Fig. 4: Export-related emission flows along the interregional supply chains in 2017.

Here, all emissions are converted by APE. The leftmost bar shows the provincial production-based emissions driven by national exports. The rightmost bar denotes the provincial consumption-based export-related emissions, including emissions driven by international exports as final consumed products (i.e., the upper bar) and as intermediate products for foreign countries’ further exports (i.e., the lower bar). The gray flow represents the production-based emissions of each production layer (i.e., PL) driven by national exports. The pale yellow flows represent provincial emissions at upstream supply chains driven by foreign countries’ further exports. For example, the flows between PL⁰ and PL¹ represent emissions from all provinces embodied in the output of foreign countries at PL¹ purchased by foreign countries at PL⁰. The detailed explanation for other flows between PLs could be found in Methods. The emissions of foreign countries driven by Chinese exports are not included here. Given the small quantity of emission flows in Western provinces, we integrate them together into one single entity according to the regional classification in Supplementary Fig. 1.