Page 8
On May 24 I posted about Global Warming and in particular about a chart on page 8 of JoNova's The Skeptic's Handbook. Today, someone appearing to be JoNova commented on my blog about that post. The comment was polite but lends little to expand upon that page 8 chart.
So I did some Googling.
First, here is my post and JoNova's comment on my blog. Now mind you I have a hard time convincing myself that important people in Perth Australia stay up at night reading my blog, so maybe someone is spoofing me or is serving as proxy for JoNova's effort. Be that as it may. I am, after all, a skeptic, aren't I?
At her website, JoNova gives references for her Skeptic's Handbook.
JoNova gives this reference as the source of the bar chart on Page 8 of her Skeptic's Handbook. The same chart appears as Figure 17 in this May 2007 presentation by David Archibald.
Archibald references his own work copied here as the source of Figure 17 in the paper listed above. The very same chart appears in this paper as Figure 4. A stacked bar chart showing similar information is shown as Figure 11 in this Archibald paper.
Archibald refers in his text concerning this chart to "the MODTRANS facility maintained by the University of Chicago" which appears to be this online calculator. Reference to this was found in comments here.
An interesting rebuttal to Archibald's use of this calculator is given here by "david" who, it appears, may be Dave Archer who maintains the calculator - reference "Response" to response number 10 on this site.
So the person responsible for maintaining this calculator used by Archibald and referenced by JoNova on Page 8 of her Skeptic's Handbook claims that Archibald is deriving incorrect (deceptive) data by using an unreasonably small conversion factor in the conversion from the calculator's results to temperature change. Archer claims the error to be a factor of 10. The point is that Archer's MODTRANS calculator does not predict the results that Archibald is plotting in this chart and then crediting to MODTRANS.
So I'm thinking maybe I need to keep looking. Maybe this handbook isn't quite what it purports to be.
So I did some Googling.
First, here is my post and JoNova's comment on my blog. Now mind you I have a hard time convincing myself that important people in Perth Australia stay up at night reading my blog, so maybe someone is spoofing me or is serving as proxy for JoNova's effort. Be that as it may. I am, after all, a skeptic, aren't I?
At her website, JoNova gives references for her Skeptic's Handbook.
JoNova gives this reference as the source of the bar chart on Page 8 of her Skeptic's Handbook. The same chart appears as Figure 17 in this May 2007 presentation by David Archibald.
Archibald references his own work copied here as the source of Figure 17 in the paper listed above. The very same chart appears in this paper as Figure 4. A stacked bar chart showing similar information is shown as Figure 11 in this Archibald paper.
Archibald refers in his text concerning this chart to "the MODTRANS facility maintained by the University of Chicago" which appears to be this online calculator. Reference to this was found in comments here.
An interesting rebuttal to Archibald's use of this calculator is given here by "david" who, it appears, may be Dave Archer who maintains the calculator - reference "Response" to response number 10 on this site.
So the person responsible for maintaining this calculator used by Archibald and referenced by JoNova on Page 8 of her Skeptic's Handbook claims that Archibald is deriving incorrect (deceptive) data by using an unreasonably small conversion factor in the conversion from the calculator's results to temperature change. Archer claims the error to be a factor of 10. The point is that Archer's MODTRANS calculator does not predict the results that Archibald is plotting in this chart and then crediting to MODTRANS.
So I'm thinking maybe I need to keep looking. Maybe this handbook isn't quite what it purports to be.
posted by Bill | 5:37 PM
2 Comments:
Bill, you're right, I usually don't comment on the hundreds of links to the Handbook, but yours was so genuine, it made my day.
I'm puzzled that you think my comment might be a spoof. You presumably have my url. My email joanne AT joannenova.com.au is posted on my site, so you could easily verify my comment.
As for the criticisms of Archibalds graph. 1/ Note, even the critics are not arguing that it's not a log curve. Starts steep, trends towards zero. When I say adding new carbon will have less effect than the CO2 we've already put up there, that's true.
2/ Idso's paper (which gave the estimate of climate sensitivity that Archibald used is a lot lower than the IPCC) is it also based on observable evidence. There are other low estimates in a similar ballpark by independent methods. All we're arguing about is the steepness of the curve down.
In a perfect world I would have liked to see a log graph of several sensitivities. I'm a volunteer. So in Archibald. Why doesn't the multi million dollar IPCC arrange for graphs like this? Could it be that it wouldn't help their case, no matter what sensitivity they put there? Where is the honesty in that? (I asked Archibald about other sensitivities btw, and he replied that he did those calcs and they made very little difference.)
Recall in your original post you said "I had been led to believe that the logarithmic effect was just the opposite of what this bar chart shows."
The IPCC keep telling us that the greenhouse effect "keeps the world warm", but they don't mention that the warming effect of CO2 gets lower and lower, and that it's possible it's effectively almost saturated.
They also don't mention that Co2 has been as high as 4000ppm millions of year ago and the world slipped into an ice age.
PS: Your link-in popped up on my wordpress register. That's how I noticed your post.
Hmmmmmmmmmm...
I do indeed find this conversation interesting.
The fact that the MODTRANS guy disputes Archibald's use of his tool doesn't necessarily mean Archibald misused the tool. But the fact that Archibald made his point by lowballing the calculations raises red flags. If he indeed ran these calculations with figures recognized as valid by the IPCC and found that it didn't impact his findings enough to put them in doubt, why did he choose to use a disputed value instead and indeed put his findings in doubt? If, as Joanne seems to have said, the runaway factor is not carbon dioxide but water vapor, or if it is the ocean's release of methane gas with ocean warming, then wouldn't the prudent approach to casting doubt be to use the highest level of CO2 effect rather than the lowest one and demonstrate that even that amount of warming doesn't trigger a runaway warming? I mean, if the calculations were already done and that is indeed what they showed...
So I don't know. I'm no scientist. But if you're a skeptic you have to be skeptical of the skeptics too.
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