Towards net zero carbon buildings: Accounting the building embodied carbon and life cycle-based policy design for Greater Bay Area, China

Abstract

Carbon mitigation of buildings is critical to promote a net-zero society. The international society has vigorously promoted “Net Zero Carbon Buildings” across the globe, and accounting for building carbon emissions is critical to support this initiative. Embodied carbon, which represents carbon emissions from the entire lifecycle of the buildings, is fundamental for realizing the idea of zero carbon. However, only limited studies have been conducted so far that take into account the city scale. This paper aimed to act as a first try to account for the embodied carbon emissions in buildings in 2020 for the Guangdong-Hong Kong Macau Greater Bay Area in China (GBA). We integrated remote sensing techniques such as night-time light data (NLT) and building material flows analysis to calculate and spatialize the newly generated building material stocks (MS). Based on the MS data, we further applied life cycle assessment (LCA) to assess the embodied carbon in the buildings. The results highlighted that over 163 million tons of embodied carbon in buildings of GBA are expected to be generated, from 497 million tons of newly generated building MS in 2020. The embodied carbon in each life cycle stage is valuable for further lifecycle-based policy designs for: (i) supporting the updating of the green building certification system with consideration of the embodied carbon; (ii) promoting the green building material application and certification; and (iii) reducing the embodied carbon intensity from compact urban planning policy, such as the urban agglomeration policies in GBA. The goal of this paper was to shed a light on reducing carbon emissions from the perspective of the entire lifecycle and promote the development of net zero carbon buildings in China and Asia-Pacific.