The phenomenon of global warming, the anthropogenic theory of its genesis and some of the implications of that theory are introduced as a case-study of a global environmental problem involving issues of equity between peoples, generations and species. In particular, recognition of the view that the absorptive capacities of the atmosphere comprise an instance of the Common Heritage of Humankind would have a key bearing on negotiations downstream from the Kyoto Protocol, suggesting the proportioning of emission quotas to population, and (...) also limits to the inter-state trading of quotas. This view and these possible implications are discussed; international regimes with such a basis are argued to have a firmer foundation than ones based on historical emission levels (such as the Kyoto agreement), and to escape the charge of anthropocentrism to which stress on the Common Heritage of Humankind appears to expose them. The anthropogenic theory might be held, instead, to favour tying emissions quotas to aggregate historical emissions of the last two centuries. But intergenerational equity requires a sustainable international regime, based on universal principles rather than history. (shrink)