ABSTRACT
The application of techniques of impact assessment to the field of climatic change is quite new. The impact approach is based on the assumption of a direct cause and effect relationship between a climatic event and a response within the system under study. There are two general techniques for examining the response of agricultural crops to climatic changes: the measurement of crop suitability by agroclimatic indices, and the estimation of potential productivity by crop-climate modelling. The impact approach also characterized an extensive effort in the late 1970s to estimate the possible effects of long-term climatic change on crop yields and agricultural production. A fully integrated impact assessment assumes that study is made not only of interactions between different orders, but also of interactions within the same order, both within individual sectors and between different sectors and the feedback effects operating between them. Impact assessments have considered only a small number of feedback effects.
