The Effects of Carbon Dioxide
In November 2002, NewScientist published an article called Plague of Plenty, examining research leading up to that time, and finding that as plants often grow faster from absorption of increased atmospheric CO2, nutrient intake of minerals essential for human health declines. Apparently increasing CO2 levels means more photosynthesis, so plants make more carbohydrate than they can use in growth and store the extra starch and sugar in their vacuoles. The plant ends up with more carbohydrate than normal and less essential nutrients than it had previously.
Staple crops like rice and wheat have been insufficiently studied, but increasing atmospheric carbon dioxide has been observed to coincide with lower concentrations of micro-nutrients than in previous generations of crops. There may be other factors at work than the continually increasing CO2 in our atmosphere, such as overuse of soils, but if plants are storing increasing amounts of starch in their vacuoles resulting from increasing CO2 in preference to soil nutrients and these are readily available in soils, then we have what could be a more immediate threat to life on this planet than climate change, in the direct threat to essential nutrients for human and animal life.
If plants directly supply more than 80 per cent of human calorie intake, then the quality of the nutrients provided from the soil to our foods becomes crucial when one considers human health and our escalating health costs. Research over 15 years prior to 2002 from nearly 3000 published studies has reported on how elevated CO2 affects plants. More recently, Science 2010 reported a University of California Davis study which found that CO2 interferes with plants’ ability to convert nitrate into protein (wheat and the mustard plant, Arabidopsis). The shift in nitrogen alters food quality and may even be expected to impact on pest control, where the lower level of protein in plants will mean insects must eat more to survive. This may apply to all creatures that live from plants including ourselves. In this 2010 report, nitrogen status was found to decline as CO2 rises. If this means that protein levels diminish in the plants even our beef animals eat, we must expect that they too will need to eat more for survival. Then what about our meat? Must we expect increasing starch and less protein? We need the research to advise us of such a trend.
The CSIRO is comparing the ability of pine forests and pastures to act as carbon sinks to help store greenhouse gases. In agriculture, most carbon in the soil is lost as greenhouse gas when soils are converted to agriculture, so to reverse this trend, bio-char created from the process of slash and char, rather than previously slash and burn which created atmospheric CO2, has been found to increase the soil’s carbon content permanently and establish a carbon sink for atmospheric CO2. This method is proposed for depleted soils, particularly in the tropics. Bio-char soil management systems can deliver tradeable carbon emission reduction, which is easily verifiable and accountable.
However when Plague of Plenty was written in 2002, it stated that plants were exposed to 30 per cent more CO2 than in pre-industrial times and by 2010 the level was expected to double. Despite agriculture’s best efforts, we must expect to have to deal with the increasing results of rising CO2. While carbon dioxide in the soil is necessary for plant growth, atmospheric carbon dioxide, which farmers may applaud for even quicker plant growth, now becomes questionable in relation to human health.
Apart from lower protein levels in our plant foods, the diminishing of elements on which the chemistry of our bodies is based becomes critical for every aspect of our health. Hidden hunger, the world’s number one health problem is increasing, with iron deficiency recorded as leading the way. Princeton biologist Irakli Loladze collated much of the research for Plague of Plenty and in another article he poses the question, “Why is it important to look specifically at those elements?” (Those increasingly being lost in our foods, also from overused soils and food processing.) He points out that over a quarter of a million words are based on 26 letters in the English language. Likewise a cell contains thousands of complex substances, but all life forms require less than three dozen elements. The lack of a single element puts an enormous strain on life’s machinery. These principles are expounded in the emerging science of Ecological Stoichiometry published by Sterner and Elser in 2002.
Dr Marten Stapper, former CSIRO farming systems agronomist in his article from Soil Fertility Management 1/6/2009 says, the road to sustainability points out that we turn our “clean and green” image into reality through the balance of minerals and microbes in both soil and human health. Over the past 60 years, mineral density in foods has declined to less than half of former levels.
Practising mineral therapists observe symptoms of essential element deficiencies in almost everyone with whom they consult. Therefore to learn that increasing atmospheric CO2interferes with the uptake of these elements, when ancient Australian soils tend to be depleted anyway, makes it all the more imperative that we seriously reduce atmospheric CO2.
Words: Irene Fisher