"The results are bad news, especially for the nutrition of the poorer population in less-developed countries, because this population depends for nutrition on rice", said study co-author Kazuhiko Kobayashi at the University of Tokyo.
The researchers found that rice grown under higher concentrations of carbon dioxide had lower levels of iron, zinc, protein and B vitamins.
Current concentrations are about 410 parts per million, but they're growing at about 2 parts per million every year - and could reach the study's levels in the later part of this century.
A study on this issue was published this week in the journal Science Advances. It was led by Chunwu Zhu of the Chinese Academy of Sciences. The researchers also found that certain B vitamins declined significantly, some by up to 30 percent.More news: Sebastian, Vero Beach to get minimal impact from Tropical Storm Alberto
In addition, to the vitamins, there was a reduction of about eight percent in the iron content, about 5.1 percent in the zinc content and about 10.3 percent in the protein content.
As of today, 1 billion people are tagged food-insecure, or lacking a reliable food source, and 795 million are malnourished, and these numbers will only increase if essential foods stop providing basic nutrition. What we don't know is that this also impacts the crops. For the research plants were exposed to atmospheric carbon dioxide concentrations of 568 to 590 parts per million. Focusing on the top 10 highest rice-consuming nations in the world, it compared rice consumption-and the nutrient losses under higher CO2-with each country's gross domestic product per capita.
It's the change in this makeup of the plant itself that could, in turn, translate into changes in its nutritional content for those who consume it.
"We have some rice varieties that show a stronger response to Carbon dioxide and they are able to convert more of that Carbon dioxide into seed, which can be good", said senior study author Lewis Ziska, a scientist with the Department of Agriculture.More news: Netflix, Ryan Reynolds, Michael Bay team up for Six Underground
"But often when plants grow more, that doesn't necessarily mean that you get the same quality of the plant".
"This technique allows us to test the effects of higher carbon dioxide concentrations on plants growing in the same conditions that farmers really will grow them some decades later in this century", said Kobayashi.
And it isn't just rice.
Myers cautioned that a more detailed modeling study-which examines exactly how much of each nutrient a person derives from rice, as opposed to other food sources-would be needed to fully evaluate the public health concerns raised by the new research.More news: Man United set to pull out of £53m deal to sign Brazilian
"I haven't seen anything about the vitamins, that was new in this paper", Rice said, "but there's other reports that show, or ate least model and have done some lab estimates, that anywhere from 2 to 10 percent less protein content for grains under [an] elevated Carbon dioxide environment".