DeSmog Leaks Advance Copy of Think Tank's IPCC Attack

McKitrick....one of the usual suspects. Gee, I wonder if...I wonder if the Fraser Institute....maybe might have been doing the "second-hand smoke is not bad for you" dance back in the mid nineties....?

Bingo!
http://www.fraserinstitute.ca/shared/readmore.asp?sNav=nr&id=386

Is it just my imagination, or is there a whopping ten references in the report?

I found the site slow and couldn;t get the whole report. However in the first pages I saw that they were also pulling out leaf stomata as an indicator of CO2 levels.

A lot of the names on it were also on the letter to PM Harper signed by 60 scientists.

On a better note, the Globe and Mail (Canada's National Newspaper) had a good series of articles on global warming in the weekend edition. Several good reviews and one poor one by a generally conservative columnist who pulled out the old "new-middle ground" argument. And who did she use for the middle ground - Kevin Vranes, Roger Pielke Sr and Jr.

But all in all a pretty good set with some interesting statistics. 73% of Canadians think that global warming is caused by man and 55% of Canadians say they would accept major sacrifices. Of course only 27% would strongly support higher gas prices - go figure!

Also a 2 page colour spread called Canada 2099 - How Global Warming will Change the Country we Live in.

Leaf stomata can indeed be used as a CO2 proxy and there are indeed some differences between them and ice cores; if you accept the stomata results, then there is some variability that ice cores don't pick up. For example:

Wagner, F. et al. (2002) Rapid atmospheric CO2 changes associated with the 8,200-years-B.P. cooling event. PNAS, 99, 12011-12014.

By applying the inverse relation between numbers of leaf stomata and atmospheric CO2 concentration, stomatal frequency analysis of fossil birch leaves from lake deposits in Denmark reveals a century-scale CO2 change during the prominent Holocene cooling event that occurred in the North Atlantic region between 8,400 and 8,100 years B.P. In contrast to conventional CO2 reconstructions based on ice cores from Antarctica, quantification of the stomatal frequency signal corroborates a distinctive temperature-CO2 correlation. Results indicate a global CO2 decline of {approx}25 ppm by volume over {approx}300 years. This reduction is in harmony with observed and modeled lowering of North Atlantic sea-surface temperatures associated with a short-term weakening of thermohaline circulation.

Steve F., I think the hypothesis of stomata as an important proxy has been pretty well discredited; see this dicussion and the responses to this previous comment on the same blog.

Steve,

I'm not an expert on stomatal analaysis, but am a bit bored so I thought I'd play devils advocate (plus I'm a palaeoecologist, so I feel duty bound to defend my bretheren). The above review is a good one and makes some interesting points. However, one significant paper that was not mentioned is the following:

Wagner, F. et al. (2004) Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quaternary Science Reviews, 23, 1947-1954.

Abstract: The majority of the stomatal frequency-based estimates of CO2 for the Holocene do not support the widely accepted concept of comparably stable CO2 concentrations throughout the past 11,500 years. To address the critique that these stomatal frequency variations result from local environmental change or methodological insufficiencies, multiple stomatal frequency records were compared for three climatic key periods during the Holocene, namely the Preboreal oscillation, the 8.2 kyr cooling event and the Little Ice Age. The highly comparable fluctuations in the palaeo-atmospheric CO2 records, which were obtained from different continents and plant species (deciduous angiosperms as well as conifers) using varying calibration approaches, provide strong evidence for the integrity of leaf-based CO2 quantification.

Wagner et al. paper here.

I guess I could use the title Urban Ecologist if pressed, so I'll state that the CA cheer squad would be all over this paper if it disagreed with their received world views. Meaning, there needs to be some degree of robustness here wrt other researchers finding the same thing; if we can model phenotype and genotype response ranges, we might be able to have a decent discussion on this issue.

Best,

D

Dano,

Entirely agree about the sceptics stance on this paper. Anyhoo, here is an interesting looking recent paper:

Garcia-Amorena, I. et al. (2006) Stomatal responses in deciduous oaks from southern Europe to the anthropogenic atmospheric CO2 increase; refining the stomatal-based CO2 proxy. Review of Palaeobotany and Palynology, 141, 303-312.

Herbarium specimens of Quercus robur L. from 25 localities on the Iberian Peninsula covering the time period from 1901 to 2003 were studied to develop a suitable stomatal index (SI)-atmospheric CO2 inference model that met the specific demands of the abundant fossil material from this geographical region. Significant SI changes were observed under the atmospheric CO2 increase since the onset of industrialization, resembling a sigmoidal response. The highly comparable SI response rates of Iberian and Northwest European data sets confirmed that Q. robur has reached its response limit at 330 ppmv, and adaptation of Quercus to changing CO2 concentration is in principle the same. A 3.5% SI difference between both data sets is likely to be a result of the differences in irradiation level at the high and low latitudes. An adjusted SI-CO2 calibration data set for the Northern Iberian Peninsula is provided for the CO2 range from 295 ppmv to 330 ppmv, where the best statistical fit for the CO2 inference model is achieved when data are restricted to an altitudinal range of 0-1000 in a.s.l. Geographical extension of the model is attained by the incorporation of the month irradiance average (W/m(2)) as an independent factor. Additional pore length increase was observed over the same CO2 range. Usage of the Stomata-Pore Coefficient (proportion of pore length over the Stomatal length) was introduced in order to give a better description of the response of stomatal dimensions to the rising atmospheric CO2 concentrations.

CO2 at ground level was far too variable for Keeling, which is why he went to the top of Mauna Loa in the middle of the Pacific to get a well mixed atmosphere to sample.

Are oak trees all that much better at deriving a global average from local air?

-------- end serious, begin wry -----

On another note, to be a proper member of the conspiracy, you _must_ take your language from the accepted authorities. We no longer speak of a "think tank" -- the correct term since last Sunday is "belief tank"
http://images.ucomics.com/comics/db/2007/db070128.gif

"A belief tank?"

"It's like a think tank, only without the doubt."

Now, I like the sigmoidal curve response, SteveF, and I'm intrigued by the maximum response limit, which gives a bound for genotypic response if robust. My sub is horrible and I don't have that journal, so I can't read the paper but it looks interesting. I think Hank gets at a confounding factor as well.

Best,

D

Dano writes, "I don't have that journal, so I can't read the paper but it looks interesting."

I have access to the journal and can send you a pdf file of the article. Uh, how can I send it to you?