March 26, 2009

Farmers Face Challenges To Curb Greenhouse Gas Emissions

An Australian scientist said Thursday that farmers of the future will have to use sheep and cattle that produce less methane, and crops that emit less nitrous oxide. They must also become experts in reporting their greenhouse gas emissions to governments, said University of Melbourne scientist Richard John Eckard on Thursday.

Agriculture represents a significant source of global greenhouse gas emissions, and is only expected to rise as an increasing human population demands more and more food, he said.

However, farmers face the enormous challenge of feeding the world's population while trying to cut emissions and adapt to greater extremes of floods and droughts brought about by global warming, a Reuters report quoted Eckard as saying.

In the years ahead, farmers will be required to track and report their emissions as more nations implement emissions trading schemes.

"We want agriculture to feed the world. We want farmers to be viable and continue to increase the rate of productivity growth. At the same time, we're telling them they are going to face a more harsh climate they need to adapt to," Eckard told Reuters during a climate change conference in Perth, Australia.

"On top of that you impose a policy that you can now only emit a fraction of the emissions that you were emitting," said Eckard, who also works for the Victorian state government

Research into methods of reducing these emissions while maintaining production growth have not adequately progressed, Eckard said.

Australia is a major producer of dairy, beef, wheat and wool, and is seeking to enact the world's most comprehensive emissions trading scheme in mid-2010.  However, agriculture emissions will be exempt until at least 2015 because technology to curb emissions is still in its early stages.  Furthermore, adding costs to the nation's farmers is politically unpopular now.

However, the Australian government has said it is resolute in addressing agriculture emissions because they comprise 16 percent the nation's total greenhouse gas emissions.  In New Zealand, agriculture comprises roughly half of the country's total emissions.

Methane, which comes from the stomachs of ruminants like sheep and cattle, is 20 times more powerful at warming the atmosphere than carbon dioxide (CO2).   Nitrous oxide, which comes from the soil in wheat, rice, maize and sugar cane crops, is roughly 310 times more powerful than CO2.

Australia had launched a national initiative to find new ways of addressing emissions of nitrous oxide (N2O) and methane, said Eckard, who leads a team that primarily works with livestock systems and N2O emissions from wheat and grazing.

Measures under development  included vaccines and dietary supplements that curb methane production in livestock, as well as making improvements in the source, rate and timing of nitrogen fertilizer use.

"We've evaluated oils and found out that for every one percent extra oil we put in the diet of a ruminant you get about a six percent reduction in methane," Eckard said, speaking of canola and cottonseed oil.

Another major project is now underway to breed a "super variety" of beef, sheep and dairy cattle that require less food to grow.  Researchers are also working to develop crop varieties that require less water and nitrogen fertilizer, Eckard added.


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