Carbon dioxide (CO2) in the atmosphere is having negative effects on plants and the quality of wheat crops. It might also have deleterious effects on other types of crops like barley, rice, and potatoes. It’s not that carbon dioxide is a bad thing for plants, it is actually good for them. It is the excessive amounts of it that are being trapped in the Earth’s atmosphere, along with other greenhouse gases, that is causing problems. CO2 is emitted, in large part, by the burning of fossil fuels from human activities, which is a major cause of global warming. This causes the warming of climates, and large amounts CO2 to collect in the atmosphere, thus affecting plants and crops.
A new study, the first of its kind, performed by researchers at the University of California, Davis, demonstrated the inhibition of wheat crops to convert nitrate into a protein, due to increased CO2 levels, which affects its nutritional value. In the past, studies have exhibited this reaction in plants, but this is the first time it is shown in field grown crops. Lead author of the new study and plant scientist Professor Arnold Bloom said “Food quality is declining under the rising levels of atmospheric carbon dioxide that we are experiencing.” Plant protein is vital to the entire food chain because humans assimilate it from the plants, or from animals that eat the plants, into energy.
The researchers at UC Davis analyzed samples of wheat that were grown in the late 1990s at the Maricopa Agricultural Center in Arizona. These crops were grown in plots where air enriched with carbon dioxide was released, to simulate what might be the reality in coming decades. Since chemical analysis is now available, researchers studied these samples, and came to the conclusion that the increased CO2 levels impeded the assimilation of nitrate into protein, in the crops. Experiments will need to be done on other crops like rice, barley, and potatoes to assess the risks to those foods, but the assumption among researchers that the outcome will be the same.
If carbon dioxide levels continue to rise and negatively effect plants and crops, the amount of food proteins in the whole world could drop as much as three percent in just a few decades. There are already people all around the world without enough food or proper nutrition, especially protein.
A similar study was done at the University of Hohenheim in Germany. Dr. Andreas Fangmeier and Petra Högy grew wheat crops and exposed them to high levels of carbon dioxide over a three-year period. The concentrations of CO2 that were used, are the same as the projected amounts for the Earth in 2050. The results showed that not only are amino acids like protein affected, but trace elements as well. There was a 14 percent increase in lead and an eight percent drop in the iron content of the crop. These are both negative for the health of people around the world, many of which, are already iron deficient. Too much lead in the body is a health risk. This wheat is also potentially harder to sell with smaller grains and the potential of a different dough consistency, due to the change in protein levels.
Historical documentation reveals that the concentration of atmospheric carbon dioxide has increased by 39 percent since 1800. Presently, projections show that this could increase by 40 to 140 percent by the end of this century. It is not clear to researchers exactly why higher amounts of carbon dioxide has negative effects on plants and crops, but fertilizing heavily with nitrogen is not a quick fix. It might help compensate the food quality, but ultimately it would only worsen problems due to higher costs, more nitrates seeping into groundwater, and an increase in the emission of nitrous oxide, a strong greenhouse gas.
By Twanna Harps