2 Zooming in on the Global Hotspots of Rainfed Agriculture in Water - constrained Environments

Rainfed agriculture is practised on 80% of the world’s agricultural area and generates 60–70% of the world’s staple food1 (FAOSTAT, 2005). In semi-arid and dry subhumid zones, rainfed agriculture dominates food production systems, and water is a key limiting factor to crop growth (SEI, 2005). Since approximately 70% of the world’s poor are women, the importance of rainfed sources of food weighs disproportionately on women (WHO, 2000). Agriculture plays a key role for economic development (World Bank, 2005), poverty reduction (Irz and Roe, 2000) and economic growth (van Koppen et al., 2005). Every 1% increase in agricultural yield translates to a 0.6–1.2% decrease in the percentage of absolute poor2 (Thirtle et al., 2002). In sub-Saharan Africa for example, agriculture accounts for 35% of the gross domestic product (GDP) and employs 70% of the population (World Bank, 2000), and more than 95% of the agricultural area is rainfed (FAOSTAT, 2005). Thus, in this region, agriculture is the engine of overall economic growth and, therefore, broad-based poverty reduction (Johnston and Mellor, 1961; World Bank, 1982; Timmer, 1988; Abdulai and Hazell, 1995; IFAD, 2001; DFID, 2002; Koning, 2002). There are thus strong reasons to believe that in many areas poverty is strongly influenced by agricultural production, which in turn is dependent on climate in general and water availability in particular. Despite the complex driving forces behind poverty, the social–ecological interactions between livelihoods, agriculture and water constraints make it important to analyse the degree of interdependence and the regions of the world where these factors interact. Identifying such regions can provide an important guide for new investments in upgrading rainfed agriculture. The aim of this chapter is to identify global hotspots of rainfed agriculture where water constitutes a key limiting factor to crop growth. Thus, the focus is on the dry subhumid, semiarid and arid zones. First, we investigate the link between climate and poverty. Thereafter, the number of people living in water-constrained agricultural areas is estimated. Based on this analysis, the global hotspots for rainfed agricultural areas in water-constrained environments are identified.