Rising carbon dioxide emission may make grain less nutritious: expert
22/2/2005 17:19
A Chinese soil scientist has warned that rises in global carbon
dioxide emission may make grain less nutritious -- the protein level in cereal,
for example, may be lowered by 10 percent in the coming four decades.
"With
higher density of greenhouse gas, plants will breathe in more carbon dioxide and
grow faster -- but not necessarily better, " said Zhu Jianguo, a researcher with
the Nanjing Institute of Soil Science, a branch of the Chinese Academy of
Sciences.
Song's institute teamed up with a Japanese institute of
agricultural environmental technologies in 2001 for a joint research program on
how higher carbon dioxide density in the coming decades may affect the cropland
ecosystem in Wuxi and Jiangdu cities of east China's Jiangsu Province.
The
scientists simulated a closed agricultural environment with increasingly higher
density of carbon dioxide, and by the time the emission reached the level
forecast for 2050, rice in the field had grown 10 to 14 percent faster than
normal and wheat, 12 to 20 percent, said Song.
"Higher density of carbon
dioxide is like a 'gassy fertilizer' that speeds up their growth, but shortens
their growth period, too, by an average six to nine days," said Song, who is
chief scientist for the three-year research program. "As a result, the grain
becomes less nutritious, with contents of protein, amino acid and trace elements
such as iron and zinc all declining."
He said these changes might impact
China's soil as well as its grain quality and food security. "With more carbon
dioxide inhaled, the rice may appear whiter and taste more glutinous, but you
might feel hungry again two or three hours after a full meal because the actual
intake of necessary nutritious elements has dropped".
Song welcomed the Kyoto
Protocol that came into effect on Feb. 16, noting it marks mankind has finally
taken a decisive step forward to safeguarding the planet by curbing global
warming.
Experts have warned time and again that the warming climate can
cause the sea level rising, glaciers shrinking, desertification accelerating and
biological diversity lessening. Livestock husbandry also bears the brunt as
certain species, particularly in some alpine and polar regions, could be
endangered with extinction.
Xinhua
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