From local production to global consumption: Assessing the carbon footprints of Chinese cities in global value chains.
Level 5 - mechanism / opinion, no new human data
Economic and environmental input-output modeling study without clinical or epidemiological data
PubMed 41841038 · doi:10.1093/pnasnexus/pgag050
What was done
The authors developed a carbon accounting framework by nesting a multiregional input-output (MRIO) model of 313 Chinese cities within a global MRIO system. They quantified the upstream and downstream carbon footprints of these cities across global value chains (GVCs) and assessed economic gains relative to emissions.
What was found
Foreign demand-driven emissions (FDEs) were concentrated in major coastal hubs, with the top 10 cities accounting for 25% of national FDE and intermediate goods trade driving up to 43% of FDE in those cities. International trade emissions per unit of gross domestic product were 1.5 times higher than those from domestic industrial chains alone. In 54 service- and high-tech-oriented cities, over 20% of emissions occurred outside their borders via international supply chains. Nationally, the United States accounted for 43.7% of embodied emissions in gross exports from the 313 cities.
Why it matters
The model traces carbon flows at the municipal level through international supply chains, helping identify how global trade patterns distribute emission responsibilities across cities.
Limits
The abstract does not report the data years, source databases, or uncertainty intervals for the modeled estimates. The findings are derived from input-output economic modeling rather than direct physical emission measurements and are limited to Chinese municipal trade flows.