What drives the carbon mitigation in Chinese commercial building sector? Evidence from decomposing an extended Kaya identity.

Energy efficiency in the building sector is expected to contribute >50% to the nationwide carbon mitigation efforts for achieving China's carbon emission peak in 2030, and carbon mitigation in Chinese commercial buildings (CMCCB) is an indicator of this effort. However, the CMCCB assessment has faced the challenge of ineffective and inadequate approaches; therefore, we have followed a different approach. Using the China Database of Building Energy Consumption and Carbon Emissions as our data source, our study is the first to employ the Logarithmic Mean Divisia Index (LMDI) to decompose five driving forces from the Kaya identity of Chinese commercial building carbon emissions (CCBCE) to assess the CMCCB values in 2001-2015. The results of our study indicated that: (1) Only two driving forces (i.e., the reciprocal of GDP per capita of Tertiary Industry in China and the CCBCE intensity) contributed negatively remi to CCBCE during 2001-2015, and the quantified negative contributions denoted the CMCCB values. Specifically, the CMCCB values in 2001-2005, 2006-2010, and 2011-2015 were 123.96, 252.83, and 249.07 MtCO2, respectively. (2) The data quality control involving the CMCCB values proved the reliability of our CMCCB assessment model, and the universal applicability of this model was also confirmed. (3) The substantial achievements of the energy efficiency project in the Chinese commercial building sector were the root cause of the rapidly growing CMCCB. Overall, we believe that our model successfully bridges the research gap of the nationwide CMCCB assessment and that the proposed model is also suitable either at the provincial level or in different building climate zones in China. Meanwhile, a global-level assessment of the carbon mitigation in the commercial building sector is feasible through applying our model. Furthermore, we consider our contribution as constituting significant guidance for developing the building energy efficiency strategy in China in the upcoming phase.