Historical assessment and future scenario modelling: How do inter-provincial migrants affect the process of carbon peaking in residential buildings?

The inter-regional carbon emission transfer caused by inter-provincial migrants (IPMs) is an important factor influencing China's provincial residential building carbon emissions (RBCEs). Based on census data and the per capita residential building carbon emissions (PCRBCEs), this study assesses the number of IPMs in China year by year from 2011 to 2020, quantifies the amount of RBCE transfers generated in the process, and further simulates the impacts of different IPM sizes in the future on the timing and pathways of carbon peaking in provincial residential buildings. The results of this study show that the total number of IPMs in China has been increasing year by year since 2015, with the number of new IPMs ranging from 20 to 25 million per year. During the decade from 2011 to 2020, IPMs in China cumulatively led to an increase in RBCEs of 98 MtCO₂. For provinces with large net inflows or outflows of population, such as Beijing, Henan, and Guizhou, the different sizes of future IPMs will have a significant impact on the time of their RBCE peak. Overall, this study fills in data gaps and provides a valuable reference for formulating better carbon peaking pathways at the provincial level.