Tracing Chinese provincial CO2 emissions in cross-border production – An accounting base for decarbonizing production chains

China promotes interplay between domestic and international economic systems while striving to peak CO2 emissions and achieve carbon neutrality. As key implementers in achieving these targets, with diversified resource endowments, locations, and development stages, Chinese provinces urgently need to understand current CO2 emissions and their structures in relation to the interprovincial and international production. This study traces Chinese provinces' CO2 emissions in cross-border production using an Inter-Country Input-Output model for 2017 embedding Chinese provinces. Results show that CO2 embedded in cross-border production, particularly those crossing borders multiple times, dominated Chinese provincial emissions. Less CO2-intensive manufacturing and service sectors play a major role in mid- and down-stream production, with differences in production crossing borders once and multiple times. For regions, several well-developed provinces transfer China's CO2 domestically and internationally. Compared with destinations where CO2 first crosses borders, more international regions are involved in leading multi-time cross-border production networks. The United States (US) is a crucial final destination in multi-time cross-border production and some emerging economies are found in mid- and down-streams. These findings indicate the potential efficacy of considering cross-border production networks in decarbonization policies, with technological progress and international cooperation contributing to CO2 reduction.