International Trade Pattern Of Fossil Fuels Based On The Theory Of Complex Network And Emergy

Coal, crude oil and natural gas are the main fossil fuels in important strategic positions in the national economy and also important positions in the international trade. Implementing international trade strategy of fossil fuel is an important task to ensure sustainable development of national economy. A better understanding of the pattern of the international fossil fuel trade and the relationships between the countries is the premise and guarantee of better strategies and policies for international fossil fuel trade. The reserves and production of fossil fuels of China are far from sufficient to supply the huge domestic demand. Thus, it is important for China to learn the dynamics of international fossil fuel trade patterns, and to learn the evolution of the relationships between the countries. The main research work and conclusions are as follows:(1) We introduce the Emergy theory into the study of international fossil fuel trade, and with the combination of complex network analysis we establish a comprehensive network model of international fossil fuel trade. Emergy-based network model can better reflect the "energy value" of the goods flowing between the countries. Through the overall characteristics and individual characteristics of the network, we find that the number of trade relationships follow a power law distribution that a few countries have a large amount of trade partners and most of the countries have a smaller number of partners. A few trade relations bear most of the trade quantity. The trade density of fossil fuel is increasing. Countries with more than 20 trade relationships tend to have a hierarchy structure, and this phenomenon was becoming more pronounced during the observation period.(2) We apply an algorithm to detect the communities of the 4 types of network each year, and design three types of Normalized Mutual Information(NMI) to measure different characteristics of the network group. We find that the natural gas trade network is the most partitioned. The U.S. mortgage subprime crisis in 2008 had an obvious impact on the communities of international fossil fuel trade. Crude oil was the main factor impacting the fossil fuel trade communities; however, natural gas became the main factor in 2013. 2012 is a turning point in which the partition of fossil fuel trade was the most deviated from 2000 with the lowest stability from 2011 to 2012. The geographical factor is reinforced and the roles of the USA and Russia have become more important. The two communities containing Asia Pacific countries are less stable and most of the changes occurred between these two communities.(3) We proposed an index of dominance to measure the dominance of countries according to their positions in the network. We calculate the dominance of all countries in the network, combined with analysis of international events and the overall pattern of the evolution of the regional pattern. The global dominance pattern of international crude oil trade experiences four phases. Each phase has different features and leading countries. The regional dominance patterns have specific characteristics as well as some common features. National events, new policies, political situations and changes of domestic supply and demand will cause fluctuation of a country’s dominance. The impacts of economic factors appear rapidly; usually in the same year or the next year. However, the impacts of political factors and policies usually appear a few years after the events.(4) We analyze the roles of four major countries in the international fossil fuel trade network: the USA, China, Russia and Saudi Arabia. We study the trade relations, the index of central position, the index of intermediary ability and the communities. We find that either for importing countries or exporting countries, only a few relations have huge amount of fossil fuel, most of the other relations have very low emergy value. The four countries are seeking to diversify their trade partners. The USA is in the most central position of the international fossil fuel trade network and its centrality is enhancing, but it intermediary ability is decreasing. Although the intermediary ability of the USA is still the highest, China’s central position was increasing before 2008 and slightly decreasing after 2008, and intermediary ability is increasing rapidly. The central position of Russia is increasing slowly but its intermediary ability is decreasing significantly. Saudi Arabia’s central position and intermediary ability in recent years tend to decrease. We have provided different policy recommendations for these four countries based on these results.(5) We introduce the index of Emergy Exchange Ratio(EER) and the concept of "ecological cost" into the study of international fossil fuel trade. Emergy exchange ratio is used to analyze the exchange of commodities and currency exchange in the international trade. It reflects the "energy cost" of the exchange between the two countries. We calculate the Emergy Exchange Ratio of China’s imports of coal, crude oil and natural gas. We find that the Emergy Exchange Ratio of China’s import of coal is the highest, while the Emergy Exchange Ratio of China’s import of crude oil is the lowest. China’s imports of coal from major source countries are more concentrated, and the imports of crude oil and natural gas are more dispersed. Meanwhile, a large proportion of China’s imports of coal and natural gas are from countries with low Emergy exchange ratio, but a small proportion are from countries with high Emergy exchange ratio. According to the results, we made some policy suggestion for China.This study can theoretically enrich the modeling and index analysis of complex network of international trade. It is a comprehensive study of the international fossil fuel trade with a new perspective. It also expands the scope of the application of Emergy theory. This study also practically provides a systematic quantitative analysis on the international fossil fuel trade patterns and its evolution. With an in-depth analysis of the major countries, especially China’s position and role in the international fossil fuel trade network, we provide useful references for policy development and strateges.