The structural change and determinants of global carbon footprint network embodied in international migration: A social network analysis

The carbon footprint embodied in international population mobility has a complex spatial correlation, which exacerbates the difficulty of global climate governance. However, the features, changing trends, and determinants of the carbon footprint flow embodied in global population migration are poorly understood. This study employed social network analysis and the exponential random graph model (ERGM) to investigate the structural changes and drivers of the carbon footprint network embodied in global migration from 1995 to 2015. The results showed that approximately 50% of carbon footprint flow embodied in international migration flowed from developing to developed countries. The spatial connections between countries in the network were becoming increasingly close, displaying a typical small -world structure, and showing low reciprocity and negative assortativity. Moreover, centrality analysis highlighted the United States and the European Union as being at the core of the network, whereas some emerging economies (e.g., China, India, and South Africa) were shown as having an increasing influence on the network. The determinants of network formation were divided into three effects. For node attribute effect, countries with developed economy, high proportion of industrial value added, urbanization and openness were becoming the destinations of carbon inflows from immigrants, while countries with high consumption of renewable energy and energy intensity had a trend of carbon outflows with emigrants over periods. As for exogenous network effect, the significance of economic integration on the formation of the network was strengthening, while that of geographical proximity and cultural similarity was declining. Additionally, the positive impact of self -organizational effect on the network was decreasing. This study provided guidance for countries to formulate policies to reduce the carbon emissions embodied in international migration.