Rising Carbon Dioxide Levels Impact Food Quality: Global Warming Affects Crops

As our world warms and as levels of carbon dioxide rise in our atmosphere, we have to consider exactly how this gas will impact our environment. Now, new research has shown carbon dioxide levels may negatively impact crops, which could mean a less than optimistic future for our world's food supplies.

"Food quality is declining under the rising levels of atmospheric carbon dioxide that we are experiencing," said Arnold Bloom, lead author of the new study, in a news release. "Several explanations for this decline have been put forward, but this is the first study to demonstrate that elevated carbon dioxide inhibits the conversion of nitrate into protein in a field-grown crop."

The researchers examined samples of wheat that had been grown in 1996 and 1997. At that time, carbon-dioxide enriched air was released in the fields. This created an elevated level of the gas at the test plots-similar to levels that are expected to be present in the next few decades. The scientists then harvested samples, placed them on ice, and used chemical analysis.

So what did they find? It turns out that the elevated gas levels inhibited nitrate assimilation into protein in the field-grown what. This, in turn, impacts food nutrition.

"When this decline is factored into the respective portion of dietary protein that humans derive from these various crops, it becomes clear that the overall amount of protein available for human consumption may drop by about three percent as atmospheric carbon dioxide reaches the levels anticipated to occur during the next few decades," said Bloom in a news release.

It's important to note that fertilizers could potentially help curb this decline somewhat. However, more fertilizer would also have the negative consequences of impacting the environment. It could contaminate groundwater and actually increase emissions of the greenhouse gas nitrous oxide.

"These field results are consistent with findings from previous laboratory studies, which showed that there are several physiological mechanisms responsible for carbon dioxide's inhibition of nitrate assimilation in leaves," said Bloom.

The findings are published in the journal Nature Climate Change.