Researchers have discovered that higher levels of atmospheric carbon dioxide can negatively impact wheat quality. The study from researchers at the University of Gothenburg, Sweden, was recently published in the journal Climate Change.

The researchers found that rising levels of carbon dioxide can decrease wheat quality by stimulating photosynthesis and the growth of most plants. Unless plants increase their uptake of nutrients to a corresponding level, their yields will have a lower nutritional value. A lower level of nitrogen reduced the protein content of the wheat and therefore the nutritional quality.

The protein content in wheat drops as carbon dioxide increases. If nitrogen uptake does not keep up with the increased growth of the wheat grain, a dilution effect takes place. What is worse is that as carbon dioxide levels rise and the protein content drops, the size of the wheat yield can remain unaffected.

“This indicates that carbon dioxide has a negative impact on plants’ ability to absorb nitrogen,” said professor Håkan Pleijel, one of the researchers in the study. “This is a novel an unexpected finding, and is something we need to study in greater depth in order to understand the causes.

The researchers are investigating further if this effect is also seen in other crops besides wheat.

“Our results indicate that reduced nitrogen and protein content as a result of elevated carbon dioxide levels is a general response in crops, and cannot be countered simply through increased fertilization,” said professor Johan Uddling, another author of the study.