7. Environmental Benefits Evaluation of Construction CO₂ Emission Reduction Management Using System Dynamics Approach

With the rapid development of urbanization, a huge amount of greenhouse-gas has been generated from increasing higher amounts of construction activities, which has significant negative impacts on the environment if they are not properly managed. Therefore, more and more scholars start to research the CO₂ emissions reduction of construction industry. However, it has been determined that existing studies with respect to CO₂ emissions reduction are mainly carried out from a static perspective, without considering the dynamic and interdependent nature of the whole CO₂ emissions reduction system. Therefore, based on literature review and interview survey, Vensim software was used to establish a system dynamic model of construction CO₂ emissions reduction management at the construction stage and simulate the environmental benefits of construction CO₂ emissions reduction management. The application of the proposed model is shown by using a case. The simulation results indicate that the CO₂ emissions reduction management can reduce 10.84% of CO₂ emissions. In the meantime, the CO₂ emissions reduction management achieves good environmental benefits including saving energy consumption of 59,718.5 kgce, saving waste landfill of 8434.28 m³ and the reduction of global warming potential of 3620.51 tCO_2-e. Scenario analysis reveals that using low-carbon materials has the optimal reduction effect in single measure, which can reduce 16.50% of CO₂emissions. Compared with a single measure, the maximum emissions reduction of multiple measures can reach 21.05%. Therefore, in order to realize best environmental benefits of construction CO₂ emissions reduction management, multiple measures should be used simultaneously, such as using low-carbon materials, recycling and reusing materials and improving operation efficiency of construction equipment. This study can help construction professionals determine the optimal emissions reduction strategy and provide references for project managers in assessing the reduction outcomes of construction projects and the environmental benefits.