The atmosphere is changing the food we eat

corn
CC BY 2.0 USDA

It's called the 'great nutrient collapse,' and yet no one is really talking about it.

Climate change is affecting the nutritional content of our food, according to preliminary research by a handful of American scientists. Dubbed “the great nutrient collapse,” this strange effect is going virtually unnoticed by most people on Earth, and yet it would have enormous repercussions for human health.

In an article for Politico, health writer Helena Bottemiller Evich interviewed mathematics professor Irakli Loladze from Nebraska, who is also passionate about biology. Loladze first realized there was something odd going on in 1998, when a lab experiment found that using light to grow additional quantities of algae to feed zooplankton did not result in the zooplankton’s growth. This seemed counterintuitive, and upon closer examination, it was discovered that the faster algae grew, the few nutrients it contained. It was, in a sense, junk-food algae, incapable of nourishing the zooplankton properly.

It’s not a stretch to see how this could happen to human food sources. Food crops don’t get more light, but they do get more carbon dioxide these days, a requirement for growth. The increasing presence of CO2 in the atmosphere is one of the only aspects of the climate change debate that is not hotly contested; everyone agrees it has increased measurably. Bottemiller Evich wrote:

“Before the industrial revolution, the earth’s atmosphere had about 280 parts per million of carbon dioxide. Last year, the planet crossed over the 400 parts per million threshold; scientists predict we will likely reach 550 parts per million within the next half-century—essentially twice the amount that was in the air when Americans started farming with tractors.”

So, what happens when there’s more CO2 in the air? The limited studies published to date have found that mineral, vitamin, and protein content drop – a pattern that’s been seen steadily over the past 50 to 70 years, which coincides with the rise in CO2. Some scientists think this has to do with breeding higher-yield crops, like wheat, tomatoes, and broccoli, which tend to have fewer nutrients. Another possibility we’ve written about on TreeHugger is pesticide spraying, which weakens plants’ natural defenses because they’re not forced to fend for themselves, thereby decreasing their nutrient profile. Similarly, disfigured produce is believed to be healthier because it has 'battle wounds.'

But Loladze and other scientists wonder if there’s more to the problem than we realize – that “the atmosphere itself may be changing the food we eat.”

“As best scientists can tell, this is what happens: Rising CO2 revs up photosynthesis, the process that helps plants transform sunlight to food. This makes plants grow, but it also leads them to pack in more carbohydrates like glucose at the expense of other nutrients that we depend on, like protein, iron and zinc.”

And we all know that the last thing the world needs is more carbohydrates...

Scientists have experimented with growing plants in an enclosed space with high levels of CO2 blown onto them. These are compared to plants grown outdoors in regular air:

“These experiments and others like them have shown scientists that plants 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.”

It’s a frightening thought. Many people around the world already struggle with nutrient deficiencies, especially anemia, and for food to have less iron, zinc, vitamin C, and calcium could have devastating effects.

As the Politico article reveals, very few nutrition scientists are talking about this problem, or are even aware of it, although many expressed concern after reading the limited research sent to them. Fortunately, Loladze is less alone in his field of research than he was two decades ago, and papers on the topic are slowly starting to trickle in.

This could very well be the biggest environmental problem you’ve never heard of – yet.

Tags: Agriculture | Farming | Food Safety | Food Security | Fruits & Vegetables | Health

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