Cloud seeding could be expanded across the Sahel

Cloud seeding, the practice of firing salt-based chemicals into pregnant clouds to force them to shed rain, has proved so successful in Burkina Faso that the programme could soon be extended to other semi-arid countries in West Africa, the Inter State Committee Against Drought in the Sahel (CILSS) has said.

Burkina Faso began using light aircraft to seed clouds in 1998, and its positive experience persuaded the CILSS heads of state to look at ways of using this technology to enhance rainfall across the region when they met in the Mauritanian capital Nouakchott in January.

“All CILSS countries are from the Sahel where water remains a crucial problem and rainfall levels are a major source for concern and are set to become even worse in coming years according to projections,” Issa Martin Bikienga, the major policies programme coordinator of CILSS told reporters in Ouagadougou on Wednesday.

“That is why we need to make efforts to artificially modify the weather,” Bikienga continued. “It is our responsibility at CILSS to explore all existing technologies that will help to make water fill our reservoirs or feed our plants when there is a shortage of rains.”

The Burkinabe government has estimated that cash earnings from agriculture have increased by 10 to 15% since it began the cloud seeing programme eight years ago.

The additional rainfall created has helped to fill reservoirs, allowing irrigated cultivation to continue during the dry season in many areas that were previously only able to grow one crop a year during the rainy season.

Production has therefore increased and imports, particularly of cereals, have dropped. In some parts of Burkina Faso, fresh tomatoes are now available all year round as a result of the artificially induced rain.

The first two countries expected to follow Burkina Faso’s lead are Mali and Niger, where cloud seeding is expected to begin in 2005 at the latest.

However funding has yet to be secured. CILSS is organising a meeting in Ouagadougou next week with potential donors to seek the US$ 60 million needed to extend the programme across all nine countries for five years.

The meeting, which will also be attended by representatives from the Economic Community of West African States (ECOWAS) and the West African Economic and Monetary Union (UEMOA), the World Bank, the African Development Bank and other major donors, will also be used by CILSS as a forum for extolling the benefits of cloud seeding.

The practice involves releasing silver iodide, usually from a plane, into an existing cloud formation to encourage the enlargement of water droplets and ultimately rain. However, it is an expensive process and does not always yield results. The CILSS project therefore includes the establishment of more meteorological stations and sophisticated radars to monitor cloud formations so that the rain-bearing potential of each cloud mass can be more accurately evaluated.

Cloud seeding works on the principle that all air contains moisture and generally the warmer the air temperature the greater the capacity of the air to hold water and not release it as rain. The silver iodide acts as giant condensation nuclei, gathering moisture around them and pulling it out of the cloud and to the ground.

The nine members of CILSS are Burkina Faso, Cape Verde, Chad, Mali, Mauritania, Niger, Gambia, Guinea Bissau and Senegal.