In a world richer in CO2, there will be fewer nutritious crops

Carbon dioxide (CO2), plants need it. They use it for photosynthesis. And some appreciate the increase in CO levels2 in our atmosphereatmosphere. This allows them to grow faster. Getting bigger. But new work now looks set to dampen that enthusiasm somewhat. This “good side” of ours emissionsemissions of CO2.

To understand, remember that CO2 is integrated by plants i sugarssugars from which they derive theirs energyenergy. But the process doesn’t give them the essential minerals they need to thrive. These mineralsmineralsthese arenitrogennitrogenthat phosphorusphosphorus or even ironiron. And plants can lift them from the ground through their roots.

Mechanisms that remain to be understood

However, the review carried out by researchers from the Institute of Plant Sciences in Montpellier shows that under the conditions expected at the end of our century, the nitrogen concentration in most plants should decrease. This is difficult because the plants will then have difficulty building up their tissue. And because they will also have trouble making proteinprotein. It is thus to be expected that the composition in nutrientsnutrients of the largest crops in the world – rice or wheatwheat — is negatively affected. Scientists envision a 20-30% decrease in the amount of protein in the plants we eat.

Are rising CO2 levels good for plants?

In addition to the problem of food security, the phenomenon can also lead to a negative feedback loop in the fight against global warming. If plants lack minerals, they may not be able to store as much carbon as scientists had hoped. It remains to understand the mechanisms behind the phenomenon. Already four numbers have been mentioned:

  • that “direct dilution” who wants it with more than biomassbiomassthere are fewer nutrients for each plant;
  • closing and narrowing of the openings in the plates which serve toabsorptionabsorption and transport of nutrients;
  • disruption of the molecular pathway that converts nitrates extracted from the soil into usable proteins;
  • and dysregulation of the nitrate uptake system in the roots.

The last two seem to play a predominant role. But all this needs to be clarified if we hope to counter the phenomenon.

Rising atmospheric CO2 will reduce the quality of staple foods

In 2050, the increase in the amount of CO2 in the atmosphere will reduce the nutrient quality of many crops. Follow: missingmissing in zinczinciron, protein will affect millions of people around the world.

Futura article with AFP Relaxnews published on 29/08/2018

According to researchers at Harvard University, who looked at 225 different foods, the increase in the concentration of CO2 in the atmosphere, which could reach 550 parts perppmppm) around 2050 against 405 ppm in 2017, “expected to reduce the iron, protein and zinc content of many staple crops by 3 to 17 percent.”

This decrease in the nutritional quality of food would result in “Zinc deficiency in 175 million people, but also protein deficiency in 122 million people by 2050, while existing deficiencies in over a billion people worsen”. These people will be added to the 662 million already suffering from protein deficiency, 1.5 billion from zinc deficiency and 2 billion from iron deficiency worldwide.

“Zinc deficiencies affect immune systemimmune systemwhich puts children at greater risk of getting diseases, such as respiratory infections, malariamalaria or diarrheal diseases”explains researcher Matthew Smith, interviewed by AFP. “An iron deficiency can causeanemiaanemia » Where ” increase mortality during childbirth “, he continues. Lack of protein, often combined with malnutrition, can result in stunted growth in children.

Grain products such as rice or wheat provide protein and minerals

The most vulnerable regions are North Africa, the Middle East and Asia, with countries such as India, Indonesia and even China, according to this study published in the journal Nature climate changewhich is explained by the eating habits of these countries.

Plants play a significant role in providing zinc, iron and protein in the diet. Among them wheat, rice and corncorn “contributes about two-thirds of the world’s protein, zinc and iron intake. However, wheat and rice are more sensitive to the increase in CO2 in the atmosphere, when corn is clearly less affected”explains Matthew Smith.

The decisions we make every day make our food less nutritious and endanger the health of other people and future generations

The poorest populations are also the most vulnerable because plants form a larger part of their diet, while the richest supplement their diet with meat. “The decisions we make every day – how we heat our homes, what we eat, how we get around, what we buy – make our food less nutritious and endanger the health of other people and future generations”warns Samuel Myers, co-author of the study.

Article by Nathalie MayerNathalie Mayer published on August 4, 2017

Every day, the list of consequences of global warmingglobal warming seems to extend a bit more. Now it is the nutritional quality of certain staple crops that seems threatened. According to a study, carbon dioxide would have a negative effect on vegetable proteins.

Researchers at Harvard University (USA) are concerned about the results of a study they have just published. This actually concludes that the increase in carbon dioxide (CO2) in the atmosphere reduces the amount of protein present in staple crops such as rice or wheat.

Based on data from field trials with plants exposed to high concentrations of CO2American experts estimate that by 2050barleybarley will contain 14.6% less protein, rice 7.6%, wheat 7.8% and potatoes 6.4%!

A new threat associated with global warming

But about 76% of people depend on vegetable proteins to ensure a proper diet. Without them, growth becomes difficult, diseases more frequent and, in fact, early mortality increases. The experts’ report predicts that India could lose 5.3% of the protein in its diet. A loss that may seem small, but would still threaten the health of nearly 53 million people.

Unfortunately, researchers at Harvard University do not yet provide explanations for the phenomenon. One hypothesis is that the level of carbon dioxide leads to an increase instarchstarch in plants and therefore a decrease in protein. But nothing is proven. Especially since other studies already indicate that the increase in CO2 in the atmosphere also reduces the amount of key minerals (iron, zinc, etc.) present in plants.


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