If you've seen the latest septic drivel (the clearest example of the need for open peer review that I've seen for a while) then you may find Comment on “The phase relation between atmospheric carbon dioxide and global temperature” worth a read, as well as the rest of the blog.
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Been there, done that.
My understanding is that ice cores were used to show how increased C02 caused higher temperatures until it was discovered that higher temperatures actually preceded increased C0 by upwards of 800 years. It would not surprise if this first(?) attempt to determine a short term lag is incorrect in part or whole.
[That sounds somewhat garbled in both halves. The 800 years is not correct, stated so baldly. Do you have an example of the first bit? -W]
It's also #11 by popularity, still going strong.
PK, you could only have understood such a thing by swallowing whole the lies to be found on denialist blogs.
In fact, I faintly recall having personally set you straight on this very question two or three years back.
It's as if you really, really want to believe the lie. Imagine that.
Anyway, a little googling, e.g. at Skeptical Science, will find the truth. Of note, that there would be a lag was predicted in a paper before it was measured and long before the first lie was told about it.
If you think about it a little, you'll realize that CO2, being just a gas, necessarily will change in such a manner only if forced by something else. Now what other climate fundamentals do you have wrong?
Oh, aha, I failed to notice that JM had already linked to SS.
The paper essentially makes the same error as Murry Salby. Correlations are insensitive to the mean value of the time-series on which they are evaluated, and the long term increase in atmospheric CO2 is largely due to the mean value of DIFF12 C02, which means that the correlations tell you very little about the cause of the rise. See the SkS article (yes, another one!) on Salby's presentation
Evidence from the Pacific Warm Pool is quite convincing. In the transition from LGM to Holocene
(1) the deep ocean warmed;
(2) CO2 concentrations increased;
(3) surface ocean warmed.
There is a recnet paper laying out the full sequence of events including data from the far north and far south; it is a bit complex.
Yes, Shakun, et al, try this gliss
Yep, this is the same error made by McLean et al., and by Murry Salby, and probably by innumerable others over the years. Here's yet another example, again from SkS:
Remarkable how the "skeptics" keep making the same obvious mistake over and over and over again.
Re: my 11:24 comment. Note that in page 2 of the comment thread, Lon Hocker himself showed up to muddy the waters. Despite a lengthy back-and-forth in which the logical flaws in his argument were made painfully, abundantly clear, he never gave any sign of being able to recognize them.
Mr Hocker was very enamored of his "model" that appeared to prove that the long-term increase in CO2 was due to outgassing from the oceans. He obtained this result by detrending the CO2 data, then showing that the detrended CO2 data were (modestly) correlated with temperatures. From this he concluded that the (slight) increase in temperature following the Little Ice Age had caused the past century's increase in atmospheric CO2.
The problems with Lon's argument were many and obvious.
He really was convinced that he'd found an exciting new proof that humans were not responsible for the rise in atmospheric CO2. At one point he challenged me to produce a model similar to his own but using anthropogenic CO2 emissions as the independent variable, rather than temperature. This was the result.....
Garbled? No doubt. My intent was not to start an argument over the significance of the lag. The only example of misapprehending CO2 lag I have is An Inconvenient Truth, which is, to be fair, polemics rather than science. Don’t remember exactly where I got the 800 years. Monnin 2001 quantifies the lag as around 800 ± 600 years, Caillon 2003 at 800 ± 200 years, and Stott 2007 1000 ± 300 years. If 800 years is incorrect, it seems to be on the low side.
[I think you're wrong about AIT - if you're asserting that it mentions the lag. I don't think it does. Certainly my review didn't mention that. You're also wrong to talk about "the" lag - the actual situation is far more complex than that. http://scienceblogs.com/stoat/2007/03/12/yet-more-tco2-lags/ is good to read, if you haven't already; and maybe http://scienceblogs.com/stoat/2007/03/13/even-more-tco2-lags/ -W]
The 800 years comes from the early papers about Co2 and temperature at the end of the ice ages. Try this for some links
And here I tought you stopped blogging... guess its just the RSS
[Oh. I hope my RSS feed is OK. It works from google reader -W]