Global emission of black carbon from motor vehicles from 1960 to 2006

Black carbon (BC) is a key short-lived climate change forcer. Motor vehicles are important sources of BC in the environment. BC emission factors (EF _BC), defined as BC emitted per mass of fuel consumed, are critical in the development of BC emission inventories for motor vehicles. However, measured EF _BC for motor vehicles vary in orders of magnitude, which is one of the major sources of uncertainty in the estimation of emissions. In this study, the main factors affecting EF _BC for motor vehicles were investigated based on 385 measured EF _BC collected from the literature. It was found that EF _BC for motor vehicles of a given year in a particular country can be predicted using gross domestic product per capita (GDP _c), temperature, and the year a country's GDP _c reached 3000 USD (Y ₃₀₀₀). GDP _c represents technical progress in terms of emission control, while Y ₃₀₀₀ suggest the technical transfer from developed to developing countries. For global BC emission calculations, 87 and 64% of the variation can be eliminated for diesel and gasoline vehicles by using this model. In addition to a reduction in uncertainty, the model can be used to develop a global on-road vehicle BC emission inventory with spatial and temporal resolution.