tion. The basic unit for food security within a poor community is the family. Parental sacrifices for children's welfare are demonstrated daily under conditions of scarcity. Families are affected by certain policies, which, perhaps as externalities, create unemployment, inconsistent agricultural prices, and credit-based farming and lifestyles; this is why they are the logical focus for definitions of food security. A family's food supply must be secure "at all times", not simply on average, thereby implying that local storage facilities must be effective, that staples are available out of season, and that distribution systems are uninterrupted by adverse weather, political or budgetary cycles. Food insecurity can be limited to small pockets or affect entire regions. Famine, in contrast, is used to define chronic hunger affecting entire populations over an extended period of time in a famineaffected area, potentially leading to the death of part of the population. Famine may have multiple causes, from political and institutional ones to social, ecological and climatic causes (WFS, 1996).

     Temporary food insecurity may be overcome when a harvest comes or when conditions such as weather, wages or employment opportunities improve; it may require action before, during, and even after the period of food insecurity. Household livelihood strategies reflect this. For example, a household that anticipates an upcoming "hungry season" may seek to accumulate savings in advance in the form of cash, grain, or livestock, or it may diversify its economic activities by sending a household member away to seek employment elsewhere. A household experiencing a hungry season may draw on those savings or receive remittances from household members working elsewhere. In more severe cases, a household may borrow money, draw on informal social networks, seek food aid, or even be forced to sell assets (decapitalization)-perhaps achieving temporary food security only at the expense of the ability to generate income in subsequent periods. Other strategies include post-harvest technologies, which may improve storage of products and hence increase both the quantity and quality of available food.

      In seeking to meet current needs, some households may be forced to deplete their resources to the point that they remain food insecure for extended periods of time or for recurring periods over many years. In extreme cases, households may have depleted their reserves, exhausted other assets, and be reduced to destitution-with their labor being their only remaining asset. The worst off may, in addition, be burdened with debt and poor health, further limiting their ability to meet current needs, let alone begin rebuilding their capacity to face future challenges.

     Whether addressing temporary or chronic food insecurity, it is clear that the challenge goes well beyond ensuring sufficient food in any given period of time. Rather, understanding and meeting the challenge requires a broader perspective on the full range of needs and choices faced by households, the resources and external conditions that influence those choices, and the livelihood strategies that could enable families to meet their food needs over time.

     Availability of and access to animal genetic resources can be a problem for pastoralists and poor households. An emerging problem is management of epidemics, as currently

illustrated in Asia and increasingly in other parts of the world, where thousands of animals are killed prophylactically because of avian influenza (GTZ, 2006).

1.1.3 Emerging issues

What can agriculture offer globally to meet emerging global demands, such as mitigating the impacts of climate change, dealing with competition over (dwindling) resources? Projections of the global food system indicate a tightening of world food markets, with increasing scarcity of natural and physical resources, adversely affecting poor consumers. Improved AKST in recent years has helped to reduce the inevitable negative environmental impacts of trade-offs between agricultural growth and environmental sustainability at the global scale. Growing pressure on food supply and natural resources require new investment and policies for AKST and rural development in land-based cropping systems.

     AKST is well placed to contribute to emerging technologies influencing global change, such as adaptations to climate change, bioenergy, biotechnologies, nanotechnology, precision agriculture, and information and communication technologies (ICT). These technologies present both opportunities and challenges, and AKST can play a central role in accessing the benefits while managing the potential risks involved.

     About 30% of global emissions leading to climate change are attributed to agricultural activities, including land use changes such as deforestation. Additionally, environmental variations resulting from climate change have also adversely affected agriculture. In extreme cases, severe droughts and floods attributed to climate change make millions of people in resource poor areas particularly vulnerable when they depend on agriculture for their livelihoods and food. AKST can provide feasible options for production systems, manufacturing and associated activities which will reduce the dependence on depleting fossil fuels for energy. Similarly, AKST can provide information about the consequences of agricultural production on the hydrology of watersheds and groundwater resources. AKST can also be harnessed to reduce greenhouse gas (GHG) emissions from agriculture, as well as increase carbon sinks and enhance adaptation of agricultural systems to climate change impacts (Chapter 6).

     Continuing structural changes in the livestock sector, driven mainly by rapid growth in demand for livestock products, bring about profound changes in livestock production systems. Growing water constraints are a major driver of future AKST. Soil degradation continues to pose a considerable threat to sustainable growth of agricultural production and calls for increased action at multiple levels; this can be strongly supported by AKST. Forestry systems will remain under growing pressure, as land use systems and urbanization continue to spread particularly into these ecologically favorable areas. Biodiversity is in danger as a result of some agricultural practices. Finally, there is significant scope for AKST and supporting policies to contribute to more sustainable fisheries and aquaculture, leading to a reduction of overfishing in many of the world's oceans.

     Bioenergy is being promoted in several countries as a