Surface and gully erosion exacerbate problems of low productivity, further diminishing soil resources, threatening the future productivity of the land. Water quality can become impaired, which when coupled with high sediment levels, constrains developing sustainable water-resource management. Clearly, action must be taken on many fronts to develop sustainable solutions and improve management of land and water in CWANA.

1.1.2.4 Agrobiodiversity

Agrobiodiversity or agricultural biodiversity includes all components of biological diversity relevant to food and agriculture: "Agricultural biodiversity is a broad term that includes all components of biological diversity of relevance to food and agriculture. It encompasses the variety and variability of animals, plants and microorganisms, at the genetic, species and ecosystem levels. They are necessary to sustain key functions of the agroecosystems, their structures and processes for, and in support of, food production and food security. So it refers primarily to genetic variability in cultivated plants and domesticated animals together with their progenitors and closely related wild species growing and evolving under natural conditions. Plants and animals gathered from, and hunted in, the wild are also included in this term" (www.biodiv.org/convention).

CWANA has a wide range of diversity in climate, topography and soils; genetic diversity of many globally important crops and their wild relatives, such as cereals, food legumes, forages, industrial crops, fruit trees and vegetables and farm animals. Its cultural diversity affects agriculture. Agriculture began independently in different sites about 12,000 to 11,000 years ago. It spread along the East Mediterranean, North Africa and South Europe, southwards to Egypt and the Ethiopian Plateau and eastwards to Central Asia and Indus. Agriculture in CWANA centers upon sheep, goats, cattle, cereals (wheat, barley), and legumes (lentil, pea, vetch), flax, which are early domesticates of the Near East (Harlan, 1995). Historical evidence suggests that West Asia and North Africa (WANA) are among the most important domestication centers, from where small ruminant production expanded to other parts of the world. The small ruminants found in the region represent a rich source of the genetic diversity necessary for production, orientation and diversification efforts.

Most crops in the Near East were domesticated during the Neolithic period. CWANA is significant and unique for plant diversity. Vavilov's (1926) Near Eastern, Mediterranean and Central Asian centers of origin extend into the region. This, of course, indicates that CWANA is a center of origin or diversity of several crops and many other plant species. The wild plant relatives and landraces, with enormous genetic diversity, are still found for cereals, legumes, fiber and oil crops, pasture and forage plants, fruits, nuts and vegetables (Harlan, 1992).

Near Eastern centers of diversity, including Jordan, Lebanon, Palestine, Syria, southeast Turkey, southern Iran and Iraq, extend northeast to the Caucasus and south to Arab Peninsula. They encompass a megadiversity of important food crop and pasture species and have a nuclear center and center of origin (Vavilov, 1926). Here numerous species, notably wheat, barley, lentil, pea and vetch, of temperate zone

agriculture originated 10,000 years ago. In Turkey, Harlan (1951) described microcenters for Amygdalus spp., Cucumis melo, Cucumis sativus, Cucurbita moshata, Cucurbita pepo, Lens culinaris, Lupinus spp., Malus spp., Medicago sativa and other Medicago spp., Onobrychis viceaefolia, Phaseolus vulgaris, Pistachio spp., Prunus spp., Trifolium spp., Vicia faba, Vitis vinifera. Almond, olive and pistachio trees also originated from this region and have dominated traditional agricultural systems. They have diverse wild relatives and local varieties. The biodiversity in this region is most outstanding for within-species genetic diversity and the many endemic species. Furthermore, the indigenous crop and food plants of the Near East are known for their resistance to disease and abiotic stress, making them valuable for germplasm enhancement, upon which global food security depends.

Central Asia is also an important center of diversity in cultivated plants. It has the richest species and intraspecies diversity for many globally important crops. Agriculture must have reached this center from the Near East about 5000 BCE (Zeven and de Wet, 1982). Major crops include apple, apricot, peach, pear, plum, grape, almond, pistachio, pomegranate, fig, wheat, barley, rice, maize, sorghum, bean, chickpea, tomato, potato, onion, garlic, coriander and melon. Industrial and stimulant crops cotton, sugar beet, groundnut, sesame and tobacco are also cultivated.

1.1.3 Climate change

The vulnerability of CWANA to variable rainfall and drought is compounded by the anticipated effects of global climate change.

Drylands, CWANA included, are net sources of CO₂ (Sombroek, 1995) from overuse of plant resources. Annual CO₂ emissions of CWANA total about 1.8 billion tonnes- about 7.8% of the world's emissions. Inventories of greenhouse gases show most emissions in most CWANA countries come from burning fossil fuel. In Sudan and Somalia, CO₂ emissions can be correlated to changes in land use, particularly deforestation. CO₂ can be sequestered through better soil management. In some Central Asian countries almost half the emitted CO₂ was absorbed, 90 million tonnes, by changing land use (UNDP et al., 2003). Some atmospheric pollution caused by human activity is related to oil production and export, fertilizers, cement factories and motor vehicles.

Seasonal sand and dust storms contribute to air pollution in the region. The US Environmental Protection Agency (US EPA, 1996) estimated annual dust fallout of about 1000 tonnes per km2 along the coast of Kuwait. Dust storms absorb pollutants, such as pesticides, and transport them long distances. Transboundary air pollution is an emerging issue in the region. Climate change will potentially have major effects on the Nile Delta and Darfur (Box 1-1).

1.1.4 Macroeconomic indicators

1.1.4.1 Gross domestic product (GDP) and agriculture's share

The GDP varies among the countries from US$889 in Yemen to US$22,420 in United Arab Emirates (UAE). Most countries fall in the range of US$2,000-7,000; oil-producing countries have an average of US$16,657 (Table 1-2).

Though agriculture is a major employer in CWANA countries, with 50% of the labor force, its share in the GDP