four SRES scenarios, the four Millennium Ecosystem As­sessment Scenarios, and the four GEO-3 scenarios (West-hoek et al., 2005) also show lower growth projections for the period 2025-2050 compared to 2000-2025.

4.3.2.2 Implications of income growth for agriculture
Changes in per capita income growth do affect the mix of economic activities, and this affects agriculture in a signifi­cant way, with important implications for access to labor. Along with economic development, demand for food quan­tity in countries initially increases and then stabilizes; food expenditures become more diverse (see also 4.4.1). At the same time, the demand for nonagricultural goods and ser­vices increases more than proportionally. A general tenden­cy observed in the past (and assumed in most assessments) is that the economy responds to this trend by shifting resourc­es out of agriculture; and the share of agricultural output in total economic activity declines (Figure 4-6). While high-income countries typically produce more output per hectare as a result of higher inputs, industrial and service output grows much faster so the relative contribution of agriculture declines. Technological change further replaces most of the labor force in agriculture. In this context, it is important to note that many factors discussed in elsewhere in this chapter are closely related. For instance, demographic factors (gray­ing of the population, labor supply) (4.3.1) may have im­portant implications for growth projections. Similarly, de­velopments in energy supply in the coming decades (e.g., oil scarcity) could have important consequences for economic projections. High economic growth rates are likely to have an upward pressure on energy prices and, in turn, might increase the demand for alternative fuels such as bioenergy.

4.3.2.3. International trade and agriculture Increasing trade patterns in the future. Trade is as an important distinguishing factor for scenarios in several as­sessments: the MA, GEO and SRES have scenarios with and without trade liberalization. Nevertheless, in terms of actual

trade flows the scenarios all show an increasing trade, even in scenarios without trade liberalization (Bruinsma, 2003; MA, 2005a). An important reason for this increase is that population growth and the development of agricultural pro­duction is expected to occur unevenly. The largest increase is expected for total trade in grain and livestock products (see also Table 4-6). Some region specific patterns are expected also, e.g., the OECD region is likely to respond to increas­ing cereal demands in Asia and MENA. The very rapid yield and area increases projected in sub-Saharan Africa could turn the region from net cereal importer at present to net grain exporter by 2050. Net trade in meat products increas­es 674%. Net exports will increase in Latin America, by 23000 Gg, while the OECD region and Asia are projected to increase net imports by 15000 and 10000 Gg, respectively (MA, 2005a). Asian demand for primary commodities, such as natural rubber and soybean, is likely to remain strong, boosting the earnings of the exporters of these products. China will become the world's largest importer of agricul­tural commodities in terms of value by 2020, with imports increasing from US$5 billion in 1997 to US$22 billion in 2020 (UNCTAD, 2005).

     At a more aggregated scale important trends can be noted (see Rosegrant et al., 2001). The overall trade surplus in agricultural commodities for developing countries may dissappear completely and by 2030 they could, as a group, become net importers of agricultural commodities, espe­cially of temperate zone commodities (FAO, 2003). At the same time, the agricultural trade deficit of the group of least developed countries could quadruple by 2030 primarily due to the fact that industrialized countries tend to be the major beneficiaries of trade arrangements (FAO, 2006b). Many countries have faced much less pressure to reduce support for their agricultural sector primarily due to the fact that commitments to liberalize were based on historically high levels of support and protection. The future of this driver hinges on the outcomes of the Doha Round of trade talks about agricultural support and market access. Export subsi-