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refrigeration/preparation,
32%
Agricultural
production, 21%
Transport, 14%
Restaurants/caterers, 7%
Food retail, 4%
Processing, 16%
Packaging, 7%
Figure 13.1
Percentage of energy consumed at each stage of the food supply chain in the United States.
The total energy consumed by the US food system is 10.25 quads (10.25 × 10
15
Btu), which is equivalent to
10.81 exajoules (EJ; 1 EJ = 10
18
J).
Adapted from Heller and Keoleian, 2000.
Table 13.1
Commodity shipment by sector in the United States during 2002.
Commodity
Tonne-km (millions)
Ton-mile (millions)
Percentage of Total
Food
986,466
678,263
21.6
Petroleum and coal
products
386,411
265,684
8.5
Chemicals
390,594
268,560
8.6
Wood products
186,077
127,941
4.1
Paper
172,429
118,557
3.8
Iron and steel
136,618
93,934
3.0
Fabricated metal products
62,074
42,680
1.4
Transportation equipment
101,340
69,678
2.2
Remaining commodity
shipments
2,141,751
1,472,601
46.9
All commodities
4,563,759
3,137,898
100.0
From Environmental Protection Agency (EPA), 2007.
TRANSPORTATION MODES
From the point of moving food products, and depending on the medium where vehicles circu-
late, transportation can be classified into land, water, and air. Land transportation includes
trucks, trains, and pipelines. Water transportation has two types: inland and ocean transport.
Air transportation is performed exclusively by planes. There are other transportation modes
that are used in special applications, for instance, helicopters, spacecrafts, and hovercrafts,
which are not regular commercial transport methods for food products, and therefore, they
will not be included in this discussion.
