How Global Warming Could Lead to Smaller Loaves of Bread
Global warming could leave loaves of bread diminished in size due to a reduction in the amount of protein in grains, scientists say.
Researchers for the state government of Victoria, Australia, in cooperation with the University of Melbourne, baked loaves based on atmospheric carbon dioxide levels for 2050 predicted by the Intergovernmental Panel on Climate Change.
The scientists at the Australian Grains Free Air Carbon Dioxide Enrichment facility in Victoria found that rising carbon dioxide will increase the size of wheat plants and make them more efficient at using water, which in turn will affect the quality of the grain.
Dr. Glenn Fitzgerald, a senior researcher for the state government of Victoria said the amount of protein in the grain is set to reduce by anywhere between 2 and 14 percent if carbon dioxide levels increase as anticipated.
He and his colleagues used grain harvested in December to bake loaves, finding them to be much smaller than those baked in the current climate.
The research group is now attempting to establish whether it can reverse the protein decline through the selection of new varieties of wheat.
"It can take 10 to 15 years for a new trait to be worked into a new variety [of grain] so if we're looking ahead at 35 years, that means we can do several generations of testing. It gives us lots of time," Dr. Fitzgerald said.
"There are positives, and we're trying to accentuate those," he said.
Yields increase by about 25 percent, on average, under elevated carbon dioxide.
Carbon dioxide levels reached 400 parts per million last year, up 120 ppm since pre-industrial times. By 2050, the level is expected to be at 550ppm.