Ray, you might want to read this article. It turns out that CO2 may not be all that good for plants after all. Because, like, science.
http://www.politico.com/agenda/story/2017/09/13/food-nutrients-carbon-dioxide-000511?lo=ap_a1
Peter,
I see no evidence at all in the article that CO2 might not be good for plants. If elevated levels of CO2 were not good for plants, then the plants would not thrive, as they obviously do. It's indisputable that elevated levels of CO2 have the effect of greening the planet and increasing the biomass of plants and trees in general.
The issue raised in the article is that the food crops grown in elevated levels of CO2 might not be as nutritious for us humans, and that is a separate issue.
The nutritional quality of the food we eat is dependent upon a huge number of factors. However, both water and CO2 are fundamental necessities for any growth at all to take place.
Whether or not a particular food contains a normal or average amount of vitamins, minerals and proteins that we think it is supposed to have, depends upon soil health, soil fertility, soil pH, soil structure, the type of natural microbes, bacteria, insects and worms that normally thrive in natural soils and help roots take up nutrients, and more specifically the mineral content of the soil.
The presence or absence of certain minerals in the soils can either aid or supress a plant's uptake of certain elements that humans consider to be beneficial for their own health (but not necessarily the health of the plant). The following article gives an idea of the complexity of the issue.
http://www.ecogrowth.com.au/soil.htmlIf plant growth is encouraged, by introducing CO2 from bottled gas into greenhouses, for example, it's quite likely that the final crop will not contain the same proportional increase in minerals and vitamins and/or proteins,
if additional minerals and fertilizers have not been added to the soil.Nature consists of a balance. There is no natural law that dictates that a particular plant should have a particular percentage of a certain mineral, trace element or vitamin just because such elements are beneficial to humans.
For example, if a soil does not contain the trace element Selenium, or very little of it, that would not necessarily prevent a plant such as the 'Brazil Nut tree' from flourishing,
but it would result in the Brazil Nut having an unusually small amount of Selenium.The following site describes the benefits of Selenium.
https://www.livescience.com/43566-selenium-supplements-facts.htmlBrazil nuts are recommended as a good source of Selenium. However, the attached graphical image shows the great variation in the quantity of Selenium in a Brazil nut, depending on where it was grown. A similar situation applies to the nutrients in all varieties of the food we eat.
Sure you could increase the protein content of wheat simply by reducing CO2 levels. You could increase the protein content even further by restricting the amount of available water, keeping everything else the same, such as the same amount of fertilizers, pH and soil structure. The result would be about half the total quantity of wheat production. We could do it for all food crops, resulting in mass starvation world-wide. What a crazy idea!
"Nitrogen is a primary constituent of protein, so an adequate soil nitrogen supply is an essential ingredient for producing wheat with a high protein content. Grain protein is modified by the grain yield of the crop - increasing grain yield has a diluting effect on grain protein.
This is why in drier seasons or seasons of low grain yield, a larger proportion of the crop is of a high protein percentage, whereas, in wetter growing seasons, high yields can be produced but may be at a lower protein. This seasonal variation is why paddock grain yield, protein and rainfall records should be kept for a number of years to obtain a true indication of its nitrogen fertility."