“…However, some other researchers argue that the higher the degree of trade openness is in a country, the slower the growth of pollution intensity (emission intensity) per unit of output is, thus rejecting the pollution paradise hypothesis [9,10]. Moreover, the third opinion focuses on the uncertain effect of trade openness on the environment, but the influence covers four aspects: relocation of production, competition for natural resources between industries, pollution emission decreases with output growth, and the impact of income effects on consumer behavior [11][12][13]. Despite considerable controversies, there is little evidence on how trade opening-up policy affects carbon emissions, especially in developing countries [14].…”