The embodied flow of built-up land in China's interregional trade and its implications for regional carbon balance

Built-up land intensively concentrates human activities, and its area or the changes in its intensity dramatically affect the regional carbon balance. This study proposed a new framework to assess how in China, the interregional trade's use of built-up land affects regional carbon balance with regard to the initial maintained land and the expanded built-up land. Then, a multiregional input−output model was used to simultaneously analyse China's built-up land flow in interregional trade and the effect on carbon balance. Finally, hidden regional inequality was analysed. The results show that the domestic trade pulled indirect external built-up land use reached to 100286 km2 in 2012 and caused 28084 × 104 t external province pulled carbon emissions for whole China, including 286 × 104 t from vegetation carbon storage loss. Regionally, more developed regions were always net receivers of built-up land use, in contrast, less developed regions more frequently acted as net suppliers, but most regions experienced economic and environmental deficits. The majority of other provinces experienced a contradictory status of loss of economic profit or environmental profit. For sustainable development and regional equality, more developed regions should provide more economic and technological support for effective built-up land use and emissions reduction to less developed regions.