Tropical 'hotspots' may get too warm to farm

Marlowe Hood Yahoo News 3 Jun 11;

PARIS (AFP) – Climate change is on track to disrupt lifeline food crops across large swathes of Africa and Asia already mired in chronic poverty, according to an international study released Friday.

More than 350 million people face a "perfect storm" of conditions for potential food disaster, warns the report by scientists in the Consultative Group on International Agricultural Research (CGIAR).

Temperature increases projected by UN climate scientists could, by 2050, shorten growing seasons below critical thresholds, worsen weather variability, and render many regions dominated by subsistence farming unsuitable for key crops.

If these areas have a history of persistent food shortages to begin with, the mix could be lethal.

"We are starting to see much more clearly where the effect of climate change on agriculture could intensify hunger and poverty," said Patti Kristjanson, a scientist at CGIAR's Research Program on Climate Change, Agriculture and Food Security (CCAFCS).

Farmers know from experience how to cope with fickle weather patterns by changing planting schedules and moving livestock.

But rapid and major climate shifts may force them to use "entirely new crops or new farming systems," and many may not be able to adapt, Kristjanson said.

The 100-page study identifies potential food crisis "hotspots" by overlaying three kinds of data onto global and regional maps.

One identifies areas likely to heat up beyond optimal conditions -- or even outright tolerance -- for major crops, including rice, maize (corn) and beans.

Average maximum temperatures during growing seasons, for example, are poised to rise above 30 degrees Celsius (86 degrees Fahrenheit) across parts of west and southern Africa, India and China by 2050.

In some agricultural zones growing seasons may be shortened by at least five percent, and in others year-on-year variation in rain will likely to exceed 21 percent, both considered viability thresholds for certain crops, the study found.

To assess potential impacts, agricultural density and current food insecurity are also taken into account.

"When you put these maps together, they reveal places around the world where the arrival of stressful growing conditions could be especially disastrous," said Polly Ericksen, a scientist at CGIAR's International Livestock Research Institute in Nairobi.

Even in rich nations, climate-related impacts can be highly disruptive -- French livestock farmers, reeling from the most severe spring drought in more than a century, are culling herds for lack of feed.

But in much of Africa and Asia, where farmers are already struggling to meet basic needs, "survival is strongly linked to the fate of regional crop and livestock yields," Ericksen said.

Scientists are working furiously to breed new strains of staple grains that will be able to resist future warming, but some regions may have to shift to new crops altogether to meet nutrition needs, the researchers said.

"The window of opportunity to develop innovative solutions that can effectively overcome these challenges is limited," said Philip Thornton, a scientists at CCAFS and co-author of the study.

"Major adaptation efforts are needed now if we are to avoid serious food security and livelihood problems later."

Climate to wreak havoc on food supply, predicts report
Jennifer Carpenter BBC News 3 Jun 11;

Areas where food supplies could be worst hit by climate change have been identified in a report.

Some areas in the tropics face famine because of failing food production, an international research group says.

The Climate Change, Agriculture and Food Security (CCAFS) predicts large parts of South Asia and sub-Saharan Africa will be worst affected.

Its report points out that hundreds of millions of people in these regions are already experiencing a food crisis.

"We are starting to see much more clearly where the effects of climate change on agriculture could intensify hunger and poverty," said Patti Kristjanson, an agricultural economist with the CCAFS initiative that produced the report.

A leading climatologist told BBC News that agriculturalists had been slow to use global climate models to pinpoint regions most affected by rising temperatures.

This report is the first foray into the field by the CCAFS initiative. To assess how climate change will affect the world's ability to feed itself, CCAFS set about finding hotspots of climate change and food insecurity.

Focusing their search on the tropics, the researchers identified regions where populations are chronically malnourished and highly dependent on local food supplies.

Then, basing their analysis on the climate data amassed by the United Nations Intergovernmental Panel on Climate Change (IPCC), the team predicted which of these food-insecure regions are likely to experience the greatest shifts in temperature and precipitation over the next 40 years.
Mapping hunger

By overlaying the maps, the team was able to pinpoint which hungry regions of the tropics would suffer most.

With many areas in Africa predicted to become drier, countries such as South Africa which predominately farm maize have the option to shift to more drought resistant crops.

But for countries such as Niger, in western Africa, which already supports itself on very drought resistant crop varieties, like sorghum and millet, there is little room for manoeuvre, explains Bruce Campbell, the director of CCAFS.

"West Africa really stands out as problematic. Burkina Faso, Niger, Mali. They are already dependent on sorghum and millet.

"In many places in Africa you are really going to need [a] revolution in farming systems," he says.

"We need everything we can lay our hands on," said Sir Gordon Conway, professor of international development at Imperial College London.

Governments are aiming to limit the average increase in temperature to 2C by the end of the century, he explained. But if temperatures continue to follow their current trajectories "we are on for a 3-4C increase", Sir Gordon explained.

If this was correct "things get very alarming", the professor said.

Professor Martin Parry, a visiting professor at the Centre for Environmental Policy at Imperial College London, who co-chaired one of the working groups in the IPCC's last climate assessment, responded to the report by saying he thought that CGIAR, the parent body to the CCAFS, had been slow to move into the field of climate change as a key area of research. But he added that this step was very welcome.

But he cautioned: "This gives us a better local picture of where the most vulnerable areas might be… but it doesn't make strong enough connections between the changes in the weather and its impacts on yields."

This made it difficult to plan for adaptations, Professor Parry told BBC News.