Energy use and carbon emissions from freight in 10 industrialized countries: An analysis of trends...

Pergamon

Tmnspn REX-D, Vol. 2, No. 1, pp. 57-76, 1997 Published by Elsevier Science Ltd. Printed in Great Britain

1361-9209/97 317.00+0.00

PII: SMl-9209(%)00014-4

ENERGY USE AND CARBON EMISSIONS FROM FREIGHT IN 10 INDUSTRIALIZED COUNTRIES: AN ANALYSIS OF TRENDS

FROM 1973 TO 1992

LEE SCHIPPER,* LYNN SCHOLL and LYNN PRICE International Energy Studies, Energy Analysis Program Lawrence Berkeley National Laboratory,

1 Cyclotron Road, Berkeley, CA 94720, U.S.A.

(Received 12 June 19%; accepted 29 July 1996)

Abstract-This paper reviews trends in freight activity and energy use in IO industrialized countries from 1973 to 1992. We review changes in modes used to carry freight and analyze changes in the role of trucks. We carry out a decomposition of changes in freight energy use to identify the relative contribution of activity, modal structure, and energy intensity to the rise in energy use observed in each country. A similar analysis is carried out for carbon emissions, one of the many environmental problems associated with freight. Our three major findings are: (1) domestic freight volumes rose, with trucks carrying most of the increment, in almost every country we studied, (2) freight energy use and associated carbon emissions increased markedly and are rising v&a-w’s those associated with passenger travel in the IO industrialized countries studied, and (3) energy use for freight will continue to rise unless there are substantial reductions in the energy intensities of truck freight. We conclude that restraining or reducing emissions from freight will be particularly difficult because the factors that increased energy use and emissions for freight in the past are still important to raising energy use for freight. Noting that emissions from most other sectors have either fallen or grown less than freight, we discuss technologies and policies that might lead to restraint in this sector in the future.

INTRODUCTION

Energy used for transportation is primarily derived from petroleum products and is associated with a myriad of environmental problems including global climate change, urban air pollution, acid rain, noise and vibration, congestion, and accidents with motorists, pedestrians, and animals. Fuel use for transport is a significant source of carbon dioxide (CO2) emissions. The oxidation of carbon during combustion of fossil fuels accounts for 70-90% of total anthropogenic CO2 emissions, and CO2 emissions have been estimated to account for 60% of the increase in radiative forcing since preindustrial times (IPCC, 1995).

Energy and environmental policies of industrialized countries have increasingly focused on the transportation sector, with particular emphasis on passenger travel. At the same time, the movement of goods within individual countries has increased at nearly the rate of economic growth, leading to rising energy use and carbon emissions from freight. One recent study projects that energy use for freight will exceed that for travel on a world-wide basis in the year 2020 (WEC, 1995).

This paper reviews trends in freight activity and energy use in 10 industrialized countries that we have studied closely. We show that carbon emissions from freight energy use have been rising along with freight energy. We also decompose changes in energy use and carbon emissions to identify the relative contribution of changes in freight activity levels, modal shares, energy intensities, and fuel mix. Finally, we discuss what factors or measures might decrease freight energy use and carbon emissions in the future.

TRANSPORTATION AND FREIGHT ENERGY USE IN CONTEXT

Transportation comprises approx. 30% of total final energy use among member countries of the International Energy Agency, which is part of the Organization for Economic Cooperation

*On leave to the International Energy Agency, 75739 Paris, Cedex, France, to whom all comments should be addressed.

57

58 Lee Schipper et al.

and Development (IEA and OECD, respectively). The share of transportation in total final energy use has risen in nearly all industrialized countries. The only deviations from this trend come from the U.S. and Canada, where energy use for travel has been significantly restrained by large reductions in the fuel intensities of automobiles.

Freight accounts for roughly 28% of transportation energy use among IEA member countries. The share of energy use for freight vis-a-vis passenger travel is increasing in many countries. In the U.S., this share grew from 24 to 30% between 1973 and 1992. Further, average annual growth rates in freight energy use exceeded that of travel in several European countries, including France, Italy, and Norway.

Typically, l&12% of final energy use in each country is used to power its freight system. The energy derives overwhelmingly from oil products (road diesel, rail and marine diesel, and gasoline), with electricity providing a small share for electrified freight lines. Among the countries assessed in this study, the U.S. accounted for 63% of total freight energy use, the eight European countries combined (EU-8) accounted for 23%, and Japan accounted for 14% in 1992. The U.S. consumes more than twice as much energy for freight per capita (24 GJ/capita in 1992) as any of the countries in Europe, followed by Japan (11 GJ/capita), which ranks slightly higher than the other European countries. If we compare freight energy used per unit of gross domestic product (GDP), the gap is slightly smaller but the U.S. is still ahead. In every country, the bulk of freight energy is consumed by trucks, with most of the remainder consumed by rail and ship and a small amount by air.

METHODOLOGY*

Data The 10 industrialized countries covered in this study are the U.S., Japan, the U.K., former

W. Germany, France, Italy, Norway, Sweden, Denmark, and Finland.+ The energy used for travel and freight in these ten countries covers about 90% of total energy use in the transportation sector as reported to the 1EA.t

Our study in turn covers about 85% of that energy, omitting both energy use for pipelines [because of a lack of data on energy consumed or tonne-km (t-km)] and energy for some mis- cellaneous, non-freight trucks like cranes or fire engines.

The data used in this study come from national energy and transport statistics on fuel used for goods transport (freight) for each of the countries studied. Data include annual energy use by three main modes (truck, rail, and ship), freight volume [tonnes(t)], distance carried (vehicle-km), and fuel consumption by fuel type and mode, as well as economic and demographic data such as gross domestic product (GDP) and population. We include freight carried for own account and that carried as common carrier, include freight carried to a port for export (or from a port as an import), but exclude freight carried on vehicles of another country and exclude all freight between countries by sea or air. As a result, we slightly undercount truck freight (i.e. trucks in a foreign country, including cabotage), but count all rail freight, including transit. Using these data, we relate measures of activity (in t-km, by mode) to modal shares (percent of total t-km in each mode), energy use, and energy intensity (MJ/t-km). Our data sources (and much of our basic information) have been published yearly in the Transportation Energy Data Book (ORNL, 1996).

Estimating carbon emissions Carbon emissions are estimated using methodology and factors developed by the Inter-

governmental Panel on Climate Change (IPCC) (UN Environment Programme, 1995). Carbon emissions, unlike that of other greenhouse gases (GHGs), are directly proportional to the carbon content in a given fuel used for transport. Most of the carbon is converted to CO2 during combustion, while some is released as CO, CH4, or non-methane hydrocarbons which oxidize to CO2 over time. Heavy oil, typically used for shipping, is the most carbon-intensive, followed by

*See the Appendix for greater detail. ‘We often refer to the eight European countries as ‘EU-8’, to the U.K., former W. Germany, France, and Italy as the ‘EU-4,

and to Norway, Sweden, Denmark, and Finland as ‘NO-4’. *International sea-going freight bunkers are excluded because of the lack of data on both energy use and t-km for shipping,

particularly as this shipping does not ‘belong’ to any country. This is unfortunate, since bunkers accounted for 1.7% of energy use in IEA countries, 1.4% in non-IEA countries, and 1.56% of total world primary energy use in 1992. and roughly 5 to 10 times that figure as a share of transportation energy-use (IEA, 1995).

Energy use and carbon emissions: an analysis 59

diesel, kerosene (air), and gasoline. The carbon content of energy delivered as electricity depends on the mix of fuels used for generation. Coal is the most carbon-intensive, followed by oil and natural gas. For nuclear energy and renewable energy sources, such as biomass, hydro, and geothermal, a net carbon emission of zero is assumed. Although electricity makes up only a small share of final energy use for transportation, we count the carbon emissions from power generation.

Decomposition of energy use and carbon emissions The determinants of total freight energy consumption include the level of activity (t-km), the

share of each mode used, and the energy intensity (PJ/t-km) of each mode. We use a Laspeyres decomposition to separate the relative importance of each of these factors on changes in annual energy use over time for each country. The index calculates the percentage change in energy consumption relative to a base year that would have resulted if only one factor had changed. We repeat the analysis for carbon emissions, carbon intensity, and fuel mix, where carbon intensity is the additive effect of fuel mix and energy intensity.

These factors are not all independent. Growth in activity often leads to capital investments and turnover, which can reduce energy intensity if more energy-efficient vehicles are purchased. However, such reductions in energy intensity also reduce the cost of using energy - and releasing carbon - for freight haulage. Reduced operating costs may lead to increased shares of a given mode or increased attractiveness of obtaining goods from longer distances, with related increases in vehicle or freight energy use. However, data show that significant reductions in either freight volume or trucking energy intensity do not occur when fuel prices increase significantly. Since it is possible to substitute an expensive, low-carbon fuel (natural gas) for a cheaper, high-carbon fuel (coal), the interactions between activity, modal shares, and intensity are more complicated and we cannot model this interaction explicitly, but hope to do so in future work.

FACTORS AFFECTING FREIGHT ENERGY USE AND CARBON EMISSIONS

Freight energy use is determined by overall level of freight activity, the mixure of modes used, and the energy intensity of each mode. Carbon emissions, in turn, being proportional to energy consumed, are also determined by these factors, plus the actual fuel mix (i.e. carbon content) for each mode. In this section, we review each of these factors and offer insights as to what factors determine their values and trends.

Freight activity The usual indicator of freight activity is t-km, which measures the weight of freight and the

distance it is moved for each mode. This indicator provides only a crude description of the freight activity since it does not consider the characteristics and value of the freight, the distance a given product (or its material components) is moved, or the value-added by virtue of the goods having been moved - which is in turn influenced by the location of producers of primary materials, secondary goods, distributors, sellers, and final consumers. The total tonnage of freight shipped domestically depends on the magnitude and nature of the country’s agricultural, mining, and manufacturing output. As countries shift from economies centered on primary industries (agricultural and mining products) to ones in which manufactured goods predominate, the ratio of tonnage to GDP declines even though the distance these goods are transported may not decline, because manufactured goods have a higher value per tonne (Boge, 1993). Shipment of fuels for domestic use and export comprises a significant share of total freight t-km in many countries, so changes in the mix of primary energy sources can also affect freight transport volumes.

Total freight transport activity (t-km) grew by 45% in the U.S., 36% in Japan, and 38% in EU-8 between 1973 and 1992 (Table 1). By comparison, GDP grew 57, 104, and 51% in these regions. The ratio of total freight tonnage to GDP fell between 1973 and 1992 in most countries, as shown in Fig. l.* Data for the former W. Germany show a decline over time in the average number of tonnes per trip (DIW, 1995). This implies that the number of trips a given tonne of

*The declining ratio is also the result of the exclusion of international freight between countries (as well as transit freight) and natural gas and oil pipelines from our data. We suspect that these aspects of freight have risen more rapidly than the domestic freight we do count.

60 Lee Schipper ef al.

Table 1. Freight activity, GDP, and activity/GDP ratio for 10 OECD countries, 1973 and 1992

Freight activity (‘000 t-km) Gross domestic product (1985 PPP USS, billions)

1973 1992 % growth 1973-92 1973 1992 % growth 1973-92

U.S. 3057 Japan 408 Europe-8 780

France 196 W. Germanv Italy _

232 129

U.K. 138 Norway 18 Sweden 45 Denmark 11 Finland 29

4447 45 2986 4693 57 557 36 952 1938 104

1077 38 2467 3734 51 215 10 552 840 52 319 38 673 1044 55 232 79 480 789 64 197 42 549 745 36 26 48 32 66 106 51 12 88 118 34 17 54 52 73 40 36 24 40 59 48

cargo makes in its value-adding cycle is increasing. The evidence suggests that this trend probably holds for every country, since the number and traffic volume of light trucks and vans (under 5 t) has increased in every country we studied.

After the first oil price shock in 1973, annual growth in freight activity dropped dramatically in Japan along with GDP, but increased in the U.S. even though growth in GDP declined there. Growth in freight volume slowed in all countries except Finland and Norway following the second oil shock in 1979. After the oil price crash of 1986, annual growth in freight volumes increased at rates close to GDP growth in Japan, the U.S., France, the U.K., Sweden, and Finland, and grew faster than GDP in the remaining four countries.

Figure 2 plots freight vs industrial GDP (both normalized to population) between 1970 and 1993 for the U.S., Japan, Denmark, EU-4, and NO-4, showing three distinct levels of freight activity which can be explained by differences in geography and the role of raw materials production. We also find a tight short term correlation between changes in industrial GDP and changes in freight haulage when data for the U.S. or other countries are examined. The U.S. has the highest freight activity levels because of its major on-shore fossil fuels industry and large shipping distances. Sweden, Norway, and Finland have the highest ratios of freight haulage to GDP due to the high per capita levels of forest products and high levels of ore and metal production in these countries. Denmark, with almost no raw materials industries, has by far the lowest ratio of freight to GDP, and also the lowest share of manufacturing or industry in its GDP. We note that the geographically smaller countries (Denmark, Japan, and the EU-4) in general have relatively low levels of freight per unit of GDP but the highest shares of truck freight.

tonne-km/l995 US$ (PPP) 1.2

0.6

Fig. 1. Freight activity and total GDP: 1973 vs 1992 by mode.


tonne-km/capita (log scale)

-USA

+ Japan

+ Denmark

* EU-4

* NO-4

2.00 4.00 6.00

1083 1955 US$/cspita

lnduw w+ - nur)mluq. sol-. a*i”#. L w*UI,w. -UrmmwM**r-L-

Fig. 2. Domestic freight and industrial GDP in 10 industrialized countries: 197&93.

Freight modal structure Freight modal structure is measured by the share of freight activity transported by each mode

(truck, rail, ship). The modal choice for freight shipments is strongly influenced by the type of freight to be moved. Mining, raw materials, and basic agricultural products, which have low value per tonne and tend to be shipped in bulk quantities, are often transported via rail or ship, both of which are much less energy-intensive than trucks. As economies become more industrialized, intermediate and final goods take on a greater share of freight. Since trucks offer greater flexibility for such shipments, they tend to assume an increasing role in freight transport in more industrialized countries. The growing use of ‘just-in-time’ delivery in manufacturing also favors trucks. Other factors affecting mode choice include the nature of the transport network (roads, rail, waterways), cost factors, the distance of trip, and time requirements.

Table 2 shows that between 1973 and 1992 there was a significant shift toward trucking and away from rail in every country except the U.K. The greatest increase in the share of freight activity in trucks occurred in France, former W. Germany, and Japan. Trucks now account for over 50% of freight activity in 7 of the 10 countries studied. Within Europe the decline in the role

Table 2. Freight modal shares for 10 OECD countries, 1973 and 1992 (%)

1973 1992 1973 1992

U.S. Truck Rail Ship

Japan Truck Rail Ship

France Truck Rail Ship

W. Germany Truck Rail Ship

Italy Truck Rail

31 31 41 35 28 28

35 14 51

51 5

45

57 75 36 22 7 3

46 63 32 19 23 18

62 75 14 10 23 15

U.K. Truck Rail Ship

Norway Truck Rail Ship

Sweden Truck Rail Ship

Denmark Truck Rail Ship

Finland Truck Rail Ship

65 64 17 8 18 28

25 36 10 8 64 56

46 48 40 38 14 14

66 77 18 9 16 14

61 69 23 22 16 9


of other modes occurred in every country except in the U.K., where shipping increased from 18 to 28% due to increased barge traffic carrying crude oil. The large drop in the share of rail in France was in part due the large decrease in consumption of oil and coal products that were previously hauled by rail. In the U.S., by contrast, there has been only a slight shift from rail towards trucks.

This increased share of truck freight reflects a shift toward products for which trucks have inherent advantages over competing modes (Griibler and Nakicenovic, 1990). In Japan and most of Europe, trucks can move goods more rapidly than rail, while in the U.S., Sweden and Norway, geography gives water and rail-borne shipping advantages over long distances and explains why the share of truck freight in these three countries lies below the level elsewhere in Europe or in dense Japan. Ships and barges continue to be an important freight transport mode for agriculture and mining products in the U.S., in Japan (which has considerable inter-island shipping), and in the Nordic countries (whose main cities lie on the coasts).

Freight modal structure can also be measured as average distance per haul for each mode.* Although there is much overlap, trucks typically haul goods the shortest distances, shipping usually the longest, and rail intermediate, depending on the geography of the country. Conversely, distances depend in large part on what is hauled. Some materials and goods remain close to their places of origin, others travel a great deal. Detailed examination of freight shipments in former W. Germany shows that for bulk goods such as oil, coal, ores, scrap, and metals, distance per haul is indeed less than average, while for others, particularly manufactured goods, distance is greater (DIW, 1996). This is logical--raw materials, many of which are common and available everywhere, have low value until they are used to make finished products, which may be of higher value and worth sending a long distance. Some raw materials (ores, fuels) may not be available everywhere, however, and heavy users may wish to locate near to key inputs. An analysis of t-km hauled by type of product and mode in France shows that the heaviest, most bulky goods indeed travel by rail or ship, while trucks dominate almost all other products (OEST, 1995).

Table 3. Freight modal energy intensity for 10 OECD countries, 1973 and 1992 (MJ/t-km)

1973 1992 % change 1973 1992 % change -_ -_. -. --.^ -_-_-

U.S. Truck Rail Ship Average

Japan Truck Rail Ship Average

France Truck Rail Ship Average

W. Germany Truck Rail Ship Average

Italy Truck Rail Ship Average

EU-8 Truck Rail Ship Average

3.22 3.27 2 0.48 0.29 -41 0.42 0.29 -31 I .33 1.38 4

4.77 4.42 -7 0.27 0.21 -23 1.10 0.50 -55 2.21 2.50 IO

2.76 3.11 13 0.30 0.29 -3 0.45 0.41 -8 1.69 2.40 42

2.69 2.26 -16 0.77 0.36 -53 0.95 0.52 -45 I .49 1.52 2

2.76 2.93 6 0.37 0.33 -12 0.32 0.45 41 1.85 2.29 23

2.82 2.87 2 0.45 0.35 -22 0.96 0.77 -20 1.84 2.12 I5

U.K. Truck Rail Ship Average

Norway Truck Rail Ship Average

Sweden Truck Rail Ship Average

Denmark* Truck Rail Ship Average

Finland Truck Rail Ship Average

3.60 3.49 -3 0.84 0.59 -30 1.84 I .05 -43 2.83 2.58 -9

4.53 3.57 -21 0.51 0.44 -14 2.03 I .72 -15 2.52 2.30 -9

I .98 2.58 30 0.25 0.24 -3 0.54 0.35 -35 I .08 1.38 28

3.91 4.77 22 0.89 0.79 -12 2.86 I .82 -36 3.19 3.41 7

1.79 1.79 0 0.46 0.29 -36 0.25 0.40 61 1.23 1.34 8

* 1972 instead of 1973.

*Note this is not the same as the average distance a given shipment or product moves.


Modal energy intensity Modal energy intensity, defined as MJ/t-km, is determined by two characteristics-the energy

required to move the vehicle and vehicle capacity utilization. The energy required to move the vehicle is determined by fuel used, transport conditions (traffic and geography), and vehicle characteristics (individual models, vehicle sizes). Vehicle capacity utilization involves loading levels of individual vehicles, the relative utilization of each kind of vehicle, and the numbers of each kind of vehicle in service for an entire fleet.

Changes in freight energy intensity varied among countries, as shown in Table 3. In some cases the aggregate energy intensity increased, even though energy intensity from the individual modes decreased, due to the interaction between energy intensity and modal shifts especially towards more energy-intensive trucking. Trucking is significantly more energy intensive than any of the other modes, and there was a large shift toward trucking in many countries, as discussed above. Aggregate energy intensity increased by 4% in the U.S., by 10% in Japan and by 15% in EU-8 between 1973 and 1992. The only countries where aggregate energy intensities declined were the U.K. and Norway. We focus our discussion on the energy intensity of trucking and comment briefly on that for rail and shipping.

The energy intensity of trucking. Since trucking dominates both freight haulage (in most countries) and energy use in all countries, the energy intensities of trucks and trucking per se are the most important components of total freight energy use. Trucks can be classified as large, combination trucks (over 6 t), medium trucks (1 S-6 t), and small (or light) trucks (under 1.5 t).

Fuel choice is almost exclusively diesel for large trucks, but mixed between gasoline and diesel (depending in part on fuel price or on regulations) for medium and small trucks. Depending on fuel, light trucks use 10-25 l/100 km, with the U.S. trucks by far the most fuel intensive. In the U.S., Japan, Sweden, and Norway, most light trucks use gasoline, while in France, former W. Germany, and Italy, these are increasingly using diesel. Regular single-unit trucks require 2540 l/100 km, with the U.S. trucks lying close to those in other countries. Large, combination trucks in the U.S. and the Netherlands use even more fuel.

Along with fuel choice, traffic conditions and vehicle size also affect the energy intensity of trucking. National data from Finland, Sweden, and the U.S. confirm that the energy intensity of heavy trucking in these three relatively empty countries is indeed low, 1.5-2 MJ/t-km, compared with the higher energy intensities of the large trucks on the crowded roads in Japan, the U.K., or continental Europe. Figure 3 shows that the heaviest trucks use three to five times more fuel/km than light trucks and about 30% more fuel/km than medium trucks. Articulated units, the largest trucks, make up only lO-15% of the stock in most countries. In 1990, there were three to ten times more trucks under 1.5 t capacity than over 1.5 t capacity in most European countries (ECMT, 1995). In the two countries with more trucks over 1.5 t (France, former W. Germany), relatively

L per100 km

60/

* F MadlCombi

*US Madlum

+ US LlQht

0 I I , I 1 1 I I I I

1970 1973 1976 1979 1962 1965 1988 1991 1994

(10wo.: Ur,no. BM*w# Nwonu LabOmbq

Fig. 3. Fuel intensities of trucks by size and fuel.


light trucks (1.56 t) dominate. Regulations affect these distributions. By contrast, Swedish and Finnish regulations permit the largest units in all of Europe. U.S. trucks have the longest potential hauling distances, so their apparently small numbers are made up for by long utilization, typically about 100000 km/yr (ORNL, 1995).

Along with the vehicle intensities of trucks by size and type, the overall energy intensity of truck freight is also determined by and the relative utilization of each kind of vehicle and loading levels. Loading levels are indicated by the share of available truck t-km used to transport goods and the backhaul vehicle-km (the vehicle-km traveled by empty trucks). In Denmark the share of available truck t-km that was utilized fell slightly during the period between 1984 and 1993, from 45 to 40%, even though backhaul vehicle kilometers for heavy trucks (capacity of over 6 t) fell from over 30% to less than 20% in the same period (Danish Ministry of Transport, 1995). In the Netherlands, the reverse trends occurred, as the share of backhaul kilometers rose slightly to 30% between 1981 and 1989, but the share of total available t-km used increased slightly (Bureau Goudappel Coffeng BV, 1995). Thus, the mix of trucks and capacity utilization together determine trucking energy intensity, and the vehicle intensity of trucks by type is of secondary importance. Indeed, over time, the changes in vehicle intensity suggested in Fig. 3 are far smaller in general than the wide differences in vehicle intensity between truck classes. And the differences and changes in aggregate modal intensity turn out to be larger than changes in vehicle intensity. Hence the overall modal energy intensity of trucking is far more dependent on the type of fleet and its utilization than on the vehicle intensities.

The energy intensity of freight trucking between 1970 and 1992 for the countries studied is shown in Fig. 4 (and also given for 1973 and 1992 in Table 3). Trucking intensity was the lowest in Finland, Sweden, and the former W. Germany. In Sweden and Finland trucking is dominated by loads of forest products and other bulk materials, encouraged by the largest permissible trailer sizes in Europe. But the modal fuel intensity rose gradually in Sweden as more and more smaller trucks entered the stock to carry smaller loads of other kinds of goods. Japan had the highest truck modal intensity until 1983, at which time it was surpassed by Denmark. A study of Denmark showed that very low cost diesel fuel encouraged proliferation of smaller trucks and even abuses of truck use as private vehicles (Schipper et al., 1993).

Between 1973 and 1992, there was a slight increase in the intensity of trucking in the U.S. and the EU-8 (2% in both), but there were countries with large increases (Sweden, France, and Den- mark) and those with declines (former W. Germany, Norway, the U.K., and Japan). During this time there were many fluctuations in energy intensity that reflect important changes in the nature of trucks and trucking. Major changes occurred in truck fleets of every country. While the number of heavy trucks (including semi-trailers) rose only slowly, the number of trucks under 6 t and especially under 1.5 t rose. Since lighter trucks have intrinsically higher modal energy intensities than heavier ones (for the same loading), this contributed to higher energy intensities for trucking.

MJ per tonne-km 6

+ Denmark

+ Nomay

* Sweden

*Finland

* Germany

+ Japan

*USA

8 France

* naly

0’ 1970 1973 1976 1979 1962 1965 1966 1991

IbaLd” wm 1Nd. tarsa L- w;*q NMlDrul bbef-

Fig. 4. Truck freight energy intensities in 10 industrialized countries.


In Japan, for example, intensity rose through 1976, but fell sharply in the 1977-80 period and wound up lower in 1992 than in 1973. These fluctuations must have been caused by changes in utilization, since the stock of trucks turns over only slowly, and since the changes in fuel intensity of the stock of vehicles by size has been relatively small. Utilization is affected by congestion, but also by changes in the structure of the trucking industry and by the complicated system for delivering goods in Japan (Kiang and Schipper, 1996).

In the U.S., intensity increased through the late 198Os, then fell, and ultimately ended up only slightly higher in 1992 than in 1973. Average fuel use per vehicle-km was lower in 1991/2 than in 1973 for medium and heavy (tractor-trailer) trucks, and significantly lower for light trucks (ORNL, 1996).* It appears that improvements in technical efficiency were offset by several factors including the increase in operating speeds on major intercity highways and increasing traffic congestion in urban areas. There was also growth in the fraction of total truck traffic by the larger tractor-trailer trucks, which use more fuel per kilometer than medium trucks. The increase in energy per t-km through the late 1980s was apparently due to factors related to the operation of trucking fleets and the nature of freight carried. Despite deregulation of the trucking industry (implemented to promote more efficient operation), there was an increase in empty backhauls (Mintz, 1991), resulting in reduced tonnage per distance traveled. Growing volumes of solid waste and average distances of trips for disposal also increased the distance of empty backhauls. In addition, it appears that the weight carried per volume of truck capacity has declined. One reason for this is increased light-weight but bulky packaging for many goods. Nevertheless, by 1993 the intensity of trucking in the U.S. had declined to its 1973 level (see also EIA, 1995), clearly a function of utilization, since the vehicle intensities of new trucks declined very little in those years (ORNL, 1996).

The energy intensity of rail. The energy intensity of rail freight is much lower than that of trucking principally because the overall loads are far greater and the locomotives are efficient. Examination of our data shows rail freight requires two to five times less energy on average than truck freight, and probably only half the energy of freight sent by the largest trucks.

Between 1973 and 1992, the energy intensity of rail freight transport declined by 41% in the U.S. and by 22 and 23% in EU-8 and Japan, respectively (Table 3).+ Electrification accounts for part of the decline. The efficiency of a diesel locomotive in converting fuel to traction power is far less than that of electric motors, so replacement of diesel by electricity causes a significant decline in final energy intensity. Even if we account for the primary energy used to generate electricity, however, the resulting energy intensity of freight in Europe has still declined. Other reasons for the decline were use of stronger locomotives and the trend to cutting unprofitable lines, which presumably supported smaller trains with less than full loads. The large decline in Japan after 1987-88 was apparently due to the radical restructuring of the rail industry (Kibune, 1991; Kiang and Schipper, 1996).

The energy intensity of shipping. The energy intensity of shipping dropped in all countries except Finland and Italy between 1973 and 1992. Differences in the energy intensity of shipping reflect the size and loading of vessels: Europe and Japan activities are dominated by relatively smaller vessels, while the U.S. intensities are much lower, reflecting the dominance of larger ships carrying ores, grain, and energy products. It should be noted that much of the domestic haulage in the U.S. occurs in large coastal, river, or ‘Great Lakes’ vessels, which are more common to international rather than domestic commerce in other countries and therefore not included in this study. However, coastal shipping is included for Japan, Denmark, Norway, Sweden, former W. Germany, and France.

Fuel mix Carbon emissions are dependent on the mix of fuels used for transport and the amount of fuel

consumed. Therefore, given that fossil fuels or carbon-containing fuels are used, the factors

*For the U.S., data on t-km are published only for interstate trucking. Using data on vehicle-km of trucks by type of truck and type of service, and following Wilson (1995), we assumed that every freight light truck was loaded with 100 kg, every medium truck with 2000 kg on average for every km given. This procedure adds about 15% to the published totals for trucking t-km for the U.S., making data more comparable with that for other countries.

‘Unfortunately, most of the data on energy use are for the entire railroad system, not for the separate operations of freight and passenger haulage. Therefore, our parsing of this energy by the ratio of freight to passenger haulage using 2 passenger-km = I t-km, a procedure used by some railroads, is only an approximation.


affecting carbon emissions are the same as for energy use with the addition of the carbon content of the fuel mix. As noted above, virtually all heavy trucks and most medium trucks rely on diesel fuel. The fuel mix for light trucks and commercial vans varies between countries, with those in the U.S., Japan, the U.K., and the Nordic countries heavily dependent on gasoline, while those in

Table 4. Total freight final energy use and per capita freight energy use for 10 OECD countries, 1973 and 1992

Total freight energy use (PJ) Per capita freight energy use (GJ/capita)

1973 1992 % increase 1973-92 1973 1992 % increase 1973-92

U.S. 4056 6158 52 19.1 24.1 26 Japan 928 1393 50 8.5 11.2 32 EU-8 1439 2283 59 5.8 8.8 52

France 331 516 56 6.4 9.0 41 W. Germany 346 487 41 5.6 7.6 35 Italy 240 536 124 4.4 9.3 113 U.K. 392 509 30 7.0 8.8 25 Norway 44 60 35 11.2 13.9 25 Sweden 49 70 43 6.0 8.2 36 Denmark* 30 56 87 6.7 10.9 63 Finland 36 49 34 7.8 9.4 21

* 1972 instead of 1973

GJ/capita

Fig. 5. Freight energy use per capita in 10 industrialized countries: 1973 vs 1992 by mode.

MJ11985 US$ 1.4 1

,.* q Trucks [Zif Rail WShip NAir

n 0.8

0.6

0.4

0.2

0.0

Fig. 6. Freight energy use per GDP in 10 industrialized countries: 1973 vs 1992 by mode.


continental Europe are far more dependent on diesel. Over time, the share of light trucks using diesel has increased everywhere. But the rapid rise in the number of light trucks as a share of all trucks has kept the overall role of gasoline in the U.S and the Nordic countries fairly constant.

Fuel mix is not likely to play an important role in either the inter-country comparisons of emissions or the changes over time because of the dominance of oil products in total energy use, and the small differences in emissions among them.

FREIGHT ENERGY USE

Total freight energy use increased substantially in every country between 1973 and 1992, with Italy having the most significant increase (124%) and the U.K. the least (30%) (Table 4). Figure 5 shows freight energy use per capita for 1973 and 1992 by mode. Given the level of increase in domestic freight haulage, it is not surprising that energy use for domestic freight increased by 52, 50, and 59% in the U.S., Japan, and the EU-8, respectively. Figure 6 shows that freight intensity per unit of GDP is still the highest in the U.S., followed by Japan, the Nordic countries, and the remaining European countries.

To show how activity, modal structure, and energy intensity interacted in the development of freight energy use since 1973, a Laspeyres decomposition of changes in freight energy was per- formed (Table 5). The values for 1979, 1985, and 1992 represent the percent change in energy use if only one factor (activity, modal structure, or intensity) had changed for each country relative to 1973. Increase in freight activity was the most significant factor driving the increase in energy use in almost every country. The most extreme example is Italy, where activity alone would have increased energy use by 80% in 1992. In all cases, both the activity and the structure effect alone would have driven energy consumption up; in most countries, this structure effect was driven by modal shifts towards trucking and away from rail. In Japan, France and former W. Germany, modal shifts would have increased energy use by 31, 27, and 27%, respectively, between 1973 and 1992. Only in Sweden and the U.K. was the impact of modal change over this period held to less than a 10% increase in energy use. Energy intensities fluctuated within and across countries, decreasing energy use in some cases and increasing it others. Declines in energy intensities were seen in the U.S., Japan, former W. Germany, the U.K., Norway, and Finland. However, increases in activity and modal shifts counteracted these declines and resulted in substantial growth in energy use.

Modal mix has a large impact on freight energy use, because the energy intensity of truck freight, in MJ/t-km is as much as ten times that for shipping or rail. Consequently, the U.S. freight system, in contrast to its passenger fleet, is on average less energy intensive than any of those in Europe or Japan. We can estimate the importance of differences in modal structure among countries, vis-a-vi.s intensities, by evaluating the energy intensity of each country’s freight with actual modal intensities for truck, rail, and domestic shipping at the average modal mix for all ten countries. If aggregate intensity for a country falls when we ascribe to it the average modal mix, then that country’s modal mix was more energy intensive than the average. Bear in mind that the U.S. (for which trucks provide less than 30% of freight) dominates this average. The results,

Table 5. Results of Laspeyres decomposition of freight energy use for 1979, 1985, and 1992 (1973 = 100)

Actual energy use Activity effect Structure effect Intensity effect

1979 1985 1992 Residual 1979 1985 1992 1979 1985 1992 1979 1985 1992 (1992)

U.S. 130 142 152 0.98 122 126 145 101 102 112 105 110 92 Japan 122 116 150 0.96 108 107 136 109 125 131 103 84 80 EU-8 119 122 159 1 .oo 116 116 138 104 107 115 99 98 100

France 118 107 156 0.99 106 93 110 105 108 127 106 105 111 W. Germany 113 106 141 1.01 113 115 144 109 116 127 92 82 78 Italy 134 172 221 1.01 126 143 179 108 114 117 99 106 107 U.K. 106 103 130 1.02 128 128 142 97 98 102 89 85 91 Norway 106 121 135 1.01 97 121 148 107 109 112 106 93 82 Sweden 120 137 143 1 .oo 111 108 112 101 98 104 109 131 123 Denmark 122 156 169 0.92 123 114 127 107 108 110 87 117 112 Finland 114 123 134 1 .oo 106 113 123 97 103 110 111 107 99


MJ per tonne-km 4.0

n Actual Structure q Avg Modal Mix

2.5

Fig. 7. Freight energy intensities in comparison. Actual vs imposed average modal mix in 1992.

shown in Fig. 7, are clear: aggregate modal intensity only increased in the U.S. The freight systems of all other countries except Norway (and Sweden) are more reliant on trucks than the U.S. As can be seen, this reliance, coupled with the high energy intensity of trucking in Japan, France, and Denmark, raises energy use in those countries significantly.

In sum, while freight activity increased roughly at the rate of GDP, with a few exceptions, modal shifts towards trucking occured in all but one country. The combined impact of these two trends offset the impact of lower energy intensities and led to increased overall freight energy use in all countries. In contrast to other sectors ( Schipper et al., 1992a; Scholl et al., 1996; Schipper et al., 1996a; Greening et al., 1996), freight was the only sector where increases in activity and modal shifts led to strong increases in energy use between 1973 and the 1990s while decreases in intensity were seen only in six of the ten countries studied. In travel, modal shift was significant only in one country in raising energy use, while intensities declined strongly in the U.S. and increased (or decreased) only slightly in the other countries we studied. With these important findings in mind, we turn to the evolution of carbon emissions from freight.

CARBON EMISSIONS FROM FREIGHT

Trends in carbon emissions closely followed trends in energy use. Emissions from gasoline and diesel differ only slightly, while those from electricity depend critically on the mix of fuels used for generation. No significant shifts in fuel shares took place over the period except in one country, France, and even there the role of electricity in the freight sector remained small (less than 2% throughout the entire period). Therefore, differences in emissions among countries or over time

Table 6. Total freight carbon emissions and per capita freight carbon emissions for 10 OECD countries, 1973 and 1992

Freight carbon emissions (Mt CO2) Per capita freight carbon emissions (tC/capita)

1973 1992 % increase 1973-92 1973 1992 % increase 1973-92

U.S. 74.4 112.0 51 0.35 0.44 26 Japan 8.6 28.0 51 0.17 0.22 29 EU-8 30.3 46.1 52 0.12 0.18 50

France 6.8 10.2 50 0.13 0.18 38 W. Germany 7.6 10.1 33 0.12 0.16 33 Italy 4.9 11.0 126 0.09 0.19 Ill U.K. 7.8 10.2 31 0.14 0.18 29 Norway 0.9 1.3 44 0.23 0.31 35 Sweden 0.9 1.3 43 0.11 0.15 36 Denmark* 0.7 I.1 69 0.13 0.22 69 Finland 0.7 0.9 29 0.15 0.18 20

* 1972 instead of 1973


have been dominated by changes in overall energy use, rather than changes in fuel mix per se. In short, carbon emissions from freight grew significantly over the period for all ten countries in the study because energy use for freight grew significantly.

tC/capita

I - 1 n Trucks q Rail UShip HAir

Fig. 8. Freight carbon emissions per capita in IO industrialized countries: 1973 vs 1992 by mode.

kgC/l Oe3 tonne-km

60

50

40

30

20

- Denmark

+ Norway

* Sweden

*Finland

* W. Germany

+ Japan

* USA

*France

*UK

+ Italy

10 1 I I I 1 /

1970 1973 1976 1979 1962 1965 1966 1991 OOWM: Urmo. IMd~ Nubn.l L*oNq

Fig. 9. Freight carbon intensities in 10 industrialized countries.

Table 7. Results of Laspeyres decomposition of freight carbon emissions for 1992 (1973 = 100)

Actual carbon Activity Structure Energy intensity Fuel mix Carbon intensity emissions effect effect effect effect

U.S. 152 145 116 Japan 151 136 129 France 150 111 122 W. Germany 133 144 121 Italy _ 226 180 116 U.K. 131 142 103 Norway 146 142 112 Sweden 143 112 104 Denmark 169 I34 93 Finland 129 118 112

Residual

92 101 92 I .03 80 101 81 0.95

111 95 106 0.95 76 99 76 0.99

107 102 109 1.01 90 101 91 1.01 86 106 91 0.99

124 98 122 0.99 111 101 112 0.83 99 99 98 1 .oo


Per capita emissions grew 26% in the US, 29% in Japan and 50% in EU-8 between 1973 and 1992 (Table 6 and Fig. 8). Since GDP growth per capita was greater in the U.S. and Japan than in EU-8, emissions per unit of GDP fell during the same period. Of the European countries, growth in carbon from freight was the highest in Italy (126% change) and the lowest in Finland (29% change). Figure 9 shows freight-related carbon emissions per t-km between 1970 and 1992. Both modal mix and energy intensity contribute to the differences in per capita emissions from freight we observed, and both contributed to changes over time. Where emissions/t-km rose, this was primarily because of modal shifts, offset in a few countries by falling energy intensities of freight transport, reinforced by increasing intensities in the others.

A Laspeyres decomposition of carbon emissions from freight shows results similar to those illustrated for energy. Table 7 illustrates how higher freight activity, modal shifts, and carbon intensity (i.e. the quantity shown in Fig. 9) contribute to changes in actual carbon emissions. Carbon intensity fell in six of the ten countries while elsewhere this effect, as well as the changes in structure (except Denmark) and activity, led to increased emissions. Major electrification of railroads led to a decline in the fuel mix factor for France, while a shift away from electric rail to trucks led to the opposite effect in Norway. Otherwise fuel mix varied very little, falling slightly in a few countries. Energy intensity fell in most countries. In all cases, carbon emissions from freight were significantly higher in 1992 than in 1973. The increases were even stronger than those we measured for travel (Scholl et al., 1996) and in stark contrast to the decline in emissions experi- enced in most other sectors (Schipper et al., 1996b).

WHAT DRIVES ENERGY USE AND EMISSIONS FOR FREIGHT?

The foregoing analysis suggests that GDP drives the volume of freight and that higher GDP is associated with increasing levels of truck freight. Trucking so dominates freight energy use that the average energy intensity of freight in the EU-8, Japan, and the U.S. increased because of the rising importance of trucks. As a result, the share of total energy for freight and associated carbon emissions have increased almost everywhere.

Did changes in prices affect changes in trucking? By 1992 most of the trucks on the road were bought after the first fuel price shock, so the 1992 intensity should give a picture of the overall impact of price changes on the fleet and its utilization. Figure 10 shows real fuel prices in each country, weighted for the share of gasoline and diesel. The abrupt increases in 1973 and 1979 are dramatic, but so is the decline in 1986. One would expect that differences in fuel prices would explain differences in trucking energy intensity. But there was only a weak inverse relation between fuel price and freight intensity in 1992 and virtually none at all in 1973.* If we focus only on light trucks, there is also a slight negative relation between price and vehicle intensity. But we find no

1965 US$/L

:1:: i 1970 1973 1976 1979 1952 1955 1999 1991

-Denmark

+ Norway

*Sweden

* W. Germany

+ Japan

*USA

*France

+UK

-Italy

Fig. 10. Truck fuel prices in IO industrialized countries. Diesel and gasoline prices weighted by consumption.

*Since gasoline is important to fueling light trucks in a few countries, and medium-sized trucks in all countries in the early 197Os, its share in consumption is used to calculate a weighted fuel price.


correlation between change in trucking fuel price and change in trucking modal intensity between 1973 and 1992, although it appears that higher prices did lead to reductions in vehicle intensities in each class of vehicle. Further, we found little relationship between the ratio of gasoline to diesel price and the share of diesel used in the trucking fleet, except among light trucks. Considering the importance of the mix of trucks and the fact that medium and heavy trucks virtually all run on diesel, the share of gasoline first depends on the overall importance of light trucks (where there is still a significant component of gasoline) and then on the role of diesel within the population of light trucks.

We find it difficult to attribute changes in aggregate trucking modal intensity to changes in fuel prices for a variety of reasons. The characteristics of trucking, i.e. vehicle sizes and utilization, have evolved, which has changed fuel intensity independently of the technical properties of individual models of trucks. These conditions vary from country to country, which may obscure a relation between fuel intensity of trucking or of trucks with fuel price. And various regulatory conditions exist among the countries. For example, Norway, Finland, and Sweden have had low diesel prices (relative to gasoline) but charged a fee per km for all vehicles dependent on vehicle type but independent of actual fuel intensity (Schipper and Peraelae, 1995; Schipper et al., 1992b; Schipper et al., 1993) Therefore, diesel prices in these countries do not represent the real variable costs of driving one km. Furthermore, until 1993, Danish truck drivers with VAT registration could obtain virtually tax-free fuel from ordinary suppliers; this subsidy is not reflected in the published prices but distorts the freight sector toward the use of small and medium-sized trucks (Schipper et al., 1992~). Additionally, regulations on weight, tolls on roads, drivers’ wages, and so on, all affect true operating costs per km, in many cases more so than fuel costs. And as noted above, the mix of trucks and actual traffic conditions play a key role in aggregate intensities. Hence the role of fuel prices is most likely hidden in these aggregate comparisons by such other factors. At the same time, we cannot discount the role of low diesel prices in France and Denmark in contributing to high modal intensities there. Thus while we cannot measure a clear relationship between fuel price and fuel use (either through modal or vehicle intensity or total fuel consumed), these price distortions suggest that prices do play a role that is simply hard to discern given all the other confounding factors.

Thus, fuel costs, however important they may be, are only one of many considerations affecting fuel use for trucking. Since the equipment used is produced and bought in an international market with relatively few barriers, trucking operators presumably weigh the importance of fuel savings against other factors in choosing their vehicles. In short, improvements in fuel efficiency of vehicles have been offset by more important changes in the structure and regulation of the trucking industry itself.

tC/I 063 1980 $US 0.5

RI -

Fig. 1 I. Carbon emissions per GDP in 10 industrialized countries: 1973 vs 1991 by major end use.


WHAT COULD RESTRAIN CARBON EMISSIONS FROM FREIGHT?

Figure 11 shows carbon emissions for 10 sectors of 10 countries in 1973 and 1991 (in tonnes of carbon per GDP). Emissions from freight grew more strongly between 1973 and the early 1990s than emissions from any other end use sector in the industrialized countries The increase in the relative importance of freight (and in most countries, travel as well) contrasts with the general shrinking from all other energy uses. How can carbon emissions from the freight sector be restrained?

Technology of freight: propulsion, fuel mix? There are numerous techniques for reducing energy use per vehicle-km (see Michaelis et al.,

1996; Schipper et al., 1992a). It is expected that improvements in vehicle propulsion efficiency will continue to be made over the long term. An equally important means to reduce carbon emissions is through switching to fuels with significantly lower carbon emissions per unit of energy. Natural gas has somewhat lower emissions, and may indeed gain acceptance as a bridge towards a propellant that can be used in fuel cells. Switching to rail in high density corridors offers some relief from rising emissions, too, especially if the electricity is produced from non-fossil sources or natural gas. But unless a biomass fuel with little carbon input required for processing is developed, the prospects are dim for a truly low carbon fuel at prices competitive with fuels made from crude oil or natural gas.

Vehicle capacity utilization We have emphasized the importance of vehicle capacity utilization to the fuel (and carbon)

intensity of freight haulage. Clearly reducing empty backhauls could reduce energy use (and other costs) for freight. Allowing cabotage in Europe (i.e. permitting trucks registered in Italy to haul freight between destinations in, say, Denmark or between Denmark and a third country) could increase utilization. Increased intermodal combinations would also reduce overall handling and perhaps permit greater utilization of rail in combination with trucking. Permitting larger trucks (such as three-trailer units) for intercity hauling would also save energy, although there are some safety concerns.

Modal mix What is the likelihood of less trucking and more rail or even shipping? The trend towards

more trucking in every country is clear. Trucks have shaved market share from rail (sometimes accompanying an absolute decline in rail freight) while providing most of the increase in freight. To some extent, shifts in the relative costs of modes might favor increases in railroad freight, but the real shift ‘back’ will only occur if railroad shipping times are reduced, particularly those caused by circuity of routings. Privatization and restructing of railroads in Europe, a very sensitive political issue, might lead to a reduction in rail share in the short term, but more competition with trucks in the longer term.

Reduction of activity? Boge (1993) points to the growing distances materials and products are moved in modern

economies. Is this movement wrong? The demand for freight is derived both from the demand for materials and intermediate inputs to make final products and the final demand for these products close to consumers (including consumers in other countries). Some of this movement of goods and materials within a country (or between countries) is related to differences in costs of labor or raw materials that make it appear attractive to firms to ship partial products or inputs around in ways that minimize total production costs. Growing incomes permit consumers to sample goods made elsewhere at home, or abroad. Certainly if freight costs are artificially low then long distance sources of raw materials and goods, or, alternatively, long distance markets both look more attractive than otherwise, even if the supplier has no particular market advantage. Political difficulties with full-cost pricing - witness just the protests of truck drivers in France when the government tries to increase the tax on diesel fuel, which is way below its gasoline counterpart - contribute to this problem.

We cannot comment here on whether full internalization of externalities would lead to major changes in freight activity. However, energy per se is only a minor factor overall. After all, energy


represents typically 10% of total costs of economic activity (measured at final consumption), 15% of which goes to freight as high quality road fuel or electricity. This means the fuel cost to the economy of freight is very small. Significant changes in fuel prices could influence modal mix somewhat towards modes with lower energy costs, and perhaps discourage some long-distance shipments, but it hardly seems likely that such changes would have a major impact on freight movements, unless manufacturers begin to seek closer suppliers or markets to reduce freight costs at the margin.

SUMMARY AND CONCLUSIONS: CARBON EMISSIONS FROM FREIGHT IN A WIDER CONTEXT

Since 1973, energy use for freight transport and associated carbon emissions have increased faster than those from other sectors in the countries we studied. The underlying trends we analyzed were clear: increased freight activity, modal shifts towards trucks, and little energy saving or carbon restraint, leading to continual increases in carbon emissions. Our analysis excluded air freight, international sea bunkers, and natural gas and electricity used for pipelines. It is fair to say that these omissions, while small, lead to a clear underestimate in growth in emissions. With growth in world trade, stimulated in part by GATT, the fall of the Berlin Wall, and increasingly liberal economic rules within trading blocks, even greater future levels of freight, higher aggregate energy intensities, more fuel, and more carbon emissions can be expected.

Why did emissions for freight take a different course than those for the other sectors? The answer seems to be that freight, like personal travel, cannot be reduced easily to simple tech- nological or behavioral questions. The web of international or inter-regional trade, as well as local distribution, has become increasingly complex as society’s wealth increases. Exchange of goods is a basic part of that increase. To be sure some dematerialization - measured as less consumption of bulk materials like iron and steel, cement, bulk foodstuffs, and chemicals relative to GDP - has occurred; however, this trend has been more than offset by increased handling of both materials and products, which leads to greater distances travelled for fewer tonnes.

Nevertheless, attempts to deal with the wider environmental problems of freight shipments, such as noise, air pollution from vehicles, congestion, etc. could lead to less freight activity (through both reduced distances and more efficient handling) and more efficient freight hauling vehicles as well. Equalizing diesel fuel and gasoline taxes would certainly spark changes in truck energy efficiency. Increased road-use fees on truck use or entry into congested areas could stimu- late greater handling efficiency and fewer backhauls. For example, when San Francisco airport imposed a fee on each trip through the arrival area made by commercial passenger vehicles like vans, the number of trips was cut down remarkably! Higher fuel prices would also lead to more efficient engines and fuel use. Most of these changes would also lead to reduced carbon emissions.

The ability to reduce carbon emissions from freight does not look encouraging, though, given recent trends. Understanding and either accommodating or heading off the underlying forces responsible for ever-growing volumes of freight might be a workable strategy in the long run, even as we continue to reduce the overall carbon emissions (and other air pollutants) from trucks and other freight vehicles. Still, in increasingly competitive markets, small increases or decreases in relative costs could change patterns of production and trade enough to make a change in total freight volume as well as modal shares. It is crucial, therefore, that carbon emissions be reflected in the costs of freight through taxes. But how much the tax should be, how it should be implemented, and what precisely its effects are likely to be in short and long run scenarios remain questions for future research.

Suppose, for example, that changes in freight costs, which included a carbon tax, provoked a 20% decline in the energy intensity of truck freight, a 10% shift from trucks to other modes (whose energy intensities are much lower than those for trucks), and a 5% drop in the total volume of freight (across the board). These changes would yield nearly 30% lower carbon emissions from freight, hardly a final solution to the problem but one worth 10-l 5 yr of growth in energy use for freight, certainly a reasonable period during which to investigate improving fuel intensity and freight handling.

The energy consumption of industrialized countries now represents only 55% of world primary energy use and transport energy consumption in the same industrialized countries represents 65% of world energy use for transportation. Energy use in non-industrialized countries is rising

74 Lee Schipper er al.

rapidly, and that for transportation rising faster than in other sectors. While freight is hauled principally by railroads in a few large countries (former USSR, China, India), trucks are playing an increasing role worldwide. Rising incomes and liberalized trade will lead to increases in freight that should parallel or even exceed increases in the GDP, at least up to some point. If both technologies and policies are successful in the industrialized countries in restraining carbon emissions and other problems connected with freight haulage, these successes might be applicable in the countries where freight is growing more rapidly. If not, then either carbon emissions and other problems associated with freight will mount, or these countries may need to seek new solutions.

Acknowledgernenrs-This work was supported by the U.S. Environmental Protection Agency Climate Change Office and the U.S. Department of Energy Climate Change Research Assessment Program through the U.S. Department of Energy under Contract Number DE-AC03-765F00098. Financial support does not constitute an endorsement by the EPA or Lawrence Berkeley National Laboratory of the views expressed in this article. The authors wish to acknowledge the contributions of Claire Broido, International Energy Agency, and Steve Meyers and Mike Ting, Lawrence Berkeley National Laboratory.

REFERENCES

Blige, S. (1993) Erfassung und Bewertung von Transportvorgaengen: Die produktbezogene Transportkettenanalyse’ (Registration and evaluation of freight transportation: the product-related transportation analysis). In Laepple, Dieter (Hg.): Gueterverkehr. Logistik und Urnwelt. Analysen und Konzepte zum interregionalen und staedtischen Verkehr (Freight Transponation, Logislics and Environment. Analysis and Concepts for Interregional and City Transport), ed. Dieter Laepple. Sigma, Berlin.

Bureau Goudappel Coffeng BV (1995) Energiegebruik en milieubelasting in verkeer en vervoer 198G-1993, (Energy use and emissions in transport and traffic 1980-1993). Novem, Sitten.

Danish Ministry of Transport (1995) Transport i Danmark: Danmarks Statistik 1995. Ministry of Transport, Copenhagen. Deutsches Institut fiir Wirtschaftsforschung (DIW) (1995) Verkehr in Zahlen. DIW, Berlin. Deutsches Institut fiir Wirtschaftsforschung (DIW) (1996) Verkehr in Zahlen. DIW, Berlin. Energy Information Administration (EIA) (1995) Measuring Energy Eficiency in the United Srares. Economy: A Beginning.

EIA, Washington, DC. European Conference of Ministers of Transport (1995) Starisrical Trends in Transport 1965-1990. OECD, Paris. Greening, L. A., Davis, W. B., and Schipper, L. J. (1996) Decomposition of aggregate carbon intensity for the manu-

facturing sector: comparison of declining trends from ten OECD countries for the period 1971 to 1991. Lawrence Berkeley National Laboratory, Berkeley, CA, draft.

Griibler, A. and Nakicenovic, N. (1990) Evofurion of Transport Systems, Past and Future. International Institute for Applied Systems Analysis, Laxenburg, Austria.

Intergovernmental Panel on Climate Change (1995) Greenhouse Gas Invenrory Reference Manual: IPCC Guidelines for National Greenhouse Gas Inventories. IPCC, Bracknell, U.K.

International Energy Agency (IEA) (1995) Energy Balances of OECD Countries. Organization for International Coopera- tion and Development/IEA, Paris.

Kiang, N. and Schipper, L. J. (1996) Energy trends in the Japanese transport sector. Transport Policy 3( l/2), 2 I-35. Kibune, H. (1991) Japan Institute of Energy Economics, Tokyo. Private communication. Michaelis, L. et al. (1996) Report of the Working Group II, Mitigation of CO2 Emissions from Transport. Intergovernmental

Panel on Climate Change, London and Washington, DC. Mintz, M. A. M. (1991) Trends in demand for freight transportation. Presented at the Conference on Transportation and

Global Climate Change: Long-Run Options, Asilomar, CA, 25-28 August 1991. Oak Ridge National Laboratory (ORNL) (1996) Transporrafion Energy Dora Book: Edirion 17. ORNL, Oak Ridge, TN. Observatoire Economique et Statistique des Transports (OEST) (1995) Le memento de srarisriques des rransporrs (Annual

Absrracr of Transporr Sraristics). OEST, Paris. Schipper, L. J., Meyers, S. (with Howarth, R., and Steiner, R.) (1992a) Energy Ejiciency and Human Acriviry: Pasr Trends,

Future Prospects. Cambridge University Press, Cambridge U.K. Schipper. L. J., Howarth, R. and Carlassare, E. (1992b) Energy intensity, sectoral activity, and structural change in the

Norwegian economy. Energy: The International Journal 17(3), 215-233. Schipper, L. J., Howarth, R., Andersson, B. and Price, L. (1992~) Energy Use in Denmark: An Inrernafional Perspective.

Lawrence Berkeley National Laboratory, Berkeley, CA. Schipper, L. J., Johnson, F., Howarth, R., Andersson, B., Andersson, B. G. and Price, L. (1993) Energy Llse in Sweden: An

Inrernarional Perspective. Lawrence Berkeley National Laboratory (LBL-33819) Berkeley, CA. Schipper, L. J, and Peraelae, L. (with Johnson, F., Khrushch, M., Ting, M. and Unander, F.) (1995) Energy Use in Finland:

An International Perspecrive. Lawrence Berkeley National Laboratory (LBL-37510), Berkeley, CA. Schipper. L. J., Haas, R. and Sheinbaum, C. (1996a) Recent trends in residential energy use in OECD countries and their

impact on carbon dioxide emissions: a comparative analysis of the period 1973-1992. Mitigation and Adapfation Strategies for Global Change, 1, 167-196.

&chipper, L. J., Ting, M., Khrishch, M., Unander, F., Monahan, P. and Golove, W. (1996b) The evolution of carbon dioxide emissions for energy use in industrialized countries: and end-use analysis. Lawrence Berkeley National Laboratory (LBL-38574), draft.

Scholl, L., Schipper, L. J. and Kiang, N. (1996) CO2 emissions from passenger transport: a comparison of international trends from 1973 to 1992. Energy Policy 24(l), 17-30.

United Nations Environment Programme, the Organization for Economic Co-operation and Development, the Inter- governmental Panel on Climate Change (1995) Greenhouse Gas Inventory Reference Manual, IPCC Guidelines for National Greenhouse Gas Invenrories.


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World Energy Council (1995) Global Transport Sector Energy Demand Towarak 2020. WEC, London.

APPENDIX

Methodology Total energy use figures are aggregated, bottom up, by mode type and fuel. In many cases energy use is given by mode

and fuel type directly by a major national source. For example, Danish authorities estimate diesel fuel use for trucking as a residual after that for cars and buses is subtracted from total road diesel. But surveys and expert judgment lead to these figures, which are not published but are made available from energy and transportation authorities. Data for U.S. trucks are derived in a similar way, using surveys, fuel sales, and estimates to isolate this important mode from other road modes. In some cases we also have to estimate or derive fuel splits for freight energy shares for rail, water, and air from total energy consumed by these modes.

Where total energy use is given by mode and fuel but not divided into freight and passenger, the freight energy use for a given mode and fuel type is estimated using known or estimated freight and passenger energy shares. For example, where we only know total diesel consumption for a given mode, i.e. total rail diesel consumption, we assign freight rail diesel consumption using the freight share for total energy use.

-5 = (-%)(Fr)

where E= energy use for a particular mode, j, and fuel type, x, ET= total energy use for that mode and F= freight share of total energy use. Share of energy use is estimated by using the ratio of weighted passenger and freight activity (passenger-km and t-km) for a given mode:

Freight energy share: WI A/ F = (w, A, + w2 AP)

where the subscripts, f and p, denote freight and passenger activity in t- and passenger-km, respectively, and wi and ws are relative weightings of these two activity measures. Where there are no explicit weightings based on gross t-km or some other method, we apportion energy uses by equating 2 passenger-km to I t-km for rail, that is, w2 = 2 and wi = I. The reason for this approach is that the weight of the passengers is small compared to the weight of the overall train for rail travel. The overall burden hauled depends critically on the load factors, but we assume that a passenger and its share of the seats, car, etc. ‘weighs’ close to half a tonne. For freight, the weight of the load is far more important to total energy use, so actual t-km may be a better measure. Hence we used this approximation. Where we know part of the energy (and activity) belongs outside of this equation, such as the passenger-km and energy for local rail transit, we hold these parts outside of the equation. Using this method of parsing rail energy use means that any changes in overall energy intensity are assumed to apply equally to travel and freight. For air travel, we assume that energy use depends only on the weight of the burden, hence 7 passenger-km. (at 140 kg/passenger including baggage) is approximately equal to I t-km (w, = I, w2=7). For water-borne activity, the freight energy data are usually given completely disaggregated separate from travel, and dominate the total anyway.

The split of fuel between oil types is known for trucking for most countries. In a special case, for former W. Germany, we estimated trucking diesel consumption as total diesel consumption minus that for cars and for buses shown by Verkher in Zahlen, our main source. Gasoline for trucks was estimated using the residual of total gasoline minus gasoline consumed by motorcycles and cars, there being essentially no gasoline buses. The sum of these two was very close to the total for ‘truck fuel’ reported in the source.

To estimate the breakdown between electricity and oil for rail freight, we tried to remove electricity used for any local rail transit. Remaining electricity and oil are then split using the formula noted above, using intercity passenger-km only.

Carbon emission coejicients Carbon emissions are released directly through the combustion of fossil fuels at the point of end use or indirectly

through the consumption of electricity or district heat. The coefficients for electricity have been developed on a country-by- country basis, using given information on energy inputs, and outputs and carbon ratios for the specific mix of fuel. The coefficients for biomass, solar, wind, hydro, and nuclear power for electricity are assumed to be zero. Table Al provides the coefficients used in this paper.

Method of decomposition of the changes in energy and CO2 Laspeyres indices are used to decompose the overall changes over the study period in energy use and carbon emissions,

using 1973 as the base year. We assign each variable the following notation: Ei= energy use for mode j, Cj = CO2 emissions of mode j, Aj = activity

level of mode j, 4 = energy intensity of mode j, RJ= carbon rate of fuel f, where

R/,2 Ff

and

76 Lee &chipper et al.

Table Al. Carbon emission coefficients (IPCC, 1995)

Energy source ktC/PJ

Engine fuels Gasoline Diesel Kerosene Heavy oil

Fuels for electricity Oil Natural gas Coal Biomass Hydro Nuclear SWT Geothermal

18.90 20.20 19.50 21.10

21.1 15.3 25.8

0.0 0.0 0.0 0.0 0.0

Let the suppression of subscripts represent the sum of a given variable across all modes:

Total energy consumption from freight transport in year, i, can be expressed with the following identity:

E,j = c((A,)(l,)s,)

j=l

Total carbon emissions from freight transport in year, i, can be expressed with the following identity:

Cij = 2 c((A,)($)(S,)&l /=I ,=I

Activity:

Structure:

CO2 intensity:

Energy intensity:

Fuel mix :

where (“/AC),,i= the percent change in carbon emissions in year, i, relative to the base year 1973, if only one component i.e. fuel mix, had changed The carbon term, C, can be replaced with an energy term, E, in the first three equations to decompose energy use changes, in which case, the CO2 intensity index would become the energy intensity index. The activity, intensity, and structure (and fuel mix) indices are multiplicative of changes in tofu1 energy use (or CO* emissions), while fuel mix and energy intensity are multiplicative to give changes in CO* intensity. As a cross check of the accuracy of our method, we calculate the product (in former case) or sum (in latter case) of these components and compare the resulting interaction terms with the actual change in total energy and CO2 and report the percent differences.

The residual in this calculation is the error of approximation. If there are large changes in one of the Laspeyres indices, particularly if these are of opposite magnitude (i.e. some large increases, some large decreases), then the large residual simply tells us that there are substantial cross terms. We calculated the residual term by multiplying each index (except that for carbon intensity, which combines two other terms already included) and dividing by the index for ‘actual’. As can be seen, these are small except for Denmark (0.83).

Energy use and carbon emissions from freight in 10 industrialized countries: An analysis of trends...

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