The FAO reckons that, to keep pace, the amount of food available in developing countries will have to double by 2050, equivalent to a 70 per cent rise in world food production. If that does not happen, fears Joachim von Braun, the head of the International Food Policy Research Institute in Washington, DC, there could be a return to the food conflicts of 2007-08 which caused riots in more than 60 countries and set off a controversial worldwide land grab — a rush by rich food-importers to buy swathes of Africa and South-East Asia on which to grow food. Even if the rise in output comes about but in the “wrong” way, there could be problems, since water in some areas is growing scarce and increasing food output will make it scarcer.

The right way, argues Alexander Mueller of the FAO, is for farmers in poor countries to boost their yields. This would be better for the countries themselves, since it would make them richer. And it would be better for the world, too, because the potential for higher yields should be greatest where they are now low, especially in Africa. At the moment, cereal yields in Africa are around one tonne per hectare, compared with three-to-four tonnes in Europe and rich Asia. It should be easier to get an extra tonne per hectare by increasing African yields to two tonnes a hectare than by boosting already-fecund European or north-east Asian yields even further (water is more abundant in parts of Africa, too). Hence the hope that high prices in 2007-08 would goad farmers in poor countries to respond by increasing yields. Alas, there is little sign of that happening so far.

... contd.