Sustainable development in dry climates: The Mediterranean area

Difficulties in attaining the goal of sustainable development in dry climat es are discussed, with the Mediterranean region as a striking example. The exhaustion of soil fertility, and salinization of arable soil contributed s ubstantially to the fall of the earlier cultures. Sustainability comprises the security of food supply by a biomass productivity 2-3 times greater tha n the present level. Old techniques cannot achieve this goal; only new tech niques, involving the recycling of material on a much wider scale than in o ld, local societies, can do so. New techniques must concentrate primarily o n the efficient use of both groundwater and surface water, which also will make possible the efficient use of plant nutrients. Unrealistic ideas of a sustainable biomass production system, based on low-productive local resour ces, must be replaced by a modern model involving new techniques and knowle dge.