Global Warming, CO2 and Plants

As an admitted AGW (Anthropomorpic Global Warming) (manmade) skeptic one of the things which always makes me laugh are claims that the increasing CO2 are bad for plants. This makes me laugh because it runs contrary to every experiment in existance. Fact is just like Humans need an atmosphere rich in O2 plants need an atomsphere rich in CO2.

In fact if CO2 levels drop too low plant essentially suffocate. Now a true AGW accolyte doesn't understand this in fact there was a recent blast on many of the AGW blogs about how rising CO2 might make plants more susceptible to damage - read about it here or here

How do those who actually work with plants feel about CO2 - well let's check their supply catalog for the products they use to Increase CO2: Home Harvest Carbon Dioxide Enrichment

Yeah rising CO2 and the plant world - they are friends.

The reality is that the linked articles are classic AGW FUD. FUD - Fear, Uncertainty and Doubt. AGW is built on FUD, because the idea is to have masses of people do what they are told. Let's take the second link which is where I found this information, it has a four paragraph except of the original article but it is easier to discuss that shorter article.

The best way to introduce FUD is to first start with a true statement - "Widespread damage to plants from a sudden freeze... was made worse because it had been preceded by two weeks of unusual warmth..."

Agreed because it is true, and part of the known behavior of the plant kingdom. When plants that are sensitive to frorst damage start to bloom following a dormancy such as winter a sudden frost causes extreme damage... it's sort of like waking up from a long sleep (hibernation), using your energy reserves to get started and suddenly having all of your efforts stolen... the plants not only take damage but haven't had a chance to build a new set of reserves to restart. (thats a simplification but since I'm agreeing with the authors it shouldn't cause a problem.) The paragraph even goes on to site the addition of drought as another limiting factor in this documented event. In fact I think the entire first paragraph is true.

Second paragraph starts the FUD - "Rising levels of atmospheric CO2 are BELIEVED to reduce the ability of SOME plants to withstand freezing..."
based on what? (Lets come back to plants and CO2)
Next add some more information that is true but unrelated to CO2 culiminating with "A cold spring in 1996, in contrast to the 2007 event, caused little enduring damage because it was not preceded by unusual warmth." - again a true statement. For brevity I'm not too concerned in the remainder we could discuss but again it is a mix of obviously true and FUD statements, but the focus of the claims and what I would like to address is the claim regarding CO2 making plants more susceptible to frost.

So does CO2 make plants more susceptible to frost damage? Keep in mind this article makes two claims - first warming will result in more scenarios similar to 2007 vs. 1996, as a skeptic there is no direct evidence of this (it's the basis of the AGW debate) and no discussion is presented - I see no reason to argue this point as there isn't data.

However, the article implies that plants exposed to CO2 are intrinsicly more prone to frost damage. Again no real evidence is provided but we can consider several studies on what CO2 does to plants and common practices in growing plants to at least consider this which isn't a core discussion point of AGW proponents (for good reason).

The item that should draw your attention is that increased CO2 appears to effect plants in two ways
first there are thousands of studies that show better growth through increased CO2. In short this consists of two elements:
1. One is superior efficiency of photosynthesis. 2. The other is a sharp reduction in water loss per unit of leaf area.

To limit discussion let's not even address item 1 since photsynthesis and freezing aren't directly related, on the other hand the second item is the logical question - what does a reduction in water loss imply.

Well it implies that the plant has more water. Well somewhere around 2nd or 3rd grade most science classes explain how freezing works and one of the things which is noted is that it takes a large body of water longer to freeze. Thus if the plant is keeping more water it is actually less likely that that water will freeze. Thus increased CO2 actually makes it less likely that plants will suffer as much frost damage in such an event, because the water contained in their system will be there in greater quantity. (note once the water freezes that portion of the plant dies regardless of the quantity of frozen water.)

Which brings us back around to the CO2 generators which are used by actual farmers and others in agriculture.