It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Saturday, September 4, 2010

The Cozycene

Rockstrom's talk emphasizes what an unusual climatological period civilization emerged within. Robert Nagle has spotted an excellent graphic, but doesn't identify a source. Google finds it in a dozen PowerPoints, (search for the title phrase in quotes) many referring to an old pet peeve of mine, "anthropomorphic climate change", which would be mostly climate change caused by Disney and Warner Brothers.

Anyway. This version lacks the misfired buzz word, and otherwise, it makes the point nicely. Note the varying time scale; the anticipated warming is very rapid indeed, and may not abate in 2100 at that.

I'd much appreciate knowing the original source of the diagram.


rustneversleeps said...

I used the trick you mentioned some time ago - - and it pointed me to, amongst others, a post @ Romm's. He got the chart from Bob Corell @ Heinz Center, but that's as far as the trail goes. In the comments, Romm indicates that he is getting in touch with Corell to understand the sources, but it's not apparent that anything came of it.

Happy hunting.

Steve Bloom said...

Is there any credible recon that shows an MWP as warm as the Holocene Optimum, or for that matter such a cold LIA? Also, lining up the HO with "Mesopotamia flourishes" is just a mistake.

rab said...

found it in a talk by Hamilton

Michael Tobis said...

There's a bunch of powerpoints like that, rab, none attributing the original drawing. (Many of them feature the word "anthropomorphic", which makes me reluctant to give them much credit.)

Michael Tobis said...

Well, the info is common knowledge, though the presentation is interesting. One would only have to redraft it if necessary.

Michael Tobis said...

The use of Gill Sans makes me suspect an Englishman; the Brits love that font. The use of Arial or something like it in some of the gloss text makes me suspect that there has been more than one hand on this.

Alexander Ac said...


I just found the Documentary "Earth 2100" posted on youtube, so maybe not all of you is aware, see here:


Paul said...

Hi Michael,

I found a very similar version (Fig 2.1), in a report about the impact of climate change on Himalayan glaciers strangely enough...

It's missing the blue band, has no horizontal arrow indicating climatic stability, no arrows pointing out the band of uncertainty, and refers to the IPCC 2001 forecast.

It also appears in a book I found in google books, Global Climate Change and Extreme Weather Events: Understanding the Contributions to Infectious Disease Emergence: Workshop Summary though I can't see any data on the figure. The axes have the same labels, and this time it's attributed to WHO et al. 2003, but there is no WHO 2003 in the references!

A very odd figure...a phantom!

Paul said...

Hi again Michael,

I found the WHO report, didn't think to follow the reference in the Himalayan report...D'oh!

Figure 1.1 Climate change and human health - risks and responses.

Michael Tobis said...

Paul, I think you are the winner.

This version has consistent fonts and design.

It's a nice document, too. Should prove useful. Thanks.

Anna Haynes said...

I'd like to see it displayed front and foremost in the Smithsonian Human Origins And Climate Change exhibit - it'd go a long way toward averting the disinforming that the rest of the exhibit appears to aim for.

But I'd like to see it redrafted so the future temp is more emphasized, ala Hayhoe, and other stuff is more de-emphasized.
(and to redo it in light of Steve Bloom's criticisms)

(I am not the redrafter, just the backseat driver; I'm not familiar with the tools so any attempt I made would end up looking like crap.)

David B. Benson said...

Aha. But what is called proto-agriculture began as early as around 14,000 ya in the Jomon culture.

And the foundation of Jericho dates from over 11,000 ya:

Hank Roberts said...

Chuckle. This looks like they used the temperature curve "cartoon" from the very first IPCC, to me -- with that big round bump for a Medieval warm period that went away thereafter.

I looked following Steve Bloom's point about mistakenly lining up the Holocene Optimum with "Mesopotamia flourishes" -- you'll laugh at the first result Google found for that:

"Aug 29, 2008 ... Things were good during the warmth of the Holocene Optimum when Mesopotamia flourished, they were good during the Medieval Warm Period ...."

Here's the search:

Hank Roberts said...

it's here too, as Fig. 1.3 p6:

The statements illustrated by that chart appear to be cited to the 1995 and 2001 IPCC reports (their fn. 9 and 10), tho' they don't attribute the chart explicitly.

byron smith said...

Another drawback is that the x-axis scale also hides the alarming slope of the 21stC rise.

Bob Webster said...

Here is a far better chart whose origin is known:

This chart is by Richard Alley of Penn State (who is no skeptic) shows Greenland temperatures during the current interglacial with each successive warm period diminishing.

Alley's graph strongly suggests that, whatever the origin of the chart that is the subject of this discussion, it is misleading in it's characterization of recent climate history. Tacking IPCC projections onto the recent history is questionable.

In short, the origin of the chart isn't nearly so important as it's authenticity.

Michael Tobis said...

It's unclear what "far better" means.

I doubt Alley drew it (while I will presume the data is Alley's) and the green superposed curve seems arbitrary, but more to the point, 1) it does not compare the recent period to the longer record and 2) it does not show global mean temperature, but merely Greenland temperature, which being local, shows larger swings than the rest of the world 3) shows a "medieval warming" at the wrong time and 4) is quite deliberately cut off just before the series gets really interesting.

The original data are here. Check out specifically what happens between 14.5 kA and 15kA; the former temperature is about -32.4 C and the latter is about -45.1, indicating a drop of 13 C in 500 years, swamping anything on d'Aleo's chart.

Finally, though, you need to decide whether to read sites that are picking data to tell a story, or sites trying to use data to find the truth. icecap is a voice of obfuscation and I recommend avoiding it.