A new paper by Dr. Dana Royer of Wesleyan University demonstrates that the Warmists are still hard at work torturing the data in order to perpetuate the fiction of CO2-driven climate change… Fossil soils constrain ancient climate sensitivity
Global temperatures have covaried with atmospheric carbon dioxide (CO2) over the last 450 million years of Earth’s history (1).
Dr. Royer references his own paper (Royer, 2006) for this claim. Veizer’s and Shaviv’s reply to Royer’s previous assertion of Phanerozoic and temperature covariance (Royer et al., 2004) pointed out that this covariance was obtained through a pH adjustment to oxygen isotope data; which brought the temperatures into line with the paleo-CO2 levels. The pH adjustment was derived from CO2. So, Royer used CO2 to calibrate temperatures to CO2…
The analysis of Royer et al. (2004) assumes an unrealistically high pH correction. First, it neglects the ice-volume effect, which changes the relation between d18O and dT. Second, this large pH correction implies high temperatures for seawater even during times of extensive glaciations.
Moreover, the analysis of Royer et al. (2004) consists of bootstrapping, by introducing a correction to dT that is an implicit function of RCO2. It is then not surprising that a correlation between dT and RCO2 is obtained.
This would be the case irrespective of the RCO2 model utilized.
Then Royer suggests that the deviation of paleosol (pedogenic carbonate) derived CO2 from other methods of CO2 derivation, somehow brings those other methods into question…
One exception is the paleosol carbonate proxy, whose CO2 estimates are often more than twice as high as coeval estimates from other methods (1). This discrepancy has led some to question the validity of the other methods and has hindered attempts to understand the linkages between paleo-CO2 and other parts of the Earth system.
In the case of Royer’s 2004 paper on Paleocene-Eocene Thermal Maximum (PETM) CO2 levels, he showed that pedogenic carbonates actually yielded CO2 levels that were 4-5 times as large as those derived from fossil plant stomata indices. Yet Royer insists that pedogenic carbonates provide “the most precise view to date of Earth’s CO2 history.” Plant SI data can actually be calibrated to the modern instrumental record and can be empirically tested; yet Royer would reject these data in favor of the data that support his hypothesis of Phanerozoic covariance of CO2 and temperature.
This leads Royer to the absurd conclusion that climate sensitivity “for every doubling of CO2” is “is probably closer to 6°C”; rather than the maximum of 2°C that can be derived for a doubling of pre-industrial CO2 (*). And the 2°C can only be achieved if every bit of warming since 1880 is the result of an enhanced greenhouse effect from anthropogenic CO2. Something we know to be false.
We can take the model above and create a climate model back to the mid-1800’s using CO2 derived from ice core data…
It’s not a bad fit. The model tells us that the maximum possible warming that could result from a doubling of the pre-industrial CO2 level is ~2°C. Since we know that half of the warming since the mid-1800’s is the result of non-anthropogenic climate oscillations, solar activity and other natural forcing mechanisms and that the other half is due to instrumental error, operator bias, UHI, fraud and other non-greenhouse gas driven anthropogenic activities… We can conclude that the Earth’s climate is relatively insensitive to CO2 fluctuations between 275 and 4,000ppmv.
What could possibly lead Dr. Royer to continually torture the data until it says what he wants it to say?
Maybe it has something to do with him being an environmental activist…
* The equation that I used to calculate the maximum CO2-derived warming is from this Watt’s Up With That? post by Bill Illis… Adjusting Temperatures for the ENSO and the AMO