Robust crops, such as sugar cane, should benefit from the higher temperatures
North African agriculture will be the worst affected by climate change, according to an assessment of how 50 key crops will perform around the world under increasing temperatures over the next 40 years.
Climate change will raise average crop productivity until 2020, after which it will decline by 5–10 per cent by 2050, according to research carried out by the International Center for Tropical Agriculture (CIAT) in Colombia.
The results were presented last week (17 November) at a press conference to announce the launch of a Consultative Group on International Agricultural Research (CGIAR) mega-programme to address the effects of climate change on food security.
CIAT researchers calculated the 'climatic potential to produce food' for 50 of the world's most important crops. This is the hypothetical best-case scenario in which crops can be shifted to more suitable zones to avoid the worst, or exploit the best, climate impacts.
They concluded that most of the short-term gains until 2020 will be seen in the Northern Hemisphere.
Andy Jarvis, a research fellow at CIAT, said that rice yields on the Indo-Gangetic plains will increase by around two per cent, even up to 2050. But wheat will experience productivity losses of up to 10 per cent.
In West Africa, important crops such as wheat, potato, sorghum and soya will lose out, while more robust crops such as white yam, sugar cane and plantain will benefit from the higher temperatures.
In East Africa, similar patterns will be seen, with beans — known as the protein of the poor — predicted to experience yield losses of 3–5 per cent. North Africa will experience the worst effects, with 80 per cent of its crops losing productivity to 2050 and beyond.
"There is no single region where all crops are losing productivity," said Jarvis, "but people are depending on very specific crops for their food security, and in many cases the crop they're growing today is going to lose out in the future.
"Local cultures may need to change their practices by growing different crops from what they grow today. That is obviously quite an upheaval for those communities, and it's something that we need to work towards and try to avoid if possible," he said.
Even in areas where significant increases in crop yields are seen, there will be other knock-on effects, he added.
For example, farmers on the Indo-Gangetic plain are already experiencing lower wheat yields because of increased temperatures. Changing wheat planting times means changing rice planting times — as the two are grown in cycles — which causes problems with irrigation.
The Climate Change, Agriculture and Food Security programme, which will be formally announced on December 4 at the climate change conference (COP 16) in Cancun, Mexico, will pool knowledge on the impacts of climate change on food security to try and find a way forward.
The programme aims to reduce poverty in targeted regions by 10 per cent, and reduce the number of rural malnourished poor by a quarter, by 2020. It also hopes to put agriculture on the post-2012 international climate-change agenda.
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