Internal migration and associated carbon emission changes: Evidence from cities in China

Human activities and associated carbon emissions are mainly concentrated in cities. As big cities usually offer more job prospects than small cities, residents are increasingly migrating from small cities to big cities within a country. During such internal migration process, production and consumption patterns typically change and will end up change in ecological footprint. However, the precise role of internal migration in carbon emissions is still unclear as in-migration and out-migration are likely to result in carbon emission changes in opposite directions. Therefore, we take evidence in China in this paper to evaluate how internal migration across cities influences carbon emissions by using the Index Decomposition Analysis (IDA) method to identify impacts of internal migration across cities in China on carbon emission changes. We found a positive impact of internal migration on the national carbon emissions, which increased China's aggregate carbon emission by 16% from 2001 to 2016. The positive impact of internal migration was achieved through greater demand for energy services (e.g., transportation, heating, cooling, etc.) in big cities than that in small cities. We also found that the positive impact of internal migration on carbon emissions was even larger than that of net population growth. We anticipate our findings help policy makers take informed decisions on optimizing city patterns for the sake of achieving carbon neutrality and sustainable development.