Nutrient Collapse: A Hidden Danger of Climate Change

Scientists believe rising CO2 levels are causing plants to grow faster, upping glucose content at the expense of nutrients like protein, iron and zinc. (Image credit: Andrew Gustar/Flick

Rising temperatures, melting glaciers, and warming oceans are commonly thought of alongside the topic of climate change, but receiving far less attention is a potentially dangerous effect: the nutrient depletion of our food supply.

An in-depth treatment of the subject last month by Politico highlights the slowly growing awareness, and concern, surrounding the effects of rising carbon dioxide levels on everything from wheat and rice to honey bee health, and in turn its potential effect on human nutrition.

When it comes to carbon dioxide, less is probably more:

...greater volume and better quality might not go hand-in-hand. In fact, they might be inversely linked. 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.

Leading the charge in research is Irakli Loladze, a mathematician with a keen interest in biology, who was one of the first to study the relationship between CO2 and plant nutrients.

Part of the problem, Loladze was finding, lay in the research world itself.... He was told he could pursue his research interests as long as he brought in funding, but he struggled. Biology grant makers said his proposals were too math-heavy; math grant makers said his proposals contained too much biology.

Since Loladze's foray into the subject nearly 20 years ago, new research has offered significant findings:

Earlier this summer, a group of researchers published the first studies attempting to estimate what these shifts could mean for the global population. Plants are a crucial source of protein for people in the developing world, and by 2050, they estimate, 150 million people could be put at risk of protein deficiency, particularly in countries like India and Bangladesh. Researchers found a loss of zinc, which is particularly essential for maternal and infant health, could put 138 million people at risk. They also estimated that more than 1 billion mothers and 354 million children live in countries where dietary iron is projected to drop significantly, which could exacerbate the already widespread public health problem of anemia.

In 2014, [Harvard Univerity's Samuel] Myers and a team of other scientists published a large, data-rich study in the journal Nature that looked at key crops grown at several sites in Japan, Australia and the United States that also found rising CO2 led to a drop in protein, iron and zinc. It was the first time the issue had attracted any real media attention.

The picture taking shape is that Loladze's 20-year-old suspicion was correct:

Across nearly 130 varieties of plants and more than 15,000 samples collected from experiments over the past three decades, the overall concentration of minerals like calcium, magnesium, potassium, zinc and iron had dropped by 8 percent on average.