International rice experts say there must be large increases in rice production over the next 25 years just to keep pace with world population growth. But, they warn, this will be increasingly difficult as climate changes, water shortages and other factors limit the capacity of farmers to grow rice.
At the International Rice Research Institute in Los Banos, the Philippines, scientists are keeping close track of world rice production and quality, and say the future raises serious questions.
As the world's population grows, there is increasing competition for water, land and other resources needed to produce rice. As a result, plentiful supplies will be hard to maintain.
One of the institute's deputy director generals, William Padolina, says that over the next 25 years the trend is clear.
"The importance of rice in Asia is very well known, 90 percent of rice is produced and consumed in Asia and two billion people obtain 50 to 80 percent of their calories from rice," said Mr. Padolina. "That's almost half of the population of the world. And if the present trend of population growth continues, rice production must increase by 30 to 40 percent to match demand."
But population is only part of the story. When global warming and extreme weather conditions, such as droughts and floods, are taken into account, the figures are even more staggering.
John Sheehy, a senior scientist at the Institute, says that by the year 2050 the Philippines must increase production by 96 percent, India by 92 percent, Bangladesh by 99 percent, and China by 20 percent.
However, China has such a broad impact on the market it can radically affect prices. Last year, IRRI officials say, China went to the foreign market for one percent of its rice needs, and that drove up international prices by 40 percent.
While the trend of increasing population, global warming, and limited resources will take decades to unfold, Duncan Macintosh, head of the institute's information service, says the threat is imminent.
"We'd like to suggest to you that there are some very significant changes," he said. "And again with climate change, water shortages, labor shortages, land shortages, that there are some very interesting developments."
Water is key to rice production, and scientists say improved irrigation and storage techniques would do a lot to take pressure off of water resources. The institute works to produce strains of rice that require less water, and resist disease and insects, or have other properties suited to individual nations and climates.