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Wednesday, December 31, 2014

Duet on Ice: More denier silliness at WUWT

Sou | 1:26 AM Go to the first of 21 comments. Add a comment

This will be short-ish - by HotWhopper standards :). It's about a duo of articles at WUWT. About ice at opposite ends of the earth - Greenland and Antarctica.

Jim Steele's Bold Greenland Prediction


Jim Steele wrote an article (without mentioning Camille Parmesan once!) predicting that Greenland will start accumulating ice next year. He pulled something out of thin (Arctic) air and wrote:
And based on historical analyses, Greenland will likely begin gaining mass in the coming years.

As Jan Kjetil Andersen said, that is a very bold prediction. And Greenland will have a lot of catching up to do:

Fig. 3.3. Monthly mass anomalies (in Gigatonnes, Gt) for the Greenland ice sheet since April 2002 estimated from GRACE measurements. The anomalies are expressed as departures from the 2002-2014 mean value for each month. For reference, orange asterisks denote June values (or May for those years when June is missing). Source: NOAA Arctic Report Card Dec 14


 Euan Mearns opts for the outdated laggy denier meme


The second article I'll comment on is about CO2 and temperature. Euan Mearns wrote a very long article (archived here) repeating the worn out, dated denier meme that CO2 lags temperature therefore climate science is a hoax. Well, not quite, but almost. Problem for Euan is that he doesn't keep up with the science. He's relying on a very highly-cited 1999 paper in Nature, by Jean-Robert Petit and colleagues, reporting analysis of the Vostok ice core. The paper showed that:
Present-day atmospheric burdens of these two important greenhouse gases seem to have been unprecedented during the past 420,000 years.

The actual "lag" had long been questioned by scientists, including the authors of the paper, who themselves wrote:
However, considering the large gas-age/iceage uncertainty (1,000 years, or even more if we consider the accumulation-rate uncertainty), we feel that it is premature to infer the sign of the phase relationship between CO2 and temperature at the start of terminations. 

This is explained more, in this realclimate.org article from 2007.
...it is very challenging to put CO2 records from ice cores on the same timescale as temperature records from those same ice cores, due to the time delay in trapping the atmosphere as the snow is compressed into ice (the ice at any time will always be older than the gas bubbles it encloses, and the age difference is inherently uncertain). 

Last year there were two papers that came out around the same time, which markedly reduced the "lag" in the Antarctic ice cores. One was by Parrenin and co, published in Science and the other by  Joel Pedro and colleagues, published in Climate of the Past. Both are discussed in an article by Edward J. Brook in Science mag. He wrote:
One reason that the answer to the above question [which came first - CO2 or temperature change] is more complicated than it may seem is a peculiarity of air preservation in ice. Over the top 50 or 100 m of an ice sheet, the snowpack (firn) gradually becomes denser before it becomes solid ice containing air bubbles. Air diffuses rapidly through the firn, and the trapped air is therefore younger than the surrounding ice. In places with little snowfall, the age difference can be several thousand years. The age difference cannot be reconstructed perfectly, leading to uncertainty in the age of the air (containing the CO2 record) relative to that of the ice (containing the climate record).
A second problem is related to the question itself. The global carbon cycle is an interlinked set of processes that both impact, and are impacted by, climate. For example, warming of the sea surface releases CO2, and that increase contributes to further warming. Ocean circulation changes driven by changes in climate affect the amount of CO2 sequestered in the deep ocean, in turn influencing surface temperature. It seems unlikely that a change in global climate would not influence CO2 concentrations and vice versa. Seeking simple cause and effect is thus difficult.
If you don't have time to read the papers themselves but want to find out more, I strongly suggest reading Edward J. Brook's article. It not only reports the findings of the papers, it discusses what is still not known plus the inherent uncertainties in analysis of ice cores.

It's just a shame that Euan Mearns doesn't read more science.



Parrenin, Frédéric, Valérie Masson-Delmotte, Peter Köhler, Dominique Raynaud, Didier Paillard, Jakob Schwander, Carlo Barbante, Amaëlle Landais, Anna Wegner, and Jean Jouzel. "Synchronous change of atmospheric CO2 and Antarctic temperature during the last deglacial warming." Science 339, no. 6123 (2013): 1060-1063. DOI: 10.1126/science.1226368 (pdf here)

Brook, Edward J. "Leads and Lags at the End of the Last Ice Age." Science 339, no. 6123 (2013): 1042-1043. DOI: 10.1126/science.1234239 (pdf here)

Pedro, Joel B., Sune Olander Rasmussen, and Tas D. van Ommen. "Tightened constraints on the time-lag between Antarctic temperature and CO 2 during the last deglaciation." Climate of the Past 8, no. 4 (2012): 1213-1221. doi:10.5194/cp-8-1213-2012

Petit, Jean-Robert, Jean Jouzel, Dominique Raynaud, Narcisse I. Barkov, J-M. Barnola, Isabelle Basile, Michael Bender et al. "Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica." Nature 399, no. 6735 (1999): 429-436. doi:10.1038/20859 (pdf here)

21 comments:

Millicent said...

Ah well, using recent WUWT logic Greenland isn't losing ice, it's degaining it.

Anonymous said...

ha!

cabc

Brandon R. Gates said...

The Euan Mearns article was a comedy of errors when it rolled off the press, and it snowballed -- literally -- as the comment thread ran downhill. Various WUWT geniuses have decided that high CO2 and CH4 concentrations contribute to cooling because Petit et al. 1999 data clearly shows that temperature downturns occur after GHG concentrations rise.

If I hadn't read it at Watts' joint, I would have had to read it twice.

A few of the rabble did recognize that it might be a good idea to at least look at some orbital parameters. Here's a sample:

------------------

don penman
December 28, 2014 at 3:38 pm

The connection between the earths tilt and glaciation is not very clear so far as I can see,there are more than four oscilation in the tilt graph over the the same time period as the last four ice ages.

https://archive.today/KMews

------------------

Well no, don, that's what we're trying to tell you: things become a lot more clear when you factor in the radiative effects of GHGs. Termination III is still kind of an oddball even then, but things make a whole lot more sense from the Eemian to the Holocene when the correlation analysis also at least includes CO2 and CH4. When you do that, it becomes quite stinking clear that GHGs reduce the rate of energy loss from the system, and nowhere is that more evident than after an insolation peak. From there it's not a stretch to see that radiative gasses accelerate and amplify warming during periods when insolation is rising.

I don't think it would be hard to convince these guys that the next time they run out of ice cubes at a party, they should put the trays into the oven instead of the freezer. Monckton would do a bang up job selling them that one.

Brandon R. Gates said...

Losing ice is so alarmist. When will we silly warmunists learn that the proper scientific term is gaining water?

Blanche said...
This comment has been removed by a blog administrator.
Blanche said...

http://nsidc.org/arcticseaicenews/

Blanche said...

What are we to make of this? Why isn't this splashed all over the media?

This week, Arctic sea ice in Canada......had more sea ice than was present in the early 1970s. Globally, the ice is spitting-distance close to the 1981-2010 average calculated by the NSIDC for this date

https://archive.today/EVmjk

[Live link replaced as per comment policy - this was actually posted at 4:41 pm before the second comment from Blanche - Sou]

Sou said...

I don't know where she got her notions of the "early 1970s" but it doesn't tally with what the science shows:

http://nsidc.org/icelights/files/2010/11/mean_anomaly_1953-2010.png

http://nsidc.org/icelights/2011/01/31/arctic-sea-ice-before-satellites/

http://www.the-cryosphere.net/6/1359/2012/tc-6-1359-2012.html

Sou said...

Brandon, I saw that Anthony Watts got very hoity toity over your "Deniofascist" in a comment when you were quoting someone who used the term "Warmunists".

https://archive.today/HyfZn#selection-8677.0-8713.38

Hmmm - showing his politics? Does that make Anthony Watts a communist sympathiser? A warmist? Or maybe he's a closet Warmunist.

:D

BBD said...

It's just more confused denier crap. They are so ignorant of the behaviour of natural systems that they see any such change (aka interannual variability) as evidence that radiative physics doesn't work. 'Clowns' doesn't even cover it.

Blanche said...

Seems to be some contradiction in early 70s ice estimates. Hmmmmmm.

Interesting stuff. Thanks for the links. One statement from your second link:

"Scientists have pieced together historical ice conditions to determine that Arctic sea ice could have been much lower in summer as recently as 5,500 years ago."



Sou said...

Yes, that is the tail end of the Holocene "climatic optimum" or "thermal maximum" or other labels. You can read about it on Wikipedia to get an idea - and in the research - such as here.

Anonymous said...

"Scientists have pieced together historical ice conditions to determine that Arctic sea ice could have been much lower in summer as recently as 5,500 years ago"

keep in mind high latitude summers had higher insolation 5,500 years ago

cabc

Anonymous said...

Sou - thanks for the links. I was wondering where the pre-satellite information came from and that second link explained it. The archived article seems to have created the bar graphs on the Environment Canada ice graph site:

http://iceweb1.cis.ec.gc.ca/IceGraph20/page1.xhtml?lang=en

I wasn't able to duplicate one of those graphs but that seems to be a problem with my tablet rather than the site. Two important points: the graphs and information (both on the Environment Canada site and in the archived article) cover only Canadian Arctic waters, and the graphs clearly indicate that the info for the 1970s is interpolated, not directly measured. (Don't deniers reject interpolated data?)

FLwolverine

Anonymous said...

I went back and looked again: the data before about 2004 is almost all interpolated. I did not explore the EC site to find out where their data comes from. Also I should have said I couldn't reproduce any of the graphs (tablet shortcomings, I think).

FLwolverine

BBD said...

(Don't deniers reject interpolated data?)

Only if it produces a warming trend.

BBD said...

Notice that contrarians will point to the reduced Arctic sea ice extent in the HCO but refuse to accept that modern warming will produce a sustained reduction in Arctic sea ice extent.

One more impossible thing before breakfast.

Brandon R. Gates said...

Sou, I thought you might have picked up on that one. I wonder if Anthony would have said anything at all if davidmhoffer hadn't chastised me for my tit-for-tat coinage. I apologized to both of them as directed, Hoffer more sincerely so because he did note that my contributions there are generally bereft of that sort of cheapshottery. SAMURAI, the bloke I was responding to was quite graceful at first, calling it "clever". He then went full on Godwin by dropping the N-word. Nary an apology asked for. I much prefer folk who don't ask for quarter when they've no intent of giving it. In short, the whole exchange could not have been more satisfying from my point of view.

Brandon R. Gates said...

PS, archived here just in case I do get the banhammer and anyone is interested in the exact context of my demise: https://archive.today/4c7NQ

Brandon R. Gates said...

Because contrarians know it's not really warming. Antarctic sea ice extent proves that NCDC has been futzing with the instrumental surface temperature record. All hail RSS TLT!!

Harry Twinotter said...

Some of the deniers with crystal balls may be hoping the Greenland ice cap does increase due to extra precipitation - it is possible. For example the increase in Antarctic sea ice extent has been a god-send for them.

But it is just a delay on the inevitable of course - extra snow may accumulate until it gets too warm in summer, then the ice cap will lose mass fast.