Title / Titre :
IMPACT OF CLIMATE CHANGE ON THE AGRICULTURAL AND TOURISM INDUSTRIES IN SOUTHERN AFRICA: A CASE STUDY OF BOTSWANA

Author(s) / Auteur(s) :
J.A. Adedoyin

Address / Adresse :
Department of Physics, University of Botswana,
Private Bag 0022, Gaborone, Botswana
e-mail: adedoyin@mopipi.ub.bw
Fax: +267-356591 or 585097

Key words / Mots clés :

Abstract / Résumé : The norm in scientific circles is to convert the greenhouse effect of gases that absorb infrared long-wave radiations, emitted by the sun-heated Earth, to their carbon dioxide equivalent. This way, climate change can be quantified in terms of percentage increases in carbon dioxide. Given this norm, it is easy to quantify how the effect of, for instance, doubling the amount of carbon dioxide in the atmosphere will impact on various sectors of the Southern Africa economy. For example, the effect of climate change on agriculture in Botswana is two-fold: livestock and crops. While it is envisaged that some crops will yield more if carbon dioxide concentration doubles in the atmosphere, it is proposed that this boost will not affect tropical crops like sorghum and maize, which are planted in Botswana. The consequent higher grain prices may then lead to costlier livestock production.

In a study by Adedoyin(1999), it was shown that by monitoring the sea-surface temperature of the Pacific Ocean NIŅO 34 region (i.e. lat 130-175W, lon 20S-25N) region about six months ahead of the rainy season in Botswana, and linking this with a zero-lag sea-surface temperature anomalies of the Indian and South Atlantic Oceans, it is possible to qualitatively predict 94% of the total amount of water that will be available in the Okavango River Basin in the following January - May period, relative to the 1975-96 average. This relationship has implications for the survival and availability of wildlife in this region and, by implication, the tourism industry in Botswana.

The mechanism for these inter-annual variability in climate is discussed in relation to the modulating effects of continental rain-belt mode, large-scale atmospheric circulation and SST patterns. Observations show that above-normal (below-normal) Kalahari rainfall is usually accompanied by the southward (northward) displacement in the rain-belt mean axis, and there is a concurrent increase (decrease) in the total rainfall (Shinoda and Kawamura, 1994). Also, above-normal (below-normal) Kalahari rainfall is accompanied by dominant negative (positive) anomalies of 700 hPa heights over southern Africa. The correlation between Kalahari rainfall and global 700 hPa height anomalies is investigated with the aid of a two-layer model of the atmosphere. Simulations reveal that the most unstable modes occur when the interface between continental air masses is exactly at 700 hPa (Adedoyin, 1997).

Adedoyin, J.A. (1997) Instability of squall-inducing waves, global sea-surface temperature anomalies and climate change in tropical North Africa, Meteorol. Atmos. Phys., 62, 79-89

Adedoyin, J.A., 1999. The impact of climate variability on the tourism industry in Botswana, Practical Applications of Seasonal to Inter-annual Climate Prediction and Decision-making in Agriculture and Water Resources Management in Africa, Niamey, Niger Republic, 30 June-8 August, 1997, pp 19-23

Shinoda, M. and Kawamura, R. (1994) Tropical African rainbelt and global sea-surface temperatures: Inter-hemispheric comparison, Proceedings of the International Conference on monsoon variability and prediction, I.C.T.P., Trieste, Italy, 9-13 May, 1994