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

Abstract

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.