As one of corresponding authors, Prof. DUAN Hongbo from the University of Chinese Academy of Sciences (UCAS) and Prof. LU Bo from Dalian University of Technology (DUT) revealed the characteristics of global offshore carbon emissions from 2015 to 2020 and the allocation of carbon reduction responsibilities with consideration for both fairness and efficiency. The findings were published in Patterns (https://www.cell.com/patterns/pdf/S2666-3899(23)00156-3.pdf), a journal of Cell families, on July 31, 2023.
In this study, researchers first calculated annual carbon dioxide emissions by combining the route distance and the operating conditions of container ships. Subsequently, they constructed a network of global offshore carbon emissions in the shipping industry. To further investigate the spatiotemporal evolution trend and complex network characteristics of global oceanic carbon emissions, the researchers employed a modified gravity model to build the oceanic carbon emission network from 2015 to 2020.
Figure 1. Offshore carbon emissions correlation between countries
This study has led to many fascinating and significant findings. The carbon correlation among the top 20 countries is measured by the modified gravity model, as shown in Figure 1. From the overall perspective, countries with large offshore carbon correlation are more likely to be on the same continent owing to the short geographical distance and convenient port traffic. Among them, carbon correlation within Asia is the largest, centered on China and Singapore, with two-way exchanges with other countries, including South Korea, Japan, India, and Malaysia.
The spatial correlation of global offshore carbon emissions is not limited to the neighbor relationship in the geographical sense, instead demonstrating a directed complex network structure. Figure 2 shows that the average of the network correlation approximates 1, implying a steady development trend with few isolated countries. The mean value of the network hierarchy is only 0.053, indicating that the carbon correlation between countries is bidirectional and spatially related.
Figure 2. Global offshore carbon emissions network and centrality characteristics
Figure 3. Allocation of carbon emissions reduction responsibility based on the offshore carbon emissions network
The results of carbon emissions responsibility allocation are displayed in Figure 3. The top 5 countries with the largest responsibilities are China, the US, Singapore, India, and the Netherlands, with values of 0.320%, 0.305%, 0.298%, 0.254%, and 0.210%, respectively.
The results in this study deepen our understanding of the characteristics of global offshore carbon emissions, while an allocation scheme for emission reductions based on equity and efficiency will ensure economic growth while slowing down global warming.
This research was financially supported by the National Natural Science Foundation of China, the Major Program of National Fund of Philosophy and Social Science Foundation of China, and Liaoning Revitalization Talents Program of China.
