Sustainable development of agricultural systems: competing objectives and critical limits

The sustainability of agricultural systems has become a major focus for debates about future human survival. Much of the argument appears to rely on simplistic interpretation of ecological models, and fails adequately to define what sustainability objectives are being sought. We explore the implications of two alternative approaches to agricultural sustainability: the Critical Limits view which would require future farming systems to accept the ecosystem-imposed limits on the number of people in the world and the lifestyle they can enjoy; and the Competing Objectives view would balance agricultural sustainability with economic viability, reduction of environmental harm and fulfilling public demands for food and landscape benefits. The development of farming systems of the future will depend on which of these views is adopted by planners and policy makers. This paper challenges some of the ecological assumptions underlying the Critical Limits approach and questions the conventional view that extensive farming systems are more sustainable agriculturally than intensive systems. We may be able to deal more effectively with the environmental side effects of intensive farming systems by treating them as unwanted externalities and taking direct action to avoid or remove them rather than attempting to change fundamentally the nature of modern farming systems. To cope with the increasingly complexity and inter-connectedness of modem farming systems in the context of globalisation and potential perturbations like climate change, we need a pluralistic approach to policy, which can cope with the high levels of uncertainty in these areas and which allows maximum flexibility of response to changing circumstances. (C) 2000 Elsevier Science Ltd. All rights reserved.