Export trade, embodied carbon emissions, and environmental pollution: An empirical analysis of China's high- and new-technology industries

China's export trade has been expanding steadily in recent years, significantly increasing resource consumption and environmental pollution. High- and new-technology industries are essential for achieving sustainable economic development and improving environmental quality. This study employs a multi-regional input–output model to estimate the economic benefits and environmental costs of export trade in high- and new-technology industries. Then, it analyzes the impact of economic benefits and technological levels on environmental pollution using the Stochastic Impacts by Regression on Population, Affluence, and Technology model. An input–output multi-objective linear programming model and a non-dominated sorting genetic algorithm II are adopted to combine economic development with environmental pollution and determine the optimal path for export trade. The results show that technological progress in China's high- and new-technology industries is conducive to reducing embodied carbon emissions in developed countries while increasing emissions in developing countries. Moreover, a nonlinear three-stage accompanying relationship exists between the economic benefits and environmental costs of high- and new-technology exports; this is because exports with low economic benefits generate fewer carbon emissions whereas exports with high economic benefits generate significant carbon emissions. An increase in exports with ultra-high economic benefits will generate excessive embodied carbon emissions that hinder coordinated economic–environmental development. Lastly, technological progress in the electrical and optical equipment sector can effectively promote pollution reduction; thus, it should be further developed to improve the comprehensive benefits of exports.