(Repeats story issued on Friday, June 10 with no change in text; Read this story in a PDF: r.reuters.com/nyp99r)
* Global effort to double crop yields, make them climate resilient
* Food consumption outpacing farm output in more prosperous world
* Food prices seen doubling in 20 years amid rising social unrest
* Evidence climate change already depressing crop yields
* Call for new agronomy revolution, especially for developing world
CANBERRA, June 10 Charlie Bragg gazes across his lush fields where fat lambs are grazing, his reservoirs filled with water, and issues a sigh of relief. Things are normal this year and that's a bit unusual of late.
His 7,000-acre farm near the Australian town of Cootamundra is testament to the plight facing farmers around the globe: increasingly wilder weather is making food production more unpredictable. It's the new normal they must prepare for.
Bragg's farm in New South Wales state has been in the family for generations and has weather records for the area stretching back 110 years. After seven years of costly drought, the weather switched last year to unseasonably wet with flooding rains.
"It's screaming to me that things are getting hotter and drier at different times of the year," said the 40-year-old Bragg during a recent visit to his property, about two hours drive to the west of Canberra, the Australian capital.
"Our summers are getting wetter and if this trend continues, then we will have to find different means of farming," he said.
Across the globe, rising temperatures and more intense droughts, floods and storms are forcing a rethink in how to grow food, from breeding hardier crop varieties and changing planting times to complete genetic overhauls of plants.
Growing populations, changing diets and insatiable demand for grains, meat and vegetables is putting pressure on global food production and prices like never before.
Soaring food prices, civil unrest and worries about weather have spurred a global race to create more productive crops that can thrive in a warmer -- and more prosperous -- world.
The World Bank estimates 925 million people are hungry in the world today. The figure has been rising since 1995-97 due to rising food prices, a succession of economic crises, and a neglect of agricultural innovation, especially relevant to the poor.
It is going to get much worse for the hungry because global food prices will more than double within 20 years, aid agency Oxfam International said in a June 1 report. Flat-lining yields, a scramble for fertile land and water, and environmental crises are reversing decades of progress against hunger, it said.
The challenge is to speed up the creation of new crops more adaptable to climate change and capable of much greater yields. A laboratory in the leafy heart of Canberra could hold some of the answers.
Inside, hundreds of seedlings on a conveyor belt file through a high-tech chamber, each plant bar-coded and scanned for signs of genetic superiority. A selection process that took months in the past, now takes a fraction of the time.
"I call this digital agriculture," said plant scientist Bob Furbank of Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO). The 3-metre high PlantScan chamber uses 3D laser radar and other devices to measure size, growth and water use.
"It's like the plant Olympics. We have to rapidly pick the best of the best," Furbank, scientific director of CSIRO's Plant Phenomics centre in Canberra, said on a recent visit to the laboratory brimming with high-tech equipment after a multi-million dollar refit.
The centre is part of renewed global efforts to create a new generation of crops that will dramatically boost yields, particularly for wheat and rice.
Investment into creating a new generation of staple crops, especially wheat and rice, has lagged since the Green Revolution of the 1960s, which led to years of bumper harvests, easing worries about lack of food.
The new green revolutionaries must find ways of doubling yields as the global population, set to hit 7 billion later this year, heads for 9 billion by 2050, with greater affluence changing diets and triggering ever greater demand.
THE HEAT IS ON
To feed 2 billion more mouths by 2050, food production will have to increase by 70 percent, the U.N.'s Food and Agriculture Organization (FAO) says.
Climate change is perhaps the greatest threat to meeting the target as rising temperatures and droughts dry out farmlands or more intense floods and storms inundate them.
"What we expect in the future is there will be much more unexpected events, much more extreme climate change," said Concepcion Calpe, a senior economist with the FAO in Rome.
Boosting yields has become almost an obsession with governments, seed companies such as Syngenta and Monsanto, and scientific bodies such as Australia's CSIRO.
Global yield growth of wheat and rice has stagnated at 0.6 percent to 0.7 percent annually over the past 10 years -- about half the production growth rate of 1.2 to 1.4 percent annually needed from now to 2050, the FAO says.
Scientists say they are running out of time to boost yields.
With greenhouse gas emissions rising quickly, the world is already on track to exceed a 2 degrees Celsius threshold that scientists say risks triggering dangerous climate change. The planet has already warmed about 0.8 degrees Celsius on average since 1900.
Unless emissions growth is slammed into hard reverse, the world could be 2 to 3 degrees warmer on average by 2050, and much more by 2100.
Computer climate models show large areas of Australia, Africa, the United States, eastern Brazil and southern Europe drying out in the coming decades. But Russia, Canada and Indochina would become wetter, potentially benefiting crop production or allowing new crops to be grown in previously cooler climes.
Overall, for many major cereal crop-growing regions, the future will hinge on drought and heat-tolerant varieties, better weather forecasts and a likely shift in cropping to new areas.
A U.S. study published last month in the journal Science found climate change was already exerting a considerable drag on the yield growth of crops.
The authors used crop yield models with and without changes in temperature and rainfall to show global falls in wheat output of 5.5 percent and 3.8 percent for corn as a result of climate change from 1980-2008.
That was equivalent to the entire annual corn crop of Mexico, or the wheat crop of France, the European Union's biggest producer, it said.
SEEDS OF CHANGE
The global forecast is for increasingly bad weather, amid spiralling demand from an expanding global middle class.
"2.5 billion people entering the world's middle class is a lot more important than climate change," said Jeffrey Currie, global head of commodities for Goldman Sachs in London.
The World Bank's food price index, which measures global prices, jumped 36 percent in April from a year ago to near its 2008 peak, before dropping again.
"While it might not be the primary cause, it definitely is an underlying cause for some of the instability you're seeing in North Africa and the Middle East right now," said Rick Leach, chief executive of the World Food Program USA. "The very poor can spend up to 80 percent of their income on food," he said, adding: "We're now moving into a period of extreme worry in terms of the implications of food price increases."
More than 680 million people in Asia and the Pacific region live on less than US$1.25 a day, the International Fund for Agricultural Development, a U.N. agency, says. More than 70 per cent of these are in South Asia -- Bangladesh, India, Nepal and Pakistan -- making the region among the most vulnerable to food price inflation and climate
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