Decomposition of aggregate carbon intensity for freight: trends from 10 OECD countries for the period 1971–1993

Historical patterns of aggregate carbon intensity from freight are different than those from other sectors. While aggregate carbon intensity declined for all other sectors, aggregate carbon intensity for freight increased. The Adaptive Weighted Divisia rolling base year index specification is applied to carbon emissions from the freight sector of 10 OECD countries for the period 1970–1993. Increases in aggregate carbon intensity for nine of the countries range from less than 20% to over 150% and may be primarily attributed to shifts in modal structure toward more carbon-intensive modes. These increases in aggregate carbon intensity are driven primarily by an increase in activity, which parallels the growth in GDP. Furthermore, changes in fuel price and vehicle purchase taxes do not appear to be effective instruments for reducing energy consumption for this end use. Alternative policy options, including less-carbon intensive fuels and technologies, and reduced congestion, appear to be better choices.