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

emissions. The snapshots display that emission levels and the temperature anomaly are equally sensitive to both parameters. The global temperature anomaly becomes less sensitive to the variation in believing or rejecting probabilities along with their corresponding forgetting probabilities as time passes (S4 and S5 Figs). Fewer parameter combinations lead to higher temperatures in 2200 than in 2070 and 2021, which implies that changing the believing (ω) or rejecting (z) probabilities and forgetting probabilities (ρ, σ) does not impact the temperature and emission levels after the rumor dynamics becomes stable. Also, the temperature anomaly is more sensitive to the for- getting probability in rejectors than the forgetting probabilities in believers (S4 and S5 Figs). High forgetting probabilities in rejectors lead to higher emissions and temperature levels. Max- imum emissions are found at higher forgetting probabilities (in rejectors) and lower rejecting probabilities (S5 Fig). Rejectors forgetting the rumor has greater risks than the believers for- getting the rumor as rejectors act as mitigators and are the ones who adopt mitigative strategies to combat with climate change. Univariate sensitivity analysis enables us to understand how sensitive the model is to a sin- gle parameter when it varies along its range by holding all other parameters at the baseline value. Only three points in the time series are considered to generate the univariate sensitivity plot: the peak value, the value in 2050, and the value in 2200.

Varying the total number of groups, X along its range (S1 Table) helps to understand the sensitivity of the model compartments concerning the parameter (S6 Fig). The baseline value for X is 40. A lower number of groups in the system leads to a sluggish rumor spreading. At lower X values, most of the population belongs in the susceptible compartment, and few are in the believer and rejector categories. The emission and temperature levels are also higher at lower X values than the higher ones, which implies that more groups assist in propagating the Fig 4. Global temperature anomaly is more sensitive to the emission-liming constant than group rejecting probabilities. (a-c) Parameter planes of CO2 emissions (GtCO2yr-1) at (a) 2021, (b) 2070, and (c) 2200 and (d-f) temperature anomaly (˚C) at (d) 2021, (e) 2070 and (f) 2200 by varying group rejecting probability (z) and emission limiting constant (C). https://doi.org/10.1371/journal.pone.0317338.g004 PLOS ONE Climate-denying rumor propagation in a coupled socio-climate model: Impact on average global temperature PLOS ONE | https://doi.org/10.1371/journal.pone.0317338 January 16, 2025 10 / 18