2011-01-31 13:33:11Most of the last 10,000 years were warmer
John Cook

john@skepticalscience...
123.211.149.21

Gareth at Hot Topic granted permission for me to use his blog post debunking Easterbrook's "most of the last 10,000 years was warmer than now". I edited his blog post, removed some of the Hot Topic centric stuff and also Gareth's potty talk which while 100% accurate is not really SkS style. Here's the rebuttal:

http://www.skepticalscience.com/10000-years-warmer.htm

Feel free to examine and post any feedback - we can continue to refine the rebuttal if there is anything that needs work.

2011-01-31 14:17:55
nealjking

nealjking@gmail...
84.151.54.211

Digestion of this article seems to require a lot of staring at and comparing graphs, entailing a lot of jumping back & forth. Is there some way of reducing this?

For instance, the article says: Look at this graph; then look at this graph; and then look at this graph. Then finally there is something pointed out. It would be easier for the reader if, when the first graph is introduced, s/he is told what it is about this graph that should be noted. Give the reader some warning of what s/he is to be looking out for, don't just hit them with the wet fish three graphs in. 

I don't have much time at the moment, or I would try to draft something. But your reader may also not have that much time at the moment s/he is looking at the article, and in that case won't get that much out of the current version. 

It is said that one picture is worth 1000 words. I don't believe this is true for graphs, unless a few key words have been said to provide proper orientation to the information thereon represented. Most graphs have a message: We should make that message explicit as early as possible, so it can be digested.

2011-01-31 15:44:59Emailed comment from Robert Way
John Cook

john@skepticalscience...
123.211.149.21

Robert emailed me about this rebuttal, questioning the final graph which gives the impression current temperatures are the warmest during the Holocene. Perhaps its better to compare GISP ice core temperatures to GISP instrumental temperatures which Robert does in this graph:

 

I'm going to ask Robert if we can continue this conversation here (and invite Gareth to come here too, to see his blog post critiqued by real skeptics).

2011-01-31 15:48:58Note also this graph from a previous SkS thread
John Cook

john@skepticalscience...
123.211.149.21

We have discussed this before. Earlier Robert's work including the 1990 temperature at GISP:


2011-01-31 15:52:36Comment
Robert Way

robert_way19@hotmail...
134.153.163.105
The previous work there shows the last marker at 1895 when it was actually 1855. My mistake.
Something to consider is that Alley's testimony before congress said that it was 1 °C warmer on the interior of Greenland during the Hypsithermal. I think this is supported by both relatively okay.

Also note that 2010 was by far the warmest year on record in Greenland.
2011-01-31 16:33:06
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.0.210

It might be worth noting toward the beginning that because Greenland is in the Arctic and icy, it tends to have larger temperature swings than the planet on average due to changing albedo.

After the first figure, you've got an open parenthesis without a closed parenthesis.

It doesn't seem necessary to show both Easterbrook's Figures 4 and 5, since they show the same thing.  In fact you could take out the first two figures without really losing anything from the rebuttal.

Otherwise it looks good.

2011-01-31 17:02:12
Andy S

skucea@telus...
66.183.184.89

The "my thanks" at the bottom should perhaps be reworded to indicate that it was Gareth who was thanking Alley. Some indication that the post has been edited is required, I think. I don't know how much licence we have to rewrite or paraphrase the original. Maybe I've been reading DeepClimate too much ;-)

The data can be found here . Alley's 2000 paper on the Younger Dryas is available here and it's probably worth adding the link since the title is given in full  in the article, even though the paper itself is not directly relevant to the particular topic since it deals with temperatures older than 10,000 BP. There is a good but brief explanation of oxygen isotope paleothermometry in that paper in section 5. 

I found another  paper on ice core paleothermometry that deals with the subject in more depth. I'll put it on my reading list.

Kooiti Masuda makes a good comment at Michael Tobis's blog here about the local/regional/global nature of ice core temperature data.  Actually, there are number of good comments there.

There's also discussion of Easterbrook's cherry picking here and a follow up post at Hot Topic here

Easterbook's failure to make retractions or admit error is similar to some of the stuff Dana has been writing recently about Lindzen. 

 

2011-01-31 20:07:16
MarkR
Mark Richardson
m.t.richardson2@gmail...
134.225.187.80

Can you determine how many years out of the last 10,000 have actually been warmer than the last decade based on this analysis? Would be interesting to give a 'quantitative' correction.

 

Also, is decadal resolution appropriate for ice cores? 

2011-01-31 22:42:14
Riccardo

riccardoreitano@tiscali...
192.84.150.209

AndyS, "it was Gareth who was thanking ". Indeed, Gareth is the author of the post :)

I read the original post at the time and I noticed the same problem highligthed by Neil and Dana, the narrative is messed up by too many useless figures.

2011-02-01 03:06:35
Rob Honeycutt

robhon@mac...
98.207.62.223

Might want to check out Miller 2010 (Temperature and precipitation history of the Arctic) on this topic as well.  Dr Alley sent me a copy of this paper specifically directing me to section 12. 

Well worth reading. 

2011-02-01 03:12:19
Rob Honeycutt

robhon@mac...
98.207.62.223
Also, in the first paragraph where you state that GISP2 is a local temperature record...  Alley 2010 has a point where they clearly state that the O18 record is one that measures the ratio where the isotopes are "precipitated out" of the atmosphere.  Not that you want to say all that but you could certainly reference Alley 2010 to back up the statement that GISP2 is a local record.
2011-02-01 03:32:01
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Rob et al.,

See my post here concerning Holocene temperatures, I think I got it right.

2011-02-01 03:34:07
Rob Honeycutt

robhon@mac...
98.207.62.223

Another thing.  There's a lecture at the AGU site from Ellen Mosley-Thompson that's well worth watching.  Somewhere around 10 mins in she talks about different lines of evidence through the holocene.  She shows clearly that the LIA and MWP were not present in the ice record of the Himalayan plateau.

This whole this is just another example of how the GISP2 record gets trotted out by the deniers.  What I've not seen is a clear multi-proxy graph of the holocene.  There's one on wikipedia but I don't find it very compelling.  

I think it's good to whack this mole every time it gets used.  Easterbrook, Carter, the lot of them. 

2011-02-01 03:43:24
Rob Honeycutt

robhon@mac...
98.207.62.223
Albatross...  I'm confident you got it right there.  I just wonder if there is a simple and compelling way to paint the picture.  You know, a way that the most brain-dead, uber denier could not reject.  The way Richard Alley describes it using his bald spot is totally on the right track.  Put together numerous holocene proxy records, combine that with a simple diagram of changes in obliquity... and voila! (maybe).
2011-02-01 04:38:38
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Thanks Rob. 

 "You know, a way that the most brain-dead, uber denier could not reject."

That is probably asking the impossible ;)  But I know what you are saying.

 "Put together numerous holocene proxy records, combine that with a simple diagram of changes in obliquity"

Good idea. What would be nice is a graph of summer insolation at say 65 N superimposed on the Holocene temperature reconstructions.  Has anyone done that or is anyone aware of such a graph.  Maybe that nifty new interactive tool that was recently featured at SkS could be used to do just that, but not sure how to get a HQ graphic from that.....if John is pushed for time (and I think he is) then he could link to the software package and people could look themselves...at least initially.

 

 

 

2011-02-01 04:47:15comment
Robert Way

robert_way19@hotmail...
142.162.14.78
You have to be very very careful with what you show when including the insolation variables as the holocene climatic optimum occurred at different times in different places as regions were still being affected by the remainder of the laurentide ice sheet. For example in Baffin Island and Labrador the hypsithermal was about 4000 years ago but in other regions it was 8000 or 7000.

Robert Way
2011-02-01 05:05:15
Rob Honeycutt

robhon@mac...
98.207.62.223

This is way outside my skill set but...  what about something similar to the carbon tracker video that shows numerous proxies and then an inset showing what the planet is doing to create what Miller 2010 calls a "neo-glaciation."

I know, that would be a huge project. 

2011-02-01 05:06:42
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Thanks Robert, this is obviously not my area of expertise.

 

2011-02-01 06:22:49
Andy S

skucea@telus...
66.183.184.89

Albatross, thanks for pointing out the Miller et al paper. I found a free copy of it here. (Otherwise it's $36 for those of us who don't have online subscription privileges.)

As Rob Honeycutt wrote, this contrarian  talking point comes up frequently and it would be great to have a once-and-for-all rebuttal, As well as Easterbrook, Carter and WUWT I have seen it raised also at JoNova's blog and I tried to rebut it myself on another discussion forum a couple of years ago. It would be great if someone like Alley could be persuaded to write such an article for the general reader.

2011-02-01 11:13:29Rebuttal
John Cook

john@skepticalscience...
123.211.149.21
Just heard back from Gareth who says he's okay with us making changes. I'm thinking we should rebuild this from scratch doing our usual 5 star peer-review system. I didn't realise this argument was so ubiquitious but now I'm seeing it everywhere. So rather than do a stealth rebuttal, just quietly add it to the list of rebuttals, I think we write a proper rebuttal and do a blog post about it. Probably as a Monckton Myth as he mentions this so often.
2011-02-01 11:50:59
Rob Honeycutt

robhon@mac...
98.207.62.223

One point I'm not sure I get about Gareth's article.  

He's comparing the modern temperature record from the GRIP site to the termination of the GISP2 data.  There is a big difference there.  But I believe the two sites are only about 12 miles from each other....   Oh, I get what he's doing.  It's just a little confusing plotting the two real temps for GRIP on the same chart where he's showing the increased modern temps of 1.4C.

I think better graphics are in order there. 

The other thing I think is interesting is, the GISP2 data shows that the last glaciation was 20C colder than the holocene.  That's a large amplification over the 8C we see in the Vostok record.

2011-02-02 12:32:01More 10,000 years cooling nonsense
Andy S

skucea@telus...
66.183.184.89

Hat-tip to Captain Pithart

 

From a post by Alaskan geologist David Lappi on Jo Nova's blog.

Added: there's some good discussion after post 130 with some good points made by Sphaerica, wondering where the red bit on the right (the temp change after the ice core top)  came from, the true origin of BP (1950) and the irregular time intervals on the horizontal scale. The graph you see was the one replaced by Nova, not Lappi's original.

Plimer, Carter, Easterbrook, Lappi; all geologists, all cluelessly parroting the same nonsense. Sometimes I'm ashamed of my profession.

More nonsense in German No translation necessary.

 

2011-02-03 05:21:54An Inconvenient Temperature Graph
John Hartz
John Hartz
john.hartz@hotmail...
98.122.68.19

"An Inconvenient Temperature Graph", posted on ScienceofDoom may contain some information. relevant to this discussion. 

http://scienceofdoom.com/2009/11/22/temperature-history/

2011-02-03 06:09:15
Rob Honeycutt

robhon@mac...
98.207.62.223

Andy...  You're right.  That little red blip at the end is totally bizarre.  It's part of the same record!  It never ceases to amaze me how underhanded these folks get!  The very same people who are claiming that the process has been corrupted keep using blatantly wrong techniques to try to make their case.

The number of times the GISP2 data has been used in this manner is nothing short of stunning.  It really would be great to tackle this issue more frequently.  Richard Alley sums it up quite succinctly saying, "GISP2 is GISP2, not the world."

I'm going to start printing T-shrts that say that. 

2011-02-03 21:13:16
MarkR
Mark Richardson
m.t.richardson2@gmail...
134.225.187.80

Badgersouth, the first graph they post is a [URL=http://www.skepticalscience.com/Common-graphical-tricks-and-the-Medieval-Warm-Period.html]common trick[/URL] used against the 'hockey league'.

1920s/30s England is not the entire Northern Hemisphere today, even though I do miss Empire...