I’ve been involved in the AGW debate for more than a decade now and find the sneering from people who do not understand the actual issues more than a bit annoying.

My “ostrich” comment was not intended to be offensive, but I see now that it was. To everyone reading this: I apologize.

Doug’s pretense that Mann et al are credible scientists is more than a little infuriating.

The only reason I linked to a paper by Mann in the first place (way back in comment #181!) was to show how similar his chart was to the one published by Ross McKitrick, which EW1(SG) linked to (#174) to demonstrate Mann’s debunkitude (debunkment?).

(#206) Doug, are you still not realizing how many of those temperature “reconstructions” reuse the same unreproducible datasets? The idea that you would cite to any Mann papers is itself incredible given how he’s obstructed any examination of his basic data and algorithms.

Only three of the papers on that page are by the bogey-Mann. No, I would not trust such a dramatic conclusion based on research by only one person; I thought I made that clear. That’s why I linked to that page which lists many different methods used to reconstruct past temperatures.

What Mann et al have done is simply not science. It is not science to play “hide the ball” with data, methodology, statistical processes and to even continue to do that in congressional hearings.

(#202) IF ?! IF ?! The pretense of rational debate just got dropped on the ground, and a herd of wildabeast are doing the jitterbug on it.

When I said “if”, JD, I wasn’t denying the existence of these periods. I know there is some controversy surrounding them, and was trying to avoid it. The fact that I accomplished the exact opposite is an indictment of my communication skills.

I believe the general consensus is that the evidence for the LIA is strong, the evidence for the MWP, less so (which is expected since it was longer ago) and regional where it does exist.

This 2002 paper (by the thoroughly discredited Michael Mann) gives a good summary of the evidence.

Surveys of climatologists suggest substantial disagreement about humanity’s impact on the climate. In a 1997 poll, most state-government climatologists disputed the claim that ”human activities are already disrupting the global climate.” True, the environmental group Ozone Action got 2,600 scientists, including several Nobel Laureates, to sign a petition making that claim. But a counter-petition, circulated with a letter from Frederick Seitz, past president of the National Academy of Sciences, has garnered over 18,000 signatures, including many from physicists, geophysicists, climatologists, meteorologists, oceanographers, and environmental scientists. Scientific truth is not determined by majority vote, but there is clearly no ”consensus” that human-induced warming is here.

Predictions of global warming in the future are largely based on computer models that can’t even predict current temperatures accurately. And as the models improve, they consistently predict less warming. Last May, America’s most prestigious scientific journal, Science, reported that ”most [computer] modelers now agree that the climate models will not be able to link greenhouse warming unambiguously to human actions for a decade or more.” One month later, the Bulletin of the American Meteorological Society published a paper suggesting that computer models exaggerate the climate’s sensitivity to industrial emissions.

(emphasis mine)

To paraphrase a good movie: “You’re an ostrich, huh?”