This paper constructs an Economy-Energy-Emissions (3E) System Dynamics Model using the megacity of Beijing, China, as an example, to estimate the effects of different policy scenarios (including three single-policy scenarios and four combined-policy scenarios) on the core variables of Beijing's 3E system from 2021 to 2035. The results suggest two main points. (1) Following the current development trend, the proportion of the GDP represented by the added value of advanced high-precision industries (Gao Jing Jian in Chinese) will only be 43% in 2035, implying a limited role in promoting economic growth. Despite effective control of total energy consumption, fossil energy's share of total consumption will reach 57% by 2035, hindering the process of making the energy consumption structure cleaner and leading to failure to achieve the targeted inflection point in CO2 emissions by 2025. PM2.5 control shows some successful results and will decrease to 19 μg/m3 in 2035. However, a gap compared to other world-class cities remains. (2) The implementation of a single policy for either industrial structure optimization, energy structure transformation, or emissions control cannot simultaneously meet the goal of high-quality coordinated development of Beijing's 3E system, whereas the comprehensive implementation of policies in all three dimensions is demonstrably effective.
Keywords: Beijing-China; Economy-energy-emissions (3E) system; policy scenario; simulation; system dynamics (SD) model.