Rising Carbon Dioxide Levels May Be Putting Entire Planet On A Junk Food Diet

Global warming is creating junk food for every animal on the planet. That’s the theory described in an incredible Politico article about the declining nutrient quality of the entire food chain. For years, one of the climate deniers arguments was that carbon dioxide was necessary for plant growth and that increasing levels of carbon dioxide would lead to more and higher quality food. Lamar Smith, the ignorant Republican chair of the House Committee on Science, explained, “A higher concentration of carbon dioxide in our atmosphere would aid photosynthesis, which in turn contributes to increased plant growth. This correlates to a greater volume of food production and better quality food.” Greater volume, yes. Better quality, well, it turns out, no.

For years, scientists have know that the nutrient quality of what we eat is declining. Mineral, vitamin and protein levels in fruits and vegetables have dropped considerably in the last half century or more. Another study of fruits and vegetables “found that everything from protein to calcium, iron and vitamin C had declined significantly across most garden crops since 1950.” But scientists have always attributed these declines to our choice of breeding these plants for higher yields while ignoring the decline in nutrient content. Accordingly, for years there was no examination of how the impact of increasing levels of carbon dioxide might effect plant nutrition.

New studies, however, seems to indicate that the decline in nutrient quality has less to do with the strains of fruits and vegetables we grow and more to do with the increasing levels of carbon dioxide in the atmosphere. Faster growth actually leads to a reduction in nutrient quality. “[P]lants change in important ways when they’re grown at elevated CO₂ levels. Within the category of plants known as ‘C3’―which includes approximately 95 percent of plant species on earth, including ones we eat like wheat, rice, barley and potatoes―elevated CO₂ has been shown to drive down important minerals like calcium, potassium, zinc and iron. The data we have, which look at how plants would respond to the kind of CO₂ concentrations we may see in our lifetimes, show these important minerals drop by 8 percent, on average. The same conditions have been shown to drive down the protein content of C3 crops, in some cases significantly, with wheat and rice dropping 6 percent and 8 percent, respectively.”

Another study looked at goldenrod, a source of food for bees, and found that “protein content of goldenrod pollen has declined by a third since the industrial revolution—and the change closely tracks with the rise in CO₂.” Some now theorize that this decline in protein content could be a part of the reason for the collapse in bee colonies as they are weaker and unable to ward off other environmental stressors.

If this theory holds up, the effect on human population could be severe. One study estimates that by 2050 over 150 million people could be at risk of protein deficiency simply because of the loss in plant nutrients. The reduction in zinc content could put 138 million at risk and the loss of iron could impact one billion mothers and 354 million children. And that is just he human cost. Similar losses will be seen throughout the animal kingdom, even among carnivores that consume herbivores. The rise in CO₂ levels looks like it is putting the entire planet on a junk food diet. This will not end well.

Do yourself a favor and read the entire fascinating article in Politico.