Causal effects of population growth on energy utilization and environmental pollution: A system dynamics approach

Population growth will change the demand for food and energy resources and environmental pollution. Although early energy resources modeling has made vital efforts to model the energy system in the world, because of increasing complexity and integration of environmental, social, and economic functions, these models still need to be developed to show a system close to the real world to enhance sustainable management of natural resources. Hence, the main objective of this study is to design a system dynamics model for the food production system and energy demand in Iran in order to evaluate the effects of different population scenarios on key variables. In this regard, an integrated system dynamics simulation model was developed in Iran where managing energy resources is seriously challenging due to population growth and increasing food demand. The results of the behavioral test showed that the designed model can be used to investigate and simulate the effects of different population growth rate scenarios. Findings illustrated that by increasing population, if no further energy demand management policies were implemented, the total food demand and energy use increase by more than 1.35% and 3.31% respectively. Also, the annual air pollution change during 2014-2030 is expected to be around 4.41%. By changing the population growth rate in the form of population scenarios, the average annual energy demand in the first population scenario will be 20,277 barrels of crude oil and in the second population scenario will be 20049 barrels of crude oil. It seems that the change in the population growth rate will lead to an increase of 3.23% and 2.16% in average annual energy demand, respectively. The results showed that in the first population scenario, with a further increase in population variables, food demand and energy demand, the average change in pollution emission is 4.79%, which is at a higher level than the baseline conditions. In the second population scenario, changes in environmental pollution will be reduced to 4.31%. Therefore, given the effectiveness of population growth on the behavior of the energy system and pollution, the adoption of energy management policies should be considered by policy makers.