Mathis VJackernagel and William Rees describe the 'ecological footprint' (i.e. the ecological capacity, rneasured in hectares of biologiGJ11y productive land, needed to supply a given person's consurnption of
natural resources and absorb their waste) as a conception of environmental sustainability, and have accunllliatcd significant data to n1casurc the footprints of nations, cities and even individual persons. Although the authors refrain frmn explicitly dravving nonnative inferences frorn their rneasurernents, such
implications lie not far beneath the sur£"lce of their work. Besides providing an empirical tool tor assessing efforts to i1nprove environrnental perfOnnance, the footprint irnplies a nonnative ideal of global resource
infinitely renewable and those which are not.