Embodied Carbon Emissions,Mitigation Potential And Emission Responsibility Of China’s Building Sector

The building sector is key to achieving China’s carbon peaking and neutrality goals.While for the building sector,from the annual cross-sectional perspective,embodied carbon emissions（ECs）are becoming increasingly significant and play a more important role in emission reduction.However,most existing studies focus on building operational carbon emissions（CEs）.There is a lack of systematic and in-depth research on the key issues of the annual ECs in China’s building sector,such as evolution law,influencing factors,emission reduction potential,development trends,and emission responsibility.This study follows the logic of“emission accounting-influencing factor deconstruction-reduction potential analysis-responsibility decomposition.”The main research works are as follows:（1）Developing a model for accounting total building ECs based on the input-output and process analysis methods and subsequently unfolding the evolution laws of total emissions,emission intensity,and composition in China’s building sector.（2）Proposing an extended STIRPAT（the Stochastic Impacts by Regression on Population,Affluence,and Technology）-based model,which aligns the general theoretical framework of IPAT（Impact=Population Affluence Technology）with the input-output features of the building sector,for deconstructing influencing factors and clarifying their impacts on the total,indirect and direct building ECs.（3）Establishing a comprehensive ECs mitigation potential assessment model based on material flow analysis,life cycle assessment theory,and index decomposition analysis and subsequently exploring ECs trends and emission reduction potential by 2060 in China’s building sector under different scenarios.（4）Developing a regional emission responsibility accounting model for the building sector under multiple principles based on the environmentally extended multi-regional input-output model and finally unveiling the emission distribution and transfer among sectors and regions from varying perspectives.The main findings are as follows.（1）The total building ECs in 2020 is as high as2.28 billion t CO₂,accounting for 25.2%of China’s total energy-related CEs.From 2005to 2020,building ECs contributed 38.7%of China’s total CEs growth,while the ECs intensity showed a downward trend,indicating that the increase in China’s building ECs is scale-driven.（2）Building construction area and indirect EC intensity are the main factors affecting the total and indirect ECs.The energy rebound effect induced by technological progress has a significant offsetting effect on the direct carbon reduction effect.（3）Building ECs are already at the peak plateau,and the future ECs up to 2060 in all scenarios show a downward trend with varying magnitudes.The main contributors to the EC reduction potential are new building areas,emission factors,and material consumption intensity.Moreover,additional scenarios related to building scale indicate that the lifetime-extending strategy for existing buildings also has significant emission mitigation potential.（4）Due to the heterogeneity in demand and supply among regional sectors,the emission responsibilities of the building sector for the same region under various principles are incredibly different,while for various regions’building sectors under the same principle,the disparities are also significant.This demonstrates that implementing“common but differentiated”responsibilities and policies in the building sector is of necessity and rationality.The theoretical value of this study may be summarized as systematically promoting the extension of CEs theoretical approach from individual buildings to the building sector,as well as enhancing understanding of the evolution laws and development trends of CEs in China’s building sector.From a practical perspective,the findings on influencing factors and emission responsibility may provide references for making emission reduction targets and policies aligned with the concerns of focus areas and key stages.