CO2 emission induced by international trade brings a plenty of pressure on global warming. Hence, it is important to understand multi-regional CO2 flows that result from global trade and flow variation of different paths. After transforming capital flows into CO2 carbon flows, we built an ecological network model of the global trade system's carbon metabolism. Through ecological network analysis, we identified the direct and indirect effects of temporal CO2 flows in the network. We found that the total integral flow through the network experienced a remarkable increase during the study period. In addition, total import and export flows of four countries, including US, China, Germany and Russia, turned out to be rather big. Direct flow share was usually beyond 50% between two geographical adjacent countries, while that share was below 50% when two countries are far away. This research reveals the importance role of indirect flows and can therefore provide an empirical basis for adjusting and optimizing global trade network.