2012-01-06 15:46:28Lean and Rind Estimate Man-Made and Natural Global Warming
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.137.110.252

Post on Lean and Rind 2008 - similar to Foster and Rahmstorf 2011.

Lean and Rind Estimate Man-Made and Natural Global Warming

2012-01-06 16:32:52
Tom Curtis

t.r.curtis@gmail...
112.213.145.36

It is probably worthwhile mentioning the contribution of the large 2008 La Nina to the difference between ENSO contributions between LR 2008 and FR 2011.

Other than that, I like it. 

2012-01-07 02:42:18
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Dana,

Your introducrtory sentence-paragraph is too long and too complex. Breaking it up into two or three shorter sentences will make it easier to comprehend.

Re the title, replace "Man-Made" with "Manmade".

2012-01-07 03:12:40
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Okay, changed the title (to 'Human and Natural'), tweaked the first sentence, and added a comment about the 2008 La Nina.

I also added a penultimate paragraph because I think one really interesting aspect about this analysis is that it doesn't make any assumptions about direct or indirect solar effects.  Thus the regression accounts for anything correlated with solar activity, including solar magnetic field and thus galactic cosmic rays.  So it also basically rules out the cosmic ray hypothesis, indirectly.

2012-01-07 06:52:51
KR

k-ryan@comcast...
216.185.0.2

dana1981 - Don't forget the EUV hypothesis as well, which is currently being bandied around the idiosphere - it's also temporally correlated to the TSI...

Also: Tisdale's latest on WUWT complains a lot about F&R 2011 - he doesn't seem to understand exogenous factors == independent components for regression, that the residuals would show his claimed 'step change' during ENSO transitions (it doesn't), and in fact doesn't really seem to understand multiple regression at all.But I would expect that sort of complaint in response to this post as well.

Does the blog post need something about the framework and usage of multiple regression techniques, given that it's in common to both F&R and Lean and Rind? Not everyone is familiar with linear systems analysis.

2012-01-07 07:29:39
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

KR - what's EUV?  You mean the hypothesis that UV radiation is somehow responsible for climate change?  I think the argument there is that UV tends not to correlate as well with TSI and other solar activity indicators.

It probably wouldn't hurt to have a paragraph explaining how multiple regression is done, but I'm not qualified to write one.  If anybody else feels up to the task, I'd be happy to add a co-author to the post.  Just try to keep it relatively simple.

2012-01-07 07:47:52
KR

k-ryan@comcast...
216.185.0.2

dana1981 - I meant "Extreme UV", probably being too picky.

Even if (as per http://www.skepticalscience.com/upside_down.html) UV has climate effects in inverse phase to TSI, there is still a time-correlated variation, and the TSI index should handle it. It will just be a weaker influence on temperature if the UV intensities act as a cooling factor.

If you can give me a day, I can scribble up something fairly simple on multiple regression...

2012-01-07 08:32:52
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Sounds good, thanks KR.  I'll add UV to the solar list too.

2012-01-07 10:05:55
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Dana,

The sentence immediately prceeding Table 1 now reads:

Table 1 shows the resulting contributions to the global surface temperature changes which are illustrated graphically in Figure 1 (click for a larger image).

Sugested revision:

Table 1 shows the resulting contributions to the global surface temperature changes which are illustrated graphically in Figure 1. [Note: click on Table 1 for a larger image.]

2012-01-07 10:22:36
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Roger that.

2012-01-07 11:24:59
Albatross
Julian Brimelow
stomatalaperture@gmail...
23.17.186.57

Is there any way to translate their numbers into percentages like Huber and Knutti did? Right now I'm afraid that there are a lot of numbers but not quite enough context and am afraid that the message may not come across strongly enough.

2012-01-07 12:10:02
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.137.110.252

Oh yeah, I had meant to do that.  You can do it pretty easily from Figure 1 and/or Table 1.  I'll add that in.

I was also thinking it's probably about time to do a comprehensive summary post on AGW estimates.  We've got Lean and Rind, Foster and Rahmstorf, Huber and Knutti, Meehl (2004), and our own back-of-the-envelope estimates.  All are in very close agreement about the dominant anthropogenic contribution to the recent warming.

2012-01-07 12:38:22
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.137.110.252

Table 2 added per Alby's suggestion.

2012-01-08 00:48:31
Ari Jokimäki

arijmaki@yahoo...
91.154.97.114

There are actually quite many papers doing similar analysis to Lean & Rind. Some of those can be found in this and this paperlist. As you can see from the latter list, Lean & Rind had not flown under my radar. I have actually used Lean & Rind since 2008 in various Internet discussions rather succesfully.

2012-01-08 03:45:45
Tom Curtis

t.r.curtis@gmail...
112.213.145.36

I just remembered where I have come across Lean and Rind before.  I believe I have seen it quoted by deniers as disproof that global warming leads to arctic amplification.  The idea is that the zonal mean temperatures changes shown in figure 3 disagree with the models, and show no arctic amplification for the warming signal.  Just a heads up on a possible line that may be taken by our (few remaining) resident deniers.

2012-01-08 04:03:14
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.137.110.252

When I say 'flown under our radar', I just mean SkS hasn't done a post on the paper yet.  I can delete that comment though - no biggie.

Nice list you've got there Ari.  I'll put a link to it in the comprehensive post.  I may add Stone 07 in the analysis too.

2012-01-08 17:40:21
Ari Jokimäki

arijmaki@yahoo...
91.154.97.114

I didn't mean that anything should be done to that radar comment, I was just fooling around with tongue halfway in the cheek.

2012-01-09 08:50:04Suggested MLR text
KR

k-ryan@comcast...
69.138.165.234

(add as second+ paragraphs?)

"Multiple Linear Regression analysis (MLR) (see here and here for information and examples) is a technique of analyzing the contributions of multiple independent influences upon a depecaundent variable (in this case temperatures). "Independent" means that the contributors are not correlated, that (for example) the influence of the ENSO cannot be replicated by summing up TSI and volcanic changes, as they have quite different variations over time. MLR gives an indication of the relative influence of various contributors over the temperature, and what happens to temperature when a contributor changes. Analyzing what is left over (the "residuals") after summing the various contributions shows whether the most significant contributions are being considered.

Any large trend or variation left in the regression residuals would indicate that other, uncorrelated, factors are in play - but as both Lean and Rind (2008) and Foster and Rahmstorf (2011) have shown, once TSI, volcanic influences, anthropogenic warming, and ENSO variations are accounted for, there is very little variation left.

Note that a multiple regression analysis with small residuals does not necessarily indicate causal relationships - but it does indicate that the causal factors for the temperature changes are quite well correlated with the indices used in the analysis. "

I will freely admit that I am often too wordy, but hopefully this contains some usable bits...

2012-01-09 09:58:50
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.137.110.252

Thanks KR, but what the heck is "depecaundent"?  Is that supposed to say dependent?

2012-01-09 10:46:37
KR

k-ryan@comcast...
69.138.165.234

Oh my - yes, that's supposed to be "dependent". As in the variable that is driven by the various contributors.

Obviously I did not have a spell-checker running :)

2012-01-09 10:54:41
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Dana,

You might want to use the "&" sign rather than the word "and" in the title, e.g., "Lean & Rind..." 

2012-01-10 01:38:11
KR

k-ryan@comcast...
216.185.0.2

Looks good