The El Niño–Southern Oscillation (ENSO) phenomenon is one of the predominant causes of climate variability in southern and eastern Africa. It thus has a considerable impact on agriculture in the region. This paper will define the ENSO signal in terms of its relevance to commercial agriculture in southern and eastern Africa. The ENSO signal is often generalized in terms of either a drought year or heavy rains over a season. Analysis reveals, however, that the ENSO signal shows great variability both within and between events with obvious implications for the use of climate information by potential users. Information requirements also vary substantially from user to user. The ENSO effect is first isolated through superposed epoch analysis of rainfall data on a variety of time scales. This analysis clearly shows the variability of the signal. For example, ENSO impacts the reliability of the start of the rains in Zambia, whereas in southern Tanzania ENSO has a greater influence on the seasonal distribution of rainfall. The significance of these variations for commercial agriculture is very much related to the particular operation that is affected. Semi-structured interviews with commercial operators in Swaziland were used to assess the impact that climate variability might have on their activities. Focused interviews produced historical time lines to illustrate the influence on decisions that climate information could have. The results show that the use of climate information varies considerably between companies. A preliminary assessment highlights certain constraints on use, primarily in terms of forecast timing and scale. Recommendations for further work include a thorough exploration of the constraints issue as well as economic assessment of the perceived value of forecasts, including how these estimates are reached.
- El Niño–Southern Oscillation
- climate variability