The maximum potential number of inhabitants which can be supported in a given area. The upper limit is set at the point where the environment deteriorates. Carrying capacities are far from being universal constants, but alter with value judgements and objectives. ‘In human society, institutional arrangements are likely to alter the carrying capacities and desired levels of populations, and carrying capacities in the shorter term may differ greatly from those in the longer term’ (Seidl and Tisdell (1999) Ecol. Econ. 31, 3). See Daily and Ehrlich (1996) Ecol. Applics 6, 4 on increasing equality of opportunity and increasing Earth’s carrying capacity.

Seidl and Tisdell (op. cit.) maintain that carrying capacity is a political concept ‘generally highlighting that exponential growth, and thus environmental pressures, have to be curbed’. Clarke (2002) Pop. & Env. 23, 4 recounts the difficulties in trying to convert the ‘vague carrying capacity concept into a functional, qualitative method’ and Benjaminsen et al. (2006) AAAG 96, 3 decry ‘the continued dogged insistence on the application of rigid carrying capacity rules and concepts’.