Unraveling the effects of increasing human population on CO2 level and crop yield: A study of deterministic and stochastic systems

Human-driven climate change, marked by rising CO2 emissions, threatens agriculture crop production by causing global warming. While a moderate increase in CO2 and temperature can initially enhance crop growth, exceeding critical thresholds disrupts photosynthesis, reduces leaf area, and shortens plant longevity, leading to decreased productivity. This study investigates the impacts of rising atmospheric CO2 level, temperature increase, and human population expansion on agricultural productivity through the formulation and analysis of a novel nonlinear mathematical model. Our model incorporates both deterministic and stochastic elements, revealing critical thresholds in CO2 emission and temperature tolerance that significantly affect crop yields. Stability analysis indicates that crop productivity remains viable below a certain emission threshold; however, exceeding the limit induces different kinds of bifurcations, such as saddle–node, Hopf, and Bogdanov–Takens bifurcations that lead to complex dynamics, including oscillations and reduction in crop yield. Additionally, the encroachment of arable land due to human activities further reduces the carrying capacity of crops, amplifying the adverse effects of climate change. Our findings suggest that government and agricultural policies should prioritize the development of crop varieties with enhanced temperature resilience to mitigate these impacts. By identifying optimal temperature ranges for crop growth and highlighting the interplay between emissions, land use, and climate factors, this research provides valuable insights for adaptation strategies in agriculture. Enhancing crop resilience to temperature fluctuations and developing sustainable agricultural practices can help safeguard food security and ecosystem’s stability in a changing climate.