Large parts of Eastern Africa are arid and semi-arid, and annual rainfalls below 500 mm are common. Amounts of rain and its distribution are highly unpredictable, both from year to year and in terms of distribution within a given year (FAOSTAT 2000). These conditions make the sub-region particularly vulnerable to the impacts of climate change on food production and security of livelihoods. These are accordingly priority issues.
Air pollution is not currently a major problem in the sub-region, as rates of urbanization and industrial production are relatively low at present. However, these rates are rising rapidly in comparison with other parts of Africa and effective long term development plans are needed to prepare for potential increases in emissions.
Drought impacts on soil
Eastern Africa has experienced at least one major drought in each decade over the past 30 years. There were serious droughts in 1973/74, 1984/85, 1987, 1992-1994, and in 1999/2000 and there is some evidence of increasing climatic instability in the subregion, and increasing frequency and intensity of drought (FAOSTAT 2000). For example, records of dry and wet years for Uganda between 1943 and 1999 show a marked increase in the frequency of very dry years over the past 30 years (Department of Meteorology 2000). Rainfall records also indicate that, in some parts of the sub-region, the drought in 2000 was worse than that experienced in 1984 (DMC 2000).
Persistent deficits in rainfall in Eastern Africa have had serious impacts including total crop failure which has led to increasing food prices and dependency on food relief in Burundi, Ethiopia, Kenya and Uganda (DMC 2000). In Ethiopia, the 1984 drought caused the deaths of about 1 million people, 1.5 million head of livestock perished, and 8.7 million people were affected in all. In 1987, more than 5.2 million people in Ethiopia, 1 million in Eritrea and 200 000 in Somalia were severely affected (DMC 2000). Severe water shortages and rationing, continued reductions in water quantity and quality, increased conflicts over water resources, and the drying up of some rivers and small reservoirs have contributed to death of livestock from hunger, thirst and disease, and increased conflicts over grazing belts.
Additional impacts in the sub-region include persistently low water levels in rivers, underground aquifers and reservoirs, impacting on hydrology, biodiversity and use of water for domestic, industrial and irrigation purposes. Low reservoir levels have also reduced the potential for hydropower generation leading to the introduction of power rationing in the domestic and commercial sectors which has caused interruptions of economic activities and declines in manufacturing output. This was the case in Kenya where low rainfall between 1998 and 2000 led to reductions in hydropower generation and the need for drastic rationing schedules. The Kenya Power and Lighting Company was estimated to have lost US$20 million (IRI Climate Digest 2000) and there were additional losses to the economy resulting from the enforced closure of industrial facilities.
By contrast, some areas have experienced aboveaverage rainfall, triggered by the ENSO phenomenon. The very warm ENSO event during the rainy season of 1997 resulted in record rainfall in some areas (averaging 5 to 10 times more than normal in many areas) and disastrous flooding. Thousands of people were displaced and extensive damage to property was caused. In Uganda, about 525 people died and another 11 000 were hospitalized and treated for cholera which broke out after flooding and landslides. About 1 000 more people were reported to have died in floodrelated accidents and 150 000 were displaced from their homes (NEMA 1999). About 40 per cent of Uganda's nationwide 9 600-km feeder road network was destroyed and the country experienced widespread crop failure resulting in dependency on food imports and aid.