Ongoing conflict over the fair allocation of greenhouse gas emissions among nations is a significant impediment to progress in international climate change negotiations. This article considers the strengths and weaknesses of a crucial argument within the allocation debate asserting the atmospheric capacity to absorb greenhouse gases should be distributed oil an equal per capita basis. While noting the argument's many appealing qualities, the paper argues that the per capita perspective also encompasses important practical and ethical limitations. Besides potentially encouraging Population growth and discriminating against those with greater (but still legitimate) energy needs, early evidence suggests that the equal per capita idea may hinder progress in climate change talks by invoking a more absolutist and uncompromising rhetoric of rights. Alternative ideas of fairness, Such as the distinction between Subsistence and luxury emissions, or the Common Heritage of Mankind idea, offer a more flexible mix of egalitarian and other allocation principles that should be considered carefully, even by those sympathetic to the equal per capita perspective. (c) 2004 Elsevier Ltd. All rights reserved.