CO2 often destroys nutrients in plants

High CO2 concentration in the air causes reduced formation of nutrients in plants

09/05/2014

The increasing carbon dioxide concentration in the air leads to a reduction in the nutrient content of many plants. This is reported by an international research team in the journal „In particular, the levels of iron, zinc and proteins in the future could shrink dramatically and make many staple foods less nutritious. "Researchers talk about the greatest health threat from climate change to date.

High concentration of CO2 reduces zinc, iron and protein content of many plants
Climate change is becoming the biggest challenge for humanity - that has been known for years. Scientists warn against the melting of polar ice caps, rising temperatures, the spread of diseases, drought catastrophes of many more. An international research team led by Samuel Myers of Harvard University in Boston has now discovered another horrific scenario of unprecedented proportions: the increasing concentration of carbon dioxide (CO2) in the air causes a reduction in the nutritional content of many plants.

In their research, the researchers analyzed data from seven experimental plots of peas, wheat, rice, corn, soy and millet in the US, Japan and Australia over several years. A CO2 concentration of between 546 and 586 ppm (parts per million) has been generated on the land, roughly equivalent to the values ​​predicted for the middle of this century. The results are alarming: The zinc content fell by 9.3 percent and the iron content by 5.1 percent in the wheat grains. Similar results were obtained from analyzes of soy, rice and peas. The increased CO2 concentration also affected the protein content of wheat and rice, which was 6.3 and 7.8 percent lower than today. In contrast, millet and maize, which belong to the so-called C4 plants and can bind CO2 better than C3 plants such as wheat or rice, did not show any large fluctuations in the nutrient content. C4 plants are less sensitive to changes in CO2 concentration.

Lower levels of nutrients in plants through CO2 could be the biggest health threat from climate change
„Dietary deficiencies of zinc and iron are a major global public health problem“, the researchers write in the journal. „An estimated two billion people are currently suffering from these deficiencies, leading to a 63 million year loss each year. Most of these people are dependent on C3 grains and legumes as the primary source of zinc and iron.“

The exact mechanism for the poorer nutrient formation of plants by CO2 is not yet known. Even the serious effects are only roughly estimable. „The consequences of global climate change on public health are difficult to predict and we expect many surprises, "the researchers write. „A decline in the nutritional value of C3 food crops is such a surprise that we can now better predict and prepare for. "Thus, research could concentrate on growing plants that were less sensitive to changes in CO2 levels. ( ag)