Climate-denying rumor propagation in a coupled socio-climate model: Impact on average global temperature

RESEARCH ARTICLE Climate-denying rumor propagation in a coupled socio-climate model: Impact on average global temperature Athira Satheesh KumarID1,2*, Chris T. Bauch1, Madhur Anand2 1 Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada, 2 School of Environmental Science, University of Guelph, Guelph, Ontario, Canada * asathees@uwaterloo.ca Abstract Individual attitudes vastly affect the transformations we are experiencing and are vital in miti- gating or intensifying climate change. A socio-climate model by coupling a model of rumor dynamics in heterogeneous networks to a simple Earth System model is developed, in order to analyze how rumors about climate change impact individuals’ opinions when they may choose to either believe or reject the rumors they come across over time. Our model assumes that when individuals experience an increase in the global temperature, they tend to not believe the rumors they come across. The rumor rejectors limit their CO2 emissions to reduce global temperature. Our numerical analysis indicates that, over time, the tempera- ture anomaly becomes less affected by the variations in rumor propagation parameters, and having larger groups (having more members) is more efficient in reducing temperature (by efficiently propagating rumors) than having numerous small groups. It is observed that decreasing the number of individual connections does not reduce the size of the rejector population when there are large numbers of messages sent through groups. Mitigation strat-

egies considered by the rejectors are highly influential. The absence of mitigative behavior in rejectors can cause an increase in the global average temperature by 0.5˚C. Our model indicates that rumor propagation in groups has the upper hand in controlling temperature change, compared to individual climate-denying propagation. 1 Introduction Sustainability challenges have spanned multiple systems such as forest degradation [1–3], air pollution [5–7] and water systems [8–10], and accelerated anthropogenic global warming. Since the Industrial Revolution, humans have been emitting increasing amounts of greenhouse gases (GHG) into the Earth’s atmosphere, leading to anthropogenic global warming. The Intergovernmental Panel on Climate Change (IPCC) reports [4, 11] outline the social transi- tions required to limit the increase in the average global temperature to between 1.5˚C and 2˚C. Lifestyle and behavioral changes like reduction in household and industrial energy con- sumption, switching to renewable energy, and changes in diet can assist in achieving this goal PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0317338 January 16, 2025 1 / 18 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Satheesh Kumar A, Bauch CT, Anand M (2025) Climate-denying rumor propagation in a coupled socio-climate model: Impact on average global temperature. PLoS ONE 20(1): e0317338. https://doi.org/10.1371/journal.pone.0317338 Editor: Pierluigi Vellucci, Roma Tre University: Universita degli Studi Roma Tre, ITALY Received: April 14, 2024

Accepted: December 26, 2024 Published: January 16, 2025 Copyright: © 2025 Satheesh Kumar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting information files. Emission data is published by the Integrated Carbon Observation System (ICOS) Carbon Portal and are available at https://doi.org/10.18160/gcp- 2020. Funding: This research was funded by Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grants to Chris T Bauch and Madhur Anand. The funders had no role in study design, data collection and analysis,