Building sector plays an important role in carbon neutral transition, and commercial buildings become key starting point in the building decarbonization. Taking China and the United States (US) as cases, this study is the first to assess carbon-dioxide (CO2) mitigation in commercial building operations at different emission scales and investigate the carbon mitigation efficiency of the two countries in the past decades. The results show that: (1) Economic efficiency and energy intensity are key to reduce CO2 emission intensity in commercial buildings in China and the US, respectively; (2) CO2 mitigation efficiency in China was around 1.5 times that in the US, though CO2 mitigation in China and the US was close; (3) the paths for energy efficiency improvement in commercial buildings in China and the US were mapped to explore the strategy that best decarbonizes buildings operation in the future. Overall, the evaluation model of CO2 mitigation proposed in this study is able to be a guidance for other economies or regions to measure the effect of historical carbon mitigation in building operation.
Keywords Commercial building, CO2 mitigation, Mitigation efficiency, Index decomposition analysis