'Critical Natural Capital' and Social Justice (Part l)
LET me begin by recalling the principal features of the 'critical natural capital' conception of environmental sustainability that I developed in Chapter 2. Of the four organizing questions, the first, 'what to sustain?', is answered by the notion of critical natural capital--for example 'ecological processes'. This answer is underpinned by a belief in the possibility of considerable substitutability between human-made and natural capital, but not between human-made and some critical natural capital. In this conception of environmental sustainability the question of why capital availability should be sustained through time is answered by the importance to human welfare (material and aesthetic) of such capital over time. The implications of this answer, in turn, are reflected in the objects of concern for Conception A: present and future generation human needs take precedence over present and future generation human wants, and secondary concern is devolved onto the non-human natural world to the extent that a sustained natural environment is functional for human welfare.
There are five fundamental contexts in which this conception of environmental sustainability bears upon distributive justice (and vice versa). In the order in which I propose to deal with them these are: international justice, future generations, the relationship between human welfare and environmental sustainability, the role of property ownership in policies for sustainability, and substitutability between human-made and natural capital. Consideration of these contexts is divided between this chapter (the first two) and the next chapter (the last three): to have dealt with them all here would have produced a chapter more ungainly than it already is.