A linear programming study of the effects of climatic change on Scottish agriculture

Abstract

Although there is considerable uncertainty in the literature about the effects of greenhouse gases on the climate there is little doubt that the composition of the atmosphere has changed in recent times. As a result of human activities the concentration of C02 is likely to double from pre-industrial levels by the middle of next century and as a consequence global temperatures are likely to rise. The potential importance of a change in the climate for the environment and agriculture and the complexity of the issues that are involved means that it is important to develop analytical tools to study this problem. The principle aim of the study is to evaluate the possible effects of a change in climate on the pattern, structure and viability of agriculture in Scotland. To address this objective it was necessary to evaluate the effects of climate change at a range of different levels of resolution.

A linear programming model was developed that includes a large amount of biological, physical and economic detail. The models of crop growth (grass, grass /clover, swedes, potatoes, barley, vining peas, oilseed rape and wheat) account for variations in weather conditions, soil types, weeds, applications of nitrogen and pesticides, different planting dates and cropping rotations. The livestock operations that are modelled include sheep, dairy and beef fattening enterprises. In addition a considerable amount of effort was devoted to modelling variations in machinery requirements (and the sensitivity of these operations to climate), labour, buildings and finance. The inclusion of this information has allowed the types of adjustments that farmers may implement to be considered.

The model is structured as a series of linked sub-problems where the most basic units are farms. In turn the interactions between farmers in terms of flows of intermediate goods, land, and labour are considered at the regional and national level. While further developments to the model would allow the status of Scottish agriculture to be more accurately modelled, in its current stage of development, the model has allowed a realistic evaluation of the effects of climate change. The results of this study suggest that climate change will have a detrimental effect on Scottish agriculture, however, the effects of climate are likely to vary between the different farm types and regions. In general, cropping farms are likely to benefit from a change in climate while the profitability of livestock farms, and sheep in particular, will decline.