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Climate Hustle

Plants cannot live on CO2 alone

What the science says...

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The effects of enhanced CO2 on terrestrial plants are variable and complex and dependent on numerous factors

Climate Myth...

CO2 is plant food
Earth's current atmospheric CO2 concentration is almost 390 parts per million (ppm).  Adding another 300 ppm of CO2 to the air has been shown by literally thousands of experiments to greatly increase the growth or biomass production of nearly all plants.  This growth stimulation occurs because CO2 is one of the two raw materials (the other being water) that are required for photosynthesis.  Hence, CO2 is actually the "food" that sustains essentially all plants on the face of the earth, as well as those in the sea.  And the more CO2 they "eat" (absorb from the air or water), the bigger and better they grow. (source: Plants Need CO2)

In the climate change debate, it appears to be agreed by everyone that excess CO2 will at least have the direct benefit of increasing photosynthesis, and subsequently growth rate and yield, in virtually any plant species: A common remark is that industrial greenhouse owners will raise CO2 levels far higher than normal in order to increase the yield of their crops, so therefore increasing atmospheric levels should show similar benefits. Unfortunately, a review of the literature shows that this belief is a drastic oversimplification of a topic of study that has rapidly evolved in recent years.

Climate control vs. climate change

The first and most obvious retort to this argument is that plants require more than just CO2 to live. Owners of industrial greenhouses who purchase excess CO2 also invest considerable effort in keeping their plants at optimum growing conditions, particularly with respect to temperature and moisture. As CO2 continues to change the global climate, both of these variables are subject to change in an unfavorable way for a certain species in a certain region (Lobell et al. 2008, Luo 2009, Zhao and Running 2010, Challinor et al. 2010, Lobell et al. 2011). More and more it is becoming clear that in many cases, the negatives of drought and heat stress may cancel out any benefits of increased CO2 predicted by even the most optimistic study. 

But there is a more subtle point to be made here. The majority of scientific studies on enhanced CO2 to date have been performed in just these types of enclosed greenhouses, or even worse, individual growth chambers. Only recently have researchers begun to pull away from these controlled settings and turn their attention to outdoor experiments. Known as Free-Air CO2 Enrichment or “FACE”, these studies observe natural or agricultural plants in a typical outdoor setting while exposing them to a controlled release of CO2, which is continuously monitored in order to maintain whichever ambient concentration is of interest for the study (see Figure 1).

Figure 1 - Example FACE study in Wisconsin, USA with multiple CO2 injection plots; courtesy of David F Karnosky, obtained from Los Alamos National Laboratory.

FACE studies are therefore superior to greenhouse studies in their ability to predict how natural plants should respond to enhanced CO2 in the real world; unfortunately, the results of these studies are not nearly as promising as those of greenhouse studies, with final yield values averaging around 50% less in the free-air studies compared to greenhouse studies (Leaky et al. 2009, Long et al. 2006, Ainsworth 2005, Morgan et al. 2005). Reasons for this are numerous, but it is suspected that in a greenhouse, the isolation of individual plants, constrained root growth, restricted pest access, lack of buffer zones, and unrealistic atmospheric interactions all contribute to artificially boost growth and yield under enhanced CO2.

C3 & C4

Photosynthesis comes in a few different flavors, two of which are C3 and C4. Together C3 and C4 photosynthesis make up almost all of modern agriculture, with wheat and rice being examples of C3 crops while corn and sugarcane are C4. The distinction deals mainly with the specific enzyme that is used to collect CO2 for the process of photosynthesis, with C3 directly relying on the enzyme RuBisCO. C4 plants also use RuBisCO, but unlike C3 plants, they first collect CO2 with the enzyme PEP-carboxylase in the mesophyll cell prior to pumping it to RuBisCO (see Figure 2).

Figure 2 - A simplified diagram contrasting C3 vs. C4 plant photosynthesis. From Nature Magazine.

The relevance of this distinction to excess CO2 is that PEP-carboxylase has no natural affinity for oxygen, whereas RuBisCO does. RuBisCO will just as readily collect oxygen (which is useless) as it will CO2, and so increasing the ratio of CO2/O2 in the atmosphere increases the efficiency of C3 plants; the extra step in the C4 process eliminates this effect, since the mesophyll cell already serves to concentrate pure CO2 near RuBisCO. Therefore excess CO2 shows some benefit to C3 plants, but no significant benefit to C4 plants. Cure and Acock 1986 (a greenhouse study) showed excess CO2 gave a 35% photosynthesis boost to rice and a 32% boost to soybeans (both C3 plants), but only a 4% boost to C4 crops. More recently, Leaky et al. 2006 (a FACE study) did not find any statistically significant boost in photosynthesis or yield for corn (a C4 crop) under excess CO2.

Going a bit deeper, it has recently been found that in some C3 plants—such as cotton and many bean species—a further enzyme known as RuBisCO activase is required to convert RuBisCO into its “active” state, the only state in which it can be used for photosynthesis. The downside of this is that the activase enzyme is much more sensitive to high temperatures compared to RuBisCO itself, and also responds poorly to excess CO2: Heat can destroy the structure of the activase enzyme at temperatures as low as 89.6 F, while excess CO2 reduces the abundance of the cellular energy molecule ATP that is critical for RuBisCO activase to function properly (Crafts-Brandner & Salvucci, 2000, Salvucci et al. 2001). This effect may potentially nullify some of the gains expected from excess CO2 in these plants. 

Chemical Responses & Nutrition

Even within a specific type of photosynthesis—indeed, even within a specific species—the positive responses to enhanced CO2 can vary widely. Nutrient availability in particular can greatly affect a plant’s response to excess CO2, with phosphorous and nitrogen being the most critical (Stöcklin and Körner 2002, Norby et al. 2010, Larson et al. 2010). The ability of plants to maintain sufficient nitrogen under excess CO2 conditions is also reduced for reasons not fully understood (Bloom et al. 2010, Taub and Wang 2008).

It has also been found that excess CO2 can make certain agricultural plants less nutritious for human and animal consumption. Zhu 2005, a three-year FACE study, concluded that a 10% decrease in the protein content of rice is expected at 550 ppm, with decreases in iron and zinc contents also found. Similarly, Högy et al. 2009, also a FACE study at 550 ppm, found a 7% drop in protein content for wheat, along with decreased amino acid and iron content. Somewhat ironically, this reduction in nutrient content is partially caused by the very increase in growth rates that CO2 encourages in C3 plants, since rapid growth leaves less time for nutrient accumulation.

Increased CO2 has been shown to lead to lower production of certain chemical defense mechanisms in soybeans, making them more vulnerable to pest attack and diseases (Zavala et al. 2008 and Eastburn et al. 2010). Other studies (e.g. Peñuelas and Estiarte 1999) have shown production of phenolics and tannins to increase under enhanced CO2 in some species, as well as many alkaloids (Ziska et al. 2005), all of which may have potential consequences on the health of primary consumers. The decreased nutritional value in combination with increased tannin and phenolic production has been linked to decreased growth rate and conversion efficiency of some herbivores, as well as an increase in their relative demand and consumption of plants (Stiling and Cornelissen 2007).

Furthermore, many “cyanogenic” species—plants which naturally produce cyanide, and which include 60% of all known plant species—have been found to increase their cyanide production in an enhanced CO2 world. This may have a benefit to the plants who use cyanide to inhibit overconsumption by pests and animals, but it may in turn reduce their safety as a food supply for both humans and animals (Gleadow et al., 2009a and Gleadow et al. 2009b).

Interactions with other species

Competing plant species have also been shown to drastically alter expected benefits from excess CO2: even in the best FACE studies, most research still involves artificial experimental plots consisting of fewer than five plant species, and often only one species is present. It has long been understood that due to increased growth of competitor species, benefits from isolated experiments cannot be scaled up to explain how a plant might respond in a monoculture plot (Navas et al. 1999). The distinction is even greater when comparing the behavior of isolated species to those of mixed plots (Poorter and Navas 2003).

That some plant species may benefit more fully and/or rapidly from excess CO2 also introduces the possibility that the abundance of certain species in an ecosystem will increase more than that of others, potentially forcing the transformation from one type of ecosystem to another (Poorter and Navas 2003). There is also some evidence suggesting that invasive species and many “weeds” may show relatively higher responses to elevated CO2 (Ziska and George 2004), and become more resistant to conventional herbicides (Ziska et al. 2004, Ziska and Teasdale 2000).

There is some evidence that interacting bacterial communities, particularly in the roots, will be affected through elevated CO2, leading to mixed results on overall plant health. Mutualistic fungal  root communities (known as ‘mycorrhizae') are typically shown to increase under excess CO2, which facilitate nutrient transport to the roots (Treseder 2004), although infections of pathogenic species such as Fusarium (the agent of the disease known as ‘crown rot’) have been shown to become more severe under excess CO2 as well (Melloy et al. 2010).


It has long been known that stomata (the pores through which plants take in CO2 and exhale oxygen and water) tend to be narrower and stay closed longer under enhanced CO2. This effect is often cited as a benefit in that it increases water efficiency in drought situations.

But there is another key piece to reduced stomatal conductance, considering that 90% of a plant’s water use is actually for cooling of the leaves and nothing more: heat from the sun is absorbed by the water in the leaf, then carried out as vapor in the form of latent heat. So while it is true that the plant may retain water better under enhanced CO2, doing so may cause it to retain more heat. This can potentially carry a plant to less optimal temperature ranges (Ball et al. 1988 and Idso et al. 1993). An image present in Long et al. 2006 (Figure 3) shows this effect quite clearly; while a 1.4 C increase is probably not enough to cause significant damage in most cases, global warming will only serve to exacerbate the effect.  It is also of note that the study above represented a well-watered situation, and so during a drought condition the temperature increase would be even higher. 

Figure 3 - Increase in local temperature under enhanced CO2 due to reduced evapotranspiration. From Long et al. 2006

On the cold end, it has been found that for seedlings of some species of evergreen trees, excess CO2 can increase the ice formation temperature on the leaves, thereby increasing their sensitivity to frost damage (Roden et al. 1998).


CO2 is not the only atmospheric gas that is on the rise: concentrations of ground-level ozone (O3) are expected to rise 23% by 2050 due to continuing anthropogenic emissions of precursor gases like methane and nitrous oxides. In addition, Monson et al. 1991 found that natural plant emissions of volatile organic compounds (another group of O3 precursors) increase under excess CO2 in many plant species, thereby introducing the potential that local O3 concentrations around plant communities may rise even higher than the baseline atmospheric level.

O3 has long been known to be toxic to plants: Morgan et al. 2006 found a 20% reduction of soybean yield in a FACE study of 23% excess O3. Similarly, Ainsworth 2008 showed a 14% decrease in rice yield at 62 ppb O3, and Feng et al. 2008 (a meta-analysis of 53 peer-reviewed studies) found on average a 18% decrease in wheat yield at 43 ppb O3. Ozone also appears to reduce the structural integrity of plants as well as make them more vulnerable to certain insect pest varieties such as aphids (Warrington 1988).

With respect to this effect, excess CO2 may actually prove beneficial in that it causes a narrowing of leaf stomata, thereby reducing the quantity of ozone that can enter the more sensitive internal tissues. Needless to say, the combined effect of excess CO2 and excess O3 is complex, and as it has only recently been given attention it is an area that requires much further research.


A specific plant’s response to excess CO2 is sensitive to a variety of factors, including but not limited to: age, genetic variations, functional types, time of year, atmospheric composition, competing plants, disease and pest opportunities, moisture content, nutrient availability, temperature, and sunlight availability. The continued increase of CO2 will represent a powerful forcing agent for a wide variety of changes critical to the success of many plants, affecting natural ecosystems and with large implications for global food production. The global increase of CO2 is thus a grand biological experiment, with countless complications that make the net effect of this increase very difficult to predict with any appreciable level of detail.

Advanced rebuttal written by dana1981

Update July 2015:

Here is a related lecture-video from Denial101x - Making Sense of Climate Science Denial


Last updated on 21 October 2016 by MichaelK. View Archives

Printable Version  |  Offline PDF Version  |  Link to this page


Comments 1 to 28:

  1. John (JC); I really don't see the need for redundant posts. It's somewhat like the multiple "planets warming" posts that can and have been incorporated into one rebuttal.

    The general public may have heard of both statements (titles):

    1. CO2 is plant food
    2. Too much of a good thing is a bad thing. Increasing Carbon Dioxide is not good for plants.

    Nonetheless, for the sake of streamlining, there should be one rebuttal. Perhaps the title could be changed, in order to capture the attention of the layman whose mind might be more focused on one phrase rather than the other.

    If you think that re-titling, for the sake of removing redundant posts, is recommended please let me know and I will think of something.
  2. Correction on the above post. Should read:

    1. CO2 is plant food.
    2. CO2 is good for agriculture.

    They're the same idea but the layman might search for one phrase versus the other. Hence the possible title change to incorporate both phrases.
  3. Did the title change on the twin post,"Too much of a good thing is a bad thing. Increasing Carbon Dioxide, as 'plant food', is not good for plants."
  4. Villabolo, making an argument that CO2 is merely plant food is understating the fact.
    Carbon is a fundamental building block for all life forms, plants being about 45% carbon, whilst animals including humans are less than 20%.
    Interestingly, by comparison the carbon content of coal ranges from about 30% in low rank coals such as lignite to 45% to 85% for the most used form of bituminous coal, up to to 98% in anthracite.
    However what I am interested in is the statement "Higher concentrations of CO2 also reduce the nutritional quality of some staples, such as wheat."
    Are you able to quantify both the reduced nutritional quality along with any associated increased yields as determined by the better performing varieties that have been tested in open field trials under enriched CO2 conditions?
  5. johnd @ #4:

    "Are you able to quantify both the reduced nutritional quality..."

    Johnd; unfortunately my link is to an abstract with a paywall.

    I could research it, but I don't believe it would be appropriate for a basic level rebuttal. I try to keep basic level rebuttals at a High School level for laymen interested in the subject of GW but not the details or specifics.

    As for the argument that CO2 is "plant food", that is the phrase that skeptics use in order to give the simplistic idea that more "food" will help all plant life.
  6. "Inputs to Photosynthesis"
    The first stage involves the photolysis of water by sunlight (this is the only place where oxygen is released to the atmosphere). This diagram: proof that sunlight (input 1) and water (input 2) are more important than CO2 (input 3) but each ingredient is considered a limiting factor to maximum photosynthetic productivity.

    "Push vs Pull"
    Just as eating (push) a protein supplement will not make you muscular unless you exercise (pull) which creates a demand for protein. So simply adding more CO2 (push) will not make photosynthesis run at a higher rate, unless CO2 was the only limiting factor. On top of that, CO2 has risen 24% since I've been alive (395/315) so we should have seen an explosion of plant life as compensation for the additional CO2 but we have not.

    "Drop in Photosynthesis due to Temperature"
    There is considerable published evidence showing that C3 photosynthesis production drops by 10% for every "F" degree over 76. Why? The stoma on the underside of leaves is the place where "CO2 enters" and "H20 can escape". At 86F most C3 plants have closed their stomas 100% to stop water loss (but this also stops photosynthesis). C4 and CAM plants have adaptations to deal with higher temperatures but the adaptations come at a cost (some of the solar energy powers the additional molecular machinery). Pineapple is one example of a CAM plant (hint: CO2 is pulled in at night). BTW, 85% of all plants are C3
  7. It seems a shame that apparently no one informed on global warming is also informed about declining soil fertility. As a result, consequences of declining soil fertility are incorrectly said to be caused by global warming. This article on CO2 is a good example. Depending on their protein requirement to be healthy, plants require a certain level of soil fertility. This soil fertility is based on the minerals necessary to support life. In low soil fertility the plants are primarily carbonaceous or high in carbohydrates with low protein content. As such, they are of little use to support animal life in health. As soil fertility is increased, the protein content of the plants is increased as a percentage of the dry matter and the carbohydrate content is decreased. This allows a greater density of animal life per acre.
    Plants being damaged by insects indicate malnourished plants that are growing in soil that cannot meet their protein requirements. Increase the soil fertility and you won't need to worry about insect damage. Adding NPK only to soil to increase fertility only creates an unbalanced soil that causes the grower to go back to the same guy who sold the grower the NPK for the poisons to treat the symptoms of the low soil fertility, i.e. the insects doing the damage, the weeds out competing the crop and the diseases the plants are getting. When it rains in conditions of high soil fertility, the top soil acts as a blanket allowing the rain to soil into the soil and thereby to gradually go down into the subsoil raising the water table. In conditions of low soil fertility the shallow surface top soil not only absorbs little water from a rainfall, it actually often seals the surface so that very little water penetrates during a rainfall and this runoff often causes erosion of the soil itself. Downstream the drainage from a large land area can often result in floods. Later in the year the complaint is about a lack of rainfall and high temperatures and the increasing severity of droughts. In droughts it is usual for the high heat to damage the protein of the plants more than the lack of water. If the plants are damaged but are not wilting, the problem is the heat, not a lack of water, i.e. corn firing in a drought.
    Wind or rain are necessary but not sufficient for soil erosion. The "dust bowl" is an example of a result of declining soil fertility.
    Where can someone learn about the consequences of declining soil fertility and perhaps, as I have, come to the conclusion that blaming consequences of declining soil fertility on global warming is a scientific mistake and we should direct our primary climatic ecological concern to the former, not the latter? "The Albrecht Papers" by the soil scientist, William A. Albrecht, Ph.D.
  8. Soilfertility @ 7, After wading through your post, I find you said
    blaming consequences of declining soil fertility on global warming is a scientific mistake
    Excuse my ignorance, but exactly which scientific papers are you referring to? I cannot recall ever hearing a scientist blame 'consequences of declining soil fertility on global warming'. It sounds suspiciously like a strawman argument to me.
  9. Hi Doug:
    I said that I have come to the conclusion that blaming consequences of declining soil fertility on global warming is a scientific mistake. I did not say that any scientist has ever written a scientific paper blaming the consequences of declining soil fertility on global warming. I am not aware of any global warming research scientist who has knowledge of the consequences of declining soil fertility that would allow his or her writing of such an paper.
    What lead to my coming to that conclusion was, as I suggested at the end of my post answering the question I posed, was my reading of papers left by the late soil scientist, William A. Albrecht, Ph.D. In his papers, Albrecht explains many consequences of declining soil fertility. Albrecht did not address global warming as he was dead before global warming became an issue. Around the middle of the last century, Albrecht explained how declining soil fertility was increasing the severity of weather hazards such as floods and droughts. He also explained that the soil fertility controls the erosion of the soil itself with lower soil fertility being the primary cause, not the wind or rain. With respect to CO2, the subject of the article above, he explains how the carbon dioxide dissolving in the rain creates a weak carbonic acid that is beneficial in increasing soil fertility by breaking positive ions necessary for life (such as calcium, magnesium and potassium) out of rocks that contain these elements when such rocks are still in the soil. This certainly suggests how to restore or increase soil fertility when parent rocks containing these minerals have been exhausted from the soil and soil fertility is necessarily declining.
    If you wish to read an article I wrote I titled "Albrecht on Droughts and Soil Fertility" you can read it here:
    Hopefully it might inspire you to wade through Albrecht's papers which I think will serve you better than wading through a post of mine.
  10. Soilfertility @ 9, you said
    I have come to the conclusion that blaming consequences of declining soil fertility on global warming is a scientific mistake
    I asked you for evidence that scientists have made such a mistake, but you have not produced any. Who, exactly, is making this "scientific mistake"? Where is your evidence?

    Without support for your allegation, it appears you have constructed a strawman argument.

    I am sure Albrecht makes some interesting points about soil fertility, but what precisely is the connection with the topic of this thread?
  11. Hi Doug:
    I was commenting on numbers 1,3,4,5 and 6 in the list of "...the effects of an increase of CO2 on agriculture and plant growth in general". I was not commenting on any topic on this thread. I thought comments were invited to made on the article itself.
    In the article I wrote for "The Bovine" titled, "Albrecht on Droughts and Soil Fertility" I have included references to where in Albrecht's papers I came across the evidence. I am not going to retype that article here. If you have any interest whatsoever in challenging the evidence provided by Albrecht you might just go and read the article and then tell me where I am wrong. Ignoring evidence does not refute it.
    I don't know the name of the person who wrote this article but the person's lack of knowledge of the consequences of declining soil fertility has resulted in the mistake of blaming more carbon dioxide in the air for consequences that are actually caused by declining soil fertility. In conditions of higher soil fertility there would be no need to plant trees and trees would grow better free from insect and disease problems and they would thereby do a better job of removing carbon dioxide from the air and they would make better firewood.
    If you knew that agriculture produces food for yield at the expense of its nutritional value, would you be concerned? If you would be concerned about this, that would give you another reason to wade through Albrecht's papers which would serve you better than wading through any post of mine.
  12. Soilfertility @11, you introduced your original comment by saying, "... consequences of declining soil fertility are incorrectly said to be caused by global warming." Your evidence of this is that certain predicted consequences of global warming are also predicted consequences of reduced soil fertility. You proceed to make the unjustified assumption that any observed feature that is predicted as a consequence of both global warming and of decreased soil fertility is in fact only a consequence of reduced soil fertility. Your argument fails at that point. Your assumption is unjustified.

    It appears to be worse, however. You point out that decreased soil fertility can result in increased floods and drought due to, respectively increased water runoff, and decreased water retention. You then simply assume the increased floods and droughts actually experienced are due to reduced soil fertility without providing evidence of that reduces soil fertility at the locations of said floods and droughts, or even checking rainfall figures to see if they have changed over time (they have). So not only do you assume that decreased soil fertility is the proper explanation without examining the evidence, you do so even when it is against the evidence.
  13. Soilfertility @ 11, I am still puzzled by your comments. Where in points 1,3,4,5 and 6 in the list, is there a scientific error? You are the one asserting there has been a scientific mistake. No-one is disputing the rôle of soil impoverishment on plant growth. Exactly what error(s) are you claiming?
  14. Hi Tom:
    Your assumption that my argument "fails at that point" is unjustified. Why? You have failed to review Albrecht's evidence. If you would only have read the article I mentioned on "The Bovine", it would have directed you to Albrecht's article, the basis for the article on "The Bovine".
    Albrecht's article, titled "Droughts-- The Soil As Reasons For Them", is chapter 23 in Volume I of "The Albrecht Papers". This is the first paragraph from his article:
    "When one follows the meteorological reports rather regularly since most of us talk about the weather, at least when the radio reports it for us daily, one might well be asking with serious concern, 'How come that we keep on breaking flood records, heat records, past records for droughts or for extent of long-time rain free periods and other weather records?' Are the meteorological conditions changing for the worse, or are the biological manifestations of weather, labeled as drought, merely intensified and on the increase as reciprocal to some other factor under serious decline through which the same meteorological disturbances are magnified in their detrimental aspects? We have larger floods and we have more severe droughts as the records truly report. But should we not examine these in relation to the soil for possibly more comprehensive explanations of them and our reduction or prevention of the disasters?"
    From the introduction to the chapter: "This paper was read before the 11th Annual Meeting of the American Institute of Dental Medicine, Palm Springs, California, 1954."
    "The Albrecht Papers" Volume I has been reprinted and is now titled, "Albrecht's Foundation Concepts" and is available from Acres, U.S.A. Also at Acres, U.S.A. there is an article available for download by Albrecht titled, "The Drought Myth--An Absence of Water is Not the Problem. It is available in this list of articles-
  15. Soilfertility @14, your response has simply confirmed my point. First, you respond by quoting Albrecht from 1954, having previously made the point that "Albrecht did not address global warming as he was dead before global warming became an issue". If he did not address global warming, then he cannot have analysed which of two potential causes (global warming or loss of soil fertility) has had the greatest impact on changes in climatology. Ergo, if you are basing your claims on Albrechtson (as clearly you are), you have not shown of any particular droughts, floods, temperature rises, etc that loss of soil fertility rather than global warming is responsible.

    You specifically mention an article by Albrechtson titled "The Drought Myth--An Absence of Water is Not the Problem". Well, in Southwestern Australia an absence of water is clearly the problem:

    What is missing in Southwestern Australia is water falling from the sky as frequently, something that is not under the control of soil fertility.

    Southwestern Australia is a good test case, because the connection between winter rainfall and climate change is straightforward; there has been no appreciable loss of soil fertility (probably the opposite as agriculture in the region is based on irrigation turning desert into wheat fields); and Albrechtson almost certainly never studied the region. Yet because of his studies of the dustbowl you expect his explanation to trump straightforward science in Southwestern Australia.

    I look forward to your evidence based proof that the decline in rainfall in Southwestern Australia is caused by declining soil fertility, or your acknowledgement that your assumption that any consequence predicted by both global warming and decreased soil fertility is explained by decreased soil fertility alone.
  16. Hi Tom:
    Where did I say that Albrechtson (sic) analysed which of two potential causes has had the greatest impact on changes in climatology? When I said he was dead before global warming became an issue, I assumed the reader would realize that, of course, it would have been therefore impossible for him to make such an analysis.
    Have you read the article I wrote or "The Drought Myth--An Absence of Water is Not the Problem"? I can understand if you have not yet read "Droughts-- The Soil As Reasons For Them" as you might not find the book in your local library and you might need to purchase it and have it sent to you. I cannot understand, however, if you have not yet read either my article or "The Drought Myth--An Absence of Water is Not the Problem" or both as they are both available on the internet.
    If you wish to challenge my position on causes and cures for increasing severity of droughts and floods, read the evidence that has caused me to come to my conclusions and refute that evidence.
  17. Soilfertility @ 14
    "This paper was read before the 11th Annual Meeting of the American Institute of Dental Medicine, Palm Springs, California, 1954."
    A reading in front of a Dental Medicine meeting does not constitute peer review. As Tom pointed out, Albrecht wrote his work without referring the the then-extant body of work on global warming, so there is no reason to believe that he came to any valid conclusions about the phenomena he reported. To claim, as you do, that current science is mistaken because a person who did not know about global warming wrote a paper without mentioning it, is wrong-headed.

    To cut to the chase, can you post one single factoid Albrecht wrote about, which current science is mistaken about? Hint: don't expect others to do your research for you, as you are currently doing by making vague claims about it all being explained in Albrecht's paper and your article. Instead, reply with quotes from and references to the information you are relying on and remember to include quotes from and references to the scientific publications that show current science is mistaken.

    The onus is on you to provide evidence. Remember, extraordinary claims require extraordinary proofs.
  18. From Volume I of "The Albrecht Papers", "It's the Soil That Feeds Us", subsection 2 "more fertility means more cover, stable soil and less erosion". I quote Albrecht's words:
    "When soils erode, our first reaction prompts us to take up the fight against running water. Much like when some disease comes over out body, we think first about 'fighting' the microbes. When we break a bone, we put the limb in splints. Similarly when a field is broken down by gulleys, we line it up with terraces.
    Whether it is our soil or our body that is in trouble, we fail to realize the preceding but gradual weakening of our body or bones and of the soil body, too. The weakening occurs long before the noticeable disaster of the fracture or the gulley befalls us. Broken bones too often are the result of malnutrition for a long time ahead to make them weak. Coffee and toast don't maintain bone strength. Unsteadiness in muscle may have come along with the weakening skeleton to bring on the fall as well as the weak and broken bones. In like matter, the exhaustion of the strength of the soil, its fertility, weakens the soil body to make erosion the consequence.
    That such are the facts for the soil body is suggested by the experimental plots on Sanborn Field at the Missouri College of Agriculture. That field, after 62 years [in 1960] of its recorded behaviours, is a sage in telling us what the experiences of the soil body mean in bringing on what can be 'old age' of it.
    Two plots have been planted to corn each year since 1888. Professor J.W. Sanborn outlined the use of six tons of barnyard manure annually on one of these, while the other was expected to go forward in corn production with no soil treatment. Fortunately these two plots are alongside each other. There is a good sod border on three sides, or in the direction water might run on these seemingly level areas. All of the crop, namely grain and fodder, is removed. Outside the return of the fertility in six tons of manure on the one plot, the management and history of these two classic soils has been exactly the same.
    That the removal of the fertility without return on any on the 'no treatment' plot has weakened the soil body to make it erosive is now clearly evident. Had the sod border not protected this plot, its soils--like so much from the rest of Missouri--would now be resting in the Gulf of Mexico near New Orleans. After that soil body is turned by the plow, a single rain is enough to hammer it flat, to seal over the soil's surface, to prevent infiltration of the rainwater, and to bring on erosion of that fraction of the surface so readily and so highly dispersed into slush by the raindrops.
    Where manure had been going back regularly each year, naturally there was a different soil body. It stood up under the rain and maintained its 'plow-turned' condition in spite of the rain. It was the same rain that was so damaging to the other plot. One could not blame the rain for any damage here on this manure plot. Instead, the rain brought benefit. Its water went deeper into the soil. It soaked a deeper layer and built up the stored water supply for the summer. The surface soil is cooler by 10 degrees in the summer than the companion plot. Here is a different soil body that behaves different under the same rainfall. It doesn't erode. The rills of running water begin at the line that divides the two plots. Narrow as these two plots are, there are rills on the 'no treatment', but none on the 'treated' plot. The former might seem to be a call to 'fight' the running water. The latter is not.
    Fortunately the 'strength' of the soil body against erosion in this case is also the 'strength' of the soil for crop production. It is also the 'strength' for soil granulation or good soil structure. The corn yield is still twice as large on the plot with manure as that on the plot without it. Weeds grow on the former after corn roots are deep enough to be beyond their use of the nitrates whcih accumulate on the surface to invite the weeds. There weeds are a nice 'winter cover'. They are one that comes without any cost. The granulation of the soil of the manured plot is so much better under laboratory test than that of the unmanured one, that water goes into the soil three times as rapidly. Also, it moves about four times as much volume of water down through and does not plug itself up quickly to stop water movement into the soil.
    Here is 'strength' of granulation. It is the 'strength' of the soil body under the hammering effects of the falling rain. It is the 'hidden' strength, and the very same strength that gives the bigger yields of crops. That 'strength' is the fertility. This fertility is distributed withing the inorganic as well as the organic fraction of the soil. Here is quiet testimony that we ought to see that the weak soil body, and the erosion of it, are brought on because we have removed the fertility, or the creative power, by which any soil naturally keeps itself in place and grows nutritious crops at the same time. Our weakening soil body is suggesting that gradually weakening human bodies are resulting from it."
    The observations made comparing these two plots speak to increased water runoff making floods more severe, the lack of water in the soil or subsoil making the consequences of a period of little or no rainfall a more severe drought and to how a soil, weakened by a loss of fertility, would be more severely eroded by either wind or rain.
    As a result, regardless of your belief as to the cause of more severe droughts, floods and soil erosion, would the better approach to mitigate the damage caused by these problems be to lower the average temperature of the planet by reversing global warming or to figure out how to restore the lost fertility to the soil?
  19. Soilfertility @ 18, nothing in your post seems to support your claim that scientists are mistaken in any way about the effects of global warming.

    At last, though, you ask a direct question that can be answered:
    would the better approach to mitigate the damage caused by these problems be to lower the average temperature of the planet by reversing global warming or to figure out how to restore the lost fertility to the soil?
    That's a no-brainer: lower the average temperature of the planet back to what it should be without our insane injection of greenhouse gasses into the atmosphere, by magically removing the excess of those gasses; that way we not only counter the effects on our soils, but also bring other systems back into balance (e.g: stop the acidification of the oceans). Second best choice: hold the current levels of greenhouse gasses, by drastically slowing our emissions.

    Why? Because we can repair soils in a suitable climate at our leisure, but we can do nothing about them in the climate we are creating. Putting fertility back into the soil will not save us from the future we are creating.
  20. Soilfertility:

    Are you serious when you suggest we should throw away decades of climate science based on a paper presented to a bunch of dentists in the 1950's??? You assert that these unreveiwed claims from 60 years ago are worth more than the considered opinion of thousands of scientists in the IPCC report? Why have no current soil scientists stepped to the plate with this data if it is so good??? Please provide an up to date citation or your basic point is useless.

    You are not being serious with your wild claims that a single scientist, who was not peer reviewed, in 1960 is right and everyone else is wrong. Provide current data to support your wild claims.
  21. Michael Sweet @20, Albrecht (50 years ago) showed that improved soil fertility results in:

    1) Improved water retention in the soil, enabling plants planted in that soil to better resist drought;

    2) Reduced water runoff during light and moderate rainfall, reducing the risk (but not the possibility of) flooding;

    3) Cooler soil temperatures during the day, and no doubt warmer soil temperature at night - probably a result of improved water retention increasing the thermal capacity of the soil.

    These are, now, well known and uncontroversial results.

    Soilfertility, not Albrecht, now appears to claim without any support from Albrecht or independent evidence, that improving soil fertility is an adequate mitigation strategy by itself for the effects of global warming. He has previously appeared to claim that loss of soil fertility is in fact responsible for many of the observed consequences of global warming. Again, this is without evidence and certainly without evidence from Albrecht.

    Soilfertility's claims are, or course, without merit. He provides no evidence of wide spread loss of soil fertility, and modern farming practices attempt to improve soil fertility. Uncultivated land is unlikely to have either lost or gained soil fertility because it is in a near equilibrium state with its environment. Ergo, Soilfertility has no basis beyond mere assertion for any claim that the increased frequency of floods, droughts etc are due to a loss of soil fertility. Equally he has no basis beyond mere assertion for any claim that improving soil fertility would mitigate the effects of climate change.

    On top of that, his discussion is plainly off topic; repetitive and amounts for the most part to sloganeering. His wall of text quotation @18 probably does not violate additional comments policies, but is clearly contrary to the spirit of them.
  22. There is a refreshingly excellent article on, quoting scientists who specialize in tropical forests, countering a recent study's disinterpretation as meaning that CO2 rise will result in more tropical rainforests.

  23. The first link in point 3 of the basic explanation is bad.
  24. Given the information presented in the following article, an update of this rebuttal may be in order.

    Climate change making food crops less nutritious, research finds

    CO2 levels significantly reduces essential nutrients in wheat, rice, maize and soybeans, Nature paper reveals

    Damian Carrington, The Guardian, May 7, 2014 

  25. Hey guys, CO2 is not plant food.  It is a reactant along with water for photosynthesis.  The food of plants, as well as everything other living organism,  is glucose which it makes itself through photosynthesis.  More CO2 in the atmosphere would increase photosynthesis, however a plant only gives off oxygen during the light dependent reactions.  It uses oxygen during cellular respiration 24 hours per day.  Therefore, the increase in oxygen in the atmosphere from an increase in CO2 would be more than offset by the increase in the consumption of oxygen when a plant undergoes cellular respiration which happens 24 hours a day. 

  26. james baggett @25, fundamental to the ecology of plants is that they are preyed on by a great variety of insects and animals. To remain healthy in the face of this predation, they must produce far more organic matter (sugars and cellolose) than they themselves directly use.  Further, if they are to grow in mass, they must draw down the carbon in that mass from the atmosphere by photsynthesizing carbon.  Because of that, in any healthy plant  over the course of a year, it draws down far more CO2 through photosynthesis then it produces by oxidizing sugars.  If plants did not do this, the presence of plants would not have substantially increased the O2 content of the atmosphere today relative to values prior to the carboniferous.  Ergo, it is simply wrong to assume that any excess draw down of CO2 due to the CO2 fertilization effect will not only be matched, but exceeded by an increased production of CO2 by cellular respiration.

  27. I would like to know if there are measurements done showing the output of CO2 at night above seas, forests and grassy lands. If someone knows how many tons of CO2 is released at night and how much is absorbed by day.

    Also when plants die they release a lot of CO2 in the atmosphere, almost as much as they took in while they were growing and alive. One of the reasons I bring this up is to see what is the natural cycle and volume of CO2 going out and back into the atmosphere as we need some standard as to how nature processes CO2 .

  28. Hans @27, there are a large number of studies of carbon exchange in a variety of ecosystems and seas, many of which will also analyse the day/night (diurnal) cycle.  As examples, Leinweiber et al (2009) analyze the diurnal cycle in Santa Monica Harbour.  Friend et al (2007) compare model and observaltional values net ecosystem exchange of CO2 (NEE) across a variety of land based ecosystems, including the diurnal variation in NEE (Figure 5, bottom panel).  However, it is easier to just look at the gross fluxes from the IPCC AR5 Figure 6.1:

    The gross fluxes are are indicated by the large arrows.  Where the gross flux is two way, the net flux is indicated above the brackets.  Values inside the boxes are the total amount in the reservoir.  Black figures indicate preindustrial values, while red values indicate the change to the preindustrial value due to anthropogenic influence.

    Although the gross flux is what you appear to be interested in, it is the net flux that is the relevant comparison for anthropogenic emissions, given that the gross flux largely represents churning which does not alter atmospheric concentrations, except locally on a diurnal basis, and regionally on a seasonal basis.

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