Guest Post by Willis Eschenbach
I came across this beautiful example of chartsmanship today in a Chris Mooney post of raw, pure, visceral alarmism, it’s a gem. It’s from the Mother Jones website and comes with the lovely headline “Humans Have Already Set in Motion 69 Feet of Sea Level Rise”. I do love the claims that something is “set in motion”, it’s scientific cowardice to make that claim, it’s totally impossible to falsify. I could claim that Vladimir Putin has “already set in motion” the next financial meltdown … could you falsify my claim? In any case, Mooney’s post shows the terribly worrying loss of ice from Greenland, from a study by Jason Box
Figure 1. Cumulative loss of ice area in Greenland. As you can see, Greenland is toast … it’s losing well over a hundred square kilometres of ice per year, and the chart shows it heading to the cellar, looks like a total meltdown coming up.
So … what actually is happening with Greenland? To figure that out, we need another chart, the real chart—the chart of the post 2000 ice loss, and what might happen over say the next century if it continues losing over a hundred cubic kilometres of ice per year.
To do that, we have to start by finding out the area of the ice sheet that covers Greenland. As usual, there are various estimates. The Physics Hypertextbook is great for this kind of thing because it gives a variety of estimates from various authors. They range from a low end of 1.7 million square kilometres to a high of 2.2 million square km. I’ll take an average of 1.9 million square km.
So … here is the effect on the Greenland ice cap that a continued loss of -131.5 km2 per year every year until 2100 would have:
Figure 2. Effect of -131.5 km2/yr ice loss on the ≈ two million square kilometres of the Greenland ice cap.
Pretty scary, huh? By the year 2100, if it continues losing ice at the rate Jason Box claims above, -131.5 km2 per year, the total ice area of Greenland will have gone from 1.90 million square km all the way down to … well, to two decimals of accuracy, by the year 2100 the ice will be down to 1.90 million square kilometres …
Gotta love those charts … in any case, let us consider the headline, “Humans Have Already Set in Motion 69 Feet of Sea Level Rise”. I suppose it is true IF we are the cause and IF the decline continues, both of which seem doubtful. Assuming all that were true, at the current rate of -131.5 km2 of ice loss per year, Greenland will be ice-free fairly soon, in only … well … 1,900,000 km2 ice area / 131.5 km2 per year annual loss ≈ 14,500 years from now …
Rats … I guess it’s a bit early to be looking for a nice piece of land for my Greenland vineyard …
w.
[UPDATE] Well, it is inevitably true that what I think is clear actually isn’t … no surprise there. From the comments:
Kasuha says:
February 7, 2013 at 8:28 am
Um, you know… “Greenland marine-terminating glacier area changes” and “cumulative loss of ice area in Greenland” are two a bit different things. Or rather, very different things.
Maybe you should take one more look at what exactly are you doing here.
I completely agree with the conclusion that the alarmism is unsubstantiated in this case. But the way you used to get there is not valid.
I agree with you, Kasuha, that “Greenland marine-terminating glacier area changes” and “cumulative loss of ice area in Greenland” are two very different things. That’s the problem. Mooney is using a chart of the changes in the area of the discharge of the Greenland ice into the ocean as the screaming visual for a claim that we’ve set in motion a 69 foot sea level rise … and the two have absolutely nothing to do with each other.
I didn’t know how to best discuss that kind of lunacy, so I took the path of saying well, suppose Boxes’ results were correct and it actually made a difference regarding the ice area, what difference would it make? I was not attempting to model the entire ice loss of Greenland, as I’ve been through that question in some detail already …
Perhaps there are better ways to get the point across, as you point out … that’s the one I picked.
Thanks,
w.
My God! It’s even worse than I thought!
Figure 2. Classic. I read that 125,000 yrs ago the north pole warmed by as much as 8 degrees and 25% of the Greenland Ice sheet was lost over a period of 6,000 yrs (during the Eemian). That would make a nice chart too, when compared with current ice loss / time duration.
Ah, it can be disconcerting to learn we might only be, that fly, which was so casually swatted away.
She holds no favorites, nuclear annililation would only rate a footnote in Her journal, which is only nearing the half-way point.
I’m hoping there is a heaven, I’ve so much to learn.
“MarkW says:
The glacier is not 268 feet higher, the plane is 268 feet lower. As the new snow falls, it pushes down the ice that is beneath it.”
Yes and No. Just to be clear, you are correct that accumulating snow gradually compresses into ice and eventually flows downhill; but the force that compresses the snow into ice is the weight of the snow accumulating on top of it.
Glacier Girl was in relatively pristine condition under 268′ of snow. This indicates relatively little compression of the snow surrounding her. If the snow around her had compressed into solid ice, she would have been destroyed. Therefore, it’s safe to assume that at least 268′ of snow (and probably a bit more) had fallen on top of the plane since she was abandoned.
You are also correct that the plane was pushed deeper into the glacier; however it’s unlikely that it was 268’. That could only happen if the rate of compressed glacial ice flowing from beneath the plane was exactly equal to the rate of accumulation of loose snow above it.
‘ it’s totally impossible to falsify.’ and that it idea .
When it comes to PR.spin and BS has opposed science the idea that something must be true becasue it can’t be proved wrong actual works . The trouble is people think their in a argument based on scientific approach when they are simply not .
Louis Hooffstetter says:
February 7, 2013 at 2:39 pm
—
Actually, ice doesn’t compress. At 268 feet, the snow around Glacier Girl had already turned to ice.
And I stated that it was the weight of new snow that compresses old snow.
The actual stratigraphy was 24 m (79 feet) of snow above 61 m (200 feet) of ice. See the following link for details:
http://www.sensoft.ca/Resources/Case-Studies/Ice/Glacier-Girl.aspx
Anyone who saw the documentary of the 1992 recovery of the P-38 now called “Glacier Girl” knows that the plane was not at all in “pristine” condition. Photo shows the plane after the surrounding ice was melted and pumped away, leaving the plane in a “grotto” where it was dismantled and parts hoisted out the access shaft.
http://kstp.com/article/stories/s2706136.shtml
The plane landed in 1942, gear up on the surface. There are no 1942 photos of the plane but it’s in good shape, the pilot got out ok. By 1992, the plane was under 80 meters of ice. So were all the other planes. The larger B-17 was reported to be squashed beyond recovery. It seems the smaller P-38 fighter was designed to be relatively stronger compared to a bomber.
Snow would have completely engulfed the plane within months, partially supporting the structure during the accumulation. The snow piles on top and compresses over the years and the structure remains partially intact. The added weight does not push the plane into the surface, the snow accumulates on top of the plane. The amount of compression is known, glaciologists have plenty of data on how the glacial ice develops. The weight increases yearly on top of the plane. However, the stresses crushing the plane would have partially pushed around the structure, something like an arch structure.
Estimate ice at 0.9 tonnes per cubic meter, then by 1992 the weight on the plane would have been nearly 80 tonnes per square meter.
A quick description of glacial ice developement says about 40 to 50 years to reach final state.
http://www.geographypages.co.uk/glacier.htm
It seems there was little (if any) summer melting at the surface from 1942 to 1992, based on the weather shown in the documentary of the recovery. There is also clear video of people entering the access shaft. It looked to me that the “blue ice” was present within a few meters of the surface, then was uniform ice for most of the shaft down to the plane.
It takes a lot of snow to compress into 80 meters of ice within 50 years. Looking at charts, it seems the planes landed not many miles in from the SW coast. It’s not clear that the amount of precipitation at the crash site is anything unusual.
http://www.worldclimatereport.com/index.php/2007/10/16/greenland-climate-now-vs-then-part-i-temperatures/
If the depth of the southwest Greenland ice sheet increased by 1.6 meters per year from 1942 to 1992, then I’m not concerned about Greenland losing its ice sheet anytime soon. Plenty of source material for future icebergs.
MarkW says:
February 7, 2013 at 3:13 pm
Louis Hooffstetter says:
February 7, 2013 at 2:39 pm
—
Actually, ice doesn’t compress. At 268 feet, the snow around Glacier Girl had already turned to ice.
And I stated that it was the weight of new snow that compresses old snow.
====
Mark, so how little snow did fall on top of Glacier Girl?
SCheesman says:
February 7, 2013 at 4:24 pm
The actual stratigraphy was 24 m (79 feet) of snow above 61 m (200 feet) of ice. See the following link for details:
http://www.sensoft.ca/Resources/Case-Studies/Ice/Glacier-Girl.aspx
=====
Thanks SC, answered my question of Mark: at least 79 feet. Huh. And the concern is?
Louis Hooffstetter says:
February 7, 2013 at 2:39 pm
“You are also correct that the plane was pushed deeper into the glacier; however it’s unlikely that it was 268’. That could only happen if the rate of compressed glacial ice flowing from beneath the plane was exactly equal to the rate of accumulation of loose snow above it.”
================
Wow, we’ve got a battle on our hands.
My, what a collection of self-important, pompous asses there are here. I am a self-important, pompous ass and you guys make me look like an amateur.
REPLY: See the next comment, and your pomposity will have perspective – Anthony
Barking at the Moon(ey). It took me a sum total of 3 minutes to scholar.google an unimpeachable source, the IPCC 2007 AR4 second order draft http://www.meteosat.com/ipcc4/Ch04_SOD_Text_TSU_FINAL.pdf
Fancy a warmist not knowing that between lines 35 and 35 in the Richard Alley, chair, draft of the warmista bible one can find a table showing the sea level equivalent of Greenland ice is 7.3 meters (24.95 feet).
Obviously they are going to need some Antarctica melt. Last time I checked it was edging colder, so no joy there.
Fail.
Michael Buchanan Clark says:
February 7, 2013 at 5:59 pm
…..”I am a self-important, pompous ass and you guys make me look like an amateur.”
===================
Wait your turn, these things take time 🙂
Michael Buchanan Clark says: February 7, 2013 at 5:59 pm
“…. I am a self-important, pompous ass and you guys make me look like an amateur….”
Hello, Michael.
I am sure you, your ass, your inexperience, and your opinions are welcome here. As is your brevity.
However, I am having doubt regarding your wits.
Well, since I was there (at scholar.google.com) I thought I would look at a few of my last search results.
Here’s a gem:
http://www.geo.umass.edu/faculty/jbg/Pubs/Milleretal2010TempandPrecip.pdf
From the abstract:
“During the penultimate interglaciation, ~130 to ~120 ka ago, solar energy in summer in the Arctic was greater than at any time subsequently. As a consequence, Arctic summers were ~5 C warmer than at present, and almost all glaciers melted completely except for the Greenland Ice Sheet, and even it was reduced in size substantially from its present extent. With the loss of land ice, sea level was about 5 m higher than present, with the extra melt coming from both Greenland and Antarctica as well as small glaciers. The Last Glacial Maximum (LGM) peaked ~21 ka ago, when mean annual temperatures over parts of the Arctic were as much as 20 C lower than at present. Ice recession was well underway 16 ka ago, and most of the Northern Hemisphere ice sheets had melted by 6 ka ago. Solar energy reached a summer maximum (9% higher than at present) ~11 ka ago and has been decreasing since then, primarily in response to the precession of the equinoxes. The extra energy elevated early Holocene summer temperatures throughout the Arctic 1-3 C above 20th century averages, enough to completely melt many small glaciers throughout the Arctic, although the Greenland Ice Sheet was only slightly smaller than at present.”
From Mooney’s article
“The answer is staggering: 69 feet, including water from both Greenland and Antarctica”
Willis’s article and the comments have successfully knocked over some windmills – just not Mooney’s.
It appears the pomposity does not have perspective.
Lies by omission are lies nevertheless. Deliberately leaving out context is an omission. Therefore the ice loss graph is a lie.
During the Eemian, global sea level peaked at levels that were 4–7m above present. The contribution of the Greenland Ice Sheet to this peak in Eemian sea level is estimated to range between 2.2 and 4.5 m, representing a loss of 30–60% of its present-day volume.
Eemian near-surface summer temperatures were higher than today, by about 2 K in Europe and 2–4 K in the Arctic, comparable to the temperature rise in 2100 following Intergovernmental Panel on Climate Change projections for a business-as-usual scenario.
According to researchers it took temperatures equivalent to future IPCC ‘no action’ projections PLUS a massive increase in isolation: 60 W/m2, compared to the total forcing over the industrial period of 1.6 W/m2 according to best estimate of the IPCC AR4.
Significant contribution of insolation to Eemian melting of the Greenland ice sheet (2011) van de
Berg etal
http://www.staff.science.uu.nl/~broek112/home_files/MB_pubs_pdf/2011_vdBerg_NatGeo.pdf
markx says:
February 7, 2013 at 8:09 pm
Good catch! The link is broken, but placing the title in your post allowed me to find the paper with scholar.google. This is the link that worked for me:
http://www.staff.science.uu.nl/~berg0138/Download/Berg011a.pdf
More on the Glacier Girl story here, includes map of Greenland showing position of crash site, southeast coast of Greenland. http://p38assn.org/glacier-girl.htm
Without weather stations, it looks like precipitation has to be estimated from analysis of the ice thicknesses. Two papers with estimates of Greenland precipitation show the crash site is located in a high precipitation area.
http://www.igsoc.org/journal.old/37/125/igs_journal_vol37_issue125_pg140-148.pdf
http://journals.ametsoc.org/doi/full/10.1175/2008JHM1014.1
Ha ha. At least you guys have a sense of humor. However, you have absolutely no idea about my experience, if any. BTW, I have seen the Glacier Gal several times and have spoken with her crew. Beautiful story, however, it has been somewhat misrepresented here. I’ll continue to sit at your feet and learn.
William McClenney says: February 7, 2013 at 8:21 pm
” This is the link that worked for me:”
http://www.staff.science.uu.nl/~berg0138/Download/Berg011a.pdf
Thanks William.
Greenland and the ocean front homes sure seem to be looking pretty safe with a 2–4 K Arctic temperature rise PLUS an insolation increase of 60 W/m2, required to cause only 2.2 to 4,5 meters of SLR. (Eemian levels – modelled, of course)
(compared to the total forcing over the industrial period of 1.6 W/m2 ( IPCC AR4))
MarkW says:
February 7, 2013 at 8:25 am
Peter Laux says:
February 7, 2013 at 7:02 am
—
If you believe that the fact that “Glacier Girl” was found under 268 feet of ice means that the glaciers are 268 feet higher than they were 50 years ago, then you need to study up on how glaciers work. To grossly simplify it, snow falls at the top of the glacier. As more snow falls, it the weight compresses it to ice. As more snow falls, the weight forces the ice to start flowing downhill. Every bit of ice at the bottom of the glacier was, at one point in time, higher up in the glacier, some of it at the top.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Mark , I think your statement stating your explanation ” To grossly simplify” should read ” Too simply gross”.
Your assertion that I need to study how glaciers work does little to show you do.
I read a piece by Sean Pitman – “In a telephone interview, Bob Cardin (who excavated her) was asked how many layers of ice were above the recovered airplane. He responded by saying, “Oh, there were many hundreds of layers of ice above the airplane.” When told that each layer was supposed to represent one year of time, Bob said, “That is impossible! Each of those layers is a different warm spell – warm, cold, warm, cold, warm, cold.” Also, the planes did not sink in the ice over time as some have suggested. Their density was less than the ice or snow since they were not filled with the snow, but remained hollow. They were in fact buried by the annual snowfall over the course of almost 50 years.”
Note, “layers” Mark.
peter laux says:
February 8, 2013 at 3:29 am
“…..”many hundreds of layers of ice above the airplane.” …..[…..]….the planes did not sink in the ice over time as some have suggested. …… They were in fact buried by the annual snowfall over the course of almost 50 years……”
Are yo telling Greenland is getting taller? Ya might be onto something here Peter: So I went searching… it’s perhaps just a question of scale..
Greenland Ice Sheet Surface Elevation Change and Influence of Atmospheric Teleconnections in the Northern Hemisphere Chen, L Thesis 2010 http://www.nersc.no/node/8033
Note the conclusion … I worry Mr Chen may not have received his doctorate having just come out and said such a thing!
But, by the way, this 3.8 cm/year, if constant over 60 years, only accounst for 228 cm of ice/snow…
But, Forsberg reckons its not changing, at least not recently…
Elevation change measurements of the Greenland Ice Sheet
R. Forsberg etal 2000; http://www.terrapub.co.jp/journals/EPS/pdf/5211/52111049.pdf
This one is a PowerPoint, showing 5 cm/year increase since 1992 … getting closer, but still only 300 cm (3 metres) over 60 years.
http://earth.esa.int/cryosat2005/participants/14/pres_khvorostovsky.pdf
Interesting to note these were the first few I pulled up – and all are showing neutral or elevation gains….