“…Assuming identical fleet structure and exhaust tailpipe control technologies, annual average emissions of CO, HC, NO x , and CO 2 could reach 12,780, 14,799, 10,322, and 424,218 metric tons, respectively, in the lower-altitude sector (540–1940 m above sea level); 10,780, 12,016, 8,585, and 489,212 metric tons, respectively, at intermediate high altitudes (1940–3293 m above sea level); and 3,718, 3,940, 3,289, and 141,585 metric tons, respectively, at the highest altitudes (3293–4693 m above sea level) after the completion of the CPEC, representing a serious environmental threat. Applying the 20- and 100-year global warming potential calculations from the previous studies [ 41 , 42 ] (see Table S5 ), total CO 2 -equivalent emissions on the CPEC portion between Islamabad and the Khunjerab Pass could represent 2,173,142 and 1,731,079 metric tons. Moreover, considering the geographical proximity of the Tibetan Plateau, further analysis of simultaneous emissions from pollutants and greenhouse gases along the CPEC in Pakistan should be conducted to quantify the impact of freight transport by trucks on air quality and climate and to evaluate potential mitigation policies.…”