Impact of anthropogenic emissions of carbon dioxide and related temperature rise on wildlife population: A modeling study

Climate change is driven by the increase in greenhouse gases in Earth's atmosphere, especially carbon dioxide (CO2), leading to a rise in the global average temperature. This temperature rise unleash far-reaching and profound consequences on various living organisms. In this research work, we formulate a nonlinear mathematical model to perceive the impact of rising temperature on wildlife species. In formulating the model, we take into account that the escalating CO2 concentration contributes to a rise in the global average temperature, thereby impacting the growth rate of wildlife population. We pinpoint the sufficient conditions for all the dynamic variables to reach their simultaneous equilibrium levels. The model analysis reveals a spectrum of bifurcations, including transcritical, Hopf, saddle–node, and Bogdanov–Takens bifurcations. Further, the examination of transcritical bifurcation led to the identification of a critical reduction rate of wildlife species due to human activities above which the wildlife population may teeter on the brink of extinction under the considered stressor of temperature rise. This extinction of wildlife species can be avoided by increasing the carrying capacity of forest biomass. Also, we have shown that for a specific set of parameter values, there exists a bistability between the forest-wildlife free equilibrium and the coexisting equilibrium.