What was the change in temperature that can be correlated with that CO2 change after removing the effect of the primary initiators of change?1 degree C.
In what part of your voluminous contributions does that figure appear?
The issue is clear that CO2 not a major "driver" as shown clearly in reviewing the data and the statement of Brenner.
Incorrect. Crowley and Berner 2001, which I have made a copy of over the weekend but which requires access to Science magazine online if you want to read it online have an excellent figure that I wish I could reproduce here. It shows the total net radiative forcing over the Phanerozoic, combined with the CO2 concentrations (which also appear in one of your figures, which is why I felt it necessary to bring Berner into this discussion), as well as low-latitude paleotemperatures and glacial epochs. There is only one extended glacial epoch -- the Ordovician -- which does not correlate with the periods of lowest radiative forcing. Note that radiative forcing was calculated for changing solar luminosity as well as CO2 concentrations. However, the periods of highest net radiative forcing uniformly occur when CO2 levels are elevated. The glacial epochs, with the exception of the Ordovician, uniformly occur with low CO2 concentrations. As the authors note:
"For comparison with climate indices, it is important to consider the net radiative forcing, which combines the logarithmic relation between CO2 and radiative forcing with estimated increases in the sun's output over time. The latter term, generally considered robust (ref. Endal and Sofia 1981) corresponds to 1% increase in the solar constant per 100 million years and modifies the relative size of the early Phanerozoic and Mesozoic (245-65 Ma) CO2 peaks substantially."
So, attempting to directly correlate CO2 concentration with temperature is fallacious in the Phanerozoic. Summary: the primary factor determining net radiative forcing in the Phanerozoic is atmospheric CO2 concentration, but the value of net radiative forcing is modified (not determined) by variability in solar luminosity.
We'll examine what Crowley and Berner say about the anomalous Ordovician glaciation tomorrow, and then get to what they say about Veizer's research. And then I plan to delve deeper into the Vostok ice core correlations, a topic that I began discussing with "gatex".
1 degree C.
In what part of your voluminous contributions does that figure appear?
from reply #35, which you conveniently overlooked in your hurry, however just for you straight from the presses:
... we revisit the Geophysical record of CO2 and it's correlation to global temperture, this time we remove the catastrophic initiations of ice ages due to factors clearly not associated with CO2 concentration.
From the geological record, we can see a remainder trendline of CO2 concentration with respect to temperature by running a trend through the peak global tempertures.
As you have acknowleged the initiation of the deep iceages are clearly due to other factors such as plate tectonics, Gamma Ray Bursts, Meteoric events, etc.which initiate atmospheric cooling incident to the creation of high altitude cloud cover & icefields altering the mean albedo of the earth. Such effects lower overall irradiation of the earths surface and hence cools the surface. Under such conditions the major multi-million year iceages are induced. Remove their effects on the overall record, and what is left behind is a residual that can be perceived, to the first order, as a correlation of CO2 and temperature if we assume an essentially constant Solar radiation flux, which the IPCC modellers insist as being true.
I bring your attention to the two redline additions to our favorite chart:
:
The upper horizontal red line represents a peak temperature of 22.8oC as represented at the chart Cambrian CO2 peak of 7000ppm. The second and descending redline is a rough approximation of the average peak temperatures which should be somewhat representative of any residual correlation between CO2 & temperature, we note that the downtrending redline terminates at approximately 21.6oC and today's 320ppm CO2 concentration.
It should also be noted here that the relationship between CO2 radiant absorption capacity varies logrithmically with concentration of the gas under consideration in the atmosphere. For any fixed multiplier of change in concentration there is a linear incremental change in absorbed energy of the gas. Thus doubling, or halving, the concentration of CO2 will result in a linear increment in the absorbed radiation at the wavelengths CO2 is responsive to where incident radiative flux is constant.
7000ppm/320ppm = 21.9 (~ 4.45 doublings) with 22.8-21.6 = 1.2oC change in temperature.
Overall atmospheric correlation between CO2 & increment of energy absorbed of necessity includes any temperature/concentration linkages that may actually occur in the atmosphere.
for 1.2oC & 4.45 doublings, CO2 doubles for ~ 0.27oC increase in global temperature
A value which is much less than the lowest 1.5to2.5oC/doubling estimate built into the UN/IPCC global climate models, which suggests the relationship between CO2 and temperature built into the IPCC models is substantially overstated and in error.
Somes just mere observation of published information is sufficient to see the relationships and their magnitude for one's self.
"For comparison with climate indices, it is important to consider the net radiative forcing, which combines the logarithmic relation between CO2 and radiative forcing with estimated increases in the sun's output over time. The latter term, generally considered robust (ref. Endal and Sofia 1981) corresponds to 1% increase in the solar constant per 100 million years and modifies the relative size of the early Phanerozoic and Mesozoic (245-65 Ma) CO2 peaks substantially."
Gee it was good that I utilized a logrithmic measure for the effect of CO2 to establish that doubling of CO2 concentration associated each 0.27oC increment change in temperature wasn't it?
Looking back to 640Ma again along temperature peaks to maintain as near constant conditions as possible, we can also adjust for the percentage change in temperature due to 540ma of increase of solar flux.
That would mean that solar flux increased by a factor of 1.01(5.4) = 1.0552 and by stephan-boltzman the temperature factor would be increased by the 4th root of the variation of solar flux, (i.e. 1.013).
Hmmm 1.013*0.27oC= 0.274oC associated with each doubling of CO2.
Thanks for reminding me to adjust for the change in solar faction, always glad to assure precision in my measurements.