Who says that the climate debate is not evolving? According to the daily newspaper the Guardian, a new application (‘app‘) has been written for iPhones that provides a list of climate dissidents’ arguments, and counter arguments based on more legitimate scientific substance. The app is developed by John Cook from ‘Skeptical Science‘. It’s apparently enough to have the climate dissidents up in arms – meaning that it’s likely to have some effect? Some dissidents are now thinking of writing their own app.
Here on RC, we have developed a wiki, to which I also would like to bring the reader’s attention. Furthermore, I want to remind the readers about other useful web sites, listed at our blog roll.
135, Completely Fed Up: wilt is just projecting.
Everybody really ought to drop the faux psychoanalysis. It’s completely independent of science, evidence, and human reasoning.
Just posted this on Klimazwiebel.blogspot.com
Henk Hak said…
Hans, a question regarding the physics of heat exchange between the earth’s crust and the oceans. I have tried to Google this a bit but didn’t get very far. Is there any information about the amount of heating the ocean’s deepest water receives from the core? There is mention of “petit” volcanoes apparently quite numerous in areas around tectonic shifting. After all the earth’s crust is thinner at the ocean’s bottom than anywhere else.
Maybe this wasn’t the right place to post but don’t know where else.
Thanks
Henk
Do you have an archived posting , or any other information on this?
Thanks
H.Hak
[Response: Average flux is around 0.04 W/m2 – higher at the mid ocean ridges, lower in the abyssal plains. – gavin]
Wilt, the solar magnetic field mechanism and the GCR mechanism are the same. Thus, the fact that GCR fluxes eid not change significantly from 1950-2000 (modula the solar cycle) indicates that this mechanism has not been operant.
Likewise the recent Solomon paper is also not relevant to long-term trends. We can and have measured stratospheric water vapor concentrations for decades. Result: no consistent trend. So, on the one hand we have a 114 year-old prediction by Arrhenius that anthropogenic CO2 would cause temperatures to rise and a seeming confirmation of that hypothesis. This hypothesis also explains stratospheric cooling, polar amplification, seasonal patterns… On the other hand, we have a myriad of patchwork suggustions–most without any real mechanism–and which really cannot reproduce all of the trends we are seeing. If you were a scientist, based on ALL the evidence, which hypothesis would you pick?
Doug Bostrom (133) wrote:
“Surely in the interest of fairness and avoiding any appearance of suppression of “differently perceptive” viewpoints Denial Depot should be included in Real Climate’s list of “Other Opinions.””
Would you likewise expect a site dedicated to evolutionary biology to link to young-earth creationist Ken Hams blog? He even has an article “critiquing” global warming (just like he “critiques” evolution) so maybe realclimate should link to him as well?
Any crank can set-up a web-site and post whatever nonsense or spin they want. There’s no reasonable obligation or expectation for a legitimate science oriented web-site like realclimate to link to all of them.
Ray Ladbury (#153), solar magnetism is also related to solar luminosity, as discussed in the Lockwood paper (I suppose that you have read this important Nature article, or do you only read the verdicts given on Real Climate?). And this article (and several others) surely demonstrates that there was no decrease in solar intensity during the last part of 20th century (actually an increase), so if solar forcing was important during 1910-1940 temperature increase it was certainly important during 1975-1998. Furthermore, what you call no consistent trend in stratosphere water vapor, can also be seen as an oscillation. In this case I have more trust in Susan Solomon’s opinion than in your judgement, if you don’t mind.
“[Response: Correct. It’s more multidisciplinary, more difficult, and in many ways, more sophisticated. Very few scientific disciplines address global scale processes that affect a large number of vested economic interests. Zero in fact. You want to see “PR”, you need to look there.–Jim”
The blistering arrogance and complete lack of self awareness (not to mention innacuracy) of this comment is staggering. I can add nothing to it.
[Response: Nice. When you bring forth legitimate arguments that support your broad brush assertions, people will listen. The idea that you think the “PR” on this issue comes from the scientists, is ludicrous beyond belief. And arrogance is thinking one can pronounce on a topic without in fact actually knowing it’s bases or history–Jim]
re 152
Thanks Gavin . I guess that means negligible in the greater picture. Thanks for all your work on this blog.
BTW, Roy Spencer did a quick recalculation on Phil Jones’ CRUTem3NH data and his results were identical.
Henk
Perhaps we need to get South Dakota politicians the iPhone app. This link here…
http://legis.state.sd.us/sessions/2010/Bills/HCR1009P.pdf…
is their resolution for “balanced” teaching of global warming in the schools. Check out their reasons–they are a list of long debunked canards, falsehoods and fabrications, and just plain fractured logic (or more bluntly, stupidity).
Somehow global warming has become the new creationism. “Teach the controversy”.
South Dakota: Doomed (a la Dr. Plait and his Bad Astronomy poster he uses whenever creationism tries to worm its way into legislation).
H Hak, I provided some links to detailed info on crustal heating, on SkepticalScience.com thread Volcanoes Emit More CO2 Than Humans, in my three comments 234, 235, and 236.
re: #147 Richard
Another nit, albeit bigger this time.
I think that list could confuse someone unfamiliar with this turf about peer review and credibility. After all, that list has papers in E&E, and the G&T paper was a review paper in an odd place.
The other issue is that some papers get refuted pretty quickly. It might be nice to have a dense table showing:
– paper
– journal
– some assessment of journal nature & credibility, and whether the specific article was full-peer-reviewed, editorial-board reviewed, or just “rushed into print” as per Sonja B-C.
– status, including if clearly refuted, when and where.
A one-pager like that could be a useful reference.
#144 Ken
Context is key. It’s a common mistake people make. They see a piece of information and don’t know how it fits in the bigger picture.
This certainly illustrates how easy it is to misinterpret a single piece of information. The argument is also similar to the Arctic ice extent vs. ice mass argument.
http://www.ossfoundation.us/projects/environment/global-warming/arctic-ice
We hear people argue the Arctic ice is recovering every winter because they are only looking at the extent and not the thickness of the ice.
Snow extent and precipitation values are expected and in fact showing some degree of change. But snow extent is not the same as precipitation events.
http://www.ossfoundation.us/projects/environment/global-warming/myths/images/changes-future/fig3-5.jpg/view
I have a reasonable degree of confidence that earth will see certain regions drier and others experiencing more precipitation in the future. Like the Arctic recovering argument, precipitation is not extent of precipitation.
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Ken W says: 20 February 2010 at 11:53 AM
Take a look at the site. ;-)
DenialDepot mission statement:
“I believe that one day all science will be done on blogs because we bloggers are natural skeptics, disbelieving the mainstream and accepting the possibility of any alternative idea.
We stand unimpressed by “textbooks”, “peer review journals” and so-called “facts”. There are no facts, just dissenting opinion. We are infinitely small compared to nature and can’t grasp anything as certain as a fact.
Nothing is settled and we should question everything. The debate is NOT over Gore! When so-called “experts” in their “peer reviewed journals” say one thing, we dare the impossible and find imaginative ways to believe something else entirely.”
#156
“The blistering arrogance and complete lack of self awareness (not to mention innacuracy) of this comment is staggering. I CAN ADD NOTHING TO IT.”
(My caps.)
The last sentence speaks volumes.
John Mashey says:
“””re: #147 Richard
Another nit, albeit bigger this time.
I think that list could confuse someone unfamiliar with this turf about peer review and credibility. After all, that list has papers in E&E, and the G&T paper was a review paper in an odd place.
The other issue is that some papers get refuted pretty quickly. It might be nice to have a dense table showing:
– paper
– journal
– some assessment of journal nature & credibility, and whether the specific article was full-peer-reviewed, editorial-board reviewed, or just “rushed into print” as per Sonja B-C.
– status, including if clearly refuted, when and where.
A one-pager like that could be a useful reference”””
Good point, I will try to draw one up. However, it might still be confusing to non-science people…but oh well it’s a start in the right direction.
Psst psst KenW think … ‘The Onion” …
Except Denial Depot is much funnier, as he does a perfect job of capturing the tone set by so many denialist blogs.
RE- Comment by Richard Ordway — 19 February 2010 @ 10:22 PM:
Ha! You say “heat from other sources (chaleur de feu) does not,” but I proved beyond a shadow of a doubt and with geometric logic that adding a little magnesium to the feu will make it work. Research? We ain’t got no research. We don’t need no research. I don’t have to show you any stinkin’ research!
It was fun trying out being a denier, but it was sort of……not very filling. I think that something like my original post, 19 February 2010 @ 9:03 PM (but with the correct prior to 1997 date), is a good response to those who think that it has stopped warming.
Steve
Re:155 wilt says: 20 February 2010 at 12:06 PM
“Ray Ladbury (#153), solar magnetism is also related to solar luminosity, as discussed in the Lockwood paper (I suppose that you have read this important Nature article, or do you only read the verdicts given on Real Climate?).
No solar hiding place for greenhouse sceptics
http://www.nature.com/nature/journal/v448/n7149/full/448008a.html
Nature 448, 8-9 (5 July 2007) | doi:10.1038/448008a; Published online 4 July 2007
Quirin Schiermeier
Sun not to blame for global warming.
“A study has confirmed that there are no grounds to blame the Sun for recent global warming. The analysis shows that global warming since 1985 has been caused neither by an increase in solar radiation nor by a decrease in the flux of galactic cosmic rays (M. Lockwood and C. Fröhlich Proc. R. Soc. A doi:10.1098/rspa.2007.1880; 2007).”
W: “And this article (and several others) surely demonstrates that there was no decrease in solar intensity during the last part of 20th century (actually an increase), so if solar forcing was important during 1910-1940 temperature increase it was certainly important during 1975-1998.”
Surely not. How about, oh horrors!, reading the paper?
But Wilt, solar luminosity is measurable–even more easily than heliomagnetism, and solar irradiance was not changing significantly during the last half of the 20th century. It was increasing both from 1860-1880. Moreover, Solomon is quite clear in her paper that she is looking to explain short-term variability, not long-term forcing. You seem confused on your forcers. Maybe you need a source other than WUWT.
I’m a low-impact greenie, if you please!
Do I now really have to go out and buy an iPhone, yet another bit of techno-tat, just to keep up in the game?. :-)
#151 Septic Matthew
First, the Freudian community is feuding on the validity of psychoanalytic process so faux has many connotations in your statement, though you have attempted to use it narrowly.
Second, you can’t separate psyche form human reasoning. You had to use it to construct your post.
Third, understanding or analyzing motive is key to understanding confirmation bias. While some may have validity to the scientific argument depending on context, other things may not. This is not unimportant to human reasoning and understanding in the context of debate.
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Septic matthew @ 151
So that characters like Mesa @ 156, who are totally lacking in self-awareness, can get off the hook for writing arrogant tripe like the following in response to Jim’s comment?
And denialists aren’t really denialists because denialists don’t like being called denialists, because if you call them that, then people might start paying attention and figure out for themselves that those engaged in denialism are actually denialists.
If denialists really wanted out of the house of mirrors they’ve constructed for themselves, they would have dumped the denialism long ago and, oh I don’t know, actually paid attention to the science, evidence and human reasoning. Instead we get Lilliputians with no peer reviewed literature of their own, trying themselves in knots trying to pick apart the peer reviewed work of others which they aren’t qualified to evaluate in the first place.
I found this searching through Skeptical Science via the app for Lockwood 2008 in “Articles citing this article.”
Is there some reason the search window found on the web is omitted in the app?
http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm
Solar change and climate: an update in the light of the current exceptional solar minimum
http://rspa.royalsocietypublishing.org/content/466/2114/303.full
Proc. R. Soc. A 8 February 2010 vol. 466 no. 2114 303-329
excerpt
“Lockwood & Fröhlich (2007) demonstrated that since 1987 the long-term changes in solar outputs, which have been postulated as drivers of climate change, have been in the direction opposite to that required to explain, or even contribute to, the observed rise in Earth’s global mean air surface temperature (GMAST). Since then, the solar trends noted by these authors have continued. By the end of solar cycle 23, the annual mean of the open solar magnetic flux (deduced from geomagnetic activity) had fallen to a value last seen in 1924, in the minimum between sunspot cycles 15 and 16 (Lockwood et al. 2009). Other aspects of this decline in solar activity are reviewed by Russell et al. (in press). In this paper, we study the implications.”
Concluding remarks
excerpt
“In the case of climate change, there is no doubt that global mean temperatures have risen, so that the effect is known to be real. Furthermore, there is a viable explanation of that effect, given that the amplification of radiative forcing by trace GHG increases by a factor of about 2 is reproduced by global coupled ocean–atmosphere models. What is alarming is that in the face of this strong scientific evidence, some Internet sources with otherwise good reputations for accurate reporting can still give credence to ideas that are of no scientific merit. These are then readily relayed by other irresponsible parts of the media, and the public gain a fully incorrect impression of the status of the scientific debate.
“The direct influence of cosmic rays on cloud albedo is much harder to put in context. If it has operated alongside GHGs, but there were no climate feedbacks, its effect on the term containing ?G must have exceeded that of the term containing ?A by the total 2.46?W?m?2 attributed to feedbacks. To argue that it replaces the GHG forcing requires that one find major errors in the calculation of radiative forcing or errors in the experimental data on the rise of GHG concentrations: neither is a realistic possibility. What is certain is that the uncertainties and lack of homogeneity in long datasets is a real problem for the evaluation of any such effect (i.e. for quantifying its contribution or finding if it exists at all).
“It is important not to make the mistake made by Lord Kelvin and argue that there can be no influence of solar variability on climate: indeed, its study is of scientific interest and may well further our understanding of climate behaviour. However, the popular idea (at least on the Internet and in some parts of the media) that solar changes are some kind of alternative to GHG forcing in explaining the rise in surface temperatures has no credibility with almost all climate scientists.”
Tim Jones (#167, thanks for the reference to the Lockwood/Frohlich article. In his Nature article (1999) Lockwood presents data about the continuing rise of the solar magnetic field, and in his discussion mentions several other proxies like long term analysis of the number of sunspots, and cosmic rays-related isotopes. In his article in Proc R Soc, Lockwood does not revoke those earlier observations, as a matter of fact he does not even make a reference to his previous Nature article. This seems rather peculiar and puzzling to me: you can not publish two opposing articles as a first author and then pretend they do not both exist.
Doug Bostrom (162) wrote:
“Take a look at the site. ;-)”
dhogaza (165) wrote:
“Psst psst KenW think … ‘The Onion””
Dang, too many threads going on to keep up with who uses satire and who just posts dumb stuff. I walked right into that one :-(
wilt (150) — That solar contribution has been earlier argued against on at least two earlier thread here on RealClimate. Search for GCRs.
Anyway, the claim is completely put to rest by noting that the atmosphere contains a su0prabundance of CCNs everywhere but maybe the interior of Antarctica, where it doesn’t matter.
The Solomon et al. paper is certainly interesting, but contributes mainly to the understanding of factors lumped under the rubric of internal variability. It is rather small compared to the hammer of CO2.
David Horton #129: let’s not get carried away. Likening oneself to the French Resistance is skirting close to Godwin’s Law.
Still it is a pretty uphill battle fighting scientific illiterates who gullibly believe any garbage spewed by the Exxon-Mobil propaganda machine.
I do not possess an iphone (thank god); but to make a totally unrelated point, that I have been meaning to mention for some time, I am pleased to see in recent posts that the word “denier” is gradually being replaced by ie “denialist”. “Denier” to me (I’m 66), has connotations of youth & stockings (not good for my heart at my age!); so how about “denyer”? Maybe Bunyanesque; maybe spellcheck unfriendly; but helps you climatologists keep your minds on your (important) work (especially the older ones!).
Edward Greisch @131:
Brilliant!
The only real issue is this: how do you get to the point with them, where they are actually prepared to listen?
Given that, quite often, denialists are frequently doing their best to overcome some of the more blatant anti-science tenets of fundamentalism, I will typically start with Galileo.
“Soo… up until Galileo, did the sun revolve around the earth? Once Galileo’s ideas took hold, did the earth start revolving around the sun? And, during the time Galileo caved to the threat of excommunication, did the universe temporarily revert back to geocentrism? No?
“So what does politics and the manipulative agenda of the powerful have to do with science?”
And *then*… well, I’m liking your CO2 infrared opacity bit…
Could someone please debunk this ‘editorial’ conclusively. This from an AG professor emeritus at the University of Georgia. I’m too tired at the minute.
Forum: Hot air abounding on greenhouse gas
Washington is debating how tough legislation should be to reduce carbon emissions and slow global warming. Doomsayers are predicting the 21st-century rise in carbon dioxide will bring heating of the Earth, flooding of coastal cities, increases in hurricane strength and frequency, proliferation of tropical diseases, extinction of species and more. Yet the pessimistic prophets dare not weaken their revelations with one certainty: Rising CO2 will make fields and forests more productive.
(more here)
http://www.onlineathens.com/stories/022010/opi_565162957.shtml
[Response: Carbon dioxide does indeed promote faster growth rates in many plant taxa having a particular photosynthetic system (C3), by reducing the loss of carbon that would otherwise occur in photorespiration. However the rates thereof vary widely even in ideal conditions, and CO2 is but one potentially limiting factor among several in typical production settings. As with all such factors, the effect is greatest when other requirements are not limited. Higher water use efficiency (WUE: the amount of carbon fixed per unit of water used), and hence ability to tolerate drought, is where higher CO2 might really have a definite postive effect. The effect on crops has received far more attention than on forests, and statements on effects on the latter are highly uncertain. There are some wild over-generalizations and questionable statements in the piece, e.g. in reductions in ag land and improper comparisons with greenhouses, where the CO2 levels are not comparable to ambient. –Jim]
catman306, if what you are seeking to produce is poison ivy, then he is certainly right. Poison ivy thrives as CO2 increases. So do many other noxious weeds. And without the occasional fros to make them die back, there’s nothing to keep the country from being completely overrun with kudzu and poison ivy.
The problem is that your prof is confusing fetid with fertile.
#176 Philip “let’s not get carried away. Likening oneself to the French Resistance is skirting close to Godwin’s Law”, yes, cheeky, wasn’t it?
#179 catman306
Well, although most FACE experiments were dealing with fixing carbon there is some indicative evidence that non legumes (crops that don’t fix nitrogen) drop proteins in higher Co2 environments.
Change Biology (2008) 14, 565–575, doi: 10.1111/j.1365-2486.2007.01511.x Effects of elevated CO2 on the protein concentration of food crops: a meta-analysis. DANIEL R . TAUB, BRIAN MILLER and HOLLY ALLEN.
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Tim Jones #167: better still, you can read the latest follow up on this work for free (Royal Society in celebrating its 350th anniversary is making all its content free this year):
Mike Lockwood. Solar change and climate: an update in the light of the current exceptional solar minimum, Proc. R. Soc. A February 8, 2010 466:303-329; published online before print December 2, 2009, doi:10.1098/rspa.2009.0519
This is an excellent paper (in my inexpert opinion), highly recommended reading, especially if you can read and don’t stop at the bits that confirm your prejudices :(
Gavin, Rasmus et al.: I’d like to see a summary of this paper here. Any chance of that?
catman306 :
There is not really much to debunk. He cites no source for his 25 to 50 percent yield increase. He seems to think that there is no difference between field and greenhouse agriculture. He downplays the risks of global warming.
etc. etc.
http://www.skepticalscience.com/global-warming-positives-negatives.htm
Maybe this should be added to your Wiki:
Dallas snow storms and warmth (55F) in Vancouver is a result of the planet warming up as a whole.
“That’s one aspect of the science that everyone should understand.”
http://www.youtube.com/watch?v=JPwHnU5ObPY&feature=player_embedded
These scientific words of wisdom were uttered by none other than our President.
Anne
A Blue Marble slide show:
http://www.livescience.com/php/multimedia/album.php?aid=33566
A posting above states that solar activity cannot explain the warming of the last part of the twentieth century. Another says that what the global warming movement needs is impetus from a prolonged warm spell. The video from a recent American Geophysical Union conference session bears on both points. See:
http://eventcg.com/clients/agu/fm09/U34A.html
The speakers point out that the latter part of the twentieth century saw a “solar maximum” period. To many solar scientists, this explains the relative warmth of that period. Recently, the sun’s state and the earth’s climate have changed in unison. One of the AGU speakers expresses the belief that the sun is heading into a Dalton-minimum like period, which was very cold. Thus, it is unlikely the global warming theory will get bailed out by a period of hot weather; rather it is more likely it will be definitively doused by continued cold temperatures. This will be a nice way to demonstrate that CO2 at .04% of the earth’s atmosphere in no way can trump solar influences on climate. It seems increasingly likely that CO2 is an insignificant player in determining climate since it has been discovered by Lindzen and Spencer that the feedback effects on water vapor necessary for CO2 to cause harmful warming do not exist.
[Response: Feedbacks work exactly the same way for all forcings – solar and GHGs included. If sensitivity is small, then none of the forcings can make much of a difference. Nothing Lindzen has claimed supports solar forcing being dominant – and in fact he is extremely scathing about the level the pseudo-scholarship involved in the various solar correlations out there. On this topic, we actually agree. – gavin]
[edit]
#187 fred g
Re. Daulton-minimum
When you are at or around thermal equilibrium an extended solar minimum can cause cooling.
But that is not where we are at. We are around 1.6 W/m2 positive forcing. So, even if we had an extended solar minimum, which many were claiming last year… until of course solar cycle 24 kicked in… we would not get cooling but only slightly less warming forcing.
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Correct me if I am wrong, but the “hide the decline” comment in the Emails refers to tree ring data that has diverged from the real temp measurements for the last 50 years, and was never purported to be a conspiracy to hide any decline in real temperatures.
However, My question is, is there even a single statistically sound reason why someone could reasonably assume that the current divergence of tree ring data that has occurred over the last 50 years (tree rings indicating that the temps are much cooler than they actually are) has not occurred many times before (since there is no known cause for this anomaly) therefore completely rendering any assertion that one might make about past temps from tree rings completely invalid?
Is it not a statistical NIGHTMARE to graft 50 years of real thermometer temps onto hundreds of years of tree ring data (the “trick”)because the last 50 years do not agree with real temps now, while having NO idea whether or not this has happened many times in the past? Would it not result in confidence intervals that are on par with chance (50% or less?) Hiding this decline in the relationship between temperatures and tree ring data so that one could use the remaining data to continue to insinuate lower temps in the past seems more than adequately shoddy science to impeach the credibility of those doing it without having to insinuate that they are out and out lying.
They are purposefully obfuscating the VERY poor reliability of their data in order to justify its continued use, and making assumptions about past temperatures with that data that are obviously baseless.
If there is a CLEAR explanation for why I might be wrong about this, please respond.
RE Joel Shore
That they do, and they do not like discouraging words. Back in December I tried to pull a “Joel Shore” (introduce science into hostile territory – I’ve seen and admired your postings on WUWT) by commenting on an article there and got banned, and my posts yanked, after 3 posts. (I was responding to this statement: “One of the most encouraging reactions to this mess comes from the working scientists.”) What’s funny is that the ghost of my brief career as a poster there still remains.
fred g, the solar maximum was reached, and then plateaued (or even decreased), starting around 1960. Some increase in temperature was due to that increase in solar radiance up to that maximum’s plateau.
But later than 1960 is the “latter” part of the 20th century when temperature increased despite the lack of increase in solar radiance. We know that the temperature increase since 1960 cannot simply be a continued or lagged response to that plateaued maximum, because the Earth’s energy imbalance has continued to increase.
If the Sun’s output dropped to levels similar to past grand minima such as the Dalton and Maunder minima, the effect on Earth’s temperature would be small. Historically colder periods that coincided with such minima had additional negative temperature forcings.
Rising CO2 will make fields and forests more productive.
Yep.
And droughts did wonders for the Indus Valley civilization and Egypt’s Old Kingdom.
Shrinking grasslands forced to Huns to move west
across Central Asia until they invaded Europe.
Everybody won!
183, Phil Machanik, thanks for the link to that paper.
#179 Catman
As an agriculturalist, Harold Brown ought to know better.
I would like to see some references. He quotes from a published report (an old reference – U.S. Global Change Research Information Office 2000) “Within the next 50 years, forest productivity is likely to increase with the fertilizing effect of atmospheric carbon dioxide.”
But then he adds his own opinion; ‘Hundreds of actual experiments in fields and greenhouses show that growth and yield will increase by 25 to 50 percent if CO2 rises to double the present levels.’ The latter was never part of the original reference though it was made to look that way.
In fact the effects of CO2 on crop production has been well documented and considered, though they are often overstated. For example the Fourth IPCC assessment (1) states
“Recent results from meta-analyses of FACE studies of CO2 fertilisation confirm conclusions from the TAR that crop yields at CO2 levels of 550 ppm increase by an average of 15%. Crop model estimates of CO2 fertilisation are in the range of FACE results [5.4.1.1]. For forests, FACE experiments suggest an average growth increase of 23% for younger tree stands, but little stem-growth enhancement for mature trees. The models often assume higher growth stimulation than FACE, up to 35% [5.4.1.1, 5.4.5].”
Earlier studies showing the higher stimulation rates were usually based upon closed environment systems. In fact while the average might be as stated the effect is very variable with forest trees showing the greatest effects and some food crop plants showing the least.(2)
In addition while most early studies focussed their attention on crop yield, later studies have shown that greater care needs to be taken since the effects are rather more varied.(3, 4)
For example while rice yields did increase, the quality (protein content) decreased. (5) Similarly wheat yields increased, but the quality (protein content) decreased and the grain size was significantly reduced. In addition the gluten and other characters were sufficiently altered to cause the conclusion that there would be a major effect on consumer nutrition and on its use for industrial food processing. (6)
In yet other studies increased CO2 caused a greatly increased level of toxic cyanogenic glycosides in Cassave (7) while also reducing the total yeild of Cassava tuber; by as much as 90% in the worst case. Cassava of course is a staple food source for more than 10% of the world’s population. It also caused increased cyanogenic glycosides in clover(8) which is likely to adversely affect its use as animal feed.
So, increased carbon dioxide levels are likely to have some benefits, these are mixed and have been overstated. In addition, taking into account all the negative effects of increased carbon dioxide, I would think that anyone conversant with the evidence would have to conclude that overall, increased CO2 is not a good thing, even within a narrow agricultural context.
1. IPCC Fourth Assessment Report: Climate Change 2007 (Part 5.8.1)
http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch5s5-8.html
2. Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations
Stephen P. Long,1,2,3* Elizabeth A. Ainsworth,4,1,3 Andrew D. B. Leakey,3,1 Josef Nösberger,5 Donald R. Ort4,1,2,3
Science 30 June 2006:
Vol. 312. no. 5782, pp. 1918 – 1921
DOI: 10.1126/science.1114722
http://www.sciencemag.org/cgi/content/abstract/sci;312/5782/1918
3. Carbon Dioxide Concentration, Photosynthesis, and Dry Matter Production
Paul J. Kramer
BioScience, Vol. 31, No. 1 (Jan., 1981), pp. 29-33
http://www.jstor.org/pss/1308175
4. What Have We Learned from 15 Years of Free-Air CO2 Enrichment (FACE)? A Meta-Analytic Review of the Responses of Photosynthesis, Canopy Properties and Plant Production to Rising CO2
Elizabeth A. Ainsworth and Stephen P. Long
New Phytologist, Vol. 165, No. 2 (Feb., 2005), pp. 351-371
http://www.jstor.org/pss/1514718
5. Growth and Yield Response of Field-Grown Tropical Rice to Increasing Carbon Dioxide and Air Temperature
Lewis H. Ziska,* Offie Namuco, Toti Moya, and Jimmy Quilang
AGRONOMY JOURNAL. VOL. 89. JANUARY-FEBRUARY 1997
other effects
Much higher level of toxic cyanogenic glycosides in clover.
http://www.springerlink.com/content/k81533177x6x3169/?p=3261b37c42b542baaea2901c77c0f00a&pi=9
6. Effects of elevated CO2 on grain yield and quality of wheat: results from a 3-year free-air CO2 enrichment experiment
P. Högy 1 , H. Wieser 2 , P. Köhler 2 , K. Schwadorf 3 , J. Breuer 3 , J. Franzaring 1 , R. Muntifering 4 & A. Fangmeier
Plant Biology Volume 11 Issue s1, Pages 60 – 69
7. Growth and nutritive value of cassava (Manihot esculenta Cranz.) are reduced when grown in elevated CO2
Roslyn M. Gleadow 1 , John R. Evans 2 , Stephanie McCaffery 2 & Timothy R. Cavagnaro 2,3
Plant Biology Volume 11 Issue s1, Pages 76 – 82
http://www3.interscience.wiley.com/journal/122540174/abstract?CRETRY=1&SRETRY=0
8. Changes in Nutritional Value of Cyanogenic Trifolium repens Grown at Elevated Atmospheric CO2
Roslyn M. Gleadow & Everard J. Edwards & John R. Evans
J Chem Ecol (2009) 35:476–478
http://www.biolsci.monash.edu.au/staff/gleadow/docs/2009-clover-cg-co2.pdf
fred g(#187):
Take a look at Roy Spencers graphs for global average temperature over the past two years and observe the trend. Hint: average global temperature is at a record high (Spencers UAH data had a record smashing +0.72deg anomaly for January 2010), despite the extreme solar minimum, so the ‘solar trumps anything’ theory isn’t exactly gaining strength these days. Rather the opposite, in fact.
re: #180
Well, a Georgia Prof already has kudzu; maybe he just wants to inflict it on everyone.
Here’s a nice ,presentation by U of Toronto researchers, showing why they think that kudzu will be able to survive in lower Ontario by ~2020. Some of the maps offer nice visualizations of quite concrete effects.
“The vine that ate the South” have been moving North… and it responds quite well to higher CO2…
#189 JOHN
https://www.realclimate.org/index.php/archives/2009/11/the-cru-hack/
“As for the ‘decline’, it is well known that Keith Briffa’s maximum latewood tree ring density proxy diverges from the temperature records after 1960 (this is more commonly known as the “divergence problem”–see e.g. the recent discussion in this paper) and has been discussed in the literature since Briffa et al in Nature in 1998 (Nature, 391, 678-682).”
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John@189,
Well the chief reason why the tree-ring data are not suspect in times past and are today include:
1)the situation of the trees in question is quite a bit different (more stressful) today than it was in the past.
2)The tree-ring data agree with the other proxy data over the rest of the reconstructed period. Even if you exclude the tree-ring data altogether, you get pretty much the same reconstruction.
Fred G@187 Bzzzz!! Oh, but thank you for playing.
Fred, solar irradiance stopped rising ~1960, before the current warm period even started. Moreover, we’re at the point in the Milankovitch cycles where things ought to be cooling. That being the case, don’t you wonder why it is still so friggin’ warm? The reason is that CO2 now trumps solar variability. What is more, even if we were to enter a prolonged solar minimum (See Usoskin’s article on this), it would last at most decades, while the effects of CO2 last centuries.
It sounds like somebody needs to look at where he gets his information.
137 Completely Fed Up: He can’t see your face on this blog. OR he may own coal company stock. Which means RC needs more movies. Rush Limbaugh uses emotional hooks, like getting angry, on his radio show. Science is supposed to be devoid of emotion, which gets most people to distrust science. Persuasion requires more than just science for most people. How can RC deal with that?