A ZSG-DEA model with factor constraint cone-based decoupling analysis for household CO emissions: a case study on Sichuan province.

This study employed an input-output approach to measure household CO emissions (HCEs) in Sichuan province, China from 2010 to 2017. A ZSG-DEA model with a factor constraint cone was built, to allocate such emission allowances to provincial subordinate cities and investigate their spatiotemporal heterogeneity. Using Tapio decoupling analysis, this study further examined the nexus between regional economic performance and HCEs. The results indicated that HCEs in Sichuan province initially increased and then decreased, peaking at 69.60 million tons in 2015. The structure of the HCEs changed from coal- to petroleum-dominated from 2010 to 2017. Indirect emissions from consumption-related sectors accounted for 60% of the total HCEs, including food, transportation, communication, and accommodation. The capital city of Chengdu, with the largest economic scale, overwhelmingly dominated the total household CO emissions, whereas Panzhihua, a heavy-industry-dominated city, had the highest HCEs  per capita. The Tapio decoupling results suggested that seven cities, led by Chengdu, had strong decoupling statuses, indicating that these cities performed well in the trade-off between economic growth and HCEs reduction. These results indicated that HCEs had a head effect centered on cities with advanced urbanization, but there was a virtuous cycle between CO emissions reduction and economic development. Given the spatial and temporal heterogeneity of HCEs, differentiated policymaking on emissions reduction is the key to facilitating green transformations.