Pii: S0921-8009(98)00100-1

This paper evaluates the impact on greenhouse gas emissions of beef produced under different management systems and compares these results with the estimated biophysical capital alteration of these same systems. The environmental impacts of a specific intensive US feedlot system and a traditional African pastoral system are calculated using a methodology that includes the major land-use and energy-related emissions. Although assessments of carbon dioxide emissions find much greater impacts related to the US feedlot mode, the methane intensity of the pastoral mode is much larger because of the lower productivity of these systems. It is found that when indirect sources, which include emissions from fossil fuels and foregone carbon storage on appropriated land, are considered as well as emissions from enteric fermentation and wastes, the social costs of the feedlot system at 15 kg CO2 equivalent/kg beef are more than double that of the pastoralist system. Accordingly, the results of the more complete greenhouse gas emissions analysis were found to converge somewhat with the biophysical capital alteration approach in this example, although it is also argued that the entropy-based environmental indicators may have limited use in evaluating agro-ecosystems’ contribution to climate change. Given an assumed, albeit uncertain, climate change impact value, a tax on beef production of about 9% of the unit price would represent the upper limit of the shadow costs of the associated greenhouse gas emissions flux from feedlot systems as estimated here, and a central value would correspond to a tax of about 4%. © 1999 Elsevier Science B.V. All rights reserved.