Global Freight Transport\nEmissions Responsibility

The transportation of freight by land, sea and air underpins\nthe\ncomplex network of global trade in physical commodities. Greenhouse\ngas emissions from freight transportation are a significant component\nof global emissions and are predicted to grow in coming decades. However,\nthe inclusion of freight transport in emissions accounts and environmental\nimpact studies is often incomplete. Both data availability and difficulties\nin allocating freight emissions to specific commodity trades contributes\nto this. In this study, international freight movements by transport\nmode are estimated from the bottom-up by imputing global freight transport\nroutes. Emissions are estimated from these freight movements and integrated\nwith a global multiregional input–output model. This enables\nthe calculation of carbon footprints that are complete with respect\nto freight emissions. We estimate that global freight transport emissions\ncontributed 2.8 Gt CO<sub>2</sub>-equiv in 2012, or about 41% of total\ntransport emissions. In general, freight footprints contribute about\n9% to national emissions footprints. While trade in physical commodities\n(such as construction materials, food and fossil fuels) are associated\nwith the largest embodied freight emissions, services (such as public\nadministration, education and health) also require significant freight\ntransport. Using a consumption-based allocation of freight transport\nemissions allows the decarbonisation of other sectors to be complementary\nto the decarbonisation of transport through reduction in demand, for\nexample through material efficiency strategies. To drive decarbonisation\nin maritime transport it is critical to include bunker emissions in\nnational emissions inventories, thereby completing the system boundary.