Embodied GHG emissions of building materials in Shanghai

The tremendous use of building materials poses heavy threats to resources and the environment. In order to better understand the GHG emissions embodied in the abundant building material consumption of Shanghai's buildings and search for approaches to reduce GHG emissions, this study explores the building consumption and the embodied GHG emission in Shanghai's buildings through life cycle assessment. Novel and localized life cycle inventories are applied. Based on our findings, the average annual growth rate of new constructed area in Shanghai was around 10% since 2000 to 2016. Concrete, brick, sand, gravel and cement (non-concrete use) appear as the main materials used. High GHG emission burden materials per kg are revealed to be steel, lime, wood, glass and cement (non-concrete use). Accounting the annual material consumption in 2016, steel, cement (non-concrete use), concrete and brick are found have the highest contribution to embodied GHG emission in Shanghai. The decoupling analysis reveals Shanghai experienced a general trend from non-decoupling to relative decoupling between building material use and GDP in recent 17 years. Findings in this study indicate for the high GHG emission burden materials such as steel and lime, reducing the energy use and using less CO2-intensive energy sources during manufacturing are likely to be the most effective approaches. In terms of the highly consumed building materials such as concrete and brick, the focus should be on reducing consumption or looking for substitute materials with lower GHG burden per unit.