Mapping CO₂ spatiotemporal transfers embodied in China's trade using a global dynamic network model endogenizing fixed capital

A systematic approach that accurately assesses carbon emissions is essential to design climate policies. To fully consider the impacts of the intertemporal dynamics of using the past-formed capital for future production, endogenizing capital as an input into carbon accounting system has been proposed, and lead to the reallocation of emissions. However, little is known about how this reallocation occur, i.e., how carbon flows from the past-formed capital to the products it is used to produce and to the consumers who purchase these products. Here, enabled by a global CO₂ transfer network model with capital endogenization, we take China as an example to trace the full process of CO₂ spatiotemporal transfer and re-assess CO₂ footprints. China contributed more than 40% of the global capital-related CO₂ emissions with only 14% of global capital consumption. China drove domestic and foreign CO₂ emissions mainly through purchasing service products, while foreign regions outsourced an order of magnitude higher emissions to China by importing products such as electricity, machinery and equipment. Along temporal horizons, CO₂ emitted in historical years contributed 87% of the total emissions embodied in China's capital consumption, while new-formed capital contained 5.50 Gt CO₂ emissions, which will be attributed to the future. Based on this, China's dynamic CO₂ footprint was re-assessed as 4.65 Gt, an increase of more than 1/4 over the traditional results. This increase comes mainly from service products directly consuming building structure, especially real estate and public administration services. This study provided new understanding of CO₂ accounting and identified new hotspots for differentiated climate policies.