My belief in Global Warming is getting shaky

[freeztar]

Originally Posted by TurtleMyrtle

I have heard this before, and I find experiments contrary to Craig's indication.

CO2 Science

Great link! Thanks!
The reoccurring theme in this link is that increasing levels of CO2 result in the increased growth of algae and other hydrophytes. This is not surprising at all.

The problem is that huge algal blooms are not really desirable (I'm going to pick on algae here). For example, algal blooms can cause hypoxia in lentic systems which can lead to massive ecosystem-scale disruptions.

I see no indication here of added nutrients.

Indeed, nutrient loading can cause algal blooms. Deforestation in the riparian zone can as well. All these things have something in common.

The link you provided, Turtle, does seem to tentatively support the idea of "natural sinks such as vegetation and the oceans will increase their rate of absorption to keep the amount at or near the present amount".

I'm concerned about the consequences...

[REASON]

Originally Posted by freeztar

The link you provided, Turtle, does seem to tentatively support the idea of "natural sinks such as vegetation and the oceans will increase their rate of absorption to keep the amount at or near the present amount".

I must be missing something because if this were true, why wouldn't this adjustment have already taken place to keep the amount of CO2 at the levels they were, say, in the 1970's? What's so special about maintaining the present amount?

[Turtle]

Originally Posted by REASON

I must be missing something because if this were true, why wouldn't this adjustment have already taken place to keep the amount of CO2 at the levels they were, say, in the 1970's? What's so special about maintaining the present amount?

Now that's a 64 thousand dollar question right there $$$, and one we may want to answer before we decide we know enough to deliberately fiddle with things. Specially given we are casting the blame on ourselves already for what we did by accident. Shame on us dirty human bags of water; evolving and living and all that jazz.

To offer one possiblity for your question, perhaps deforestation plays a role in the lack of up-keep (keep-up? )

PS I saw a program on TV last week on outdoor experiments where they pump in extra CO2 to plants. I haven't found that TV program yet, but here is the outfit page that I think is running it. >> FACE Program, Brookhaven National Laboratory, BNL

[freeztar]

Originally Posted by REASON

I must be missing something because if this were true, why wouldn't this adjustment have already taken place to keep the amount of CO2 at the levels they were, say, in the 1970's? What's so special about maintaining the present amount?

Good questions.

Consider what happens when these massive algal blooms start to die and decay.

[Cedars]

Originally Posted by Turtle

PS I saw a program on TV last week on outdoor experiments where they pump in extra CO2 to plants. I haven't found that TV program yet, but here is the outfit page that I think is running it. >> FACE Program, Brookhaven National Laboratory, BNL

Recently I was searching out plant growth and CO2 info and ran across some interesting studies. One study involved legumes CO2 and temps. What they found was some positive change with CO2 intro. When they boosted temps by some degrees in the enhanced CO2 environment, the growth of the plants was boosted greatly. Going from memory, 68 - 88% enhancement. I looked thru my bookmarks and cannot find the link, but maybe another could.

Another shorter study was via USDA regarding CO2 and corn. They found during the night hours, the CO2 level within (1 meter I think) of the corn jumped to around 700 ppm as the plant breathed oxygen and exhaled CO2 at night (a well known issue for home aquariums with plants and fish) then as the sun rose the reversal of this process brought the CO2 numbers back to normal ranges. They recognized more studies needed to be done using different plants to further understand the co2 +/- relationship.

[InfiniteNow]

I would like to call to your attention the results of a UCSD study conducted in May of 2006. Specifically, this quote which speaks to the issue of plant intake of CO₂:


UCSD Study Reveals How Plants Respond to Elevated Carbon Dioxide

One of the standard arguments against taking action to reduce emissions of carbon dioxide from the burning of fossil fuels is that the elevated carbon dioxide will stimulate plants to grow faster. The assumption is that plants will take up excess carbon dioxide to produce carbohydrates—their stored energy source.

However, studies have shown that, contrary to expectations, increased carbon dioxide does not accelerate plant growth. Previous research has also shown that the doubling of atmospheric carbon dioxide expected to occur this century can cause leaf stomata to close by 20 to 40 percent in diverse plant species, thus reducing carbon dioxide intake. Little was known about the molecular and genetic mechanisms controlling this response.

Schroeder and colleagues discovered that in the cells surrounding the leaf stomata calcium ion “spikes”—or rapid increases and then decreases in calcium ion concentrations within cells—changed in frequency according to atmospheric carbon dioxide levels. As the carbon dioxide concentration was increased, the rapid drum roll of calcium spikes within the cells changed to a slower beat. The cells responded by reducing the size of the pores in the leaf.

In the presence of low carbon dioxide, a quick drumbeat was induced, but the stomata opened, rather than closed.

You see, the increased concentration of CO₂ in the atmosphere is actually causing the plants to intake less. This seems to inform the questions above as to why the plants don't seem to be keeping up / up keeping with all of the human inputs.


Turtle raised another valuable point in his post above, primarily when he mentioned deforestation, and how human development is causing fewer plants and more strip malls and housing subdivisions.



EDIT: Here's a link to the actual study I referenced above:


CO2 signaling in guard cells: Calcium sensitivity response modulation, a Ca2+-independent phase, and CO2 insensitivity of the gca2 mutant -- Young et al. 103 (19): 7506 -- Proceedings of the National Academy of Sciences

[Cedars]

Originally Posted by InfiniteNow

I would like to call to your attention the results of a UCSD study conducted in May of 2006. Specifically, this quote which speaks to the issue of plant intake of CO₂:


UCSD Study Reveals How Plants Respond to Elevated Carbon Dioxide

You see, the increased concentration of CO₂ in the atmosphere is actually causing the plants to intake less. This seems to inform the questions above as to why the plants don't seem to be keeping up / up keeping with all of the human inputs.

EDIT: Here's a link to the actual study I referenced above:


CO2 signaling in guard cells: Calcium sensitivity response modulation, a Ca2+-independent phase, and CO2 insensitivity of the gca2 mutant -- Young et al. 103 (19): 7506 -- Proceedings of the National Academy of Sciences

I see that one study done on one type of plant "Arabidopsis; a genus in the family Brassicaceae. They are small flowering plants related to cabbage and mustard." Shows some inhibition of stomatal movements in response to CO2 dependent on the variety of Arabidopsis mutant.

What does stomatal apature movement do in regards to plant growth?

The study you linked to gives no indication on plant growth or productivity in heightened CO2 conditions.

[freeztar]

Originally Posted by Cedars

What does stomatal apature movement do in regards to plant growth?

The stomata are basically the "doorways" for stuff coming in and out of the plant leaf. If the stomata cinch up, then less respiration and photosynthesis occurs. The opposite occurs when the stomata open up. So, when the stomata are open, there's more potential for plant growth.

[Cedars]

Originally Posted by freeztar

The stomata are basically the "doorways" for stuff coming in and out of the plant leaf. If the stomata cinch up, then less respiration and photosynthesis occurs. The opposite occurs when the stomata open up. So, when the stomata are open, there's more potential for plant growth.

Not less growth (in an enhanced co2 environment), but maybe not extra growth for that particular type of plant.

I did not articulate my point well. The study linked to was not a 'big picture' study of plant growth in an enhanced environment and provided no information on whether higher Co2 impacted this particular type of plant positively or negatively. It was basically (for comparison) a study of how a frogs skin reacts in an enhanced/deprived water oxygen condition and how fast the skin reacts to the situation.

Common sense tells you that the frogs body is not going to kill itself off by taking in too much oxygen. We know plants turn their leaves towards the sun. The study linked to did not show plants intake less CO2.

A snippet from an easy to read site I found:

"There are tiny holes on the underside of plant leaves, called somata, which are the openings through which the plant absorbs CO2. With higher level of CO2 concentration in the air the somata do not have to be open as wide. The narrower opening means that less water is transpired and thus less water is required by the plants."

Is the above generally true with regards to stomata and its intake regulation of various plant needs?

[CraigD]

Originally Posted by Turtle

I have heard this before, and I find experiments contrary to Craig's indication.

CO2 Science

Originally Posted by freeztar

The link you provided, Turtle, does seem to tentatively support the idea of "natural sinks such as vegetation and the oceans will increase their rate of absorption to keep the amount at or near the present amount".

The linked-to article supports that plant growth, and correspondingly, carbon uptake, increase when concentration (dissolved in water) increase. However, looking in-depth at the first of the article’s referenced papers, Kubler, J.E., Johnston, A.M. and Raven, J.A. 1999. The effects of reduced and elevated CO2 and O2 on the seaweed Lomentaria articulata., the conclusion reached (illustrated most directly in figure 1) is not that carbon uptake rate is proportional to concentration, but that a “sweet spot” of maximum carbon uptake occurs at about double normal concentration () and normal oxygen concentration (). At higher or lower concentration for the same oxygen concentration, the carbon uptake rate decreases. Oxygen concentration has little effect on carbon uptake up to about double normal concentration. When both and oxygen concentrations are higher than normal, greater than normal carbon uptake can also occur, but the authors found this unimportant, as they know of no mechanism by which this can naturally (including human influences) occur on a large scale.

It’s interesting to me that the co2science.org article appears to put a subtle “spin” – and some outright additions - on the paper’s data and findings – compare its “what was learned” section:

Oxygen concentrations ranging between 10 and 200% of ambient had no significant effects on daily net carbon gain or total wet biomass production rates in this seaweed. In contrast, CO2 concentrations ranging between 67 and 500% of ambient had highly significant effects these parameters. At twice the current ambient CO2 concentration, for example, daily net carbon gain and total wet biomass production rates were 52 and 314% greater than they were under ambient CO2 conditions. Even though this seaweed was likely carbon saturated, when grown at five-times the ambient CO2 concentration, it still exhibited daily net carbon gain and wet biomass production rates that were 23 and 50%, respectively, greater than those of control plants.

To the actual article’s abstract:

We grew a non-bicarbonate using red seaweed, Lomentaria articulata (Huds.) Lyngb., in media aerated with four O2 concentrations between 10 and 200% of current ambient [O2] and four CO2 concentrations between 67 and 500% of current ambient [CO2], in a factorial design, to determine the effects of gas composition on growth and physiology. The relative growth rate of L. articulata increased with increasing [CO2] up to 200% of current ambient [CO2] but was unaffected by [O2]. The relative growth enhancement, on a carbon basis, was 52% with a doubling of [CO2] but fell to 23% under 5× ambient [CO2]. Plants collected in winter responded more extremely to [CO2] than did plants collected in the summer, although the overall pattern was the same. Discrimination between stable carbon isotopes (Δ13C) increased with increasing [CO2] as would be expected for diffusive CO2 acquisition. Tissue C and N were inversely related to [CO2]. Growth in terms of biomass appeared to be limited by conversion of photosynthate to new biomass rather than simply by diffusion of CO2, suggesting that non-bicarbonate-using macroalgae, such as L. articulata, may not be directly analogous to C3 higher plants in terms of their responses to changing gas composition.

Based on the text on its homepage Co2science.org appears to promote 2 unconventional positions on greenhouse gasses and global warming:

• that global warming is not occurring (“the fantasy world of Al Gore and James Hansen”)
• that increases are occurring and will have a significant impact on global ecosystems, but are beneficial (“The Greening of Planet Earth … Is carbon dioxide a harmful air pollutant, or is it an amazingly effective aerial fertilizer?”).

This draws attention to, I think, the importance of tracing cited research back to its source, rather than trusting “repackaged” presentations of it by manifestly agenda-driven individuals and organizations.

Originally Posted by Turtle

I see no indication here of added nutrients.

What I was alluding to (rather ineptly, I fear ) is the idea of Iron fertilization, a proposed technique for increasing the rate of ocean carbon sequestration.

An interesting figure from this article is one known as the Redfield ratio, a formula relating the proportions of elements necessary for carbon uptake by phytoplankton: 380,000 C : 58,000 N : 3,600 P : 1 Fe. Although the iron (Fe) required is the most minor part of the formula, research indicates that for the majority of Earth’s potential phytoplankton, it is the “limiting reagent” in carbon uptake.