Mapping lifecycle building material embodied carbon emissions for Beijing-Tianjin-Hebei urban agglomeration

Accurate carbon accounting is crucial for global climate change mitigation efforts. Building Material Embodied Carbon Emissions (BMCE) constitutes a significant portion of urban carbon footprints. However, the map of it at the building level remains sparse. This study proposes a model integrating multi-source remote sensing data for lifecycle BMCE mapping and assesses the building carbon efficiency according to eco-efficiency theory. Results show that BMCE in Beijing-Tianjin-Hebei urban agglomeration has a total of 3,946 ${\mathrm{MtCO}}_{2}e$, with intensity of 600 ${\mathrm{kgCO}}_{2}e/m^2$. BMCE of residential buildings is the highest, double that of public buildings. Approximately 60 % of buildings are in low carbon efficiency. They emit more than 2,367 ${\mathrm{MtCO}}_{2}e$. This study provides valuable insights into the statistical and spatial characteristics of lifecycle BMCE and highlights the importance of carbon efficiency analysis for future urban carbon reduction.