Carbon emissions trajectory and driving force from the construction industry with a city-scale: A case study of Hangzhou, China

China has promised the world that it will reach the carbon peak by 2030 and achieve carbon neutrality by 2060 (called as "dual carbon" target). Reducing Carbon Emissions from the Construction Industry (CECI) is critical to meeting the "dual carbon" target, as it shared 30% of the total carbon emissions. How to estimate carbon emissions at the city-scale is another issue. This study focuses on the materialization process of buildings and city-scale, establishing a framework to explore the carbon emissions trajectory. The driving force was clarified by the Logarithmic Mean Divisia Index method. The results show that in the case of Hangzhou in 2019, carbon emissions caused by fossil energy consumption in the construction site (called direct CECI) account for 3.3% of the total CECI. A large part of emission is from indirect CECI which includes the secondary energy (47.2%) and embodied carbon in material or production (38.9%), which are mainly emitted outside Hangzhou, because of building materials import. This paper also found that construction scale and demand structure were the main driving force of CECI growth, while the decrease in energy consumption will significantly restrain the increase of CECI. This study will contribute to the sustainable development of cities and society.