科学与发展网络(SciDev.Net)

Cattle in Kenya

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[NAIROBI] The stresses of climate-induced crop failures could be avoided if more small farmers in Africa also raised livestock, say researchers.

Climate change will result in a 10–20 per cent drop in yield for crops such as beans, maize and millet in Africa's drylands by 2050, researchers from the Kenya-based International Livestock Research Institute (ILRI) and the United Kingdom's Waen Associates found.

But many farmers in some of the affected areas could keep livestock to increase their incomes and reduce their vulnerability, the researchers say.

"We [looked] specifically at the areas of Africa where the rainfall is currently just about enough to grow some crops — although with low and variable yields — and where the rainfall changes to 2050 may limit this crop production even further," Philip Thornton, an ILRI scientist and one of the co-authors, told SciDev.Net.

"In such areas — where rainfall will still be enough for some pasture production — including more livestock in the system may be one way in which households can cope," he says.

The study focused on arid and semi-arid regions where scant rainfall is already causing crops to fail in one out of every six growing seasons. They found that from 500,000 to one million square kilometres of farmland in these areas will be incapable of supporting even subsistence for food crops by 2050.

Carlos Seré, director-general of ILRI, told SciDev.Net that communities should prepare for the inevitability of adding livestock to their farms.

The researchers warn that the change to livestock farming must be done sustainably, for example by limiting the number of livestock in an area during dry conditions so the pasture can recover quickly when rains come.

Mario Herrero, ILRI's systems analyst, acknowledges that an increase in livestock would increase greenhouse gas emissions but says the impact from the alternative — of herders migrating and cutting down forest to grow crops — could be worse.

"We have to consider the increased emissions in terms of trade-offs in the number of livelihoods protected, " he says.

The research was published in a special edition of Environmental Science and Policy this month (June).

Link to full paper via ILRI website [718kB]