Guest Post by Willis Eschenbach
This topic is a particular peeve of mine, so I hope I will be forgiven if I wax wroth.
There is a most marvelous piece of technology called the GRACE satellites, which stands for the Gravity Recovery and Climate Experiment. It is composed of two satellites flying in formation. Measuring the distance between the two satellites to the nearest micron (a hundredth of the width of a hair) allows us to calculate the weight of things on the earth very accurately.
One of the things that the GRACE satellites have allowed us to calculate is the ice loss from the Greenland Ice Cap. There is a new article about the Greenland results called Weighing Greenland.
Figure 1. The two GRACE satellites flying in tandem, and constantly measuring the distance between them.
So, what’s not to like about the article?
Well, the article opens by saying:
Scott Luthcke weighs Greenland — every 10 days. And the island has been losing weight, an average of 183 gigatons (or 200 cubic kilometers) — in ice — annually during the past six years. That’s one third the volume of water in Lake Erie every year. Greenland’s shrinking ice sheet offers some of the most powerful evidence of global warming.
Now, that sounds pretty scary, it’s losing a third of the volume of Lake Erie every year. Can’t have that.
But what does that volume, a third of Lake Erie, really mean? We could also say that it’s 80 million Olympic swimming pools, or 400 times the volume of Sydney Harbor, or about the same volume as the known world oil reserves. Or we could say the ice loss is 550 times the weight of all humans on the Earth, or the weight of 31,000 Great Pyramids … but we’re getting no closer to understanding what that ice loss means.
To understand what it means, there is only one thing to which we should compare the ice loss, and that is the ice volume of the Greenland Ice Cap itself. So how many cubic kilometres of ice are sitting up there on Greenland?
My favorite reference for these kinds of questions is the Physics Factbook, because rather than give just one number, they give a variety of answers from different authors. In this case I went to the page on Polar Ice Caps. It gives the following answers:
Spaulding & Markowitz, Heath Earth Science. Heath, 1994: 195. says less than 5.1 million cubic kilometres (often written as “km^3”).
“Greenland.” World Book Encyclopedia. Chicago: World Book, 1999: 325 says 2.8 million km^3.
Satellite Image Atlas of Glaciers of the World. US Geological Survey (USGS) says 2.6 million km^3.
Schultz, Gwen. Ice Age Lost. 1974. 232, 75. also says 2.6 million km^3.
Denmark/Greenland. Greenland Tourism. Danish Tourist Board says less than 5.5 million km^3.
Which of these should we choose? Well, the two larger figures both say “less than”, so they are upper limits. The Physics Factbook says “From my research, I have found different values for the volume of the polar ice caps. … For Greenland, it is approximately 3,000,000 km^3.” Of course, we would have to say that there is an error in that figure, likely on the order of ± 0.4 million km^3 or so.
So now we have something to which we can compare our one-third of Lake Erie or 400 Sidney Harbors or 550 times the weight of the global population. And when we do so, we find that the annual loss is around 200 km^3 lost annually out of some 3,000,000 km^3 total. This means that Greenland is losing about 0.007% of its total mass every year … seven thousandths of one percent lost annually, be still, my beating heart …
And if that terrifying rate of loss continues unabated, of course, it will all be gone in a mere 15,000 years.
That’s my pet peeve, that numbers are being presented in the most frightening way possible. The loss of 200 km^3 of ice per year is not “some of the most powerful evidence of global warming”, that’s hyperbole. It is a trivial change in a huge block of ice.
And what about the errors in the measurements? We know that the error in the Greenland Ice Cap is on the order of 0.4 million km^3. How about the error in the GRACE measurements? This reference indicates that there is about a ± 10% error in the GRACE Greenland estimates. How does that affect our numbers?
Well, if we take the small estimate of ice cap volume, and the large estimate of loss, we get 220 km^3 lost annually / 2,600,000 km^3 total. This is an annual loss of 0.008%, and a time to total loss of 12,000 years.
Going the other way, we get 180 km^3 lost annually / 3,400,000 km^3 total. This is an annual loss of 0.005%, and a time to total loss of 19,000 years.
It is always important to include the errors in the calculation, to see if they make a significant difference in the result. In this case they happen to not make much difference, but each case is different.
That’s what angrifies my blood mightily, meaningless numbers with no errors presented for maximum shock value. Looking at the real measure, we find that Greenland is losing around 0.005% — 0.008% of its ice annually, and if that rate continues, since this is May 23rd, 2010, the Greenland Ice Cap will disappear entirely somewhere between the year 14010 and the year 21010 … on May 23rd …
So the next time you read something that breathlessly says …
“If this activity in northwest Greenland continues and really accelerates some of the major glaciers in the area — like the Humboldt Glacier and the Peterman Glacier — Greenland’s total ice loss could easily be increased by an additional 50 to 100 cubic kilometers (12 to 24 cubic miles) within a few years”
… you can say “Well, if it does increase by the larger estimate of 100 cubic km per year, and that’s a big if since the scientists are just guessing, that would increase the loss from 0.007% per year to around 0.010% per year, meaning that the Greenland Ice Cap would only last until May 23rd, 12010.”
Finally, the original article that got my blood boiling finishes as follows:
The good news for Luthcke is that a separate team using an entirely different method has come up with measurements of Greenland’s melting ice that, he says, are almost identical to his GRACE data. The bad news, of course, is that both sets of measurements make it all the more certain that Greenland’s ice is melting faster than anyone expected.
Oh, please, spare me. As the article points out, we’ve only been measuring Greenland ice using the GRACE satellites for six years now. How could anyone have “expected” anything? What, were they expecting a loss of 0.003% or something? And how is a Greenland ice loss of seven thousandths of one percent per year “bad news”? Grrrr …
I’ll stop here, as I can feel my blood pressure rising again. And as this is a family blog, I don’t want to revert to being the un-reformed cowboy I was in my youth, because if I did I’d start needlessly but imaginatively and loudly speculating on the ancestry, personal habits, and sexual malpractices of the author of said article … instead, I’m going to go drink a Corona beer and reflect on the strange vagaries of human beings, who always seem to want to read “bad news”.
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Just doing some more number-crunching (basic math is the way to check these global warming scares).
The Greenland ice-sheet has a total area of 1,710,000 square kilometres. For there to be a loss of 200 cubic kilometres of ice volume, the ice-sheet elevation has to be declining by 11.7 cm/year.
Laser and radar altimetry shows that the average elevation of the Greenland ice-sheet was falling by 1.7 and 1.8 cm/year until 2004 (there may have been an acceleration since 2004 but no study seems to translate that into a straight average number, they just split the numbers into different changes at different elevations).
The glacial isostatic rebound of Greenland is said to be less than 1 cm/year, so until 2004, the net ice-sheet elevation was only declining by 2.7 cm/year or just 47 cubic kilometres per year – a factor of 4 lower.
Mike Ozanne says:
May 24, 2010 at 6:45 am
Are these species or subspecies?
Jack Simmons says:
May 24, 2010 at 5:47 pm (Edit)
The ones with three names are subspecies. For a discussion of extinction and what recent rates really reflect, see my post “Where Are The Corpses?“. As usual, the reality is far different from the hype.
Finally, the website that is the source of the list contains much misinformation. For example, their poster child for “Habitat Loss” is the golden toad, and they include the Auroch (bos taurus), which is nothing but a wild form of our modern cow … but I digress. See my post for a full discussion.
Ditto, but with Robert Heinlein’s didactic high dudgeon (that’s a good thing).
I think I’ll send this around with the subject, “Figures don’t lie. . .” and the first line, “Pseudo-science for alarmists.”
/Mr Lynn
I’m a 9th grader in NYC, and I’m interested in interviewing someone (by phone or in person) about their views about human-caused global warming. If you’re interested, please contact me at jstevenso@stuy.edu.
How could we melt enough ice for a 20ft rise in sea levels? Nuke it?
http://pathstoknowledge.net/2009/02/22/how-could-we-melt-enough-ice-for-a-20ft-rise-in-sea-levels/
The bad news, of course, is that both sets of measurements make it all the more certain that Greenland’s ice is melting faster than anyone expected.
I thought the IPCC predicted it melting in 1000 years…..if it is now going to take 10,000 or more years it is melting far slower then I expected. I guess i am not anyone.
Willis Eschenbach says:
May 24, 2010 at 6:28 pm
You beat me to that comment Willis. Yes three are subspecies. And it gets worse.
If one needs a “real” species for the cause, you can invent one. Who can check DNA ‘evidence’ after all? Perfect example:
Save the Sacramento Valley Red Fox!
Even easier to invent a “subspecies.” And then call it a “species” for lists. And easier still to invent a “distinct geographic population.” Say, the Southern San Diego harvest mouse, or the West Cleveland robin [I just made those up, but close enough]. And then just call it a “species” too, to ramp up the scary numbers.
Even so, at a rate 1,000 to 10,000 times higher than “natural” you might expect that the listers could come up with a lot more of these “species.”
One might even wonder how they could figure out that baseline “natural” extinction rate “without humans” in the first place. Could it be a model?
Where was the control area without humans in the last 10,000 years?
And, funny thing. If a researcher can find (or invent) a “species” that qualifies for listing under the Endangered Species list – which includes categories of “species” that are not actually endangered, of course – they have a job for years, often for life. No chance that could influence their research, of course. They’re Conservation Biologists, working tirelessly to save the planet, with no personal concerns whatsoever.
Hopefully the UN et al can save us from this “mass extinction.” Of course, it will require massive funding, more governmental powers, and more control of more land.
P.S. Here are the mammal franchises in Canada (from COSEWIC):
ENDANGERED – “Threatened with immediate extinction through all or significant portion of its range, owing to the act of humans.”
10, including 7 geographic populations
Beluga Whale – SE Baffin Isl. pop.
Beluga Whale – St. Lawrence River Beluga Whale – Ungava Bay pop. Bowhead Whale
Eastern Cougar (pop.)
Marten – Nfld. pop.
Peary Caribou – High Arctic pop.
Peary Caribou – Bank Isl. pop.
Right Whale
Van Isl. Marmot
Wolverine – Eastern pop.
THREATENED – “Likely to become endangered in Canada if conditions are not reversed.” Note the words “in Canada.”
8, inc. 4 geographic pops.
Beluga Whale – E Hudson Bay Harbour Porpoise – W. Atl. pop
Humpback Whale – N.Pac. pop.
Pacific Water Shrew
Peary Caribou – Low Arctic pop
Sea Otter – was extirpated in 1800s by fur trade. Now reintroduced.
Townsend’s Mole
Wood Bison
Woodland Caribou – Maritime pop.
Of note. The polar bear is only listed as ‘Vulnerable’ in Canada, the least at-risk listed status, defined as “At high risk due to low or falling numbers, occurance at the limit of range or restricted areas, or other reasons.”
Or other reasons…
They now invent
The official Australian list of extinct species is at
http://www.environment.gov.au/cgi-bin/sprat/public/publicthreatenedlist.pl?wanted=fauna#birds_extinct
Take birds for an example.
Genus, species (subspecies, population) Common Name
Aplonis fusca = Aplornis fusca Tasman Starling
Columba vitiensis godmanae White-throated Pigeon (Lord Howe Island), Lord Howe Pigeon
Cyanoramphus novaezelandiae erythrotis Red-crowned Parakeet (Macquarie Island), Macquarie Island Parakeet
Cyanoramphus novaezelandiae subflavescens Red-crowned Parakeet (Lord Howe Island), Lord Howe Parakeet
Dasyornis broadbenti litoralis Rufous Bristlebird (western), South-western Rufous Bristlebird
Dromaius ater King Island Emu
Dromaius baudinianus Kangaroo Island Emu
Dromaius novaehollandiae diemenensis Emu (Tasmanian)
Drymodes superciliaris colcloughi Roper River Scrub-robin
Gallirallus philippensis macquariensis Buff-banded Rail (Macquarie Island)
Gerygone insularis Lord Howe Gerygone, Lord Howe Warbler
Hemiphaga novaeseelandiae spadicea New Zealand Pigeon (Norfolk Island race)
Lalage leucopyga leucopyga Norfolk Island Long-tailed Triller
Lewinia pectoralis clelandi Lewin’s Rail (western)
Nestor productus Norfolk Island Kaka
Ninox novaeseelandiae albaria Southern Boobook (Lord Howe Island), Lord Howe Boobook Owl
Porphyrio albus White Gallinule
Psephotus pulcherrimus Paradise Parrot
Rhipidura fuliginosa cervina Grey Fantail (Lord Howe Island)
Turdus poliocephalus poliocephalus Grey-headed Blackbird, Norfolk Island Thrush
Turdus poliocephalus vinitinctus Vinous-tinted Thrush
Zosterops albogularis White-chested White-eye, Norfolk Island Silvereye
Zosterops strenuus Robust White-eye
As can be seen, many are sub-species or even race. It is also notable that the majority were from isolated islands many hundreds of km from the mainland, which islands are part of Australia more from the evolution of history than through matters zoological.
So it bugs me when school children are taught that Australia has one of the worst rates of species extinction of all countries in the world.
Approximate distances from mainland:
Lord Howe Is, 570 km
Norfolk Is, 1,400 km
Macquarie Is, 2,000 km
Geoff Sherrington says:
May 25, 2010 at 10:15 pm
Geoff, you are correct. Australia, as well as the remote islands of the planet, suffered greatly from the predations of introduced European creatures, plants, and diseases. The main miscreants were humans themselves, aided by foxes, rabbits, domestic cats, dogs, rats, and other species.
While this still goes on to some extent (e.g. the introduction of tree snakes in Guam), in general there are no places left on earth that have been isolated from European species.
As a result, the so-called “sixth wave” of extinctions is not going on now. It actually peaked about the year 1900, and the extinction rate has been dropping ever since.
Stacked graph of the historical extinction rates for birds (grey) and mammals (black). 17 year Gaussian average of the data from Red List (birds) and CREO (mammals). Note the peak rate of 1.6 bird and mammal extinctions per year, and the most recent rate of 0.2 extinctions per year.
My discussion of all of this is at “Where Are The Corpses“.
Willis – I just read your article ‘Where Are All the Corpses’ for the first time. Was only an occasional WUWT reader in January and I missed it, and when you noted it earlier the title didn’t alert me to how serious it was. But your graph just did!
As someone who has spent a great deal of time researching this topic – from just a North American perspective – just let me say that that is the best analysis of the real situation that I have ever seen. Absolutely excellent. And your graph effectively says it all at a glance.
The Conservation Biology gang would shudder if this got more exposure! Too bad they now have a stranglehold over most of the most relevant ‘peer reviewed’ journals (including the ones they started themselves, of course) because this is a genuine myth buster.
Again, excellent work!
P.S. On a very minor point which has no significant bearing on your analysis, there is much more to the passenger pigeon story than your condensed summary states – but something tells me you already know that.
Al Gored says:
May 26, 2010 at 1:06 pm
This was a condensed version of a longer paper, which a friend and I are trying to get published in one of the journals. It includes calculations of the extinction rates, geological and current. We’ll see how it plays out.
Yes, the passenger pigeon extinction had many twists and turns. At the end of the day, however, arguably the largest factor was the huge, unrelenting hunting pressure.
Let’s see.
Willis notes that the rate of loss is accelerating, and then proceeds to write an entire article on the premise that the current rate will continue into the future. What’s up with that?
Besides, even the worst case estimates of Greenland ice loss are on the order of centuries if not millennia; so, who is he arguing with?
BTW, how’s that recovery of arctic ice going?
Chris G says:
May 28, 2010 at 9:39 am
This is a perfect example of why I ask people to QUOTE WHAT YOU DISAGREE WITH. Chris, you say that I “note that the rate of loss is accelerating” … but I find nothing in my post about accelerating. Where did I say that?
This is totally incoherent. Whose “worst case estimates” are you talking about? What does “centuries if not millennia” mean, and why can’t you make up your mind to within an order of magnitude? Citations, citations, give us citations.
As far as I know, about as expected, I’ll tell her you asked about her health, nice to know you are concerned.
Seriously, why are you asking me this here? Go to one of the many posts on arctic ice area and bother them, there’s a good fellow …
#
Chris G says on May 28, 2010 at 9:39 am
My my, you are telling us that it will be centuries or even millenia before all the ice on Greenland melts?
Why then were all the AGW alarmists rushing to get their carbon taxes and other power grabbing measures into place now?
When will it be too late and why?