Farmers face climate challenge in quest for more food

By David Fogarty

SINGAPORE (Reuters) - If farmers think they have a tough time producing enough rice, wheat and other grain crops, global warming is going to present a whole new world of challenges in the race to produce more food, scientists say.

In a warmer world beset by greater extremes of droughts and floods, farmers will have to change crop management practices, grow tougher plant varieties and be prepared for constant change in the way they operate, scientists say.

"There certainly are going to be lots of challenges in the future. Temperature is one of them, water is another," said Lisa Ainsworth, a molecular biologist with the United States Department of Agriculture.

Spiraling grain prices in recent months have startled governments long used to affordable rice, wheat, soy and maize.

But rising demand and likely greater climate variability and more fluctuations in crop output could mean even more uncertainty for prices.

Current estimates suggest demand for cereals will jump by more than 50 percent by 2050 as the world's population rises from 6.6 billion to about 9 billion.

The world has already warmed by about 0.7 degrees Celsius on average since the 1800s and studies show higher temperatures can cut yields, particularly in the tropics where a lot of rice is grown.

"In Northeastern China, low temperatures, a short growing season and lack of water limit production, so rising temperatures in the future may have beneficial impacts there," said Ainsworth.