A Shapley decomposition of carbon emissions without residuals

Conventional decomposition techniques for historical evolutions of carbon emissions present path dependent factor weights of selected variables next to significant residuals. Especially for analyses over long periods with many variables, high residuals make it almost impossible to derive reliable conclusions. As an alternative, we present the Shapley decomposition technique for carbon emissions over the period 1960-1996. This technique makes it possible to present a correct and symmetric decomposition without residuals. The starting point of our analysis was an extended Kaya Identity with nine components. In a study of four countries, the Shapley decomposition showed that the carbon intensity of energy use and the decarbonization of economic growth-variables that are targeted with current climate policy measures-have more effect on total emissions than generally suggested in conventional decomposition exercises. Another interesting conclusion from our analysis was that the effect of population growth on emissions can be for some countries more important than the decarbonization efforts. (C) 2002 Elsevier Science Ltd. All rights reserved.