The planetary boundaries framework emerges from Earth system science and was developed to help guide the global community in its efforts to manage Anthroposphere interactions with the Earth’s bio-physical components. In the third iteration of the framework, PB3.0 (September 2023), six of the nine boundaries are found to be transgressed and anthropogenic pressure is increasing on all the boundaries earlier found to be exceeded. Metrics are, for the first time, proposed for all boundaries. Human Appropriation of Net Primary Production is proposed as the control variable for the function of the biosphere as photosynthesis represents the energy input supporting almost all life. The probability of achieving global climate goals is argued to be closely linked to the fate of global forests. Thus, the climate and biodiversity crises must be addressed together. Directions for the framework’s further development are discussed.

How to cite: Richardson, K., Steffen, W., and Lucht, W. and the PB3.0-Team: The Planetary Boundaries Framework: Status (“PB3.0”), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19347, https://doi.org/10.5194/egusphere-egu24-19347, 2024.

While Planetary Boundary science has advanced tremendously over the past decades, we still lack a deep understanding of the intricate, yet pivotal connections between many biological and physical functions of the Earth system. This is of grave concern, since the stability of the planet and interactions between its components are the foundation of human civilization. Moreover, as it stands, science only has the resources to measure and analyze the planet’s vital signs every 6-8 years (Rockström et al. 2009, Steffen et al. 2015, Richardson et al., 2003), and our imperfect measurement framework has some worrying blind spots.
To address these challenges, the Potsdam Institute for Climate Impact Research and its partners are launching a major scientific effort to close the knowledge gaps, both in terms of our ability to model how the Earth system evolves under the pressure of human activity, as well as our ability to measure the state of the Earth system with high temporal resolution. This will culminate in an annual Planetary Boundary (PB) Health Check, conceived and reviewed by a diverse international scientific and stakeholder community. Employing cutting-edge Earth-system and tipping-point modelling, ambitious whole-Earth monitoring, and exploring artificial-intelligence-based big-data analytics, the Health Check shall offer a comprehensive, timely, and unparalleled assessment of the planet's health. With yearly updates of PB transgressions at its core, the Health Check will further develop the boundary measures themselves and provide important context, e.g. via case studies and policy implications.  It will reveal current risks due to ongoing transgression of PBs and develop transformation pathways to guide global development back to Earth’s safe operating space. Besides peer-reviewed publications, these results will be communicated to the public using state-of-the-art visualizations and communication partnerships.

In this presentation we will give details about this new science initiative, the partners we work with, out short and long-term goals and give an overview of involvement opportunities in this rapidly growing project.

References

Rockström, J., Steffen, W., Noone, K. et al. A safe operating space for humanity. Nature 461, 472–475 (2009). https://doi.org/10.1038/461472a
Steffen, W. et al. ,Planetary boundaries: Guiding human development on a changing planet.Science347,1259855(2015).DOI:10.1126/science.1259855 
Richardson, K. et al., Earth beyond six of nine planetary boundaries.Sci. Adv.9,eadh2458(2023).DOI:10.1126/sciadv.adh2458

How to cite: Caesar, L., Kitzmann, N., and Rockström, J.: Advancing Planetary Boundary Science, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15269, https://doi.org/10.5194/egusphere-egu24-15269, 2024.

The recent third planetary boundary (PB) assessment replaced the original PB for ‘freshwater use’ with a new PB for ‘freshwater change’. The new PB is defined by the percentage of global land area experiencing streamflow (blue water component of the PB) and root-zone soil moisture (green water) deviations from pre-industrial baseline conditions. Here, we first present the spatiotemporally explicit results of the comprehensive analysis underlying the new PB, and then discuss possible applications of the approach and the challenges related to providing meaningful guidance for water management and policy across scales.

We find a clear transgression of both the blue and green water components of the freshwater change PB already during the first half of the 20th century. Our spatiotemporally explicit analysis reveals a general pattern of drying across a significant portion of the tropics and subtropics, contrasting with wetting in temperate and subpolar regions as well as numerous highland areas. This overall pattern is likely attributed to alterations in precipitation patterns associated with global warming. Significant increases in streamflow and soil moisture deviations are also found in regions facing the highest direct human pressures, such as irrigation, flow regulation, and land use change. In many cases, both streamflow and soil moisture deviations have increased – underlining the influence of human impacts on the freshwater cycle as a whole.

While our analysis highlights regions undergoing the most substantial freshwater changes and their potential drivers, using the results to guide water policy and management remains challenging. Key knowledge gaps include our limited understanding of the (quantitative) driver–freshwater change–Earth system response relationships, and the mismatches between spatiotemporal scales of 1) human drivers of freshwater change, 2) the Earth system impacts of freshwater change, and 3) water management and governance institutions. We conclude our presentation by proposing a research agenda to bridge these gaps, with a goal to provide policy-relevant information on freshwater change that would enable a stronger adoption of an  Earth system perspective in water management and governance.

How to cite: Porkka, M., Virkki, V., Wang-Erlandsson, L., and Kummu, M.: The new planetary boundary for freshwater change: key findings and their potential to guide water management and policy, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19383, https://doi.org/10.5194/egusphere-egu24-19383, 2024.

In the recent update of the Planetary Boundaries framework, Richardson et al. propose to use human appropriation of net primary productivity (HANPP) as a new indicator for the functional biosphere integrity boundary. They provide a planetary scale analysis and suggest to further complement this by an ecological metric.

To aid with the spatially explicit analysis of both HANPP and an ecological metric in an automated and easy way, we developed the "biospheremetrics" R package. The package combines 2 complementary metrics:

The BioCol metric operationalizes the HANPP framework in order to represent a meaningful Planetary Boundary indicator, and is accompanied by the EcoRisk metric, which quantifies biogeochemical and vegetation structural changes as a proxy for the risk of ecosystem destabilization. Both metrics are computable in a dynamic global vegetation modelling framework.

We spatially explicitly analyse both metrics over the past 500 years with simulations of the dynamic global vegetation model LPJmL and find that presently (period 2007-2016), large regions show modification and extraction of >25% of the preindustrial potential net primary production, leading to drastic alterations in key ecosystem properties and suggesting a high risk for ecosystem destabilization. In consequence of these dynamics, EcoRisk shows particularly high values in regions with intense land use and deforestation, but also in regions prone to impacts of climate change such as the arctic and boreal zone.

We additionally show how both metrics could be combined to inform the Planetary Boundary of functional biosphere integrity, compare our results with other spatially explicit global biosphere integrity metrics and discuss the setting of (provisional) thresholds.

How to cite: Stenzel, F., Breier, J., Braun, J., Erb, K., Gerten, D., Matej, S., Haberl, H., Ostberg, S., Roux, N., Schaphoff, S., and Lucht, W.: Using biosphere metrics to assess the Planetary boundary for functional biosphere integrity, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13292, https://doi.org/10.5194/egusphere-egu24-13292, 2024.

As the world’s population grows at unprecedented rates, planetary-scale environmental forcing by humankind continues to push Earth system components out of the equilibrium state. The planetary boundaries framework provides an elegant and comprehensive tool to estimate the extent to which nine key processes of human-induced biosphere alteration affect the stability and resilience of Earth system. Yet quantifying planetary boundaries and especially the interactions between them, based on a process-based understanding of ecosystem functioning, remains a great challenge, as observations and experimentation in natural ecosystems typically provide only a narrow snapshot of a process in question. While conventional controlled environment facilities, such as growth chambers and advanced greenhouses provide a standard tool to simulate environmental change and disentangle processes controlling ecosystem functioning, the capacity of such systems to provide realistic quantifications of ecosystem tipping point is limited, due to (1) a typical focus on a single environmental change process, and (2) a use of simplified, small scale experimental ecosystems. In contrast, novel state-of-the-art terrestrial and aquatic Ecotron research facilities enable both (1) simulation of a wide range of natural environmental conditions, employing  highly realistic scenarios of environmental change, as well as (2) operating with natural ecosystems in their full complexity in replicated design.  An important advantage of ecotrons is a possibility of obtaining long-term (years to decennia scale) and high resolution (minutes-to-days) time series of continues observations of multiple ecosystem functions and their drivers, allowing to infer relations between those in a process-based manner. These advantages are increasingly acknowledged by the scientific community, as having a great potential to help obtaining experimental data to quantify the ecosystem tipping points, accounting for interactions between multiple forces driving planetary boundaries. I will discuss the framework of using a European network of Ecotrons and Ecotorn-like systems within AnaEE ERIC (Analysis and Experimentation on Ecosystems European Research Infrastructure Consortium) in the context of quantification of planetary boundaries, and will present a suit of a case studies illustrating assessments of cascading effects of land use change and climate change on ecosystem integrity, terrestrial above and belowground biodiversity, terrestrial and oceanic biogeochemical cycles, and soil moisture regime. I aim to inspire a discussion about new avenues in assessment of planetary boundary levels based on high throughput experimental and observational data obtained in ecotron-like experimental facilities.

How to cite: Soudzilovskaia, N., Rineau, F., Schoelynck, J., De Boek, H., and Nijs, I.: Using Ecotron experimentation to quantify planetary boundaries, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20293, https://doi.org/10.5194/egusphere-egu24-20293, 2024.

To date, statues and trajectories of planetary boundaries have mostly been investigated separately, without fully quantifying if and to what extent transgression of one or more boundaries affects the status of respective others. To address this research gap, we have configured the state-of-the-art LPJmL Dynamic Global Vegetation Model so as to represent the terrestrial planetary boundaries (for land-system change, biosphere integrity, freshwater change, and biogeochemical/nitrogen flows) in an internally consistent, process-based framework. As the model simulates these boundaries’ underlying processes and control variables in a spatially explicit and dynamic manner, and as it also accounts for effects of climate change (a fifth planetary boundary considered through external forcing), it enables systematic studies of interactive effects among any of the five boundaries considered.

In a scenario study focused on here, we employed the model to systematically quantify the effects of different transgression levels of the climate change boundary (using gridded climate output from ten CMIP6 models for distinct atmospheric CO2 levels from 350 ppm to 1000 ppm) upon the land-system change boundary (areal extent of temperate, boreal and tropical forest biomes). Changes are analysed both by the end of this century and, to account for long-term legacy effects, by the end of the millennium, respectively. The simulations indicate that staying within the 350 ppm climate change boundary would stabilize the land-system change boundary, not inducing notable expansions or contractions of forest biome extent (on top of the historical shifts that have been brought about by anthropogenic deforestation). However, transgressing the climate change boundary beyond its zone of increasing risk (>450 ppm) is simulated to lead to increasingly substantial forest biome shifts, the higher the ppm level rises and the more time passes. Specifically, this involves a poleward tree-line shift, boreal forest dieback, expansion of temperate forest into today’s boreal zone, and a slight tropical forest expansion.

We furthermore find that these one-way interactions imply changes of the status of other planetary boundaries as well, as shifts in their control variables (e.g. large soil moisture and runoff anomalies) are simulated for the very areas where the forest biome shifts occur. Moreover, the vegetation changes are likely to provide feedback to the climate change boundary itself.

In additional simulations (making use of a planetary boundary simulation package linked to the LPJmL model), we investigate the historical evolution of the terrestrial planetary boundaries’ statuses during the past century. This examination suggests that the timing and spatial location of transgressions differs strongly among boundaries, with multiple boundaries crossed in the late 20th century, and transgression of the climate change boundary gaining increasing impact. Possible cascading and compound effects of these simultaneous transgressions, and particularly their likely aggravation in the future, require comprehensive analyses in further studies.

How to cite: Gerten, D., Tobian, A., Braun, J., Breier, J., and Stenzel, F.: Transgression of the climate change planetary boundary critically affects the status of other boundaries, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17216, https://doi.org/10.5194/egusphere-egu24-17216, 2024.

The analysis of global catastrophic events often occurs in isolation, simplifying their study. In reality, risks cascade and interact. Therefore, it is essential to consider the interconnected nature of global risks. This investigation explores the interplay between nuclear winter and planetary boundaries. It may seem reasonable to assume that respecting planetary boundaries, which define a safe operating space for the planet, is preferable before a nuclear war. However, that does not always seem to be the case. For instance, increased nitrogen emissions today could serve as a nutrient buffer during nuclear winter. Contrastingly, mitigating climate change, means an even larger temperature drop in nuclear winter in comparison with pre-industrial times. This exploratory study also highlights planetary boundaries that could enhance human survival if we adhere to their limits, both presently and after a nuclear war. The best example being biosphere integrity, as conserving it has no direct downsides and would make the Earth system more resilient to resist the shock of a nuclear winter.

How to cite: Jehn, F. U.: Anthropocene Under Dark Skies: The Compounding Effects of Nuclear Winter and Overstepped Planetary Boundaries, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2773, https://doi.org/10.5194/egusphere-egu24-2773, 2024.

How to cite: Lade, S. and the Earth Commission: Safe and just Earth system boundaries, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21091, https://doi.org/10.5194/egusphere-egu24-21091, 2024.

With ongoing anthropogenic emissions and ensuing accelerated climate change, the planet is increasingly leaving its long-stable Holocene state. In fact, recent assessments have shown that a range of climate tipping points are at risk of being crossed at warming levels well within temperature projections of the 21st century. However, such assessments have been largely based on expert judgement of scattered literature, with corresponding large uncertainties in critical thresholds and potential tipping dynamics. The Tipping Point Modelling Intercomparison Project (TIPMIP, www.tipmip.org) aims to close this research gap through a standardised framework for numerical experiments exploring tipping across systems and models. Built on precursory experiments, we here introduce the Tipping and Other Abrupt Events Detector (TOAD) method, to automatically identify spatial clusters of dynamically connected regions exhibiting tipping dynamics. This will serve as an evaluation scheme for the suite of experiments generated within the TIPMIP protocol. Overall, this systematic approach to tipping point risks at different levels of human pressures can inform quantification of planetary or Earth system boundaries to map out the safe and just operating space for humanity in the Anthropocene.

How to cite: Loriani, S., Dennis, D., Donges, J., Sakschewski, B., and Winkelmann, R.:  Systematic detection of abrupt change and tipping points in TIPMIP , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19468, https://doi.org/10.5194/egusphere-egu24-19468, 2024.

The Atlantic Meridional Overturning Circulation (AMOC) is a crucial part of the climate system that carries warm and saline water towards the northern Atlantic and is an important component in the global meridional heat transport. However, the AMOC is a so-called “tipping element”: there is observational evidence that it is in a bistable regime and may thus collapse under anthropogenic greenhouse gas emissions. Bi-stability has also been found in a hierarchy of models, from a simple two-box model up to a CMIP5 global climate model (CESM1). Considering a possible upcoming tipping, it is critical to assess how likely the AMOC is to undergo a collapse under different greenhouse gas forcing scenarios.  This issue is tightly related to the notion of resilience, which refers to the ability of a system to sustain a certain forcing while remaining in its original state or to return to its original state after being displaced.

Studying the resilience of the AMOC requires to observe its collapse, which is very difficult due to its rarity, especially in very complex models. That is why we use a rare-event algorithm called Transition-Adaptive Multilevel Splitting (TAMS). Given a certain definition of the current-day and collapsed AMOC, TAMS pushes trajectories in the direction of a collapse at a much lower cost than Monte-Carlo simulations. This method outputs typical collapse trajectories starting from a present-day AMOC, under a certain chosen hosing flux. This process is repeated for a wide range of freshwater forcings. From those trajectories, we extract observables (e.g. the AMOC strength), which are scalar functions that are interpreted as resilience observables. By monitoring these observables, we can rank different climate change scenarios depending on the risks they impose on the AMOC. Moreover, we relate these observables to existing mathematical definitions of resilience. Finally, we determine which observables are best suited to describe the resilience of the  AMOC, with a focus on those that can be measured in the field.

How to cite: Jacques-Dumas, V., Kühn, C., and Dijkstra, H. A.: Resilience of the AMOC, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4134, https://doi.org/10.5194/egusphere-egu24-4134, 2024.

All climate models project a weakening of the Atlantic Meridional Overturning Circulation (AMOC) strength in response to greenhouse gas forcing. However, the climate impacts of the AMOC decline in relation to other drivers of climate change, cannot be assessed from existing Coupled Model Intercomparison Project (CMIP) simulations. To address this issue, we conduct idealized experiments using the EC-Earth3 climate model. We compare an abrupt 4xCO2 simulation with an identical one, except we artificially fix the AMOC strength at preindustrial levels. With this design, we can formally attribute differences in climate change impacts between these two experiments to the AMOC decline. In addition, we quantify the state-dependence of AMOC impacts by comparing the aforementioned experiments with a preindustrial simulation in which we artificially reduce the AMOC strength. Our findings demonstrate that AMOC decline impacts are state-dependent, thus understanding AMOC impacts on future climate change requires targeted model experiments.

How to cite: von Hardenberg, J., Bellomo, K., and Mehling, O.: Impacts and state-dependence of AMOC weakening in a warming climate, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18673, https://doi.org/10.5194/egusphere-egu24-18673, 2024.

The climate of the Pleistocene is characterized by alternating cold (glacial) and warm (interglacial) periods. This cyclicity is mainly caused by the so-called Milankovitch cycles as a result of periodic changes in Earth’s orbital parameters. Many models have already successfully captured the non-linearities of the climate-cryosphere system responsible for the 100 kyrs cycles and the Mid-Pleistocene transition. However, these models widely differ in the number of explicit physical processes included and in the degree of complexity to solve them (from purely conceptual to Earth-system models). 

In this talk I will present a simple a-dimensional model that sequentially includes ice-sheet dynamics, ice aging and climate-cryosphere feedbacks. This model is able to capture the timing and shape of glacial cycles of the last 2 million years and can also be used to predict future glacial inceptions and thus the duration of the Anthropocene. Following different assumptions of human greenhouse gas emissions, I will show the expected timing of future glacial inceptions as well as the periodicities of the late Anthropocene glacial cycles.

How to cite: Alvarez-Solas, J.: Simulating glacial cycles from the Pleistocene to the end of the Anthropocene, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16345, https://doi.org/10.5194/egusphere-egu24-16345, 2024.

Climate tipping elements are large-scale subsystems of the Earth that may transgress critical thresholds (tipping points) under ongoing global warming, with substantial impacts on biosphere and human societies. While recent scientific efforts have improved our knowledge on individual tipping elements, the interactions between them are less well understood. Also, the potential of individual tipping events to induce cascading tipping elsewhere, or stabilize other tipping elements is largely unknown. As a contribution to the Global Tipping Points Report (GTPR) 2023 for COP28, we mapped out the current state of the literature on interactions between climate tipping elements. We find that tipping elements in the climate system are closely interacting, meaning a substantial change in one will have consequences for subsequently connected tipping systems. A majority of interactions between climate tipping systems are destabilising. While confirmation or rejection through future research is necessary, it seems possible that interactions between climate tipping systems destabilise the Earth system in addition to climate change effects on individual tipping systems. Further, we are quickly approaching global warming thresholds where tipping system interactions become relevant, because multiple individual thresholds are being crossed. Concretely, tipping cascades can neither be ruled out on centennial to millennial timescales at global warming levels between 1.5–2.0°C, nor on shorter timescales if global warming would surpass 2.0°C. To address crucial knowledge gaps in tipping system interactions, we propose four strategies forward combining observation-based approaches, Earth system modelling expertise, computational advances, and expert knowledge.

How to cite: Wunderling, N. and von der Heydt, A. and the GTPR-tipping-interactions-team: Reviewing climate tipping point interactions and cascades under global warming, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7905, https://doi.org/10.5194/egusphere-egu24-7905, 2024.

Under current emission trajectories, at least temporarily overshooting the Paris global warming limit of 1.5 °C above pre-industrial levels is a distinct possibility. Permanently exceeding this limit would substantially increase the risks of triggering several climate tipping elements with associated high-end impacts on human societies and the Earth system. It is essential to assess this risk under emission pathways that temporarily overshoot 1.5 °C. Here, we investigate the tipping risks associated with a number of policy-relevant future emission scenarios, using a stylised Earth system model that comprises four interconnected core tipping elements. Assessing tipping risks in the year 2300, we find a non-linear increase for overshoots that exceed 1.8 °C peak temperature or persist above 1.5 °C beyond the end of the 21st century. Scenarios following current policies or pledges lead to high tipping risk of 30% (median) and more, with uncertainty from climate sensitivity and carbon-cycle feedbacks translating to large uncertainties in tipping risk (45% and more) for these scenarios. Further, we show that on multi-century timescales achieving and maintaining at least net-zero greenhouse gas emissions is paramount to minimise tipping risks. Our results underscore that stringent emission reductions in the current decade in line with the Paris Agreement 1.5 °C limit are critical for planetary stability.

How to cite: Högner, A. (., Möller, T., Schleussner, C.-F., Bien, S., Kitzmann, N. H., Lamboll, R. D., Rogelj, J., Donges, J. F., Rockström, J., and Wunderling, N.: Achieving net zero greenhouse gas emissions critical to limit climate tipping risks, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7633, https://doi.org/10.5194/egusphere-egu24-7633, 2024.

Assessments of climate change effects on humans and ecosystems have previously included only limited information on the consequences of climate tipping points. While some national evaluations have touched on tipping point implications, assessment has been largely qualitative, with minimal quantitative analysis. Understanding and quantification of impacts of tipping points is recognised as a significant knowledge gap, and improving the research base in this area is essential for climate risks to be fully evaluated.

This presentation examines the current knowledge of Earth system tipping point impacts on people, exploring the evidence on impacts from individual tipping points, and assessing specific sectors and their vulnerability to these tipping points. Localised effects arise when climate tipping points, such as permafrost thaw and forest dieback, are crossed. These effects stem from land surface changes and alterations in regional climates and weather extremes. Global impacts manifest through large-scale shifts in atmospheric and oceanic circulations, altering global warming rates and sea level rise. Oceanic dynamics, like collapse of the Atlantic Meridional Overturning Circulation, can reshape regional climates and cause widespread shifts in temperature and precipitation patterns. Similarly, cryospheric tipping points, such as marine ice cliff collapse, have the potential to accelerate sea level rise, affecting flooding hazards like coastal inundation. Biosphere tipping points, such as Amazon dieback, intensify greenhouse gas concentrations, hastening global warming and its associated extreme weather events, regional climate shifts and sea level rise.

All these have the potential to impact the security of water, food and energy, human health, ecosystem services, communities and economies. The body of evidence varies across tipping points and sectors, but the implications for profound impacts across all areas of human society are clear.

How to cite: Betts, R., Dyke, J., Fuller, E., Jackson, L., Laybourn-Langton, L., Steinert, N., and Xu, Y.: Assessing impacts of Earth system tipping points on human societies , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6874, https://doi.org/10.5194/egusphere-egu24-6874, 2024.

The use of early warning signals to detect the movement of natural systems towards tipping points is well established. Here, we explore whether the same indicators can provide early opportunity signals (EOS) of a tipping point in a social dataset – views of online electric vehicle (EV) adverts from a UK car selling website (2018–2023). The daily share of EV adverts views (versus non-EV adverts) is small but increasing overall and responds to specific external events, including abrupt petrol/diesel price increases, by spiking upwards before returning to a quasi-equilibrium state. An increasing return time observed over time indicates a loss of resilience of the incumbent state dominated by ICEV advert views. View share also exhibits increases in lag-1 autocorrelation and variance consistent with hypothesised movement towards a tipping point to an EV-dominated market. Segregating the viewing data by price range and year, we find a change in viewing habits from 2023. Trends in EOS from EV advert views in low-mid price ranges provide evidence that these sectors of the market may have passed a tipping point, consistent with other evidence that second-hand EVs recently reached price parity with equivalent ICEV models. We provide a case study of how EOS can be used to predict the movement towards tipping in social systems using novel data.

How to cite: Boulton, C., Buxton, J., and Lenton, T.: Early opportunity signals of a tipping point in the UK’s second-hand electric vehicle market, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15331, https://doi.org/10.5194/egusphere-egu24-15331, 2024.

The global food system is at a critical inflection point with rising awareness of the need for change and progress on several fronts, pertaining both human health and the environment. One of the ten critical transitions envisioned by the Food and Land Use Coalitions states that global diets need to converge towards local variations of the “human and planetary healthy diet” which includes more protective foods a diverse protein supply, and reduced consumption of sugar, salt and highly processed foods. 

Positive tipping points (PTP) offer a new perspective to support and boost the implementation of solutions for sustainable and healthy food systems. A PTP in the food system can be seen as critical points where targeted interventions lead to large and long-term consequences on the evolution of that system, profoundly altering its modes of operation.  While discussions on food PTP dynamics are an intriguing theoretical debate, we still lack empirical evidence if and how such dynamics unfold in practice, especially in the food sector. Literature on inducing positive tipping and feedback dynamics in sustainability transitions almost exclusively focuses on the energy sector, leaving an important gap in the empirical research on the specific enabling factors for triggering these dynamics in respect to food and global diets transformation.  

How do different organizational, geographical, and temporal scales should interact with each other to accelerate a transition to a sustainable food system? In this study we integrate complex network theory tools with systems’ emergent properties to better define multi-scale food systems dynamics. We develop indicators (with country resolution and global coverage) to synthesize the food system’s structure and its weak and strong points where the spread of positive changes can be maximized. This quantitative framework is aimed at supporting the actions of government in repurposed agricultural subsidies, targeted public food procurement, taxes and regulations on unhealthy food; and business in redesigning product portfolio based on the human and planetary health diet. 

How to cite: Tuninetti, M., Giordano, V., Constantino, S., Perri, S., Rocha, J., Schwarz, L., Donges, J. F., Laio, F., and Levin, S.: Positive Tipping Points in the Food Systems: the Role of Scales, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-22274, https://doi.org/10.5194/egusphere-egu24-22274, 2024.

The Anthropocene is characterized by accelerating change and global challenges of increasing complexity and most recently by what some have called a polycrisis. Based on an adaptation of the evolutionary traps concept to a global human context, we explore whether the human trajectory of increasing complexity and influence on the Earth system could become a form of Anthropocene trap for humanity. We identify 14 Anthropocene 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.

How to cite: Søgaard Jørgensen, P., Jansen, R., Avila Ortega, D., Wang-Erlandsson, L., Donges, J. F., Österblom, H., Olsson, P., Nyström, M., Lade, S., Hahn, T., Folke, C., Peterson, G., and Crepin, A.-S.: Evolution of the polycrisis: Anthropocene traps that challenge global sustainability, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21005, https://doi.org/10.5194/egusphere-egu24-21005, 2024.

The Anthropocene epoch is characterized by an excessive use of natural resources and energy that drives the environmental destruction of the planet. However, large inequalities exist among different social groups that benefit to various degrees from the use of resources and energy, as well as among those suffering from the negative impacts of environmental destruction. In this paper, we systematically analyze these differences and propose a novel social stratification theory based not only on differences in terms of possessions or social status, but also on differences in how these groups can control and benefit from the planetary material cycles and energy flows or suffer the consequences of environmental degradation. Referring to consumption data, we propose six global socio-metabolic classes and show distinctive patterns in the energy use of these classes. More research is needed to reveal differences in the use of natural resources essential for maintaining the biosphere integrity, such as land, water, nitrogen, and phosphorus. Targeted policy measures that address excessive appropriation of energy and natural resources are needed, as are expansions in infrastructure and institutional change that supports the wellbeing of humankind, and especially of the most marginalized classes.

How to cite: Otto, I. M. and Schuster, A.: Socio-metabolic class conflicts in the Anthropocene, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20878, https://doi.org/10.5194/egusphere-egu24-20878, 2024.

Understanding the emergent dynamics – in particular critical transitions – in complex social-ecological systems is key to foster positive social transformations in the Anthropocene era. Regime shifts in some ecosystems may be preceded by statistical early warning signals, but systems where such signals can be tested systematically are elusive. The r/place game hosted by Reddit is a social experiment that provides data for thousands of subsystems that can undergo critical transitions. It is therefore an excellent testbed for comparing the performance of various warning indicators. In r/place, millions of users collaborated to build many discernible drawings on a canvas of pixels. A drawing undergoes a transition when it is rapidly replaced by another. We build an early warning signal indicator that uses machine learning to combine the predictive power of a number of time-dependent and system-specific variables, and we show that its performance far exceeds that of standard indicators. For example, when training the algorithm and testing its performance on separate parts of the 2022 r/place, we detect half of the transitions coming in less than 20 minutes with only a 0.6% false positive rate. The performance only slightly decreases when training on 2022 data and testing on the 2023 experiment, showing that the predictive power holds across significantly different setups. We use SHAP values to elucidate the drivers of any given warning and highlight generic properties of warnings in online social systems. Some properties, such as a decreasing return time, are at odds with standard statistical indicators. Where sufficient data is available, our tool and resulting insights can contribute to warn of – and possibly trigger or avoid – macroscopic social and ecological change.

How to cite: Falmagne, G. and Stephenson, A. B.: Interpretable Early Warning Signals in Large Human Groups, using Machine Learning in an Online Game-experiment, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12076, https://doi.org/10.5194/egusphere-egu24-12076, 2024.

The anticipated rise in the frequency of severe droughts triggered by events such as El Niño and abnormal warming of the Atlantic Ocean is expected to have profound impacts on the Amazon forest. However, whether the Amazon forest can effectively cope with changes in precipitation patterns and maintain its resilience remains to be determined. The impacts can vary across different regions of the Amazon due to the inherent heterogeneity in annual precipitation rate and periodicity in dry and wet periods. Furthermore, it is essential to highlight that resilience assessment frequently revolves around the ecosystem's ability to maintain or restore its carbon stock after a disturbance. Nonetheless, numerous other ecosystem processes and properties, such as evapotranspiration and functional diversity, might signal a shift in resilience before a consistent alteration in carbon stock becomes apparent. To address these concerns, our study will apply the trait-based vegetation model CAETÊ (CArbon and Ecosystem functional Trait Evaluation model). To comprehend the effects of an elevated frequency of decreased precipitation in the Amazon forest, we will apply a 20% precipitation reduction across three different frequencies: 7 years, 3 years, and 1 year. The model will be run across five distinct Amazon regions: northwest, center, south, northeast, and southeast. The assessment of resilience will encompass both resistance and recovery measures and will be evaluated using standard metrics such as carbon stock, while the analysis will extend to include other crucial indicators such as evapotranspiration, net primary productivity, and functional diversity. We anticipate uncovering differences in resilience among the regions, primarily influenced by natural climatic heterogeneity that selects distinct compositions of functional traits, leading to varying levels of functional diversity. Our hypothesis suggests that initially, the northwest region may experience a buffering effect from its naturally high precipitation rate. This could potentially result in more subtle impacts, even in the face of reduced precipitation. However, over time, other regions may demonstrate greater resilience, as their communities might show functional strategies acclimated to prolonged dry conditions and lower precipitation rates. Additionally, we also expect to observe a prior decrease in evapotranspiration and functional diversity before the eventual collapse of carbon stock and net primary productivity. This expectation is rooted in the anticipated intensification of environmental filtering, wherein the ecosystem undergoes a process of selecting more conservative adaptive strategies to deal with drier climatic conditions. By employing this innovative approach to assess resilience, incorporating diverse indicators beyond solely relying on carbon stock, we aim to significantly improve the understanding of Amazonian ecosystem dynamics under changing climatic conditions. Ultimately, our findings may unveil that the Amazon forests are potentially more susceptible to environmental changes than previously envisioned.

How to cite: Rius, B., Cardeli, B., Blanco, C., Darela Filho, J. P., Hirota, M., and Lapola, D.: Resilience across the Amazon basin regions under increased drought frequency and severity, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18263, https://doi.org/10.5194/egusphere-egu24-18263, 2024.

The critical challenge in a hydrological system is to predict whether the system approaches a critical threshold. The urban centres are grappled by the extreme events especially floods with the shifts from one stable state to another in an urban socio-environmental system. Here, we identified the critical transitions of hydrological processes, including precipitation and runoff, by analyzing their shifting nature. Structural break-regression models, incorporating shifts in both mean and trend, are applied to the series.  The point of change indicates the transition within the system.  These models are then evaluated using two widely employed penalized likelihood criteria for multiple changepoints. These criteria strike a balance between the quality of model fit (measured by likelihood) and the consideration of parsimony. Two models are tested i.e., bisegmentation and penalised maximum likelihood with the white noise detection. The latter was found to be better fit to both precipitation and runoff for the three cities (Guwahati, Mumbai, and Dehradun) in India.

How to cite: Jain, J., Khare, D., and Munoz-Arriola, F.: Identifying the Transitions in the Stable Socio-Environmental System Due to Extreme Events , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-947, https://doi.org/10.5194/egusphere-egu24-947, 2024.

The Brazilian Amazon is a powerful Ecosystem Service (ES) provider. Simultaneously, many Amazonian local communities still preserve an intrinsic economic and cultural relationship in this Social-Ecological System. Paradoxically, the region concentrates a significant portion of the nation's poorest people, demonstrating the risks and susceptibility to socio-ecological vulnerability that region. Thus, the Amazon Forest dieback hypothesis predicts that the increased CO₂ (eCO₂), rising temperatures and droughts may push the forest toward a tipping point, which would bring a new composition of ES and would reflect on regional economic - cultural ways of living, as well as, social wellbeing and health. Hence, the research employed a cascade model using the Functional Diversity (FD) approach. The aim was to assess the impact of climate changes on CO₂ storage related to Ecosystem Services and their implications for the adaptation capacity of both rural and urban populations in the Brazilian Amazon. The initial analysis, using the CAETE model, evaluated vegetation FD responses in a scenario of 50% precipitation reduction. This revealed a shift in plant composition towards drought-related strategies, leading to a 37-49% reduction in total carbon storage in the basin, resulting in increased carbon release into the atmosphere. This result translates direct impacts to global and local climate regulation and indirect to shifting of water flux and to native provisioning services. The second evaluating was on social dimension ambit, through drafting of Social Ecological Vulnerability Index (SEVI) with secondary data of the municipalities of Manaus, Itacoatiara e Silves in the state of Amazonas and Ilha de Cotijuba in the Belém city in the state of Pará. The SEVI points out that the common factor of the vulnerability among the municipalities was the indicators of the socio-climate exposure for susceptibility to disasters, to rising temperature and FD changes. The SEVI result summed to FD modelling demonstrate that the social well-being of communities is threated due to the impacts on the native ES, even though they are placed in the one of most biodiverse forest from the globe. In addition, the susceptibility to diseases related to climate change increases in the regions greater urbanized (score 2.5, in the range from 0 low to 4 high vulnerability) with in turn can undermine the public health system in the urban centres in expanding in the Amazonia. Thus, the SEVI reveals that the impacts, stemming from the shifting FD of the modelled plant community, do not merely pose a distant threat to social well-being, health, and income; instead, they exacerbate socio-ecological vulnerability. In view that, people recognize and link hazards in infrastructure (ES for erosion control), mobility, and food supply (ES for water flow, fish, and wild food). Therefore, all the results support the challenges for the development of public policies of climate adaptation involving social health, future maintenance of provisioning native ES, above all in the municipalities with inadequate socioeconomic indicators

How to cite: Almeida Canova, M., Rius, B., Darela Filho, J., and Montenegro Lapola, D.: Climate Change and Social- Ecological Vulnerability Index in the Brazilian Amazon: A study with a cascade model approach, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13183, https://doi.org/10.5194/egusphere-egu24-13183, 2024.

Ecosystem resilience represents the capacity of an ecosystem to withstand and recover from external perturbations, an increasingly important property for ecosystem function in an era of escalating climate extremes and anthropogenic pressures. Whilst recent studies have related forest resilience to natural factors such as climate and biomass, the link between forest diversity and resilience is not yet understood.

This study quantifies the sensitivity of ecosystem resilience on forest diversity in Europe over the period 2003-2021. Two commonly used resilience indicators are considered based on MODIS kNDVI (kernel Normalized Difference Vegetation Index) data acquired at high spatial and temporal resolution: the 1-lag temporal autocorrelation, relating to the ecosystem memory, and the standard deviation, relating to the ecosystem stability. Forest diversity is expressed in terms of horizontal and vertical structural heterogeneity metrics derived from GEDI (LiDAR) (Light Detection and Ranging) acquisitions. A Random Forest (RF) model is leveraged to isolate the interplay between forest resilience and diversity metrics by disentangling possible confounding environmental variables such as climate. The RF model is then applied to retrieve local sensitivities in terms of Individual Conditional Expectations.

The work first finds that European forests with a higher level of vertical and horizontal structural diversity are systematically associated with higher resilience levels. The relationship is coherent across bio-geographical regions in Europe. Importantly, the emerging relation between forest resilience and forest diversity is consistent under increasing temperature patterns. This suggests that forest management targeted to higher levels of forest heterogeneity has the potential to offset the decline in forest resilience associated with the projected climate warming scenarios and the consequent increasing disturbance regimes.

How to cite: Pickering, M., Elia, A., Girardello, M., Oton, G., Capobianco, S., Piccardo, M., Ceccherini, G., Forzieri, G., Migliavacca, M., and Cescatti, A.: Assessing the relationship between forest structural diversity and resilience in a warming climate, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16017, https://doi.org/10.5194/egusphere-egu24-16017, 2024.

Degradation of ecosystems can occur when certain ecological thresholds are passed below which ecosystem responses remain within ‘safe ecological limits’. Ecosystems such as drylands are sensitive to both aridification and grazing, but the combined effects of such factors on the emergence of ecological thresholds beyond which ecosystem degradation occurs has yet to be quantitatively evaluated. This limits our understanding on ‘safe operating spaces’ for grazing, the main land use in drylands worldwide. Here we assessed how 20 structural and functional ecosystem attributes respond to joint changes in aridity and grazing pressure across China´s drylands. Gradual increases in aridity resulted in abrupt decreases in productivity, soil fertility and plant richness. Rising grazing pressures lowered such aridity thresholds for most ecosystem variables, thus showing how ecological thresholds can be amplified by the joint effects of these two factors. We found that 44.4% of China’s drylands are unsuitable for grazing due to climate change-induced aridification, a percentage that may increase to 50.8% by 2100. Of current dryland grazing areas, 8.9% exceeded their maximum allowable grazing pressure. Our findings provide important insights into the relationship between aridity and optimal grazing pressure and identify safe operating spaces for grazing across China’s drylands.

How to cite: Li, C., Fu, B., Wang, S., Stringer, L., Zhou, W., and Ren, Z.: The safe operating spaces for grazing in China’s drylands, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2580, https://doi.org/10.5194/egusphere-egu24-2580, 2024.

The capacity for tipping points in the climate system was elucidated decades ago by numerical climate models, which showed that nonlinearities could arise from physical interactions between the ocean, sea ice, and atmospheric components, leading to rapid shifts between qualitatively different states. However, there has been comparatively little work on physical interactions with the human component of the Earth system through numerical modeling due, in part, to the rarity of inclusion of the human system directly in Earth system models. Earth System economics provides a new approach for doing so, by proposing a particular set of physical variables that can be used as a basis for simulating such changes. These variables include spatially resolved population demography, time allocation to activities, a spatially resolved technosphere, and spatial networks that capture transportation fluxes. New global compilations of time use and technosphere data are helping to enable this approach, by quantifying the dependencies of material fluxes on time use and context. This opens the possibility of simulating long-term dynamics through motivated changes to time allocation, with outcomes dependent on the evolution of the technosphere and other coupled features of the Earth system. Examples will be discussed regarding how this approach can provide holistic, physically-grounded ways to identify possible nonlinearities and tipping points, by explicitly resolving aspects of human activities and technosphere changes, constrained by the conservation of mass, energy, and time.

How to cite: Galbraith, E.: Estimating possible nonlinearities in the Human-Earth system with Earth system economics, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17717, https://doi.org/10.5194/egusphere-egu24-17717, 2024.