The Wall Street Journal mentioned us editorially yesterday here . While it’s nice to be mentioned, they incorrectly say the following:
The Canadians found that the Medieval warm period had indeed occurred, suggesting that periods of warming and cooling were natural trends unrelated to the number of SUVs on the road.
Readers of this blog know that we made no such claim about the MWP. We have repeatedly made it clear that we offer no alternative reconstruction of past climate. We merely demonstrated many flaws in the data and methods of MBH and stated that MBH claims that their reconstruction demonstrated 20th century uniqueness with robustness and statistical skill were invalid – a different and more nuanced assertion than attributed to us by WSJ.
Climate Audit 
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Since the WSJ cite the 2003 paper, it’s worth quoting our conclusions from it: “Without endorsing the MBH98 methodology or choice of source data, we were able to apply the MBH98 methodology to a database with improved quality control and found that their own method, carefully applied to their own intended source data, yielded a Northern Hemisphere temperature index in which the late 20th century is unexceptional compared to the preceding centuries, displaying neither unusually high mean values nor variability. More generally, the extent of errors and defects in the MBH98 data means that the indexes computed from it are unreliable and cannot be used for comparisons between the current climate and that of past centuries, including claims like “temperatures in the latter half of the 20th century were unprecedented,” and “even the warmer intervals in the reconstruction pale in comparison with mid-to-late 20th-century temperatures” (see press release accompanying Mann et al 1999), or that the 1990s was “likely the warmest decade” and 1998 the “warmest year” of the millennium (IPCC 2001).”
I think these conclusions have stood up well.
Have you guys written a letter to the editor correcting the error?
This thread doesn’t seem to have spawned much interest. But why haven’t you done a reconstruction? It seems you have all the tools. Maybe you’ve described your reasoning elsewhere….
I have sufficient tools to do the sort of thing that the Hockey Team does. It would be possible for me to cherry pick some squiggly proxies, average them together and call it a reconstruction. With a little application, I could cherry pick series which gave a plausible RE statistic. I could even add some bells and whistles with wavelets or something like. I’m sure that I can pick series that would yield a higher MWP than modern or the reverse. But what are these things really? I’m not sure what meaning any of them have. I agree with Burger and Cubasch that it may not be possible to salvage anything from the present line of multiproxy studies.
Re #2. Good point Steve. I just sent one in.
Hi Ross, that’s great (#5). I’m sorry to hear that you and Steve M won’t generate what you consider a best reconstruction (#4). Even just going back 500 years it could perhaps be of some use. But if it’s impossible to salvage anything useful from the multi-proxies, that leaves us with a very large “What’s next?”
I think the temp rise over the same period as the CO2 rise is rather suggestive of GW.
(#6) One of my profs in grad school was part of a team that published a pretty inescapable critique of a popular technique of cost-benefit analysis. They showed that the interpretation being applied to price data implied an underlying model of consumer behaviour that we knew on other grounds was not true. But they didn’t have any alternative to suggest. I asked him, so why don’t you guys come up with a better method for CBA? His answer was: Hercules’ job was to clean out the Augean stables, not fill them back up. It was an amusing answer, though I found it a bit annoying, and I understand why people would find our unwillingness to do our own recon equally unsatisfying. But in the murkier branches of CBA one does get to the point where you ask, Is some number worse than no number? It is sometimes more truthful to simply say, there are no solid numbers and you’ll have to make a decision in the context of that much uncertainty, rather than wave your wand and pretend you have a quantitative basis. For what it’s worth, that’s my view of the situation for these millennial climate histories.
Re #5: Ross’ letter has been accepted by the WSJ and will run on Friday. I’ll update then.
Ross sent the following letter which was scheduled for publication by WSJ on yesterday. I haven’t verified the final version as printed.