatology , *HUMAN evolution , *TIME series analysis , *CLIMATE change & society , *ECOLOGY - Abstract
Potential paleoclimatic driving mechanisms acting on human evolution present an open problem of cross-disciplinary scientific interest. The analysis of paleoclimate archives encoding the environmental variability in East Africa during the past 5 Ma has triggered an ongoing debate about possible candidate processes and evolutionary mechanisms. In this work, we apply a nonlinear statistical technique, recurrence network analysis, to three distinct marine records of terrigenous dust flux. Our method enables us to identify three epochs with transitions between qualitatively different types of environmental variability in North and East Africa during the (i) Middle Pliocene (3.35-3.15 Ma B.P.), (ii) Early Pleistocene (2.25-1.6 Ma B.P.), and (iii) Middle Pleistocene (1.1-0.7 Ma B.P.). A deeper examination of these transition periods reveals potential climatic drivers, including (i) large-scale changes in ocean currents due to a spatial shift of the Indonesian throughflow in combination with an intensification of Northern Hemisphere glaciation, (ii) a global reorganization of the atmospheric Walker circulation induced in the tropical Pacific and Indian Ocean, and (iii) shifts in the dominating temporal variability pattern of glacial activity during the Middle Pleistocene, respectively. A reexamination of the available fossil record demonstrates statistically significant coincidences between the detected transition periods and major steps in hominin evolution. This result suggests that the observed shifts between more regular and more erratic environmental variability may have acted as a trigger for rapid change in the development of humankind in Africa. [ABSTRACT FROM AUTHOR]
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- 2011
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221. Nonlinear time series analysis of palaeoclimate proxy records.
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Marwan, Norbert, Donges, Jonathan F., Donner, Reik V., and Eroglu, Deniz
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EARTH'S orbit , *NONLINEAR dynamical systems , *INFORMATION theory , *WALKER circulation , *SYSTEMS theory , *CLIMATE change , *TIME series analysis - Abstract
Identifying and characterising dynamical regime shifts, critical transitions or potential tipping points in palaeoclimate time series is relevant for improving the understanding of often highly nonlinear Earth system dynamics. Beyond linear changes in time series properties such as mean, variance, or trend, these nonlinear regime shifts can manifest as changes in signal predictability, regularity, complexity, or higher-order stochastic properties such as multi-stability. In recent years, several classes of methods have been put forward to study these critical transitions in time series data that are based on concepts from nonlinear dynamics, complex systems science, information theory, and stochastic analysis. These include approaches such as phase space-based recurrence plots and recurrence networks, visibility graphs, order pattern-based entropies, and stochastic modelling. Here, we review and compare in detail several prominent methods from these fields by applying them to the same set of marine palaeoclimate proxy records of African climate variations during the past 5 million years. Applying these methods, we observe notable nonlinear transitions in palaeoclimate dynamics in these marine proxy records and discuss them in the context of important climate events and regimes such as phases of intensified Walker circulation, marine isotope stage M2, the onset of northern hemisphere glaciation and the mid-Pleistocene transition. We find that the studied approaches complement each other by allowing us to point out distinct aspects of dynamical regime shifts in palaeoclimate time series. We also detect significant correlations of these nonlinear regime shift indicators with variations of Earth's orbit, suggesting the latter as potential triggers of nonlinear transitions in palaeoclimate. Overall, the presented study underlines the potentials of nonlinear time series analysis approaches to provide complementary information on dynamical regime shifts in palaeoclimate and their driving processes that cannot be revealed by linear statistics or eyeball inspection of the data alone. [ABSTRACT FROM AUTHOR]
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- 2021
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222. Social tipping dynamics in a world constrained by conflicting interests.
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Otto, Ilona M., Donges, Jonathan F., Wolfgang Lucht, and Schellnhuber, Hans Joachim
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SOCIAL dynamics , *CONFLICT of interests , *EARTH system science , *SOCIAL surveys , *PUBLIC opinion - Published
- 2020
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223. Dynamic regimes of the Greenland Ice Sheet emerging from interacting melt–elevation and glacial isostatic adjustment feedbacks.
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Zeitz, Maria, Haacker, Jan M., Donges, Jonathan F., Albrecht, Torsten, and Winkelmann, Ricarda
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GREENLAND ice , *GLACIAL isostasy , *ICE sheets , *ICE shelves , *GLACIERS , *GLOBAL warming , *MILANKOVITCH cycles - Abstract
The stability of the Greenland Ice Sheet under global warming is governed by a number of dynamic processes and interacting feedback mechanisms in the ice sheet, atmosphere and solid Earth. Here we study the long-term effects due to the interplay of the competing melt–elevation and glacial isostatic adjustment (GIA) feedbacks for different temperature step forcing experiments with a coupled ice-sheet and solid-Earth model. Our model results show that for warming levels above 2 ∘ C, Greenland could become essentially ice-free within several millennia, mainly as a result of surface melting and acceleration of ice flow. These ice losses are mitigated, however, in some cases with strong GIA feedback even promoting an incomplete recovery of the Greenland ice volume. We further explore the full-factorial parameter space determining the relative strengths of the two feedbacks: our findings suggest distinct dynamic regimes of the Greenland Ice Sheets on the route to destabilization under global warming – from incomplete recovery, via quasi-periodic oscillations in ice volume to ice-sheet collapse. In the incomplete recovery regime, the initial ice loss due to warming is essentially reversed within 50 000 years, and the ice volume stabilizes at 61 %–93 % of the present-day volume. For certain combinations of temperature increase, atmospheric lapse rate and mantle viscosity, the interaction of the GIA feedback and the melt–elevation feedback leads to self-sustained, long-term oscillations in ice-sheet volume with oscillation periods between 74 000 and over 300 000 years and oscillation amplitudes between 15 %–70 % of present-day ice volume. This oscillatory regime reveals a possible mode of internal climatic variability in the Earth system on timescales on the order of 100 000 years that may be excited by or synchronized with orbital forcing or interact with glacial cycles and other slow modes of variability. Our findings are not meant as scenario-based near-term projections of ice losses but rather providing insight into of the feedback loops governing the "deep future" and, thus, long-term resilience of the Greenland Ice Sheet. [ABSTRACT FROM AUTHOR]
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- 2022
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224. Detecting impacts of extreme events with ecological in situ monitoring networks
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Mahecha, Miguel D., Gans, Fabian, Sippel, Sebastian, Donges, Jonathan F., Kaminski, Thomas, Metzger, Stefan, Migliavacca, Mirco, Papale, Dario, Rammig, Anja, and Zscheischler, Jakob
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225. Multi-method evidence for when and how climate-related disasters contribute to armed conflict risk.
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Ide, Tobias, Brzoska, Michael, Donges, Jonathan F., and Schleussner, Carl-Friedrich
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EFFECT of human beings on climate change ,DISASTERS ,SOCIAL marginality ,ETHNIC groups ,CLIMATE change ,EVIDENCE - Abstract
• First integrated, multi-method study on climate-related disasters and conflict. • Disaster do not enhance conflict risks per se, but only in certain contexts. • Relevant context factors: large population, ethnic exclusion, low development. • Improved opportunity structures are the main explanatory mechanism. Climate-related disasters are among the most societally disruptive impacts of anthropogenic climate change. Their potential impact on the risk of armed conflict is heavily debated in the context of the security implications of climate change. Yet, evidence for such climate-conflict-disaster links remains limited and contested. One reason for this is that existing studies do not triangulate insights from different methods and pay little attention to relevant context factors and especially causal pathways. By combining statistical approaches with systematic evidence from QCA and qualitative case studies in an innovative multi-method research design, we show that climate-related disasters increase the risk of armed conflict onset. This link is highly context-dependent and we find that countries with large populations, political exclusion of ethnic groups, and a low level of human development are particularly vulnerable. For such countries, almost one third of all conflict onsets over the 1980-2016 period have been preceded by a disaster within 7 days. The robustness of the effect is reduced for longer time spans. Case study evidence points to improved opportunity structures for armed groups rather than aggravated grievances as the main mechanism connecting disasters and conflict onset. [ABSTRACT FROM AUTHOR]
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- 2020
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226. Social tipping dynamics for stabilizing Earth's climate by 2050.
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Otto, Ilona M., Donges, Jonathan F., Bhowmik, Avit, Cremades, Roger, Lucht, Wolfgang, Rockström, Johan, Allerberger, Franziska, Doe, Sylvanus, Hewitt, Richard, Lenferna, Alex, McCaffrey, Mark, Moran, Nerea, van Vuuren, Detlef P., and Schellnhuber, Hans Joachim
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SOCIAL norms , *GREENHOUSE gas mitigation , *SOCIAL dynamics , *HUMAN settlements , *FOSSIL fuel subsidies , *CLIMATE change mitigation , *ABATEMENT (Atmospheric chemistry) , *CLIMATE change laws - Abstract
Safely achieving the goals of the Paris Climate Agreement requires a world-wide transformation to carbon-neutral societies within the next 30 years. Despite decades-long efforts in international negotiations, not much progress has been achieved and few are convinced that business-as-usual technological progress and gradual policy implementations will deliver emissions reductions at rates sufficiently fast to avoid crossing dangerous tipping points in the Earth's climate system. Here, we present historical, recent empirical and theoretical evidence supporting the potential of social tipping elements (STEs) as drivers of the required disruptive change. STEs are subdomains of the planetary socio-economic system where targeted policy interventions can activate contagious processes of rapid spreading of technologies, behaviors and social norms that can ultimately propel a sufficiently fast reduction in anthropogenic greenhouse gas emissions. We identify six outstanding candidates for STEs and their associated critical intervention points based on online expert elicitation, a subsequent expert workshop, and a literature review. These critical social tipping interventions include (i) removing fossil fuel subsidies and incentivizing distributed energy generation (STE1: energy production and storage systems), (ii) building carbon-neutral cities (STE2: human settlements), (iii) divestments from assets linked to fossil fuels (STE3: financial markets), (iv) revealing the moral implications of fossil fuels (STE4: norms and value systems), (v) strengthened climate education and engagement (STE5: education system) and (vi) greenhouse gas emissions information disclosure (STE6: information feedbacks). Larger-scale empirical and modelling efforts are needed to understand the potentials of STE dynamics and their role in climate change mitigation pathways in more detail. [ABSTRACT FROM AUTHOR]
- Published
- 2019
227. Earth system modeling with complex dynamic human societies: the copan:CORE World-Earth modeling framework.
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Donges, Jonathan F., Heitzig, Jobst, Barfuss, Wolfram, Kassel, Johannes A., Kittel, Tim, Kolb, Jakob J., Kolster, Till, Müller-Hansen, Finn, Otto, Ilona M., Wiedermann, Marc, Zimmerer, Kilian B., and Lucht, Wolfgang
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INTERDISCIPLINARY approach to knowledge , *PYTHON programming language , *EARTH system science , *OPEN source software , *MODULAR construction , *LIBRARY software , *GRID cells - Abstract
Analysis of Earth system dynamics in the Anthropocene requires to explicitly take into account the increasing magnitude of processes operating in human societies, their cultures, economies and technosphere and their growing entanglement with those in the physical, chemical and biological systems of the planet. This work (i) introduces design principles for constructing World-Earth models (WEM), i.e., models of social-ecological co-evolution on up to planetary scales, and (ii) presents the copan:CORE open source software library that provides a simulation modeling framework for developing, composing and running such WEMs based on the proposed principles. copan:CORE is an object-oriented software package currently implemented in Python. It provides components of meaningful yet minimal collections of closely related processes in the Earth System that can be plugged together in order to compose and run WEMs. Developers can supplement the already existing model components with additional components that are based on elementary entity types, e.g., grid cells, or fundamental process taxa, e.g., environment or culture. To illustrate the capabilities of the framework, this paper presents a WEM example implemented in copan:CORE that combines a variety of model components and interactions thereof. Due to its modular structure, the simulation modeling framework enhances the development and application of integrated models in Earth system science but also climatology, economics, ecology, or sociology, and allows combining them for interdisciplinary studies such as risk assessment including explicitly the dynamics of human behavior and decision making. [ABSTRACT FROM AUTHOR]
- Published
- 2019
228. Dynamics of interacting generalized tipping elements on complex networks.
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Krönke, Jonathan, Wunderling, Nico, Donges, Jonathan F., and Winkelmann, Ricarda
- Published
- 2019
229. Detecting impacts of extreme events with ecological in situ monitoring networks
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Mahecha, Miguel M., Gans, Fabian, Sippel, Sebastian, Donges, Jonathan F., Kaminski, Thomas, Metzger, Stefan, Migliavacca, Mirco, Papale, Dario, Rammig, Anja, and Zscheischler, Jakob
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13. Climate action ,15. Life on land - Abstract
Extreme hydrometeorological conditions typically impact ecophysiological processes on land. Satellite-based observations of the terrestrial biosphere provide an important reference for detecting and describing the spatiotemporal development of such events. However, in-depth investigations of ecological processes during extreme events require additional in situ observations. The question is whether the density of existing ecological in situ networks is sufficient for analysing the impact of extreme events, and what are expected event detection rates of ecological in situ networks of a given size. To assess these issues, we build a baseline of extreme reductions in the fraction of absorbed photosynthetically active radiation (FAPAR), identified by a new event detection method tailored to identify extremes of regional relevance. We then investigate the event detection success rates of hypothetical networks of varying sizes. Our results show that large extremes can be reliably detected with relatively small networks, but also reveal a linear decay of detection probabilities towards smaller extreme events in log–log space. For instance, networks with ≈ 100 randomly placed sites in Europe yield a ≥ 90 % chance of detecting the eight largest (typically very large) extreme events; but only a ≥ 50 % chance of capturing the 39 largest events. These findings are consistent with probability-theoretic considerations, but the slopes of the decay rates deviate due to temporal autocorrelation and the exact implementation of the extreme event detection algorithm. Using the examples of AmeriFlux and NEON, we then investigate to what degree ecological in situ networks can capture extreme events of a given size. Consistent with our theoretical considerations, we find that today's systematically designed networks (i.e. NEON) reliably detect the largest extremes, but that the extreme event detection rates are not higher than would be achieved by randomly designed networks. Spatio-temporal expansions of ecological in situ monitoring networks should carefully consider the size distribution characteristics of extreme events if the aim is also to monitor the impacts of such events in the terrestrial biosphere., Biogeosciences, 14 (18), ISSN:1726-4170
230. Coincidences of climate extremes and anomalous vegetation responses: comparing tree ring patterns to simulated productivity
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Rammig, Anja, Wiedermann, Marc, Donges, Jonathan F., Babst, Flurin, Bloh, Werner von, Frank, David Charles, Thonicke, Kirsten, and Mahecha, Miguel D.
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13. Climate action ,15. Life on land - Abstract
Climate extremes can trigger exceptional responses in terrestrial ecosystems, for instance by altering growth or mortality rates. Such effects are often manifested in reductions in net primary productivity (NPP). Investigating a Europe-wide network of annual radial tree growth records confirms this pattern: we find that 28% of tree ring width (TRW) indices are below two standard deviations in years in which extremely low precipitation, high temperatures or the combination of both noticeably affect tree growth. Based on these findings, we investigate possibilities for detecting climate-driven patterns in long-term TRW data to evaluate state-of-the-art dynamic vegetation models such as the Lund-Potsdam-Jena dynamic global vegetation model for managed land (LPJmL). The major problem in this context is that LPJmL simulates NPP but not explicitly the radial tree growth, and we need to develop a generic method to allow for a comparison between simulated and observed response patterns. We propose an analysis scheme that quantifies the coincidence rate of climate extremes with some biotic responses (here TRW or simulated NPP). We find a relative reduction of 34% in simulated NPP during precipitation, temperature and combined extremes. This reduction is comparable to the TRW response patterns, but the model responds much more sensitively to drought stress. We identify 10 extreme years during the 20th century during which both model and measurements indicate high coincidence rates across Europe. However, we detect substantial regional differences in simulated and observed responses to climatic extreme events. One explanation for this discrepancy could be the tendency of tree ring data to originate from climatically stressed sites. The difference between model and observed data is amplified by the fact that dynamic vegetation models are designed to simulate mean ecosystem responses on landscape or regional scales. We find that both simulation results and measurements display carry-over effects from climate anomalies during the previous year. We conclude that radial tree growth chronologies provide a suitable basis for generic model benchmarks. The broad application of coincidence analysis in generic model benchmarks along with an increased availability of representative long-term measurements and improved process-based models will refine projections of the long-term carbon balance in terrestrial ecosystems., Biogeosciences, 12 (2), ISSN:1726-4170
231. Non-linear regime shifts in Holocene Asian monsoon variability: potential impacts on cultural change and migratory patterns
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Donges, Jonathan F., Donner, Reik V., Marwan, Norbert, Breitenbach, Sebastian F.M., Rehfeld, Kira, and Kurths, Jürgen
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13. Climate action ,15. Life on land - Abstract
The Asian monsoon system is an important tipping element in Earth's climate with a large impact on human societies in the past and present. In light of the potentially severe impacts of present and future anthropogenic climate change on Asian hydrology, it is vital to understand the forcing mechanisms of past climatic regime shifts in the Asian monsoon domain. Here we use novel recurrence network analysis techniques for detecting episodes with pronounced non-linear changes in Holocene Asian monsoon dynamics recorded in speleothems from caves distributed throughout the major branches of the Asian monsoon system. A newly developed multi-proxy methodology explicitly considers dating uncertainties with the COPRA (COnstructing Proxy Records from Age models) approach and allows for detection of continental-scale regime shifts in the complexity of monsoon dynamics. Several epochs are characterised by non-linear regime shifts in Asian monsoon variability, including the periods around 8.5–7.9, 5.7–5.0, 4.1–3.7, and 3.0–2.4 ka BP. The timing of these regime shifts is consistent with known episodes of Holocene rapid climate change (RCC) and high-latitude Bond events. Additionally, we observe a previously rarely reported non-linear regime shift around 7.3 ka BP, a timing that matches the typical 1.0–1.5 ky return intervals of Bond events. A detailed review of previously suggested links between Holocene climatic changes in the Asian monsoon domain and the archaeological record indicates that, in addition to previously considered longer-term changes in mean monsoon intensity and other climatic parameters, regime shifts in monsoon complexity might have played an important role as drivers of migration, pronounced cultural changes, and the collapse of ancient human societies., Climate of the Past, 11 (5), ISSN:1814-9324, ISSN:1814-9332
232. A Dynamic Network Model of Societal Complexity and Resilience Inspired by Tainter's Theory of Collapse.
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Schunck, Florian, Wiedermann, Marc, Heitzig, Jobst, and Donges, Jonathan F.
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INTERNATIONAL economic relations , *DYNAMIC models , *SOCIAL mobility , *SOCIAL structure , *ECONOMIC equilibrium - Abstract
In recent years, several global events have severely disrupted economies and social structures, undermining confidence in the resilience of modern societies. Examples include the COVID-19 pandemic, which brought unprecedented health challenges and economic disruptions, and the emergence of geopolitical tensions and conflicts that have further strained international relations and economic stability. While empirical evidence on the dynamics and drivers of past societal collapse is mounting, a process-based understanding of these dynamics is still in its infancy. Here, we aim to identify and illustrate the underlying drivers of such societal instability or even collapse. The inspiration for this work is Joseph Tainter's theory of the "collapse of complex societies", which postulates that the complexity of societies increases as they solve problems, leading to diminishing returns on complexity investments and ultimately to collapse. In this work, we abstract this theory into a low-dimensional and stylized model of two classes of networked agents, hereafter referred to as "laborers" and "administrators". We numerically model the dynamics of societal complexity, measured as the fraction of "administrators", which was assumed to affect the productivity of connected energy-producing "laborers". We show that collapse becomes increasingly likely as the complexity of the model society continuously increases in response to external stresses that emulate Tainter's abstract notion of problems that societies must solve. We also provide an analytical approximation of the system's dominant dynamics, which matches well with the numerical experiments, and use it to study the influence on network link density, social mobility and productivity. Our work advances the understanding of social-ecological collapse and illustrates its potentially direct link to an ever-increasing societal complexity in response to external shocks or stresses via a self-reinforcing feedback. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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233. Evolution of the polycrisis: Anthropocene traps that challenge global sustainability.
- Author
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Søgaard Jørgensen, Peter, Jansen, Raf E. V., Avila Ortega, Daniel I., Wang-Erlandsson, Lan, Donges, Jonathan F., Österblom, Henrik, Olsson, Per, Nyström, Magnus, Lade, Steven J., Hahn, Thomas, Folke, Carl, Peterson, Garry D., and Crépin, Anne-Sophie
- Subjects
- *
SUSTAINABILITY , *WELL-being , *SOCIAL evolution , *ANIMAL navigation , *CONCEPT mapping - Abstract
The Anthropocene is characterized by accelerating change and global challenges of increasing complexity. Inspired by what some have called a polycrisis, we explore whether the human trajectory of increasing complexity and influence on the Earth system could become a form of trap for humanity. Based on an adaptation of the evolutionary traps concept to a global human context, we present results from a participatory mapping. We identify 14 traps and categorize them as either global, technology or structural traps. An assessment reveals that 12 traps (86%) could be in an advanced phase of trapping with high risk of hard-to-reverse lock-ins and growing risks of negative impacts on human well-being. Ten traps (71%) currently see growing trends in their indicators. Revealing the systemic nature of the polycrisis, we assess that Anthropocene traps often interact reinforcingly (45% of pairwise interactions), and rarely in a dampening fashion (3%). We end by discussing capacities that will be important for navigating these systemic challenges in pursuit of global sustainability. Doing so, we introduce evolvability as a unifying concept for such research between the sustainability and evolutionary sciences. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
234. A Thought Experiment on Sustainable Management of the Earth System.
- Author
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Heitzig, Jobst, Barfuss, Wolfram, and Donges, Jonathan F.
- Abstract
We introduce and analyze a simple formal thought experiment designed to reflect a qualitative decision dilemma humanity might currently face in view of anthropogenic climate change. In this exercise, each generation can choose between two options, either setting humanity on a pathway to certain high wellbeing after one generation of suffering, or leaving the next generation in the same state as the current one with the same options, but facing a continuous risk of permanent collapse. We analyze this abstract setup regarding the question of what the right choice would be both in a rationality-based framework including optimal control, welfare economics, and game theory, and by means of other approaches based on the notions of responsibility, safe operating spaces, and sustainability paradigms. Across these different approaches, we confirm the intuition that a focus on the long-term future makes the first option more attractive while a focus on equality across generations favors the second. Despite this, we generally find a large diversity and disagreement of assessments both between and within these different approaches, suggesting a strong dependence on the choice of the normative framework used. This implies that policy measures selected to achieve targets such as the United Nations Sustainable Development Goals can depend strongly on the normative framework applied and specific care needs to be taken with regard to the choice of such frameworks. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
235. Social tipping elements instrumental for decarbonization by 2050.
- Author
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Otto, Ilona M., Cremades, Roger, Donges, Jonathan F., Bhowmik, Avit K., Allerberger, Franziska, McCaffrey, Mark S., Lucht, Wolfgang, Cornell, Sarah, Rockstörm, Johan, and Schellnhuber, Hans Joachim
- Published
- 2018
236. Can Intensification of Cattle Ranching Reduce Deforestation in the Amazon? Insights From an Agent-based Social-Ecological Model.
- Author
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Müller-Hansen, Finn, Heitzig, Jobst, Donges, Jonathan F., Cardoso, Manoel F., Dalla-Nora, Eloi L., Andrade, Pedro, Kurths, Jürgen, and Thonicke, Kirsten
- Subjects
- *
RANCHING , *DEFORESTATION , *SOCIAL ecology , *SOCIAL learning , *LAND use - Abstract
Abstract Deforestation in the Amazon with its vast consequences for the ecosystem and climate is largely related to subsequent land use for cattle ranching. In addition to conservation policies, proposals to reduce deforestation include measures to intensify cattle ranching. However, the effects of land-use intensification on deforestation are debated in the literature. This paper introduces the abacra model, a stylized agent-based model to study the interplay of deforestation and the intensification of cattle ranching in the Brazilian Amazon. The model combines social learning and ecological processes with market dynamics. In the model, agents adopt either an extensive or semi-intensive strategy of cattle ranching based on the success of their neighbors. They earn their income by selling cattle on a stylized market. We present a comprehensive analysis of the model with statistical methods and find that it produces highly non-linear transient outcomes in dependence on key parameters like the rate of social interaction and elasticity of the cattle price. We show that under many environmental and economic conditions, intensification does not reduce deforestation rates and sometimes even has a detrimental effect on deforestation. Anti-deforestation policies incentivizing fast intensification can only lower deforestation rates under conditions in which the local cattle market saturates. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
237. Earth beyond six of nine planetary boundaries.
- Author
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Richardson, Katherine, Steffen, Will, Lucht, Wolfgang, Bendtsen, Jørgen, Cornell, Sarah E., Donges, Jonathan F., Drüke, Markus, Fetzer, Ingo, Bala, Govindasamy, Bloh, Werner von, Feulner, Georg, Fiedler, Stephanie, Gerten, Dieter, Gleeson, Tom, Hofmann, Matthias, Huiskamp, Willem, Kummu, Matti, Mohan, Chinchu, Nogués-Bravo, David, and Petri, Stefan
- Abstract
The article discusses the planetary boundaries framework, which identifies nine critical Earth system processes heavily impacted by human activities. The framework aims to establish limits on anthropogenic perturbations to maintain a "Holocene-like" interglacial state, similar to the stable and warm conditions of the past 10,000 years.
- Published
- 2023
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- View/download PDF
238. Resilience basins of complex systems: An application to prosumer impacts on power grids.
- Author
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Bien, Samuel, Schultz, Paul, Heitzig, Jobst, and Donges, Jonathan F.
- Subjects
- *
ELECTRIC power distribution grids , *ELECTRIC lines , *ELECTRICAL load , *BUDGET , *SYSTEM dynamics - Abstract
Comparable to the traditional notion of stability in system dynamics, resilience is typically measured in a way that assesses the quality of a system's response, for example, the speed of its recovery. We present a broadly applicable complementary measurement framework that quantifies resilience similarly to basin stability by estimating a resilience basin, which reflects the extent of adverse influences that the system can recover from in a sufficient manner. In contrast to basin stability, the adverse influences considered here are not necessarily displacements in state space, but arbitrarily complex impacts to the system, quantified by adequate parameters. As a proof of concept, we present two applications: (i) the well-studied single-node power system as an easy-to-follow example and (ii) a stochastic model of a low-voltage DC power grid undergoing an unregulated energy transition consisting in the random appearance of prosumers. These act as decentral suppliers of photovoltaic power and alter the flow patterns while the grid topology remains unchanged. The resilience measurement framework is applied to evaluate the effect and efficiency of two response options: (i) upgrading the capacity of existing power lines and (ii) installing batteries in the prosumer households. The framework demonstrates that line upgrades can provide potentially unlimited resilience against energy decentralization, while household batteries are inherently limited (achieving ≤ 70 % of the resilience of line upgrades). Further, the framework aids in optimizing budget efficiency by pointing toward threshold budget values as well as budget-dependent ideal strategies for the allocation of line upgrades and for the battery charging algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
239. Using Causal Effect Networks to Analyze Different Arctic Drivers of Midlatitude Winter Circulation.
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Kretschmer, Marlene, Coumou, Dim, Donges, Jonathan F., and Runge, Jakob
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- *
TROPOSPHERIC circulation , *WINTER , *ARCTIC oscillation , *SNOW cover , *SEA level - Abstract
In recent years, the Northern Hemisphere midlatitudes have suffered from severe winters like the extreme 2012/13 winter in the eastern United States. These cold spells were linked to a meandering upper-tropospheric jet stream pattern and a negative Arctic Oscillation index (AO). However, the nature of the drivers behind these circulation patterns remains controversial. Various studies have proposed different mechanisms related to changes in the Arctic, most of them related to a reduction in sea ice concentrations or increasing Eurasian snow cover. Here, a novel type of time series analysis, called causal effect networks (CEN), based on graphical models is introduced to assess causal relationships and their time delays between different processes. The effect of different Arctic actors on winter circulation on weekly to monthly time scales is studied, and robust network patterns are found. Barents and Kara sea ice concentrations are detected to be important external drivers of the midlatitude circulation, influencing winter AO via tropospheric mechanisms and through processes involving the stratosphere. Eurasia snow cover is also detected to have a causal effect on sea level pressure in Asia, but its exact role on AO remains unclear. The CEN approach presented in this study overcomes some difficulties in interpreting correlation analyses, complements model experiments for testing hypotheses involving teleconnections, and can be used to assess their validity. The findings confirm that sea ice concentrations in autumn in the Barents and Kara Seas are an important driver of winter circulation in the midlatitudes. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
240. Recurrent droughts increase risk of cascading tipping events by outpacing adaptive capacities in the Amazon rainforest.
- Author
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Wunderling, Nico, Staal, Arie, Sakschewski, Boris, Hirota, Marina, Tuinenburg, Obbe A., Donges, Jonathan F., Barbosa, Henrique M. J., and Winkelmann, Ricarda
- Subjects
- *
DROUGHTS , *RAIN forests , *HUMIDITY , *CLIMATE change , *DYNAMIC models - Abstract
Tipping elements are nonlinear subsystems of the Earth system that have the potential to abruptly shift to another state if environmental change occurs close to a critical threshold with large consequences for human societies and ecosystems. Among these tipping elements may be the Amazon rainforest, which has been undergoing intensive anthropogenic activities and increasingly frequent droughts. Here, we assess how extreme deviations fromclimatological rainfall regimes may cause local forest collapse that cascades through the coupled forest-climate system. We develop a conceptual dynamic network model to isolate and uncover the role of atmospheric moisture recycling in such tipping cascades. We account for heterogeneity in critical thresholds of the forest caused by adaptation to local climatic conditions. Our results reveal that, despite this adaptation, a future climate characterized by permanent drought conditions could trigger a transition to an open canopy state particularly in the southern Amazon. Theloss of atmospheric moisture recycling contributes to one-third of the tipping events. Thus, by exceeding local thresholds in forest adaptive capacity, local climate change impacts may propagate to other regions of the Amazon basin, causing a risk of forest shifts even in regions where critical thresholds have not been crossed locally. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
241. Detecting contagious spreading of urban innovations on the global city network.
- Author
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Kitzmann, Niklas H., Romanczuk, Pawel, Wunderling, Nico, and Donges, Jonathan F.
- Subjects
- *
SUSTAINABILITY , *BUS rapid transit , *PUBLIC transit , *TECHNOLOGICAL innovations - Abstract
Only a fast and global transformation towards decarbonization and sustainability can keep the Earth in a civilization-friendly state. As hotspots for (green) innovation and experimentation, cities could play an important role in this transition. They are also known to profit from each other's ideas, with policy and technology innovations spreading to other cities. In this way, cities can be conceptualized as nodes in a globe-spanning learning network. The dynamics of this process are important for society's response to climate change and other challenges, but remain poorly understood on a macroscopic level. In this contribution, we develop an approach to identify whether network-based complex contagion effects are a feature of sustainability policy adoption by cities, based on dose-response contagion and surrogate data models. We apply this methodology to an exemplary data set, comprising empirical data on the spreading of a public transport innovation (Bus Rapid Transit Systems) and a global inter-city connection network based on scheduled flight routes. Although our approach is not able to identify detailed mechanisms, our results point towards a contagious spreading process, and cannot be explained by either the network structure or the increase in global adoption rate alone. Further research on the role of a city's abstract "global neighborhood" regarding its policy and innovation decisions is thus both needed and promising, and may connect with research on social tipping processes. The methodology is generic, and can be used to compare the predictive power for innovation spreading of different kinds of inter-city network connections, e.g. via transport links, trade, or co-membership in political networks. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
242. Modelling nonlinear dynamics of interacting tipping elements on complex networks: the PyCascades package.
- Author
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Wunderling, Nico, Krönke, Jonathan, Wohlfarth, Valentin, Kohler, Jan, Heitzig, Jobst, Staal, Arie, Willner, Sven, Winkelmann, Ricarda, and Donges, Jonathan F.
- Subjects
- *
PYTHON programming language , *OPEN source software , *INTEGRATED software , *DYNAMICAL systems , *APPLICATION software , *STOCHASTIC systems - Abstract
Tipping elements occur in various systems such as in socio-economics, ecology and the climate system. In many cases, the individual tipping elements are not independent of each other, but they interact across scales in time and space. To model systems of interacting tipping elements, we here introduce the PyCascades open source software package for studying interacting tipping elements (https://doi.org/10.5281/zenodo.4153102). PyCascades is an object-oriented and easily extendable package written in the programming language Python. It allows for investigating under which conditions potentially dangerous cascades can emerge between interacting dynamical systems, with a focus on tipping elements. With PyCascades it is possible to use different types of tipping elements such as double-fold and Hopf types and interactions between them. PyCascades can be applied to arbitrary complex network structures and has recently been extended to stochastic dynamical systems. This paper provides an overview of the functionality of PyCascades by introducing the basic concepts and the methodology behind it. In the end, three examples are discussed, showing three different applications of the software package. First, the moisture recycling network of the Amazon rainforest is investigated. Second, a model of interacting Earth system tipping elements is discussed. And third, the PyCascades modelling framework is applied to a global trade network. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
243. Stewardship of global collective behavior.
- Author
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Bak-Coleman, Joseph B., Alfano, Mark, Barfuss, Wolfram, Bergstrom, Carl T., Centeno, Miguel A., Couzin, Iain D., Donges, Jonathan F., Galesic, Mirta, Gersick, Andrew S., Jacquet, Jennifer, Kao, Albert B., Moran, Rachel E., Romanczuk, Pawel, Rubenstein, Daniel I., Tombak, Kaia J., Van Bavel, Jay J., and Weber, Elke U.
- Subjects
- *
COLLECTIVE behavior , *SOCIAL systems , *CLIMATOLOGY , *TELECOMMUNICATION , *NATURAL selection - Abstract
Collective behavior provides a framework for understanding how the actions and properties of groups emerge from the way individuals generate and share information. In humans, information flows were initially shaped by natural selection yet are increasingly structured by emerging communication technologies. Our larger, more complex social networks now transfer high-fidelity information over vast distances at low cost. The digital age and the rise of social media have accelerated changes to our social systems, with poorly understood functional consequences. This gap in our knowledge represents a principal challenge to scientific progress, democracy, and actions to address global crises. We argue that the study of collective behavior must rise to a "crisis discipline" just as medicine, conservation, and climate science have, with a focus on providing actionable insight to policymakers and regulators for the stewardship of social systems. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
244. A network-based microfoundation of Granovetter's threshold model for social tipping.
- Author
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Wiedermann, Marc, Smith, E. Keith, Heitzig, Jobst, and Donges, Jonathan F.
- Subjects
- *
SOCIAL movements , *SOCIAL interaction , *COLLECTIVE behavior , *BIFURCATION theory , *HYSTERESIS - Abstract
Social tipping, where minorities trigger larger populations to engage in collective action, has been suggested as one key aspect in addressing contemporary global challenges. Here, we refine Granovetter's widely acknowledged theoretical threshold model of collective behavior as a numerical modelling tool for understanding social tipping processes and resolve issues that so far have hindered such applications. Based on real-world observations and social movement theory, we group the population into certain or potential actors, such that – in contrast to its original formulation – the model predicts non-trivial final shares of acting individuals. Then, we use a network cascade model to explain and analytically derive that previously hypothesized broad threshold distributions emerge if individuals become active via social interaction. Thus, through intuitive parameters and low dimensionality our refined model is adaptable to explain the likelihood of engaging in collective behavior where social-tipping-like processes emerge as saddle-node bifurcations and hysteresis. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
245. Complex network approaches to nonlinear time series analysis.
- Author
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Zou, Yong, Donner, Reik V., Marwan, Norbert, Donges, Jonathan F., and Kurths, Jürgen
- Subjects
- *
TIME series analysis , *NONLINEAR analysis , *MARKOV processes , *FLUID dynamics , *NEUROPHYSIOLOGY - Abstract
Abstract In the last decade, there has been a growing body of literature addressing the utilization of complex network methods for the characterization of dynamical systems based on time series. While both nonlinear time series analysis and complex network theory are widely considered to be established fields of complex systems sciences with strong links to nonlinear dynamics and statistical physics, the thorough combination of both approaches has become an active field of nonlinear time series analysis, which has allowed addressing fundamental questions regarding the structural organization of nonlinear dynamics as well as the successful treatment of a variety of applications from a broad range of disciplines. In this report, we provide an in-depth review of existing approaches of time series networks, covering their methodological foundations, interpretation and practical considerations with an emphasis on recent developments. After a brief outline of the state-of-the-art of nonlinear time series analysis and the theory of complex networks, we focus on three main network approaches, namely, phase space based recurrence networks, visibility graphs and Markov chain based transition networks, all of which have made their way from abstract concepts to widely used methodologies. These three concepts, as well as several variants thereof will be discussed in great detail regarding their specific properties, potentials and limitations. More importantly, we emphasize which fundamental new insights complex network approaches bring into the field of nonlinear time series analysis. In addition, we summarize examples from the wide range of recent applications of these methods, covering rather diverse fields like climatology, fluid dynamics, neurophysiology, engineering and economics, and demonstrating the great potentials of time series networks for tackling real-world contemporary scientific problems. The overall aim of this report is to provide the readers with the knowledge how the complex network approaches can be applied to their own field of real-world time series analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
246. Trajectories of the Earth System in the Anthropocene.
- Author
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Steffen, Will, Rockström, Johan, Richardson, Katherine, Lenton, Timothy M., Folke, Carl, Liverman, Diana, Summerhayes, Colin P., Barnosky, Anthony D., Cornell, Sarah E., Crucifix, Michel, Donges, Jonathan F., Fetzer, Ingo, Lade, Steven J., Scheffer, Marten, Winkelmann, Ricarda, and Schellnhuber, Hans Joachim
- Subjects
- *
GLOBAL warming , *BIOSPHERE , *GLOBAL temperature changes , *CLIMATOLOGY , *TECHNOLOGICAL innovations - Abstract
We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a "Hothouse Earth" pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System--biosphere, climate, and societies--and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
247. Human agency in the Anthropocene.
- Author
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Otto, Ilona M., Wiedermann, Marc, Cremades, Roger, Donges, Jonathan F., Auer, Cornelia, and Lucht, Wolfgang
- Subjects
- *
GLOBAL modeling systems , *ANTHROPOCENE Epoch - Abstract
The human species has been recognized as a new force that has pushed the Earth's system into a new geological epoch referred to as the Anthropocene. This human influence was not conscious, however, but an unintended effect of the consumption of fossil-fuels over the last 150 years. Do we, humans, have the agency to deliberately influence the fate of our species and the planet we inhabit? The rational choice paradigm that dominated social sciences in the 20th Century, and has heavily influenced the conceptualization of human societies in global human-environmental system modelling in the early 21st Century, suggests a very limited view of human agency. Humans seen as rational agents, coordinated through market forces, have only a very weak influence on the system rules. In this article we explore alternative concepts of human agency that emphasize its collective and strategic dimensions as well as we ask how human agency is distributed within the society. We also explore the concept of social structure as a manifestation of, and a constraint on, human agency. We discuss the implications for conceptualization of human agency in integrated assessment modelling efforts. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
248. Achieving net zero greenhouse gas emissions critical to limit climate tipping risks.
- Author
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Möller T, Högner AE, Schleussner CF, Bien S, Kitzmann NH, Lamboll RD, Rogelj J, Donges JF, Rockström J, and Wunderling N
- Abstract
Under current emission trajectories, temporarily overshooting the Paris global warming limit of 1.5 °C is a distinct possibility. Permanently exceeding this limit would substantially increase the probability of triggering climate tipping elements. Here, we investigate the tipping risks associated with several policy-relevant future emission scenarios, using a stylised Earth system model of four interconnected climate tipping elements. We show that following current policies this century would commit to a 45% tipping risk by 2300 (median, 10-90% range: 23-71%), even if temperatures are brought back to below 1.5 °C. We find that tipping risk by 2300 increases with every additional 0.1 °C of overshoot above 1.5 °C and strongly accelerates for peak warming above 2.0 °C. Achieving and maintaining at least net zero greenhouse gas emissions by 2100 is paramount to minimise tipping risk in the long term. Our results underscore that stringent emission reductions in the current decade are critical for planetary stability., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
249. The microdynamics of spatial polarization: A model and an application to survey data from Ukraine.
- Author
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Chu OJ, Donges JF, Robertson GB, and Pop-Eleches G
- Abstract
Although spatial polarization of attitudes is extremely common around the world, we understand little about the mechanisms through which polarization on divisive issues rises and falls over time. We develop a theory that explains how political shocks can have different effects in different regions of a country depending upon local dynamics generated by the preexisting spatial distribution of attitudes and discussion networks. Where opinions were previously divided, attitudinal diversity is likely to persist after the shock. Meanwhile, where a clear precrisis majority exists on key issues, opinions should change in the direction of the predominant view. These dynamics result in greater local homogeneity in attitudes but at the same time exacerbate geographic polarization across regions and sometimes even within regions. We illustrate our theory by developing a modified version of the adaptive voter model, an adaptive network model of opinion dynamics, to study changes in attitudes toward the European Union (EU) in Ukraine in the context of the Euromaidan Revolution of 2013 to 2014. Using individual-level panel data from surveys fielded before and after the Euromaidan Revolution, we show that EU support increased in areas with high prior public support for EU integration but declined further where initial public attitudes were opposed to the EU, thereby increasing the spatial polarization of EU attitudes in Ukraine. Our tests suggest that the predictive power of both network and regression models increases significantly when we incorporate information about the geographic location of network participants, which highlights the importance of spatially rooted social networks., Competing Interests: The authors declare no competing interest.
- Published
- 2021
- Full Text
- View/download PDF
250. Global warming due to loss of large ice masses and Arctic summer sea ice.
- Author
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Wunderling N, Willeit M, Donges JF, and Winkelmann R
- Abstract
Several large-scale cryosphere elements such as the Arctic summer sea ice, the mountain glaciers, the Greenland and West Antarctic Ice Sheet have changed substantially during the last century due to anthropogenic global warming. However, the impacts of their possible future disintegration on global mean temperature (GMT) and climate feedbacks have not yet been comprehensively evaluated. Here, we quantify this response using an Earth system model of intermediate complexity. Overall, we find a median additional global warming of 0.43 °C (interquartile range: 0.39-0.46 °C) at a CO
2 concentration of 400 ppm. Most of this response (55%) is caused by albedo changes, but lapse rate together with water vapour (30%) and cloud feedbacks (15%) also contribute significantly. While a decay of the ice sheets would occur on centennial to millennial time scales, the Arctic might become ice-free during summer within the 21st century. Our findings imply an additional increase of the GMT on intermediate to long time scales.- Published
- 2020
- Full Text
- View/download PDF
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