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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Similar considerations apply to the Antarctic. According to NASA (http://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html) the Antarctic is losing 100 km3 per year. The volume of the Antarctic ice is around 30 million km3. So at this rate it will take another 300,000 years. We should be careful though – on their web site NASA show a curve (quadratic equation?) fitted to the ice loss numbers for the last 7 years which suggests the rate might be increasing – so it may happen a bit sooner.
I can fully understand where Willis is coming from. On my own web site we’ve started a series looking at this type of error. Only a couple so far but more to come.
http://www.climatedata.info/Discussions/Discussions/opinions.php
And to put the “time to total loss” (12,000 to 19,000 years) into perspective …
… “the ice age” refers to the most recent colder period that peaked at the Last Glacial Maximum approximately 20,000 years ago, in which extensive ice sheets lay over large parts of the North American and Eurasian continents. (Wikipedia)
Have these GRACE researchers excluded the possiblity that convection in the mantel below Greenland is causing a slow subduction? This would also make the GRACE satellites measure less gravitional pull from Greenland, I think.
Willis, I hope you enjoyed your beer as much as I found great satisfaction in your waxing wroth. Nothing like the real world of mathematics and scientifically valid measurements with error possibilities included. Keep holding their feet to the fire and requiring THE TRUTH (drum beats, please) instead of exploitation by pseudo-scientists and excrement-quality pseudo-scientific reporters. I feel for ya.
” 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….”
Thanks. You have helped me keep mine in a healthy range.
Willis wrote:
“The measurement by the GRACE satellites is not measuring the height of the ice and estimating the ice loss from that. It is measuring the weight of the ice. As such, the isostatic rebound doesn’t affect the answer, because although the underlying rock moves vertically, the weight of it doesn’t change.”
The weight of a mass does change the further away it is from the earth’s center; in space the weight becomes zero. Thus isostatic rebound does indeed change the weight of the rock. The research team has to sort out the difference between the changes in rock and the changes in ice.
For example, this article talks about similar research in the Antarctic:
West Antarctic ice sheet may not be losing ice as fast as once thought
http://www.eurekalert.org/pub_releases/2009-10/uota-wai101909.php
New ground measurements made by the West Antarctic GPS Network (WAGN) project, composed of researchers from The University of Texas at Austin, The Ohio State University, and The University of Memphis, suggest the rate of ice loss of the West Antarctic ice sheet has been slightly overestimated.
“Our work suggests that while West Antarctica is still losing significant amounts of ice, the loss appears to be slightly slower than some recent estimates,” said Ian Dalziel, lead principal investigator for WAGN. “So the take home message is that Antarctica is contributing to rising sea levels. It is the rate that is unclear.”
In 2006, another team of researchers used data from the Gravity Recovery and Climate Experiment (GRACE) satellites to infer a significant loss of ice mass over West Antarctica from 2002 to 2005. The GRACE satellites do not measure changes in ice loss directly but measure changes in gravity, which can be caused both by ice loss and vertical uplift of the bedrock underlying the ice.
Now, for the first time, researchers have directly measured the vertical motion of the bedrock at sites across West Antarctica using the Global Positioning System (GPS)….
Postglacial rebound causes an increase in the gravitational attraction measured by the GRACE satellites and could explain their inferred measurements of recent, rapid ice loss in West Antarctica.
First major oil landfall in LA is predicted to be today.
http://voices.washingtonpost.com/achenblog/2010/05/oil_slathers_louisiana.html
NOAA oil map:
http://response.restoration.noaa.gov/book_shelf/2039_TMF72-2010-05-21-1900.pdf
It is simply astounding that BP did not have more controls in place, did not properly test the well, modified the blowout preventers, did not fix said blowout preventers when they knew they were leaking hydraulic fluid, and had no plan in place to manage the spill. This is not a failure of offshore drilling, or the oil industry generally, it is a failure of BP.
Willis I will add my voice to the chorus. Thanks for your wonderful posts and Anthony for this forum. Also others who post and comment here! Please keep it up! I have been reading it daily for months!
As a retired agricultural pesticide research scientist I see from Big Government dot com that the ‘green scientists’ are attempting to get atrazine banned! Same method of alarmism! You want to see a REAL MESS, mess with our reliable food supply!
This post really SHOULD have made the MSM. Can you imagine if Beck or Sarah could give this 5 minutes in a program?! WOW
Eric
Jimbo says:
May 23, 2010 at 4:50 am
“And how is a Greenland ice loss of seven thousandths of one percent per year “bad news”?”
Jimbo – remember the cardinal rule of Climate “Science” research:
“Bad News” for the climate = Good News for my research budget!
Climate Ca$h for the Global Warming Industry – because Al Gore deserves another sea side villa!
Probably, but not certainly. We recently have been in a cycle of glacial events, but we don’t know with certainty what started them nor what will stop them. The AGW alarmists haven’t been promising that AGW will stop the glacial events, probably because that would be a good thing… or because they don’t want to remind us how much a glacial event will affect polar bears who would be waiting for seals on top of a mile of ice.
Thank you Willis, for exposing another attempt at misleading the public. This is not science it is “spin” and they hire experts to do it. I was researching another topic and stumbled onto the information below. Stan Greenberg seems to be another major behind the scene player in “Global Warming” and “Global Governance”
“He [Stan Greenberg
was also a strategic consultant to the Climate Center of the Natural Resources Defense Council on its multi-year campaign on global warming ……NGO board memberships include the American Museum of Natural History, the National Endowment for Democracy, The Africa-America Institute, the Citizens Committee for New York City, the Council on Foreign Relations, and Refugees International…….Republican pollster Frank Luntz says “Stan Greenberg scares the hell out of me. He doesn’t just have a finger on the people’s pulse; he’s got an IV injected into it.”
More on Greenburg. He is definitely the power behind the throne of many countries. Stan Greenberg provides strategic advice and research for leaders, companies, campaigns, and NGOs trying to advance their issues.
Greenberg Carville Shrum directed Campaigns in 60 countries including Bolivia That fiasco was documented in the film “Our brand is Crisis”
An Ad for Greenberg’s new book states “The fascinating “war room” memoir of a political pollster and how he helped forge the agendas of five high-profile heads of state”:
“As a hired gun strategist, Greenberg—a seasoned pollster and political consultant— has seen it all. In his memoir, he recounts his work with President Bill Clinton, British Prime Minister Tony Blair, Israeli Prime Minister Ehud Barak, Bolivian president Gonzalo Sanchez de Lozada, and South African president Nelson Mandela. Through his experiences aiding the leaders in pushing their visions for better and clearer domestic and international policies, Greenberg offers an insightful examination of leadership, democracy, and the bridge between candidate and constituency. This captivating tale of political battlegrounds provides an inside look at some of the greatest international leaders of our time from the man who stood directly beside them.”
“ Greenberg
has conducted extensive research in Europe (particularly Great Britain, Germany and France), Central and South America (Argentina and Brazil), and Africa (South Africa). He specializes in research on globalization, international trade, corporate consolidation, technology and the Internet. For organizations, Greenberg has helped manage and frame a number of issues – including education, school financing, American identity, the economy, environmental regulation, international trade, managed care, biotechnology, copyrights, privacy and the Internet….”
… Greenberg has advised a broad range of political campaigns, including those of President Bill Clinton and Vice-President Al Gore, Senators Chris Dodd, Joe Lieberman and Jeff Bingaman;
Greenberg works jointly on private sector projects with prominent Republican pollsters in the United States – including Fred Steeper (pollster to former President Bush), Bill McInturff and Linda DiVall – to bring a bi-partisan focus to public issues….”
Stan Greenberg “…specializes in research on globalization, international trade…”
Greenberg writes for the Democratic Strategist and also formed Democracy Corps
Her is his connection to Dēmos:
“Dēmos promotes responsible U.S. engagement in an interdependent world. It advances policies and ideas in support of a more democratic system of global governance, a more inclusive and sustainable global economy…”
The International Program at Dēmos promotes responsible U.S. engagement in an interdependent world. It advances policies and ideas in support of a more democratic system of global governance, a more inclusive and sustainable global economy,…. Dēmos was founded in 2000. ..[here is the connection]…This Message Builder also draws from recent, publicly available opinion research conducted by Public Agenda Democracy Corps, and World Public Opinion.
A dangerous man well worth watching.
I wonder what their most recent (last 6 months) show? This winter (2009-2010) featured a semipermanent low just SW of Greenland pumping in moisture (snow) over southern Greenland.
I bet there was a big accumulation of snow in (at least southern) Greenland this past winter.
Willis,
Afraid I have to disagree with “As such, the isostatic rebound doesn’t affect the answer, because although the underlying rock moves vertically, the weight of it doesn’t change.”
Garvity measurements extend in theory through the centre of the earth and roughly obey G=m1*m2/d^2 as you know. If a thinner ice is replaced by a denser rock rebounding from below, the gravity meters will “see” more of the rock and hence give a higher G reading.
Three interesting bits of information would be: (a) do the 2 satellites, after a few years, maintain their original separation, or is there a drift in separation that has to be corrected to get consistent gravity results? (b) what is the angular resolution of the gravity field? I’d imagine measurements could not reflect better than 1000 x 1000 km and even this overlooks edge effects like steeply sloping deep coastlines. (c) What corrections are needed for the effect of other planets and the moon, whose gravity shifts tides around?
Sure, it’s clever technology, but it has such high demands on measuring satellite separation that one should be cautious about error terms.
tty says:
May 23, 2010 at 1:45 am
Willis Eschenbach says:
May 23, 2010 at 2:43 am
I think tty is correct on this one. GRACE is measuring changes in the gravitational field. Changes in the gravitational field are generated by any & all changes in lateral density contrasts, which would include isostatic, tectonic & ice volume changes. From the changes in the gravitational field, ice loss in inferred – but it is therefore implied all other potential sources of changes in field have been eliminated. I would say tty is correct in saying the error bars on this small number are considerably bigger than 10%. David Middleton’s post above would also support that the error bars are much greater than 10%. So what do you conclude…..
…. it’s worse than you thought :))
Not only is the ice loss an incredibly small #, but we also have big error bars on exactly what that number is …. and despite the fact the the original article claims it is due to AGW, I don’t see any data presented to support that hypothesis. So, we have an insignificantly small number with huge error bars being used as proof of a hypothesis with no link between cause & effect even attempted to be shown.
Now that’s some solid science!
It is curious how scientists can be innumerate. I think they need to take a class from Cowboy Willis in using all their fingers and toes. It reminds me of the Woody Allen movie where as a boy he didn’t want to do his homework because the universe was going to end in 8 billion years…
“…meaning that the Greenland Ice Cap would only last until May 23rd, 12010.”
But: This supposes “all else equal” aka ceteris paribus and we all (should) know that in nature there is no such thing. There are no two years that are exactly equal, so how can you suggest that there would be 10,000 years of identical conditions?
Makes no sense to me. At least, if you insist on correcting malpractices and ridiculous statements, don’t do it wih statements that are every bit as uncertain as the original one 😉
DavidB says:
May 23, 2010 at 2:01 am
The most useful way of indicating the importance of the ice melt would be to say what effect it has on sea level. Taking a rough value of 350 million square km for the sea surface of the earth, 200 cubic km would be spread very thin.
An ice loss rate of 200 cubic kms/year could cause about 0.55 millimetres of sea level rise per year or 5.5 centimetres per century.
And if that terrifying rate of loss continues unabated, of course, it will all be gone in a mere 15,000 years.
Is anyone talking about the loss of the Greenland Ice Cap? No, no they are not. So this is a ridiculous straw man.
How could anyone have “expected” anything?
I can’t imagine. You’d think there were other satellites up there or something.
To this question, I fear we have no answer, as our historical records are very spotty both spatially and temporally. We will know more in twenty years or so, but at present all we can do is observe — we don’t have the historical data necessary to draw any conclusions.
And in “twenty years or so,” if the majority of the world’s scientists are drawing the correct conclusion from the data, we will be in that much worse of a pickle.
You guys always discount the downside risks. It would be an interesting intellectual exercise, except that you are gambling with huge stakes. Anyway, enjoy the beer.
So… basically, the current annual ice loss of Groenland is to the total Groenland ice cap what a loss of 4 grams is to my total weight of 58 kg. After one year. Stop the presses !
My geopolitical guesstimation of the cost to reverse this terrible trend is $6.491 gigatrillion over the course of the next 15 years. Of course, the richer nations must contribute a proportionately larger share to this cause as it was their fault that all this is happening. Since China and India have played such minor roles, and those nations around the equator, and in the Southern Hemisphere (excepting Aussie Land and New Zealand) have had no role whatsoever, these nations should pay nothing at all. Failure to meet the conditions of this UN resolution will place responsible nations in default and all real property and personal possessions of citizens in default will be sold at auction in Addis Abba on 24 May 2025. The former ‘citizens’ of these countries will be captured and sold into slavery on 25 May 2025, in lots of 10,000 – 100,000 – 1,000,000 – and 10,000,000.
Record of the UN Security Council Vote to pass the above provisions:
China – Yhep; France – Qui, Qui; United Kingdom – I am happy to say Of Course; Russia – Dah; United States of America – Si, Yes, OK, Yea, Hit Me Again, You Bet; Gabbon – Yes; Spain – No; Mexico – Si; Brazil – Absoluto; India – Yes; Iran – You Bet Bubba; North Korea – Nuc Em! I mean, Sure Bubba; Panama – No Way, Jose!; Iraq – Okeedookee; Poland – No! No! No!
PS: We should’a known this day would come.
Corona!? You’re in Chico! Have a pale ale! 🙂 Cheers!
Great article. I’m saving it to reference those percentages. Should shut down the idiots who just spout talking points. Thanks!
Great Willis.
Even if the people who put out these sort of things know they are wrong they will continue. And, just like Hansen, Mann ,and the others- nothing will happen to them. The IPCC keeps churning and the cap and trade bill will be passed. All this will happen unless the bums are thrown out and that is unlikely because about 50% of the people are on the take. Cynicism over-it’s Sunday.
Martin Lewitt wrote: “With an ocean area of 335,258,000 km^2, the 200 km^3 contributes 0.59 mm per year, or 5.9cm per century, or about 2.3 inches per century.”
And that is if absolutely nothing else is happening on Earth. From wikepedia the following list is of the largest man made reservoirs by volume:
1.Lake Kariba (180 km3 or 43 cu mi; Zimbabwe, Zambia)
2.Bratsk Reservoir (169 km3 or 41 cu mi; Russia)
3.Lake Nasser (157 km3 or 38 cu mi; Egypt, Sudan)
4.Lake Volta (148 km3 or 36 cu mi; Ghana)
5.Manicouagan Reservoir (142 km3 or 34 cu mi; Canada)
6.Lake Guri (135 km3 or 32 cu mi; Venezuela)
7.Williston Lake (74 km3 or 18 cu mi; Canada)
8.Krasnoyarsk Reservoir (73 km3 or 18 cu mi; Russia)
9.Zeya Reservoir (68 km3 or 16 cu mi; Russia)
Add in other works coming on stream like China and in the past century a lot of water has been locked up by man away from the Ocean. But all of this is but a ‘drop in the ocean’ compared to human use of water for cities, industry and agriculture across the world.
Then consider if there really is a warming trend. Warmer air contains more moisture. Globally this would make a big difference. No wonder there is no noticable change to sea-level in my over 50 years of living by the sea. I will continue to judge this sort of things by eyesight, not by the decimatl points of worked, reworked and overworked ‘scientific’ theories.
I couldn’t resist leaving a comment on the original article:
“OH! MY! GOD! 200 cubic km EVERY YEAR?? Why, that’s as much as 0.00007 of Greenland’s 3 million cubic km of ice EVERY YEAR!! Greenland could be completely ice free by May, 17010! Why, in a just a couple thousand years, the ice loss and sea level rise might even become perceptible! RUN FOR THE HILLS!! IT’S WORSE THAN WE THOUGHT!!!!!”
OK, so it might be considered a bit of a troll, and somebody might construe that I have violated two of their rules for posting:
1. Don’t be a jerk. Nobody likes jerks.
…
7. Seriously, don’t be a jerk.
However, it’s hard to take those rules seriously when the whole article is one huge troll. It might be interesting to see any replies to that. True believers don’t react well to apostasy or inconvenient analysis.
Ed
All one has to do is look at the layers of rock visible at road cuts to see the magnitude of water and rock movements that have happened every year everywhere for eons. The layers range in size from millimeters to inches. The question is, is the loss of ice (and rock?) in Greenland significant of anything? All I have to say to that is: Medieval Warm Period.
Great article Willis.
As usual it is naturally assumed that Greenland ice melt is due to GW – they have forgotten about the other possible causes like:
“Scientists have discovered what they think may be another reason why Greenland ’s ice is melting: a thin spot in Earth’s crust is enabling underground magma to heat the ice”
http://www.sciencedaily.com/releases/2007/12/071212103004.htm