I believe that the graph is probably correct, mainly because (1) I can’t think of any reason why the author – HD Tkachuck – would falsify it; and (2) it’s consistent with popular beliefs about the Little Ice Age and the Medieval Warm Period.
I realize that the paper has been produced by an organization which apparently has a religious agenda. However, in my opinion, this does not make the graph presumptively invalid. Particularly since it’s hard to see how someone’s religious agenda would make them strongly want to deny the little ice age when it did happen or claim it happened when it didn’t. The graph apparently is reproduced from a work by Hubert Lamb, who is apparently something of an authority.
Granted, one should be skeptical of papers such as this, but still, I think the graph is probably correct.
Anyway, the question for debate is this:
Does anyone seriously dispute that the graph is probably correct? If so, what should the corrected graph look like and why?
Hubert Lamb’s hypothesis of a Medieval Warm Period is regarded as suspect by modern climatologists, who believe their data is better (Lamb, they say, was working indirectly from biological data).
At any rate, Lamb claimed that Iceland was surrounded by sea ice in 1695. The article as a whole is a rather belligerent discussion of the Little Ice Age, as if someone were arguing that there had been one, followed by this conclusion:
Tkachuck is, of course, on the GRI staff, and is a Creationist. His argument is really against anthropogenic global warming, and his unstated conclusion is that AGW proponents have no idea what’s going on with the climate.
You’ve rejected the work of thousands of scientists who publish their findings in peer reviewed journals, the conclusions of the IPCC and dozens of scientific societies, and the scientific positions of most of the countries in the developed world on this issue, yet you’re going to uncritically accept this graph from a non-peer-reviewed source where it’s sandwiched between articles on creationism and intelligent design, irreducible complexity, and geology before and after the biblical flood? If your source is publishing that crap, what makes you think this will be any more valid?
I would bet that the graph is an accurate representation of the data, especially if it’s reproduced from Lamb’s work. I would also bet that the interpretation of the graph is lacking in scientific rigor, and I would guess (less certain, but still pretty likely) that the interpretations of the graph presented on that site are at odds with Lamb’s interpretations.
Any particular reason you posted only the graph rather than the entire article?
No, I’m not uncritically accepting the graph. I’m (critically) taking the position that it’s probably correct. Why?
Because – as far as I know – nobody seriously disputes that the Medieval Warm Period took place or that the Little Ice Age took place. Many warmists seem to claim that those events were limited to Europe and/or the North Atlantic region. However, Iceland is clearly located in the North Atlantic.
Not only that, but I cannot think of any reason why a creationist would be incentivitzed to exaggerate the amount of sea ice around Iceland during the Little Ice Age.
As far as “rejecting” the work of “thousands” of scientists, that’s a question for another thread.
Well there ya go.
In your view, what is the correct interpretation of the graph, and how does Tkachuck misinterpret it?
Yes, I was tired. I linked to the entire article in the GQ thread.
I’m confused then as to what the argument is here. If is agreed that the Medieval Warm Period and Little Ice Age were quite pronounced in the North Atlantic region, then wouldn’t you expect to see a plot that looks like that?
Sea ice grows and shrinks with the seasonal cycle. And, the anomaly too is expected to grow and shrink with the seasonal cycle because the more dramatic effects of the shrinking sea ice are seen in summer. There is also year-to-year variability but the general trend has been downward, with the summer 2007 minimum being easily the lowest recorded and summer 2008 being in 2nd place.
Yes I do. Lamb’s book, which can, in part, be found here, labels the graph in the article “Average number of weeks a year with drift ice at the coasts of Iceland…(After KOCH, 1945)”
Koch’s article is not online, but there are several references to it, including this fairly deep analysis (warning: PDF), which indicates that his methodology is largely unknown, and seems to mostly rely on visual records. The analysis is plainly restricted to whether sea ice east of Greenland could be seen at the coast of Iceland.
I can’t see how this is the same as “polar ice” – it’s not even part of the Greenland Ice Sheet. The labeling of the graph is inaccurate and misleading.
Sure. It seems that people are challenging the graph not because there’s anything particularly objectionable about it, but because it’s the work of an apparent creationist.
Actually, it kinda shows how silly much of the global warming debate has become.
First off, your side is the silly one. Resorting to every moonbat loony you can find instead of the vast, appropriately trained scientific community. It’s beyond pathetic.
Second, Creationists have proven by being creationists that they are willing to ignore science to promote their dogma. I don’t really have a problem marginalizing creationist scientists.
But it’s not the work of a creationist, or is KOCH, 1945, a creationist? We’ve no evidence either way.
The claim to have decent data over such a long period in such a remote part of the world is extraordinary. As Nametag points out, the providence of the numbers isn’t as clear as it might be, or as Tkachuck would have us believe.
Plus, as JShore mentions, the numbers are kinda-sorta what you’d expect, even without data to back it up.
So what we have here is small, dubious potatoes of little import. With stakes such as that, there’s little point in objecting to the author’s religious background.
I don’t think it’s extraordinary. Worthy of skepticism? Yes. But not outrageous. Especially given that it would appear to be consistent with other records.
I don’t really know, but I would imagine that there are some creationists who let their religious views foul up whatever scientific thinking they do and some creationists who do not.
If it turns out that Jim Hansen is a creationist, it would probably have little or no impact on my assessment of his work. Certainly if I were debating Jim Hansen’s claims, I would point out exactly why I think his claims are wrong. As opposed to simply saying “Well, he’s a creationist. Case closed.”