Embodied carbon emission of building materials in Southwest China: Analysis based on Tapio decoupling and LMDI decomposition

With the rapid development of urbanization, many housing constructions are being built in southwest China, which resulted in tremendous use of building materials, posing a potential threat to the environment. In order to formulate policies for low-carbon, green and sustainable development of buildings, it is necessary to explore the driving factors behind it. Taking the bottom-up material flow analysis as a framework, this research calculates the embodied carbon emissions of buildings on the basis of quantifying the stock of building materials in Southwest China from 2001 to 2020 and adopts the Logarithmic mean Divisia Index (LMDI) decomposition analysis method to investigate the contribution of factors such as technological level, economic structure, per capita GDP and population density to the embodied carbon emissions of buildings. The research shows that: (1) The total embodied carbon emissions of building materials in Southwest China increased by 218.62%, of steel and cement contributed the most of carbon emissions. (2) In the past 20 years, the degree of decoupling in Southwest China has fluctuated greatly. During the "13th Five-Year Plan" period, the provinces and cities in southwest China have an enormous degree of decoupling: Yunnan (-0.141) > Guizhou (-0.013) > Chongqing (0.047) > Tibet (0.120) > Sichuan (0.256). (3) The technological level is the first leading factor in the reduction of the embodied carbon emissions of buildings in southwest China, and the per capita GDP is the key factor to promote the growth of embodied carbon emissions. These findings could serve as a foundation for Southwest China's government to develop low-carbon building policies.