arXiv subjects

Madhur Anand

Publications and source records attributed to Madhur Anand.

13 recordsLinked to original sources

arXiv2026

Impacts of social and impact heterogeneity on social-climate outcomes

Regional heterogeneity in social characteristics, temperature change, and vulnerability to climate impacts is likely to influence the magnitude of anthropogenic climate change, but has not been considered in coupled social-climate models, which seek to represent interactions between social and climate dynamics. Here, we examine how the projected mean global temperature anomaly and population support for mitigation respond to heterogeneity in these factors across five regions of the world, using a coupled social-climate model. We find that heterogeneity in climate impacts increases the temperature anomaly by 0.2$^\circ$C, while social heterogeneity increases it by an additional 0.1$^\circ$C. The projected temperature anomaly also increases with higher variability in climate impacts across regions, even for the same average global climate impact. Finally, we identify a social-climate tipping point, where low vulnerability to impacts under existing social conditions in one region can tip the system into an alternative slow-mitigation, high-temperature state. Our results show that heterogeneity in climate impacts leads to higher global mean temperatures and efforts to reduce global disparities could improve both social and climate outcomes.

physics.soc-ph↗

arXiv2025

Space, time and altruism in pandemics and the climate emergency

Climate change is a global emergency, as was the COVID-19 pandemic. Why was our collective response to COVID-19 so much stronger than our response to the climate emergency, to date? We hypothesize that the answer has to do with the scale of the systems, and not just spatial and temporal scales but also the `altruistic scale' that measures whether an action must rely upon altruistic motives for it to be adopted. We treat COVID-19 and climate change as common pool resource problems that exemplify coupled human-environment systems. We introduce a framework that captures regimes of containment, mitigation, and failure to control. As parameters governing these three scales are varied, it is possible to shift from a COVID-like system to a climate-like system. The framework replicates both inaction in the case of climate change mitigation, as well as the faster response that we exhibited to COVID-19. Our cross-system comparison also suggests actionable ways that cooperation can be improved in large-scale common pool resources problems, like climate change. More broadly, we argue that considering scale and incorporating human-natural system feedbacks are not just interesting special cases within non-cooperative game theory, but rather should be the starting point for the study of altruism and human cooperation.

physics.soc-ph↗

arXiv2025

Coupled opinion-environmental dynamics in polarized and prejudiced populations

Public opinion on environmental issues remains polarized in many countries, posing a significant barrier to the implementation of effective policies. Behind this polarization, empirical studies have identified social susceptibility, personal prejudice, and personal experience as dominant factors in opinion formation on environmental issues. However, current coupled human-environment models have not yet incorporated all three factors in polarized populations. We developed a stylized coupled human-environment model to investigate how social susceptibility, personal prejudice, and personal experience shape opinion formation and the environment in polarized populations. Using analytical and numerical methods, we characterized the conditions under which polarization, consensus, opinion changes, and cyclic dynamics emerge depending on the costs of mitigation, environmental damage, and the factors influencing opinion formation. Our model shows that prejudice is the key driver of persistent polarization, with even slightly prejudiced populations maintaining indefinite polarization independent of their level of objectivity. We predict that polarization can be reduced by decreasing the role of prejudice or increasing the willingness to consider opposing opinions. Finally, our model shows that cost reduction methods are less effective at reducing environmental impact in prejudiced populations. Our model generates thresholds for when reducing costs or emissions is more useful depending on the factors which influence the population's opinion formation. Overall, our model provides a framework for investigating the importance of cognitive and social structures in determining human-environment dynamics.

physics.soc-ph↗

arXiv2025

When Simple is Enough, Binary Models Capture Social Complexity in Coupled Human-Environment Systems

Models of coupled human-environment systems often face a tradeoff between realism and tractability. Spectrum opinion models, where social preferences vary continuously, offer descriptive richness but are computationally demanding and parameter-heavy. Binary formulations, in contrast, are analytically simpler but raise concerns about whether they can capture key socio-ecological feedbacks. Here we systematically compare binary and spectrum social models across four benchmark settings: (i) replicator dynamics coupled to a climate-carbon system, (ii) FJ opinion dynamics coupled to the climate-carbon system, (iii) replicator dynamics coupled to a forest-grassland ecological system, and (iv) FJ opinion dynamics coupled to a forest-grassland ecological system. We employ the relative integrated absolute error (RIAE) to quantify deviations between binary (N=2) and spectrum (N=100) formulations of social opinion dynamics in feedback with ecological subsystems. Across systematic parameter sweeps of learning rates, reluctance, conformity, susceptibility, runaway amplitudes, and ecological turnover, the binary formulation typically tracks its spectrum counterpart to within 15 percent for most parameter combinations. Deviations beyond this arise mainly under very high social susceptibility or near-vanishing ecological turnover, where additional opinion modes and nonlinear feedbacks matter. We therefore present the binary formulation as a practical surrogate, not a universal replacement. As a rule of thumb, it is adequate when susceptibility is moderate, ecological turnover appreciable, and runaway amplitudes not extreme; in high-susceptibility or low-turnover regimes, especially near critical transitions, the full-spectrum model is preferable. This framing guides readers on when a binary reduction is sufficient versus when full-spectrum detail is warranted.

physics.soc-ph↗

arXiv2025

Implications of regional variations in climate change vulnerability and mitigation behaviour for social-climate dynamics

How regional heterogeneity in social and cultural processes drive--and respond to--climate dynamics is little studied. Here we present a coupled social-climate model stratified across five world regions and parameterized with geophysical, economic and social survey data. We find that support for mitigation evolves in a highly variable fashion across regions, according to socio-economics, climate vulnerability, and feedback from changing temperatures. Social learning and social norms can amplify existing sentiment about mitigation, leading to better or worse global warming outcomes depending on the region. Moreover, mitigation in one region, as mediated by temperature dynamics, can influence other regions to act, or just sit back, thus driving cross-regional heterogeneity in mitigation opinions. The peak temperature anomaly varies by several degrees Celsius depending on how these interactions unfold. Our model exemplifies a framework for studying how global geophysical processes interact with population-scale concerns to determine future sustainability outcomes.

physics.soc-ph↗

arXiv2025

Echoes Before Collapse: Deep Learning Detection of Flickering in Complex Systems

Deep learning offers powerful tools for anticipating tipping points in complex systems, yet its potential for detecting flickering (noise-driven switching between coexisting stable states) remains unexplored. Flickering is a hallmark of reduced resilience in climate systems, ecosystems, financial markets, and other systems. It can precede critical regime shifts that are highly impactful but difficult to predict. Here we show that convolutional long short-term memory (CNN LSTM) models, trained on synthetic time series generated from simple polynomial functions with additive noise, can accurately identify flickering patterns. Despite being trained on simplified dynamics, our models generalize to diverse stochastic systems and reliably detect flickering in empirical datasets, including dormouse body temperature records and palaeoclimate proxies from the African Humid Period. These findings demonstrate that deep learning can extract early warning signals from noisy, nonlinear time series, providing a flexible framework for identifying instability across a wide range of dynamical systems.

cs.LG↗

arXiv2025

Neural models for prediction of spatially patterned phase transitions: methods and challenges

Dryland vegetation ecosystems are known to be susceptible to critical transitions between alternative stable states when subjected to external forcing. Such transitions are often discussed through the framework of bifurcation theory, but the spatial patterning of vegetation, which is characteristic of drylands, leads to dynamics that are much more complex and diverse than local bifurcations. Recent methodological developments in Early Warning Signal (EWS) detection have shown promise in identifying dynamical signatures of oncoming critical transitions, with particularly strong predictive capabilities being demonstrated by deep neural networks. However, a machine learning model trained on synthetic examples is only useful if it can effectively transfer to a test case of practical interest. These models' capacity to generalize in this manner has been demonstrated for bifurcation transitions, but it is not as well characterized for high-dimensional phase transitions. This paper explores the successes and shortcomings of neural EWS detection for spatially patterned phase transitions, and shows how these models can be used to gain insight into where and how EWS-relevant information is encoded in spatiotemporal dynamics. A few paradigmatic test systems are used to illustrate how the capabilities of such models can be probed in a number of ways, with particular attention to the performances of a number of proposed statistical indicators for EWS and to the supplementary task of distinguishing between abrupt and continuous transitions. Results reveal that model performance often changes dramatically when training and test data sources are interchanged, which offers new insight into the criteria for model generalization.

physics.comp-ph↗

arXiv2025

From Opinion Polarization to Climate Action: A Social-Climate Model of the Opinion Spectrum

We developed a coupled social-climate network model to understand the interaction between climate change opinion spread and the climate system and determine the role of this interaction in shaping collective actions and global temperature changes. In contrast to previous social-climate models that discretized opinions, we assumed opinions on climate change form a continuum, and were thereby able to capture more nuanced interactions. The model shows that resistance to behaviour change, elevated mitigation costs, and slow response to climate events can result in a global temperature anomaly in excess of 2°C. However, this outcome could be avoided by lowering mitigation costs and increasing the rate of interactions between individuals with differing opinions (social learning). Our model is the first to demonstrate the emergence of opinion polarization in a human-environment system. We predict that polarization of opinions in a population can be extinguished, and the population will adopt mitigation practices, when the response to temperature change is sensitive, even at higher mitigation costs. It also indicates that even with polarized opinion, an average pro-mitigative opinion in the population can reduce emissions. Finally, our model underscores how frequent and unexpected social or environmental changes, such as policy changes or extreme weather events, can slow climate change mitigation. This analysis helps identify the factors that support achieving international climate goals, such as leveraging peer influence and decreasing stubbornness in individuals, reducing mitigation costs, and encouraging climate-friendly lifestyles. Our model offers a valuable new framework for exploring the integration of social and natural sciences, particularly in the domain of human behavioural change.

math.DS↗

arXiv2025

Social dynamics can delay or prevent climate tipping points by speeding the adoption of climate change mitigation

Social behaviour models are increasingly integrated into climate change studies, and the significance of climate tipping points for `runaway' climate change is well recognised. However, there has been insufficient focus on tipping points in social-climate dynamics. We developed a coupled social-climate model consisting of an Earth system model and a social behaviour model, both with tipping elements. The social model explores opinion formation by analysing social learning rates, the net cost of mitigation, and the strength of social norms. Our results indicate that the net cost of mitigation and social norms have minimal impact on tipping points when social norms are weak. As social norms strengthen, the climate tipping point can trigger a tipping element in the social model. However, faster social learning can delay or prevent the climate tipping point: sufficiently fast social learning means growing climate change mitigation can outpace the oncoming climate tipping point, despite social-climate feedback. By comparing high- and low-risk scenarios, we demonstrated high-risk scenarios increase the likelihood of tipping points. We also illustrate the role of a critical temperature anomaly in triggering tipping points. In conclusion, understanding social behaviour dynamics is vital for predicting climate tipping points and mitigating their impacts.

math.DS↗

arXiv2024

Early Warning Signals for Bifurcations Embedded in High Dimensions

Recent work has highlighted the utility of methods for early warning signal detection in dynamic systems approaching critical tipping thresholds. Often these tipping points resemble local bifurcations, whose low dimensional dynamics can play out on a manifold embedded in a much higher dimensional state space. In many cases of practical relevance, the form of this embedding is poorly understood or entirely unknown. This paper explores how measurement of the critical phenomena that generically precede such bifurcations can be used to make inferences about the properties of their embeddings, and, conversely, how prior knowledge about the mechanism of bifurcation can robustify predictions of an oncoming tipping event. These modes of analysis are first demonstrated on a simple fluid flow system undergoing a Hopf bifurcation. The same approach is then applied to data associated with the West African monsoon shift, with results corroborated by existing models of the same system. This example highlights the effectiveness of the methodology even when applied to complex climate data, and demonstrates how a well-resolved spatial structure associated with the onset of atmospheric instability can be inferred purely from time series measurements.

physics.comp-ph↗

arXiv2024

Predicting discrete-time bifurcations with deep learning

Many natural and man-made systems are prone to critical transitions -- abrupt and potentially devastating changes in dynamics. Deep learning classifiers can provide an early warning signal (EWS) for critical transitions by learning generic features of bifurcations (dynamical instabilities) from large simulated training data sets. So far, classifiers have only been trained to predict continuous-time bifurcations, ignoring rich dynamics unique to discrete-time bifurcations. Here, we train a deep learning classifier to provide an EWS for the five local discrete-time bifurcations of codimension-1. We test the classifier on simulation data from discrete-time models used in physiology, economics and ecology, as well as experimental data of spontaneously beating chick-heart aggregates that undergo a period-doubling bifurcation. The classifier outperforms commonly used EWS under a wide range of noise intensities and rates of approach to the bifurcation. It also predicts the correct bifurcation in most cases, with particularly high accuracy for the period-doubling, Neimark-Sacker and fold bifurcations. Deep learning as a tool for bifurcation prediction is still in its nascence and has the potential to transform the way we monitor systems for critical transitions.

q-bio.QM↗

arXiv2022

Universal Early Warning Signals of Phase Transitions in Climate Systems

The potential for complex systems to exhibit tipping points in which an equilibrium state undergoes a sudden and often irreversible shift is well established, but prediction of these events using standard forecast modeling techniques is quite difficult. This has led to the development of an alternative suite of methods that seek to identify signatures of critical phenomena in data, which are expected to occur in advance of many classes of dynamical bifurcation. Crucially, the manifestations of these critical phenomena are generic across a variety of systems, meaning that data-intensive deep learning methods can be trained on (abundant) synthetic data and plausibly prove effective when transferred to (more limited) empirical data sets. This paper provides a proof of concept for this approach as applied to lattice phase transitions: a deep neural network trained exclusively on 2D Ising model phase transitions is tested on a number of real and simulated climate systems with considerable success. Its accuracy frequently surpasses that of conventional statistical indicators, with performance shown to be consistently improved by the inclusion of spatial indicators. Tools such as this may offer valuable insight into climate tipping events, as remote sensing measurements provide increasingly abundant data on complex geospatially-resolved Earth systems.

physics.ao-ph↗

arXiv2020

A well-timed switch from local to global agreements accelerates climate change mitigation

Recent attempts at cooperating on climate change mitigation highlight the limited efficacy of large-scale agreements, when commitment to mitigation is costly and initially rare. Bottom-up approaches using region-specific mitigation agreements promise greater success, at the cost of slowing global adoption. Here, we show that a well-timed switch from regional to global negotiations dramatically accelerates climate mitigation compared to using only local, only global, or both agreement types simultaneously. This highlights the scale-specific roles of mitigation incentives: local incentives capitalize on regional differences (e.g., where recent disasters incentivize mitigation) by committing early-adopting regions, after which global agreements draw in late-adopting regions. We conclude that global agreements are key to overcoming the expenses of mitigation and economic rivalry among regions but should be attempted once regional agreements are common. Gradually up-scaling efforts could likewise accelerate mitigation at smaller scales, for instance when costly ecosystem restoration initially faces limited public and legislative support.

nlin.AO↗