Effects of International Fuel Trade on Global Sulfur Dioxide Emissions

Fossil fuel combustion is the dominant source of global sulfur dioxide (SO2) emissions. With rapid globalization, the expansion of international fuel trade may have profound impacts on SO2 emissions due to the mixing and the spatial reallocation of fuels with varied quality (e.g., sulfur contents), which has not been clearly addressed. Here, by introducing international fuel trade and three additional counterfactual scenarios, we first assessed the impacts of fuel trade on global SO2 emissions for the period 1980-2030. It was estimated that in 2014 international fuel trade caused an increase in global SO2 emissions from hard coal and oil consumption by 4% and 71%, respectively, with stronger influences found for individual countries. By changing the fuel trade choice, global SO2 emissions attributable to fuel trade would be reduced by 78%. We also showed that such effects of fuel trade on SO2 emissions continuously increased from 1980 to 2014 and will keep increasing in the foreseeable future due to more frequent fuel trading under globalization.