FOOD-SUPPLY CAPACITY STUDY AT GLOBAL-SCALE

The world population is expected to grow to 10 billion people in 2040, requiring food production at least to triple, as a combined result of population growth and dietary changes. In this study scenarios for fo od security are developed for 15 major regions of the world. Food prod uction is calculated on a 10x10 grid basis, using inputs from a digita l data base containing soil, climatic, agronomic and demographic data. This allows us to study impacts of different production scenarios and their environmental side effects. Soil area data are derived from the digitized FAO soil map, considered to be representative for soil unit s on a 1 degrees x1 degrees grid; weather variables of 978 stations ar e allocated to the grid cells. Food production estimations are made wi th a simple crop growth module, a soil water balance and a soil nitrog en balance. Calculations are done on a grid basis, each grid cell bein g characterized by its suitability for arable farming or grassland, so il and climatic conditions and the availability of irrigation water. R esults of Yield Oriented Agriculture (YOA) and Environment Oriented Ag riculture (EGA) production scenarios on food self-sufficiency are pres ented. If we assume that there is no limit to transport of food across the globe, YOA allows the entire globe an affluent diet, while EOA al lows only a moderate diet. For this scenario, regional self sufficienc y indices vary widely: most regions can produce food required for an a ffluent diet, but not East, South and West Asia that account for 48% o f the expected global population in 2040. Also Southeast Asia (9% of e xpected global population in 2040) and West and North Africa (10%) com e close to the lower limit for food self-sufficiency. With EGA, only t he former USSR, North and South America, Central and Southern Africa a nd Oceania can offer their future populations an affluent diet. Southe rn Asia will experience food shortages even under minimum food demand, and less affluent diets do not provide a solution. In this paper, att ention is given to the methodology regarding soils, and to the uncerta inty regarding soil and water in input data. Particularly soil suitabi lity for agriculture for each of the grid cells has a large effect on model calculations, as it is a rather rough approximation. Knowledge o f soils across the world shows important weaknesses with respect to th e extent of coverage, extrapolation of point observations to grid cell s, definition of soil characteristics compatible with crop models, and handling of preferential flow in soil profiles. We emphasize the need for digitized, reliable and readily available natural resource inform ation in the fields of soil surveys, climatology, irrigation water ava ilability, land use and land cover. The ultimate goal of the approach is not to predict the future of global agriculture, but to allow decis ion makers to compare various scenarios for food self-sufficiency, and to raise awareness regarding issues related to food security. In spit e of the above-mentioned shortcomings in basic data, it is demonstrate d that it is possible to develop the required scenarios now, instead o f having to wait on more reliable soil information.