regions in the world, where water scarcity has already be­come a severe constraint to food production. Water scarcity and increasing rates of soil degradation in many regions may limit the ability of agriculture systems to reduce food insecurity and to meet the MDG target of halving hunger by 2015. Moreover, increasing rates of land degradation in many regions may limit the ability of agriculture systems to provide food security. A final important factor is the role of agriculture in the N cycle, with effects on both local and regional scales. Decreasing these impacts may require im­portant changes in soil fertility management. AKST must continue to address the need to develop sustainable agricul­tural systems in these regions. In this context, it should be noted that there are several scenarios that highlight many opportunities for enhancing the positive role of agriculture in providing ecosystem services, minimizing its environmen­tal impacts and adapting to global environmental change.      Agriculture, a highly climate-sensitive sector, is already strongly affected by climate variability in many parts of the world, and it will be even more affected by climate change in the future. The relevant changes in climate of importance to agriculture include not only changes in mean temperature and precipitation, but even more importantly, seasonal and interannual variability and extreme events. The outcomes of the impact of climate change will vary significantly by regions. Current studies indicate that negative impacts tend to concentrate in low income regions. In some other regions, often at high latitude, there could be net positive impacts on yields. Developments in AKST will certainly influence the capacity of food systems to respond to the likely changes. Agriculture is also a source of CO2 and non-CO2 greenhouse gases and therefore can play a significant role in mitigation strategies. In order to play this role, new AKST options for reducing emissions of methane and NOX from agriculture are needed.      The projected urbanization will likely coincide with a decline in the percentage of population depending directly on agriculture for their livelihood. At the same time, pro­jected increasing income levels are likely to lead to changing diets and changing manner of food preparation. The conse­quences of this for the food supply chain, and in particular the role of retailers can be an important factor in future ag­riculture. Demand for food is also very likely to be affected by other demographic changes, e.g., the aging population in many industrialized countries. AKST will have to address the impact of changes from urbanization, consumption pat­terns and the agricultural labor force on agricultural pro­duction and technologies in order for food demands of the future to be met.      Energy will continue to play an increasingly important role in agriculture. Various forms of agriculture use differ­ent levels of energy; with transitions in agricultural produc­tion systems in general leading to a substitution of energy for labor. Most assessments also expect higher energy prices which could encourage the use of more energy-efficient tech­nologies in agricultural production as well as in process­ing and distributing food. The most important factor with respect to energy, however, is that agriculture may become an important producer of energy in the form of bioenergy, based on both energy-security and climate change consid­erations. Existing assessments indicate a major increase in

bioenergy production; this might lead to a tradeoff between energy security and food security, especially for the poor. In several scenarios large areas are devoted to bioenergy pro­duction. Because of potential environmental and food secu­rity impacts, bioenergy is very controversial and its value depends on assumptions about overall efficiency, tradeoffs with food production and biodiversity. Reports show that bioenergy production based on conversion of cellulose to ethanol or other hydrocarbon fuels will have less impact on food security and biodiversity than 1st generation fuels. In this context, AKST can play an important role in the devel­opment of bioenergy systems, as well as address the need to make agricultural systems more energy efficient.      While governance and other sociopolitical issues are hard to quantify in scenarios, it is known that these fac­tor will be critically important for the future of agriculture. Scenarios primarily address these issues by building scenar­ios that are based on contrasting underlying assumptions concerning the role of government. Several scenarios expect governance effectiveness to increase over time (reducing the corruption that is perceived to be prevalent in developing economies). However, improving states' capacities in gov­ernance and effectiveness in policy implementation is a long term process, and effects are still uncertain. Some scenarios emphasize these uncertainties by showing consequences of failed reforms (e.g., the Order from Strength scenario of the Millennium Ecosystem Assessment). Key options discussed in existing assessments include building "soft" infrastruc­ture, such as networks, organizations, and cooperatives, in order to produce social capital that may reduce conflicts at all governance levels. These may facilitate common-pool ag­ricultural resource management; and enhance the access of farmer groups to markets.

4.6.2 What are the conditions needed to help AKST realize development and sustainability goals?
AKST functions within a larger system of knowledge gen­eration, technological development and diffusion. The for­mal funding of this larger system will therefore affect AKST. Global spending on all research and development (R&D) is likely to increase in the future both absolutely and as a percentage of total global economic activity, though many countries outside North America, Western Europe and East Asia with small economies will probably continue to have low investments in R&D.      Public investment in AKST is increasingly less driven by the needs of agriculture per se, but is a spinoff of other research priorities such as human health and security. There is a trend in many areas to reduce investment in traditional agricultural disciplines in favor of emerging research areas such as plant and microbial molecular biology, informa­tion technology and nanotechnology. This trend is likely to be sustained and its impact on AKST is not fully explored. However, China, with a very large, poor, rural population, is now the country with the second largest total R&D ex­penditure. It is possible that China may make substantial investments in research relevant to poor rural areas.      Assessing potential development routes of the world ag­riculture system is of crucial importance if AKST is to realize development and sustainability goals. As discussed previ­ously, there are multiple significant direct and indirect driv-