It said in a report unveiled in New York Friday that 65 developing countries, home to more than half the developing world's population, could lose around 280 million tonnes of potential cereal production valued at $56 billion as a result of the climatic change.

This loss would be equivalent to 16 percent of the agricultural gross domestic product (GDP) of these countries, FAO said in a statement.

"Among these countries, India could lose 125 million tonnes, or 18 percent, of its rain-fed cereal production, while China's rain-fed cereal production of 350 million tonnes are expected to rise by 15 percent.

"Climate change not only has an impact on food security, but is also likely to influence the development and intensification of animal diseases and plant pests," said Wulf Killmann, who chairs FAO's Interdepartmental Working Group on Climate Change. 

"Temperature changes, as well as increased air pollution, can intensify human disease patterns, as does the spread of trans-boundary animal diseases caused by pathogens that are potentially dangerous to humans," the report said, pointing to the avian flu as the most recent example.

The study has used Agro-Ecological Zones (AEZ) methodology, a worldwide spatial soil and climate suitability database for use in quantifying regional impacts and geographical shifts in agricultural land and productivity potentials.

In its report prepared in collaboration with the International Institute of Applied Systems Analysis, it has forecast that the biggest beneficiaries of the climate change would be the industrialised countries, which are the biggest polluters.

"The northern industrialised countries could increase their crop production potential as a result of climate change," the report states.
 
On the other hand, "in some 40 poor, developing countries, with a combined population of two billion, including 450 million undernourished people, production losses due to climate change may drastically increase the number of undernourished people, severely hindering progress in combating poverty and food insecurity", the report says.

In Africa, 1.1 billion hectares of land have a growing period of less than 120 days, it says. By 2080 climate change could result in an expansion of this area by five to eight percent, or by about 50 to 90 million hectares, FAO said.