4.5.2 Indication of projected changes
Food systems can be classified into (1) production and (2) distribution and delivery. Most assessments discussed here concentrate much more on the first. The Millennium Eco­system Assessment, the global food projections by IFPRI and the Agriculture towards 2015/30 study by FAO provide the most relevant information in the context of the IAASTD (see Table 4-9). It should be noted the Millennium Ecosys­tem Assessment used four diverging scenarios (Global Or­chestration, Technogarden, Adapting Mosaic and Order from Strength). Together these four scenarios cover a broad range of possible outcomes for the development of different ecological services.

4.5.2.1 Changes in production systems
Agricultural production systems can be classified in different ways. A system based on two key dimensions of cultivated systems: an agroecological dimension and an enterprise/ management dimension was proposed for MA (Cassman et al., 2005). Such an approach can easily be coupled to both biogeographic factors and long-term trends in agricultural management, and hence provides a very useful structure to assess potential future changes in production systems. It pro-

vides a basis to integrate socioeconomic analysis (looking at the economic and social viability of agricultural systems) and biophysical analysis (looking at the environmental con­sequences). Unfortunately, however, the different existing assessments generally tend to analyze information at a much more aggregated scale, because data is lacking, particularly on agricultural management in developing countries.

General trends. In the system proposed above a useful distinction can be made along the management axis in the degree of intensification. Such a distinction would include (1) intensive (or fully colonized) agroecosystems (e.g., pro­ducing crops, often in monocultures, intensive livestock and specialized dairy farms); (2) intermediate (partially colo­nized) agroecosystems (e.g., pastoralism, agroforestry, slash and burn); and (3) the exploitation of uncontrolled ecosys­tems (e.g., fishing in the ocean or in big rivers, hunting and gathering). From a human perspective, this distinction of intensification refers to an assessment of costs and benefits. Taking out products from an exploited ecosystem requires a degree of "investment" (e.g., tilling the soil, taking care of animals, preparing fishing nets), which needs to deliver an adequate return in terms of value. This distinction is