2011-02-25 01:26:20Suggestion for support
Robert Way

robert_way19@hotmail...
142.162.23.66
Hey all,
Over at Curry's blog the following post http://judithcurry.com/2011/02/22/hiding-the-decline/
incited quite a reaction across the blogosphere. In particular from the skeptics and those at WUWT who bombarded Gavin for speaking out against the post. It got me thinking that in situations such as this, it would be nice to be able to provide support to people like Gavin by have some of us go over there (preferably a larger group) and engage directly with the skeptics.

Furthermore I was thinking that on really aggregarious posts perhaps we should always send over a team of authors.

Any thoughts?
2011-02-25 04:20:24blog response team
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

We've discussed something like this in General Chat - some sort of blog comment response team sort of thing.  Rob and I attempted it at the NoTricksZone blog, and I got banned for my troubles :-)

It's good to see Gavin telling it like it is.  Curry is just so damn annoying, commenting on issues she's utterly ignorant about, and basically just echoing the standard "skeptic" line every time.  It might be worthwhile for some of us to comment and support Gavin.

2011-02-25 04:49:54
nealjking

nealjking@gmail...
91.33.108.242

I waded through some of that. What a load of cr*p!

Still, in that mire, amongst all the gratuitous allegations of bad faith, and willful misreadings, there is an issue that I've never studied hard enough to settle. Perhaps someone can answer it quickly here:

Given that there is a clear divergence between the tree-ring proxies and the thermometer measurements after a certain date, which we do not appear to understand, what degree of trust can we apply to tree-ring data at earlier dates?

Maybe the best approach would be to drop out tree-rings entirely? Wouldn't that side-step the entire issue?

I am unfamiliar with the general practice of dealing with proxies, so pardon my naivité.

2011-02-25 05:12:22response
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

Neal, I covered that briefly in my comment on Curry's blog.  Also note that some studies have dropped tree ring data entirely - like Ljungqvist!

I'm thinking this may warrant a blog post and rebuttal.  We've probably got a relevant rebuttal that we could use.  So many blog post ideas, so little time...

If others would back me up in the comments (see link above), I'd appreciate the support.

2011-02-25 07:39:10Hide the decline post
John Cook

john@skepticalscience...
121.223.91.161
Im working on a hide the decline post. Because of the renewed attention on the decline, Michael Mann had a look at my decline rebuttal and told me it could be "more solid". So with the master's red ink over my work, I'm going back and having another look at it. I'm also hoping to coordinate this with a Crock video although Peter is so busy, poor guy, that may be optimistic.
2011-02-25 08:52:41tree rings
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

Does your post specifically talk about tree ring data?  I was thinking about going into Cook et al. (2004).  Great graph in there (Figure 6) showing that only northern tree rings diverge, and only after about 1960.  I was also going to specifically refute Curry's claims by quoting from the TAR and AR4.

But I don't want to step on your toes if you're already working on it.  Though I would kind of like to add Curry to my list :-)

2011-02-25 09:05:07Comment
Robert Way

robert_way19@hotmail...
134.153.163.105
I responded also regarding the cooling comment and one of the ad hom's against SKS. Apparently every single page on SKS misrepresents the *real science*

Ljungqvist uses tree rings by the way. In fact nearly 1/3 of his data is from tree rings. Moburg uses tree rings the best as he doesn't use them for low frequency signals. Mann 2008 also has a no-tree rings reconstruction. Ice core data such as thompsons is good in that regard.
2011-02-25 09:32:56Ljungqvist
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252
Ljungqvist uses tree rings?  Dang, I should have read his paper more closely.  I read somewhere - from the Idsos I think - that he didn't use tree rings.  Should have known better than to trust that source.
2011-02-25 09:48:56FYI
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

Just posted a rundown of a lakebed sediment core study:

 

Drought variability in the Pacific Northwest from a 6,000-yr lake sediment record
Nelson & Abbott 2011
doi: 10.1073/pnas.1009194108

http://www.pnas.org/content/early/2011/02/16/1009194108

 

One of the key takeaways: the Castor Lake core matched the Palmer Index reconstructed with tree-ring data and expanded on it by 4,500 years, suggesting that lake beds are better records of long-term climate change.

 

Other sediment studies may prove useful in place of tree ring data.  Just a thought.

2011-02-25 10:04:55Interesting
Robert Way

robert_way19@hotmail...
134.153.163.105
Hey Dana,

his data source is right here:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ljungqvist2010/ljungqvist2010.txt

Note: 11 of 30 of his proxies use trees rings

Nice point on the Lake cores. Lake Varves are also very good and pollen records are effective too but low resolution.
My favorite study, and one that I think you'd all be interested in reading is Anderson et al. 2008

http://www.geofaculty.org:16080/figures/Rood_Climate_Change_AOSS480_Documents/Anderson_Little_Ice_Age_GRL_2008.pdf

It uses ice caps which are the most sensitive form of glaciers to climate. Very interesting stuff and from a very interesting region. Also provides evidence of a dynamic (volcanic) origin to the LIA in the region.
2011-02-25 10:53:02hmmm...
nealjking

nealjking@gmail...
91.33.108.242

"The divergence problem only exists for high latitude tree rings, and only over the past few decades. The data matches well with other proxies in mid and southern latitudes, and in northern latitudes until about 1960."

Dana, in all fairness, this doesn't settle the question: If we don't know WHY the divergence problem exists, how can we be sure that it doesn't occur in some times for which we don't have other measurements? In other words, if we don't know under which circumstances this proxy will fail to be a good proxy, how can we know when we should rely on it?

From my perspective, this is a valid question; not like the nonsensical non-issue of "'hiding the decline". Is there a clear-cut explanation, or is it safer to focus on proxy studies that omit tree-rings?

Obviously, I'm not claiming that this is an argument that GW is not happening, blah blah blah. I'm focusing on the very specific question, Can we justify using these tree-rings as temperature proxies for all times prior to 1960 - and on what basis?

2011-02-25 11:06:16
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

I think I got the Ljungqvist claim from the NIPCC actually.  Anyway, you're right of course Robert, I went back and looked at the paper - very explicit about the use of tree ring data.

neal - this is why these reconstructions use so many different types of proxies.  Mann '08 did reconstructions with and without tree rings, and it didn't make a big difference in his results.  Tree rings are consistent with other proxies until about 1960.

2011-02-25 11:39:03
nealjking

nealjking@gmail...
91.33.108.242

Then I think it's important that we NOT spend any effort defending the continued use of tree-ring proxies: It weakens the argument as a whole. We need to learn to pick our battles.

As I see it, this is the case we can defend:

- "The issue about "hiding the decline" is just playing with words: The scientists weren't trying to trick anyone, they state clearly what they are doing in the article itself."

- "The reason they did this was that they had reasonable correlations with other proxies until the 1960s, and they hate to waste data; however, since there is legitimate concern about the reliability of these proxies, let's restrict further discussion to reconstructions that don't rely on tree rings."

As far as I can tell, that ends the beating: They don't have anything else to argue about. The remaining reconstructions still show exceptional warming over the last 1000 years, and nobody doubts that we've been having warming over the last 50 years or so.

These bloody tree rings are like a finger bitten by a cobra: Slice it off, or die.

 

 

2011-02-25 19:04:00
James Wight

jameswight@southernphone.com...
112.213.166.156

“Michael Mann had a look at my decline rebuttal and told me it could be "more solid". So with the master's red ink over my work, I'm going back and having another look at it.”

Whoops, you shouldn’t have said that, John. Now if someone hacks into the SkS forum, they’ll know we’re all corrupt stooges and our “master” is Michael Mann.

*sarcasm alert*

2011-02-27 05:31:59
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.102

Related to this: I've posted a comment on the Technical Stuff section on adding Instant Messaging capabilities to SkS in order to aid a rapid response to fighting the nonsense going on at other websites like Curry's or Motl's.

http://www.skepticalscience.com/thread.php?t=1017&r=0