Hotter nights threaten Asia's rice output, study says

Aug 10, 2010, 13:23 GMT

   Bangkok - Rising night temperatures threaten to slow rice production in Asia, where rice is the staple food for billions, a new scientific study revealed.

   The study's conclusions were based on data collected over six years from 227 irrigated rice farms in six major rice-growing countries in Asia, which produces more than 90 per cent of the world's rice.

   The report in the US publication Proceedings of the National Academy of Science was made available in Bangkok Tuesday by the International Rice Research Institute.

   'We found that as the daily minimum temperature increases, or as nights get hotter, rice yields drop,' said Jarrod Welch, lead author of the report and graduate student of economics at the University of California, San Diego.

   The study found that rising temperatures during the past 25 years had already cut the yield growth rate by 10 to 20 per cent in several locations in Asia.

   'Our study is unique because it uses data collected in farmers' fields, under real-world conditions,' Welch said.

   Rice is on the daily diet for about 3 billion people, or half the world's population. More than 60 per cent of the 1 billion poor who live in Asia depend on rice as their staple food.

   A decline in rice production would mean more people will slip into poverty and hunger, the researchers said.

   'If we cannot change our rice production methods or develop new rice strains that can withstand higher temperatures, there will be a loss in rice production over the next few decades as days and nights get hotter. This will get increasingly worse as temperatures rise further towards the middle of the century,' Welch said.

   The research team that complied the report included professors Jeffrey Vincent of Duke University, Maximilian Auffhammer of the University of California, Berkeley, Piedad Moya and Achim Dobermann of the International Rice Research Institute, and David Dawe of the Food and Agriculture Organization of the United Nations.