Representatives of world governments and the policy research community often promote expansion of exports from developing countries as a means of growing national economies of these countries and raising living standards. This type of export growth over the long term will have important implications for the international freight transportation system and for its overall level of ecological impact; however, up to the present there is little research on this issue. This paper gives a preliminary analysis of the possibility for future growth over the next several decades, in two parts. First, an estimate of the range of potential growth in total export tonne-km and associated energy use is given. Second, production and export of apparel from developing countries is modeled to illustrate the effect of growth in international freight from the perspective of product life-cycle analysis. At the upper end of the estimated growth range, substantial increases in energy use and carbon emissions will merit specific policies to counteract the full participation of industrializing countries in the world trading system, and these are discussed. The paper also identifies areas where data gathering should be improved. © 2001 Elsevier Science Ltd. All rights reserved.