Hi Ashley. I did see that there was an assertion in that link as you commented. But it doesn't make sense to me that CO2 increases within the normal range which plants have experienced won't increase growth rates. And, indeed, studies show that to be true.
Of course the plants have to be in situations where they aren't limited by something else such as lack of sulphur, potassium, iron, calcium, nitrogen, water [and even with lack of water, the plants will increase growth because they shut their breathing holes and lose less water, meaning the water they do get goes further].
I've asked Google and here are a few links: links.jstor.org
<. Carbon dioxide enrichment of the air in which crops grow usually stimulates their growth and yield. Plant structure and physiology are markedly altered. Interactions between CO2 and environmental factors that influence plants are known to occur. Implications for crop growth and yield are enormous. >
springerlink.com
<Seedlings of European white birch (Betula pendula Roth) were grown in growth chambers for one growth season under four carbon dioxide regimes (350, 700, 1050 and 1400 ppm) and at three fertilization levels (0, 100 and 500 kg ha–1 monthly). The soluble carbohydrates and secondary phenolics in the leaves and stems were analysed. It was found that fertilizer addition reduced the amounts of glucose and fructose while sucrose remained almost unaffected. The sugar content of leaves increased at 700 ppm and 1050 ppm of CO2 and decreased at the highest CO2 concentration (1400 ppm). The amounts of proanthocyanidins and flavonoids in leaves decreased with fertilization addition and increased with CO2 enrichment. The production of simple phenolic glucosides varied according to the fertilization and CO2 treatments. The triterpenoid content of stems seemed to increase with fertilization and CO2-addition >
springerlink.com
etc...
They seem to all be keen on further research and all seem to say how complicated it all is and there seems a tendentious wish to avoid saying that CO2 is good for plants and doesn't hurt them at all. The usual caveats and exclaimers aside which they give.
It's like reading Associated Octel studies which purported to show that increased lead in petrol was NOT a problem in children. It obviously was [to me anyway].
CO2 of course doesn't simplistically supply a whole lot more plant. Plants have been in chemical and physical warfare for a billion years with other plants, insects and animals, with varying conditions of CO2 and lots of other inputs essential to or harmful to plants.
Their main characteristic is that they are green because they eat CO2. Not enough CO2 and they starve. Too much and they haven't got the genetics to use it. Decreasing CO2 levels won't increase growth rates - turn it down to zero and they will not grow. There's no step function. Increasing CO2 levels does increase growth rates assuming the plants aren't at their limit already for some reason. Which is not to say that every plant under all conditions will grow faster. Plenty of plants can use more CO2 and do.
It wasn't that I ignored the statement, and other studies. I disagree with the generalized conclusion they make that increased CO2 does not accelerate plant growth. It's sort of true, but not really. I think they are like the Associated Octel people = starting with the conclusion and using words to twist the studies to confirm their conclusion. The studies seem determined that increased CO2 is bad.
My greenhouse customers who bought methane to warm and CO2 enrich their glasshouses 25 years ago seemed to think they had it figured out. Crops do better with more CO2 [which is not to say that 100,000 ppm is a good thing]. I mean within the range in which they can use the extra. Children will eat more lollipops if you give them 3 instead of 1. But give them 1000 and you will find them being used to throw or abandoned somewhere.
In regard to sea level change [increase], it seems odd to worry about gradual ones when a 10 metre or 20 metre one is likely over any hundred year period due to bolide splashes. It seems crazy to build cities right at sea level as is done all around NZ with land prices highest on the water's edge. But then, they build INSIDE Taupo's crater! A live caldera which WILL explode again. I guess sooner rather than later.
I feel like you about Iressa and your efforts, in regard to Tarken's lymphoma and Rituxan, which is now acknowledged as a good thing in his situation. When the outcome is fatal without treatment, being too prissy about the lack of scientific studies proving it's a good idea seems absurd. If Iressa or Rituxan were likely to badly harm somebody with a prospect of survival it would be perhaps not worth using. But when the outcome is clear and fatal anyway, or the harm is minor [in the case of Rituxan], use it anyway. It's not as though the cost is significant [in many instances].
If I'm personally faced with such a situation, I'll choose to die from toxicity of cod liver oil [Vitamin D and A] and other stuff I think might kill cancer cells faster than me.
It's very frustrating to deal with authorities on such things. It seems insane to me that adults are told what they can and can't use for their personal situation. Fair enough to prevent fraud. But in the absence of fraud, people should be able to choose their own demise.
I console myself that the authorities have to also sit in traffic jams they create with their dopey ideas and their children also die from cancer.
Mqurice |
