THE ENVIRONMENTAL EFFECTS OF FREIGHT ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT Paris

Internet under the responsibility of the Secretary-General of the OECD with the aim of bringing information on this subject to the attention of a wider audience. Executive summary This review of the environmental effects of freight is structured by transport mode, addressing shipping, air cargo, trucking, rail, pipelines and intermodal terminals. It begins with a brief overview of the major environmental media or mechanisms through which transport can affect the environment. These include air pollution, global climate concerns, noise, water pollution, accidents, land use and habitat fragmentation. The modal discussions focus on air pollution, global climate issues, water pollution, accidents whose costs are environmental rather than primarily in human life, and certain land use planning issues. The review describes the impacts in qualitative terms, and then provides emission factors per unit of freight transported. The most recent estimates of the marginal social cost of some of the impacts are provided in the comparisons and conclusions. The paper identifies comparable emission factors for only certain kinds of environmental harm, notably air pollution and noise. The air pollution data confirm conventional wisdom that trucking is by far the most harmful mode of goods transport. Rail seems to be somewhat more harmful than maritime transport, but this is not clear-cut; variations in the methods used to estimate the factors may outweigh the differences among them. With respect to noise the results are less clear. Conventional wisdom holds that road noise is worse than rail, but the available data only suggest this, rather than clearly demonstrating it. While airport noise is clearly an important problem, comparable noise indicators are not available for road or rail. The problems involved in quantifying and comparing other environmental impacts are also highlighted. The pollution caused by ocean freight, for example, is only indirectly linked to the quantity transported. Moreover, there is no clear objective basis for comparing air and water pollution. Even more difficult are environmental harms like the introduction of nuisance species or the disposal of contaminated dredged materials, which affect marine ecosystems more than humans. The Information and data given in this review describe the situation in the United and States and Europe. However, it should be noted that as the transportation systems in both these continents differ substantially, comparisons should not be drawn between the two continents.