Global Warming Alarmism Debate - page 2

We continue the debate from page one. Darrel Henschell continued the debate in this posting from the Fayetteville Freethinker forum. My reply follows.

Hogeye Bill on 5/25/2011:

Darrel replied to my rebuttal of 5/18/2011. On my first point, "that CO2 in the atmosphere has soaked up just about all the heat it can," Darrel agrees, saying, "The notion that CO2 sensitivity drops off rapidly is not controversial and has been known for well over a century." We agree, so no more need be said about this point. (Darrel, however, went on a well-poisoning spree here, which he admits is fallacious and I'll ignore.)

Darrel and I agree with the IPCC that a doubling of CO2 by itself (before feedback) would cause about 1.1 degrees C warming. We disagree about feedback. He accepts the IPCC estimate that feedback would triple (or more) this amount. Joanne Nova, Hermann Harde ("How much CO2 really contributes to global warming? Spectroscopic studies and modelling of the influence of H2O, CO2 and CH4 on our climate"), and I think that the actual feedback is much less. The utter failure of the IPCC models based on the "big feedback" assumption supports this. Harde's feedback estimate is about one seventh the IPCC's estimate. Bottom line: On the feedback question, we have dueling studies but a clear failure of big feedback IPCC models to predict.

Darrel mentions the "hot spot" and links to a paper by Roy Spencer which he claims is "completely debunked." But that paper has to do with corrections in weather balloon data, not the hot spot. You have to watch closely - they're notorious for poisoning the well and misleading "takes" on scientific papers. To my knowledge, the slight tropospheric temperature increase using the new "corrected" data still does not agree with IPCC model predictions for the tropics.

Nova: "There goes almost all of the warming. The models exaggerate by a factor of six. The 3.3°C scare is really only about half a degree of extra warmth."

Darrel: "Here Hogeye contradicts himself by quoting person who plainly admits the IPCC claims "3.3°C" of warming."

I don't understand where he sees a contradiction. Nova and I say that IPCC's claim of a 3.3 C increase (if CO2 doubled) is wrong, overestimating by a factor of six or more.

Which brings us to my third point - that the IPCC models failed to predict the flattened trend since 1998. Darrel asks, "Could Hogeye please point a "flattened trend" in the last sixty years. Yes I can - easily, since he provided the graph.

Note that the trend of observed temperature from 1998 on is less than the IPCC model and almost flat. Here's another graph showing the same thing:

Note that the slope of the IPCC projected trend is larger than the 10 year trend. And the 15 year trend. And even the 30 year trend. Wow!

(Here Darrel descends to ad hom again. In his opinion, scientists who agree with him are wise, educated, and paid with pristine government money, while those who disagree are stupid, incompetent, and paid with dirty old private money. Confirmation bias gone wild! He then links to a video of Patrick Michaels saying that global warming didn't stop in 1998. Darrel misinterprets him as saying that mentioning the year 1998 or trends starting then are verboten.)

Darrel wants you to ignore the 13 year trend since 1998, and the fact that none of the IPCC models predicted it. He tries red herrings (it's too short to be counted as "climate") - true but not relevant, and certainly not a good reason to ignore the evidence.

Both charts above contradict Darrel's statement that since 1998 there were "hotter temperatures perfectly inline with scientific predictions." In both, the HadCRUT3 and GISTEMP temperatures for the last few years were significantly below the IPCC "ensemble." Both show that the IPCC prediction has a larger slope than either measure of actual temperature. The temperatures were within the 95% confidence interval, but that's not saying much given the huge margin of error.