African Agriculture Suffers From Erratic Climate

• Climate change hurting African crop yields
• Farmers complain rains no longer predictable
• Africa needs development to adapt, experts say

By Tim Cocks and Loucoumane Coulibaly ABIDJAN, April 20 (Reuters) - From Africa's humid jungles and cocoa plantations to its growing semi-deserts and wilting maize fields, erratic weather linked to climate change may be ruining subsistence crops and export commodities alike. But preparing African agriculture for a warmer world will involve investing in things the fast expanding continent needs anyway, such as irrigation, roads, fertilizer and better seeds. Africa's farmers complain they can no longer predict when the rains or dry heat will come. They sow, but the rains fail, or come late. Seeds perish. "It doesn't rain regularly like it used to. It's a problem for our trees," said Ivorian cocoa farmer Francois Gueye, his face lit by harsh sun piercing through cocoa leaves. "We thought we'd mastered the rainy season, but not anymore." Gueye used to get three tonnes out of his farm in the south Ivory Coast village of Tanokro. Now he gets half a tonne. The world's poorest continent is predicted to be the most affected by climate change blamed on human greenhouse gas emissions, although it hasn't yet been proven that they are the cause of Africa's worsening droughts and floods. "Africa is going to be hit the hardest," said Christian Nellemann of the United Nations Environment Programme. "In Africa, what used to be predictable is not any more. And rising populations will need feeding -- you're looking at an additional billion people in Africa in 40 years." "ALREADY TOO HOT" As with all climate forecasts, there are big uncertainties. While some cold countries at high latitudes may actually benefit from warmer weather as they will enjoy longer growing seasons, the tropics are likely to suffer, experts say. "Agriculture in low latitude developing countries is ... especially vulnerable because climates of many of these countries are already too hot," according to one World Bank assessment. The Intergovernmental Panel on Climate Change in 2007 forecast that rain-fed crop yields in some nations could halve by 2020. Many climatologists now think that's too gloomy. Another study by Stanford University in February predicted that five staple African crops - maize, sorghum, millet, groundnut, cassava - could see yields drop by 8 to 22 percent. Africa's valuable soft commodities are also expected to suffer -- West Africa supplies two thirds of the world's cocoa. Cotton output has halved in the past five years, with African growers blaming erratic weather as well as U.S. subsidies to its own cotton farmers. Cotton is sensitive to drought. Once planted, the crop quickly perishes with no rain. "We've noticed a late arrival of the rains, coming late June instead of May," said Nouhoum Traore, technical adviser in charge of production in Africa's number two grower, Mali. "Every time it happens, we lose a lot of cotton." The research director at Kenya's Coffee Research Foundation, Joseph Kimemia, told Reuters that erratic rainfall and excessive drought had hurt coffee production, making crop management and disease control a nightmare. "Coffee operates within a very narrow temperature range of 19-25 degrees (Celsius). When you start getting temperatures above that in some cases, trees wilt and dry up," he said. In southern Africa, a dry spell has ravaged maize crops. NO EASY SOLUTION Solutions to Africa's climate woes are not all costly. One answer is genetically modified, drought resistant seeds, which are helping West Africa cotton. The African Cotton Association says yields may recover 18 percent next season from GM seeds. Another one is to halt the retreat of Africa's forests, which provide shade and trap moisture. "There's no trees here and its affecting rainfall," said Brou Kouame, an agro-climatologist in Ivory Coast. "We have to put the brakes on deforestation and start replanting trees." But analysts say the main solution is investment: African yields are low partly due to lack of fertilizer and irrigation. "A key thing is rural infrastructure," said Claudia Ringler of Washington's International Food Policy Research Institute. "You need paved roads so they don't keep being flushed away in floods, irrigation. A lot of this is coming from China." (Additional reporting by Tiemoko Diallo in Bamako, Helen Nyambura in Mombasa and Tansa Musa in Yaounde; Writing by Tim Cocks; Editing by Giles Elgood)