Climate Change Threatens To Knock Crop Yields

Rapid rises in temperatures worldwide may overwhelm farmers’ efforts to keep up, say experts who want funds to breed new crops and freeze heat-resistant strains bred over past centuries.

A Stanford University study to be published on Friday estimates that African growing seasons for the continent’s staple foods — maize, millet and sorghum — will be hotter in nine out of 10 years by 2050.
Farmers can adapt by shifting growing times or using new varieties but the pace of change will require extra help, the study in the journal Global Environmental Change concludes.

“For a majority of Africa’s farmers, warming will rapidly take climate not only beyond the range of their personal experience but also beyond the experience of other farmers within their country,” said the study, whose authors were from Stanford and the Global Crop Diversity Trust.

The EU’s executive Commission pointed in April to research which showed a net positive effect for the next 30 years, for example from milder winters, but with increasingly negative effects. “The magnitude of climatic changes may exceed the adaptation capacity of many farmers,” it said.

The development of more resistant crops, for example, involves a decade or more to breed or design new varieties, screen these and get them into the hands of farmers. One initiative is the 2001 International Treaty on plant genetic resources for food and agriculture. Its 121 signatories have agreed to give up any patent claims on their native food crops, to speed up the sharing of different strains.

But the treaty will have to overcome a lack of funding and poor seed banks in countries in Africa which have rich seams of heat and drought-resistant varieties.

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