Director of the ARC's Centre of Excellence for Translational Photosynthesis, Professor Bob Furbank, said in theory higher Carbon dioxide levels were a good thing for growth - but the reality proved somewhat different. For the research plants were exposed to atmospheric carbon dioxide concentrations of 568 to 590 parts per million. Findings of a new study have revealed it may also affect the nutritional value of food.
Increased carbon dioxide in the atmosphere will reduce the nutritional value of rice, according to an worldwide research team that analyzed rice samples from field experiments started by a University of Tokyo professor. According to the Food and Agriculture Organization, the fruits of three grasses provide the world with 60 percent of its total food: corn, wheat and rice.
The study puts the case more coolly: "For those populations that are highly rice-dependent, any CO2-induced change in the integrated nutritional value of rice grains could disproportionately affect human health". It is somewhere signaling bad news for the about two billion people whose primary food source is rice. It reinforces the inference of the earlier studies that the expected rise in the carbon dioxide level by 2100 has shown a considerable decrease in the amount of zinc, protein and the iron contents of the rice grains. Iron content fell by an average of 8 percent and dropped by as much as 20 percent. The study infers that the higher carbon dioxide level reduced the amount of the vitamins such as the B1, B2, B5, and B9.
Researchers also observed declines in iron, zinc, and protein.
A mass deficiency in vitamin B9, also known as folate or folic acid, would have particularly severe public health consequences.
"There's been studies over the past hundred years for the importance of these B vitamins", said study researcher Kristie Ebi, from the University of Washington in Seattle.
The research was conducted in Japan and China where they held experiment on 18 different types of the crop between 2010 and 2014.
The carbon dioxide humans pump into Earth's atmosphere is doing more damage to the global food system than once thought.
The research was funded by National Basic Research Program of China, Natural Science Foundation of Jiangsu Province in China, and Youth Innovation Promotion Association of Chinese Academy of Sciences.
To ensure rice-eaters can continue to get sufficient nutrients as the climate changes, scientists and farmers need to develop rice varieties with more resilient nutritional qualities.
Indeed, the research fits an increasingly common theme in climate findings, which is that the poor and disadvantaged globally would be hit hardest by these kinds of changes, and would be least able to adjust or diversify their diets in order to pick up nutrients in other ways.