2011-07-24 05:08:15The Last Interglacial Part Three - Melting Ice and Rising Seas
Steve Brown

brownsg@gmail...
80.177.115.133

Here's the draft of part 3 of the series on the Last interglacial: http://www.skepticalscience.com/LIG3-1207.html

jg (The Wizard of Wildomar) is working on a couple of illustrations which will be added to the post.  I'm heading off on a sailing trip for the next few days, so I'll aim to make the final edits next weekend.

2011-07-28 06:07:40
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Hi Steve,

This is to let you know I'm back and working on the illustrations. I've reworked the Eemian overview sketch, mostly to get the sea level and icesheets where they should be (please provide any corrections). I've also squeezed everything into the 570 pixel wide screen but if you think it looks squished, I can enlarge things or we can provide a larger version to link to. Let me know how you want to go on that and I'll draw what's needed. I'll will want to tweak this a little so please add any corrections or new inspirations. (This image is linked to my blog so we don't clog John's server with work's in progress.)

(Update: I revised the diagram on 7/31 California time)

Earth during the Last Interglacial Maximum

 

2011-07-29 04:55:03
Chris Colose

colose@wisc...
128.183.2.130

SteveBrown,

There is a new paper in this weeks issue of Science (that makes for good timing) that should find its way into this article:

Sr-Nd-Pb Isotope Evidence for Ice-Sheet Presence on Southern Greenland During the Last Interglacial: Elizabeth J. Colville, Anders E. Carlson, et al. Science 29 July 2011: 333 (6042), 620-623. [DOI:10.1126/science.1204673]


Anders Carlson, the second author, was my professor for both a glaciology and a paleoclimate course in the last two years, so I am biased :-)

A key point here is that Greenland contributed a lot to the sea level rise during the last interglacial, but at the lower end of previous estimates (maybe half or a bit less), since no areas at the southern end were completely deglaciated.  The worrysome thing though is that this means Antarctica must have responded signficantly to the radiative forcing, since it is the only source that could have contributed to the rest of the sea level rise.

University of Wisconsin also has a news release on it: http://www.news.wisc.edu/19604

2011-07-31 19:02:55
Steve Brown

brownsg@gmail...
80.177.115.133

Hi jg,

The graphic looks good.  Can you please add a couple more labels and tweak an existing one:

"Reduced Greenland Ice Sheet area and volume"

"Increased absorption of solar energy due to Arctic sea-ice minimum"

"Increased absorption of solar energy through vegetation changes and reduced snow cover"

Will you still be updating the Eemian sea-level comparison with the sea-level height probabilities from Otto-Bliesner et al?  Thanks!

 

@Chris - Thanks for the tip-off on that paper.  I've downloaded a copy and will definitely give it a mention.  It will be a very significant and worrying finding if confirmed. 

2011-07-31 19:38:27
Rob Painting
Rob
paintingskeri@vodafone.co...
118.92.78.28

Steve, worrying alright, have you seen this paper?: The role of ocean thermal expansion in Last Interglacial sea level rise - McKay (2011) . It was the subject of this post: Rising Oceans - Too Late to Turn the Tide?  

I dare say we are currently observing this phenomenon today. The steric component of SLR during the 'noughties' seems to have declined, but SLR keeps on rising - as witnessed by the accelerated ice melt and SLR data.

I would suggest that the paper deserves a mention too.

2011-08-01 04:10:37
jg
John Garrett
garrjohn@gmail...
96.229.221.76

Hi Steve,

I just posted (above) an update to the diagram. I believe I inserted your latest comments from July 31 7:02 pm. I added an illustration credit that should retain the reference to your article should the illustration travel on it's own.

I'm now working on the smaller sea-level profile diagram and will implement the changes you've suggested.

(I'm sure enjoying this contribution, and I hope other authors will tap me for similar illustrations)

jg

2011-08-02 06:04:38
Steve Brown

brownsg@gmail...
80.177.115.133

Rob - I hadn't seen it as I'm still catching up after having been in the middle of the English Channel for the past week.  It's a fantastic reference, which I'll definitely mention as it backs up the Colville et al paper that Chris pointed to.  Your link to the paper was broken but I've managed to download the original from GRL.  It's stuff like this that really hits home how vital palaeoclimate research is.

 

jg - don't worry, I've got plenty of work for you in part 4 ;-)

2011-08-02 14:44:58
Andy S

skucea@telus...
66.183.179.249
Steve, jg's inset map of Europe shows the Black Sea, which, I thought, was a freshwater lake during the last glacial maximum and only became connected to the Mediterranean in the Holocene. If Eemian sea levels were 5 m higher than now, then I wonder why the Black Sea remained cut off from the ocean (if it was cut off) during the LIG This is off-topic but I was wondering if you had a quick comment on that.
2011-08-03 01:18:44
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Andy, I think your question is relevent. I welcome any advice on how to change the illustration.  I refered to the Wikipedia topic on the Black Sea which mentioned the isolated state during the last glacial but had nothing on what it was like before. So I assumed the Black Sea would be connected with a 5 m + higher sea level. The easy solution is to crop the image and hide the controversial area (I tried that but thought it cowardly).

jg

2011-08-03 03:21:20Nice work, jg
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

I always like to point out that at no point during the last 800,000 years have CO2 concentration levels exceeded 298.7

(drives home some of the issues we have yet before us while the climate reorganizes towards some as-yet-unrealized new equilibria with temps [once those stabilize....long after I'm gone])

CO2

2011-08-03 05:50:50
Steve Brown

brownsg@gmail...
80.177.115.133

Andy - I can't give you a definite answer on the geography of the Black Sea, but a consideration may be that the region has long been subject to tectonic uplift, while Northern Europe was isostatically depressed from the previous glaciation.

jg - unless anyone comes up with a definitive answer to the riddle of the Black Sea, I'd leave it alone.  I'll make sure that the graphic is labelled clearly as an "artists impression" and not to be submitted to congressional hearings etc!

2011-08-03 06:40:08
Andy S

skucea@telus...
66.183.179.249

Thanks Steve, 

I did some digging of my own and found this paper which provides evidence for sea levels 6-8 metres higher than today in the Black Sea during the LIG, with a presumed connection to the Mediterranean.

Perhaps during the last glacial maximum, the global sea level dropped sufficiently to cut the Black Sea off again from the oceans and the surface layer in the sea became fresh, even though the Black Sea level dropped by ~100 metres, according to this paper.

So, jg's figure is probably fine as it is. Sorry for the diversion.

2011-08-03 07:34:49
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Andy: The diversion is a reflection of our concern for quality. I'll look at the paper for any useful tidbits. Since I have a complete globe of the Eemian, I might as well be thorough.

Steve: I was more worried about misleading any would-be investors in Crimean shore-front property, but if you can keep me out of the congressional spotlight, that will be fine. :)

2011-08-03 08:00:05Couldn't resist
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Enquiring minds want to know:  Is misleading would-be investors in "Crimean" shore-front property a crime...?

2011-08-03 09:11:53
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Good question. Let's see...misleading investors may not be a crime, but depending on the investors, it may be punishable. Misrepresenting information to congress, hmm... this is a crime, but depending on those involved, it may not be punishable.

2011-08-04 05:57:48
Steve Brown

brownsg@gmail...
80.177.115.133

I wouldn't be surprised if the Black Sea had been cut-off, joined to the Med and cut-off again during the LIG.  Remember that the LIG lasted 1000's of years and the period had sea-levels much lower than today (termination) as well as several metres higher (optimum).  This series is really looking at a short snapshot of an Interglacial that itself is just a blip in geological history.

Anyways, I've pretty much finished the post.  I've added a paragraph discussing the 2 recent papers that Chris and Rob highlighted.  Appreciate any final comments/suggestions:  http://www.skepticalscience.com/LIG3-1207.html

2011-08-04 06:22:53
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Steve,

Are you planning to include the sea-level sketch? I can work on it this evening and most likely have something finished by tomorrow. 

jg

2011-08-04 16:20:48
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.209.178

Looks good to me Steve.

2011-08-05 06:06:20
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Steve,

"commonsense" in the second paragraph of your article should be two words.

I put together this illustration that can provide a table of comparison of the various estimates of sea levels. The top row are the major sources with area shown to imply their relative contribution (mountain glaciers and thermo expansion are a bit oversized?).

The middle shows how estimates of relative contributions from various studies differ. This can be expanded to include more estimates. I put in Kopp and what I know of Otto-Bleisner. If you want this in the picture, let me know which papers you'd like represented here.

And lower shows the water level with room for your favorite estimates off to the left. Right now I only have the Kopp probabilities, but others could be added.

IEemian sea level

2011-08-05 14:00:58
jg
John Garrett
garrjohn@gmail...
96.229.221.76

I created a rotating 3d globe of the Eemian. It's in Flash (not for iPhones and such). You can view it at this location:

http://www.brightstarstemeculavalley.org/science/Eemian.html

jg

2011-08-08 00:53:17
Steve Brown

brownsg@gmail...
80.177.115.133

I'm just waiting on jg to make a minor amendment of the above graphic, which will be added to the post.  Should be OK to publish by mid-week.

2011-08-08 13:47:21
jg
John Garrett
garrjohn@gmail...
96.229.221.76

Steve, here's the revised illustration. Since you got me re-reading that issue, I added Kopp et al's high estimate too.

Any changes? Should I move the source credits to not conflict with any caption you had planned?

jg

 

Eemian sea level estimates from Kopp et al 2009

2011-08-08 23:30:25
Rob Painting
Rob
paintingskeri@vodafone.co...
203.173.240.243

Hey JG, can I hit you up for a couple of graphics on the carbon cycle? Most are too cluttered for a layperson to follow.

What I had in mind was two graphs, the first is the natural short term carbon cycle. Simple graphic of trees, soil, oceans with large green arrows of the same size showing the CO2 flux in and out of each balancing out.

Second is the human disruption of the short-term carbon cycle. Add picture of oil boom and side view of oil deposit being extracted. Behind is factory and smoking chimney. Same big arrows as before, but this time a small (black arrow?) leaving smokesatck with plus sign signifying more CO2, plus two smaller black arrows (with plus signs) going into oceans and forests.

Appreciate it if you could help out, my own attempts thus far look absolute shite!

2011-08-09 00:37:21
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Hi Rob. I'm honored. I'll sketch something and let you know here.

jg

2011-08-09 05:10:13
Steve Brown

brownsg@gmail...
80.177.115.133

jg - I'm more than happy with the graphic as it is.  Many Thanks!

Part 3 is good to go.  A draft of part 4 is in progress.

2011-08-09 06:25:36
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.252.164

JG - thanks mate. Much appreciated.

2011-08-09 14:12:14Carbon cycle graphics for Rob
jg
John Garrett
garrjohn@gmail...
96.229.221.76

Rob, I probably should put these somewhere else, but for now, what do you think? Too much detail? It's easy to cut back.

jg

UPDATE: I removed the Carbon Cycle illustrations to keep this on topic. See General Chat, Drawing Board: Carbon Cycle

 

 

2011-08-09 19:16:11
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.228.133

Cheers JG,

What if:

- the bottom part of the pic was 2 dimensional with a black line down to a black blob representing the oil deposit, or appears, at least, like a cut away.

- simplify and shrink the forest, factory and oil boom, so that they are are more silhouette-like, but still recognisable. That way the arrows representing the CO2 fluxes become the dominant visual feature.

- change the arrows so that appear like a conveyor belt - that way it is strongly suggestive of a cycle.

- keep the flux arrows the same colour (green aka good), but the human fossil fuel one a dirty grey, or such like to suggest bad, bad, bad.

- Have a dirty grey human CO2 arrow point into ocean with plus sign. Same with forest.

- put the CO2 label inside the arrow.

- a couple of wispy sort of clouds could represent the atmosphere, and label "atmosphere".

- Change title of first graphic to: Fast Carbon Cycle

- Change title of 2nd graphic to: Fossil fuel added to Fast Carbon Cycle (can't think of a better title at the moment, any suggestions?)

Ta muchly.

2011-08-10 00:55:29
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Rob. I'm on it. I'll post revisions when done, and put them in a carbon cycle topic under General Chat. When do you need this?

jg

2011-08-10 07:48:27
Rob Painting
Rob
paintingskeri@vodafone.co...
118.92.72.61

At your nearest covenience will be fine JG.

2011-08-10 14:39:00
jg
John Garrett
garrjohn@gmail...
96.229.221.76

Hi Rob. I created a topic called Drawing Board: Carbon Cycle under General Chat. I posted revisions that think follow your suggestions. I think the revised drawings are must better.