Could climate change make bread smaller?

by World Grain Staff
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VICTORIA, AUSTRALIA — A study by the Australian Grains Free Air Carbon Dioxide Enrichment (AgFace) facility in Victoria and reported by The Sydney Morning Herald and other publications, suggests an increase in carbon dioxide in the atmosphere due to climate change could reduce the size of bread loaves by reducing protein levels in wheat.
 
Researchers baked bread at AgFace with flour made from wheat grown in carbon dioxide levels of 550 parts per million, the amount forecast by the Intergovernmental Panel on Climate Change to be in the atmosphere in 2050. The researchers used grain harvested in December and found finished bread loaves were far flatter and smaller than current bread, i.e. it didn’t raise well.
 
AgFace grows grain in the open, surrounded by tubes that eject carbon dioxide into the air around plants. Researchers said carbon dioxide has risen from 110 ppm in pre-industrial times to 400 ppm in 2014, and was projected to be 550 ppm in 2050 based on current greenhouse gas emissions.
 
“As atmosphere concentration of carbon dioxide goes up, it reduces the nitrogen levels in plants and leaves and that reduces the protein in the grain,” said Glenn Fitzgerald, lead author of the study. “The protein in the grain affects the proteins in the flour and it leads to changes in the elasticity and strength of the dough,” thus reducing the volume of the loaf. He said the change did not affect the taste of the bread, but taste wasn’t the focus of the research.
 
Fitzgerald said the protein in the grain may decline from 2% to 14% if carbon dioxide reaches forecast levels. In addition, higher carbon dioxide levels also alter the ratio of different types of protein in wheat, the researchers said.
 
He also noted that increased carbon dioxide levels make wheat grow faster and increase crop yields by about 25%.
 
“We don’t understand completely why that’s the case,” Fitzgerald said.
 
Since generating a new trait in wheat may take 10 to 15 years, it was possible that a new trait could be bred into wheat to offset the effects of carbon dioxide levels, the report said. AgFace currently is working to develop such traits.
 
It should be noted that some in the industry are not fans of AgFace and did not give much credence to the study.
 
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