Earlier I posted a request that others here give their own assessment of the ten propositions Monckton listed as held by those who believe in AGW. A couple of skeptics posted their views and that was helpful. The only response from a warmer was not helpful because he only attacked Monckton for his wording and did not express his own opinion about the propositions. There is still more to learn from examining these propositions.

I would like to give my own assessment and ask some questions as my opinions are still forming. I especially hope to get some insight from the warmers who post on this site.

Propositions:
1. The debate is over and all credible climate scientists are agreed.
Monckton calls this proposition “False.” The fact this proposition is used by climate scientists to persuade others says more about the low web of climate science than anything else. Whether the proposition is true or false has no intellectual power. It is persuasive only to the muddle-headed and easily-led. This is a non-issue.

2. The temperature has risen above millennial variability and is exceptional.
Monckton says this is “Very unlikely.” From the evidence I have seen, including the debate on the Hockey Stick, I agree with Monckton.

3. The changes in solar irradiance are an insignificant forcing mechanism.
Monckton calls this “False.” According to one study, changes in solar irradiance were not significant but I would judge this as “Unlikely.” Even if this were found to be true, other studies have indicated UV rays and cosmic rays from the sun may play a very large role in climate change.

4. The last century’s increases in temperature are correctly measured.
Monckton calls this “Unlikely.” He is mainly referring to the Urban Heat Island effect. Some weather stations had parking lots built next to them and this would obviously skew the records. I assess this proposition as “False.” While it seems clear that temperatures have risen somewhat, a rise of half the currently assumed amount would change the debate dramatically. It seems to me the temperature record should come with error bars.

5. The greenhouse-gas increase is the main forcing agent of temperature.
Monckton says “Not proven.” The IPCC asserts that CO2 and methane are the primary culprits of the recent rise in temperature. This is the key point of the debate. At my current level of knowledge, I say “Not proven.” However, I am open to being persuaded. I have never had the opportunity to read a journal article that tests this hypothesis in a rigorous way and concludes in the affirmative. The AGW crowd all seem to assume it is true, but I have never seen it demonstrated. Other forcings that have to be considered, solar (Veizer), UV and cosmic rays (Svensmark), changes in ocean temperature (Giese) and volcanic activity, make it a daunting if not impossible task. I have no faith in computer modeling. The fact predictions from computer models have recently become “evidence” is further proof of the low ebb in climate science. Also, the ice core data seems to indicate the temperature warms prior to a rise in CO2. Can anyone point to an AGW explanation for why temperature seemed to rise prior to CO2 rising long ago? More importantly, can anyone point me to the most persuasive evidence available that GHG are mainly responsible for the recent rise in temps?

6. Temperature will rise far enough to do more harm than good.
Monckton says “Very unlikely.” In my opinion, if #5 is true, this may very well be true.

7. Continuing greenhouse-gas emissions will be very harmful to life.
Again, if #5 is true, this could be true.

8. Proposed carbon-emission limits would make a definite difference.
Monckton declares this “Very unlikely.” My gut feeling is that Monckton is correct. However, have any studies been done to actually look at this question? Please let me know.

9. The environmental benefits of remediation will be cost-effective.
Monckton says “Very unlikely.” This appears to be a question for Ross McKitrick.

10. Taking precautions, just in case, would be the responsible course.
Monckton says “False.” Again, the question goes back to #5 and #8. If #5 and #8 are true, then this is could well be true.

Look very closely and you will see that temperature has always moved ahead of CO2 – that is CO2 has lagged the temperature changes or responded to it, not the other way around.

I think it also shows there is nothing unique about a measely 0.6C temperature increase in the last 100 years. 7 ice ages in the last 750,000 years might indicate to a rational person that the earth’s climate can vary a lot in short time frames.

http://upload.wikimedia.org/wikipedia/en/e/ec/Co2-temperature-plot.png

Lee,
Since the topic is the recent change in temperature, I believe most people will understand the ellipsis:

“That greenhouse-gas increase is the main forcing agent (responsible for the recent change) of temperature.”

If you read Monckton’s discussion, he asks the question: “What role has the Sun played in recent warming?” This is the issue at hand. So again, I think most observers will agree with Monckton that this proposition is held to be true by warmers.

Yo repeate the overgeneralizatin that Monckton engaged in.

A statement that most of that warming over the last century is due to CO2 and not due to solar variation, is NOT a statement that CO2 is the only temperature forcing, or that solar is an insignificant temperature forcing.

Monckton (as he seems wont to do) overgeneralizes his statements to the point of being incorrect, often conflating two clearly different statments.

You claim Monckton has phrased his list to develop a “straw man.” However, most of his propositions seem to be very near the claims in the secondary literature, like wikipedia. I’ve organized my response to your comments under the Monckton statements of the AGW position.

1. “That the debate is over and all credible climate scientists are agreed.”
You ask “Which debate?” Rather than appear tendentious, I will not comment here.

2. “That temperature has risen above millennial variability and is exceptional.”
You say you posted evidence that 20th century temperatures were exceptional but you did not name the post with the evidence. As I glanced through, all I saw was criticisms of Monckton. What evidence? Will you provide a link?

3. “That changes in solar irradiance are an insignificant forcing mechanism.”
Your opinion seems to be at odds with the AGW folks I have spoken with. They tell me Milankovitch cycles have absolutely nothing to do with the present warming since these cycles take far too long to be responsible for the “rapid” rise in temperatures. Perhaps Monckton should have used “small” or “minor” rather than “insignificant.”

4. “That the last century’s increases in temperature are correctly measured.”
Oddly, it is possible both you and Monckton are correct. In other words, it is possible temperatures have risen (as you claim) and yet the data is still not correct (as Monckton claims). The debate certainly changes if the rise in temperature was somehow demonstrated to be half what is currently assumed.

5. “That greenhouse-gas increase is the main forcing agent of temperature.”
According to SPM: “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.” Most observers will think Monckton is right that this proposition is commonly held among AGW adherents.

6. “That temperature will rise far enough to do more harm than good.”
Lee, surely this statement cannot be considered a straw man. The hardline warmers are predicting dire, even catastrophic, conditions: animals becoming extinct — more disease — extreme weather events and on and on.

7. “That continuing greenhouse-gas emissions will be very harmful to life.”
Lee, again, you cannot say this proposition is a straw man. The hardline warmers say our only choices are mitigation or adaptation. http://en.wikipedia.org/wiki/Effects_of_global_warming

8. “That proposed carbon-emission limits would make a definite difference.”
Yes, this is policy. But the scientific question lingers: If governments successfully ended all emission of CO2, would it make a difference? Some scientists are unconvinced.

9. “That the environmental benefits of remediation will be cost-effective.”
Yes, this is policy. But if emission limits will not make any difference, then the question is easily answered.

10. “That taking precautions, just in case, would be the responsible course.”
Yes, this is policy. But it is not accurate to say this is a straw man argument.

And the additional quantitative and qualitative observations, as pointed out in several places in y answer, support our entering millennially unique temperature regimes.

In order to claim “millenially unique” you still need a) accurate current data and b) accurate past data. No matter how much hand-waving you do, b is certainly an unknown and a is a matter of debate. You’ve pointed out in several places the same nonsense you’ve always attempted to point out, which does not make it any more true. You seem to be under the false impression that quantity of posts/papers supporting your position makes them somehow true. A false premise is a false premise regardless of how many times you’ve made it.

Mark

MarkT – I stand by my statements. Essentially all credible climate scientists

There ya go with the ad-hom again. Those that disagree are otherwise not credible I guess.

You can stand by your statements all day but that doesn’t make them any more valid.

Mark

“Humans” is NOT equal to “Life.” People are claiming substantial possible harm to human economies, and to particular groups of humans, and to particular species and ecosystems. This is NOT equivalent to harm to “life.” I’ve noticed that Monckton tends to be precise in his choice of language – the choice of “life” here was false and tendentious. “Life” has survived several mass extinction events in the geological history of the planet – this doesn’t mean we’d like to have been there.

The implication of the ‘inaccurate measurement’ statement, in the context of his claim that these statements are central to the debate, is that potential inaccuracies in quantitative temps over this century mean that don’t know whether this warming is unique or problematic. The fact is, the general outline of this century’s temperatures (at least) is accurate – it warmed, then it cooled part way back for a while, then it started getting a lot warmer again. And the additional quantitative and qualitative observations, as pointed out in several places in y answer, support our entering millennially unique temperature regimes.