As Atmospheric Carbon Dioxide Increases, Plants Produce More Carbohydrates But Fewer Vitamins and Minerals
Global warming, ocean acidification and rising seas levels are well known effects of rapidly rising CO2 levels in the atmosphere, tracking the elevation of carbon dioxide levels from 280 PPM to 410 PPM over the past 250 years.
Less well known at this point is the effect higher CO2 levels are having on plants: the carbon junk food effect if you will. According to a growing body of research, more CO2 in the atmosphere shifts glucose production into overdrive, but at the expense of nutritional components. That means food is less nutritious – marginally at this point, but with ominous possibilities for the future of people who eat.
Ironically, this phenomenon is the real world scientific manifestation of a bogus climate denier argument: “well, I thought trees breathed CO2 and produce oxygen, so global warming should be a good thing.”
This nonsense is from the same school of stupid as “I wouldn’t mind a little more warmer weather.” In reality, that kind of smirky reasoning is driven by millions of dollars of campaign contributions from fossil fuel interests. Ain’t that true, Lamar?
On Earth, every thing with leaves on is producing increased levels of sugars (carbohydrates, glucose) as CO2 levels go up, an outcome expected by our knowledge of photosynthesis. In a sense, more CO2 is overfeeding green vegetation and accelerating photosynthesis. But as carbohydrate production increases, other nutrients in the food supply are diluted. This is similar to the “empty calories” alarm that has already been sounded about the fast food nation we live in: plenty of calories but fewer nutrients create the treadmill of obesity.
Agricultural researchers have noted for decades that foods consumed by humans have been getting less nutritious. Ongoing commercial and academic studies of fruits and vegetable production for the past half century prove without a doubt that calcium, iron, zinc, vitamin C and protein content has been dropping. Until recently, the assumption among scientists was that higher yield agricultural practices were the cause (it is expected that higher yield crops will be less nutritious).
At present levels, the estimated drop is a seemingly unalarming 2-4%, depending what part of the plant is consumed. However, we also know that the decadeslong forced trend toward more sugar in foods is responsible for the epidemic of diabetes and obesity in America and, increasingly, the world as a whole.
It should also be noted that atmospheric CO2 levels are accelerating quickly and will reach 550 PPM within the next several decades (AKA the hockey stick). At that point, the nutritional content of food with be an issue.
If any food is growing at all at that point.
This post distills content from the Guardian, Politico, and the Genetic Literacy Project and the original article published in Science.