Simulation study on carbon emission of China's freight system under the target of carbon peaking

The development of Chinese society needs the support of a perfect and efficient freight transport system. Nonetheless, China's freight system is facing a major challenge in reducing carbon emissions. Hence, firstly, this paper explores three major internal drivers of carbon emissions by analyzing the current situation in China's freight system: proportion of railway freight (PORF), railway electrification level (REL) and electric truck penetration (ETP). Secondly, the system dynamics (SDs) model is used to simulate the carbon emission system of freight transportation in China. Thirdly, this paper sets 13 scenarios of carbon peaking to explore the paths of carbon peaking before 2030 under the three levels of development of ETP oriented freight system. The results indicate that when PORF, REL, and ETP reach 23.96% of total freight volume, 83.7% of rail freight, and 11% of truck freight in 2030 respectively, China's freight system has the most optimistic scenario of carbon peaking. Meanwhile, the time of carbon peaking is 2024, and the peak value is 0.842 billion tons. When PORF, REL, and ETP reach 15.96% of total freight volume, 63.7% of rail freight, and 3% of truck freight in 2030 respectively, China's freight system has the worst scenario of carbon peaking. Meanwhile, the time of carbon peaking is 2029, and the peak value is 1.016 billion tons. Also, it is proved that improving PORF, REL, and ETP is an effective way to achieve green and sustainable development of China's freight industry.