[UPDATE: Several commenters, including myself, have remarked on a mathematical error in the author’s work. I note this here in the expectation that the author will return to clarify and perhaps amend his claims. Having made such public mistakes myself, it’s embarrassing if true, but that’s the function of public peer review as practiced on WUWT. Thanks to all who pointed out the error. -w.]
A graph on NOAA’s 2012 “Greenland Ice Sheet” report uses a 2006 modelled projected ice melt for 2012 that is over ten times that in the latest published paper and equivalent to 250% of the long-term sea-level rise of 3.2mm per annum.
Guest essay by Kevin Marshall (posts as ManicBeancounter)
NOAA published on 01/14/13 a “Greenland Ice Sheet” paper as part of its “Arctic Report Card: Update for 2012”. Fig 5.19 shows ice-mass balance loss in gigatonnes and sea level rise equivalent.
In 2012, the ice mass loss is modelled have raised sea levels by 8mm. This is 250% of the average sea level rise trend of the last twenty years of 3.2mm. The graph has a note “After Velicogna and Wahl 2006”. The graph used 49 months of GRACE modelled data to project 80 months forward.
I compare with more recent papers. Last Fall they could have used Rignot et. al 2011. Using 99 months of modelled data, to project 30 months forward, with Greenland ice melt contributing 1.1mm to sea level rise. Now they could use Shepard et. al 2012. Using 96 months of modelled GRACE data (plus other sources going back to 1992), to project 24 months forward, with Greenland ice melt contributing 0.7mm to sea level rise.
A common author of the NOAA paper, the 2006 paper and Shepard et. al 2012 is John Wahr, who works at University of Colorado Boulder. Another department produces the sea level rise figures.
NOAA report http://www.arctic.noaa.gov/reportcard/greenland_ice_sheet.html
My analysis
http://manicbeancounter.com/?attachment_id=3282
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And we pay for this ‘science’?
we need more crisis in our lives, otherwise there is nothing to be concerned about, we just grow older and closer to death
What’s an order of magnitude between friends?
I interpret that graph as cumulative ice loss and cumulative sea level rise. From 2002 to 2012, a total sea level rise of 6 mm, or about 0.6 mm/yr due to Greenland melt.
Interesting that the curve ends before “the sudden disappearance of the Greenland’s ice sheet in four days in July this year*” 🙂
*Farrukh Khan, Pakistan UN Climate negotiator, 11/29/12, The Express Tribune
People are actually still trying to use the GRACE data?
It is long past time for the American people to TAKE OUR REPUBLIC BACK from those that suffer from POTOMAC FEVER . . spending free money to bribe scientist, Universities, agencies like NOAA, NASA and more . . will you help us cut of the flow of borrowed money to bribe for power and more power over the people – we can end this by doing this single project . . it only take around 4,000 legislators being convinced by we the people to do this task. Then we will have returned all the powers to the many States where competition will yield a better government.
http://articlevprojecttorestoreliberty.com/article-v.html
Ice loss is (over?)estimated by NOAA at 3.5e+12 tonnes per decade. Greenland has about 2.4e+15 tonnes of ice, which is three orders of magnitude (a thousand times) the amount of the purported loss. We’re talking a tenth of a percent over a decade?
Be very afraid …
w.
I don’t understand this one. Global sea level rise from start to end of the graph (2002-2012) is about 30 mm. Are you saying the 8mm rise over the same decade that they estimate from Greenland is way out of line, and if so, why?
I suspect there is a fundamental error in your claims, one that you should rectify. The data in the graph is cumulative, not annual. The 8mm is the TOTAL rise from 2002 to 2012, not the annual rise in 2012. As a result, the Greenland melt may be wrong, but it is not 250% of the sea level rise. That claim of yours is incorrect.
Regards,
w.
‘The data in the graph is cumulative, not annual. The 8mm is the TOTAL rise from 2002 to 2012.
Regards,
w.”
#######
yup
perhaps the manic beancounter is a misnomer. or rather, keep him away from my books
I agree chris y that the authors analysis of this graph is off by 10x. The article linked to at NOAA even says 8mm over the period 2002 to 2012.
Well, the Shepard paper would have to be discounted because of the number of authors; I think we already have some science which says that more authors = less believable. I’m surprised the alarmists haven’t jumped all over that low number.
The rest is explained by the fact that the NOAA report card was written by alarmist Jason Box who loves to hype up the Greenland Ice Sheet is melting story. He needs to take a look at this picture of the outwash plain at Kangerlussuaq (Sondre Stromfjord) and ask himself why it is so massive and gets so little use these days even in the hottest of Greenland summers.
http://www.panoramio.com/photo_explorer#view=photo&position=1547&with_photo_id=56248764&order=date_desc&user=420107
GRACE is a simple concept but no-one has adequately explained how it can possibly distinguish ice melt from changes in the earth’s crust; especially when the crust is 5 times as dense as the stuff lying on top.
The text in the original paper says: “GRACE satellite gravity solutions computed according to Velicogna and Wahr (2006) are used to estimate monthly changes in the total mass of the Greenland ice sheet (Fig. 5.19). The data show that the ice sheet continues to lose mass and has contributed +8.0 mm to globally-averaged sea level rise since 2002”.
This implies that the calculation method of Velicogna and Wahr (2006) was used, but was applied to the latest data (which would then be about 120 months rather than the 49 mentioned in the post).
Is that possible?
“In 2012, the ice mass loss is modelled have raised sea levels by 8mm.”
That is not at all the claim being made at your NOAA link. It says 8mm since 2002. A serious retraction is necessary.
It is now obvious to me that you don’t need a high I.Q., and/or the ability to reason or research to become a NOAA “scientist”.
I will use the words of “Old Spock” talking to “New Spock” -> “In this case, do yourself a favor, put aside logic, do what feels right.” “Since my customary farewell would be oddly self serving, I shall simply say ‘Good Luck'”.
Until this mess is corrected, the Planet will need ‘Good Luck’.
The trick they use is the use values with big numbers which ordinary people have no reference to.
Ok 1000 Gigatons in volume, assuming as I think that one ton of ice has a volume of one cubic meter, then 1000 Gigatons has the volume of 1000 cubic kilometers which is a cube of 10 kilometers in length.
The total mass of ice on Greenland is 2,850,000 cubic kilometers.
If 1000 Gigatons melted each year, the ice would be gone in 2850 years.
Of course the rate of melting is less than that and the rate of change of ice varies depending on temperature, ice pressure, ice movement and snow accumulations.
Once again its worth remember the first rule of climate science, if the models and reality differ in value its reality which is in error .
Imagine , if you like, that your standing in a room on fire you can feel, the heat all over your body , smell the smoke , hear the roar of the flames , but the models tell you your standing at the bottom of a pool. In climate science the ‘correct’ thing to do would be to get out of the water and dry off by starting a fire . Its mad has a hatter but its meets rule one so it must be the right idea .
Once you got a grip of that approach you can understand how they can keep pushing this BS out whilst all around them the facts tell a different story.
Isn’t it nice to observe the small touches. Notice how the average line starts horizontal in 2002, as if there was never any sea level rise due to Greenland ice melt BG (before GRACE).
National Obama Agenda Administration
Just tooooooo gooooooood!!!! NOAA what? No he does not no one told him . . .
Kevin Marshal is comparing two different values with one another.
NOAA report http://www.arctic.noaa.gov/reportcard/greenland_ice_sheet.html
states that the Greenland ice sheet contributed +8.0 mm to the global averaged sea level rise since 2002. This is the sea level as measured in height averaged from various places around the globe.
This is not the rate (how fast it is changing) that global averaged sea level is changing each year.
Using Kevin Marshal’s own calculations here: http://manicbeancounter.com/
Sea level is changing at a rate of 3.2mm per year.
Given 10 years, 2002-2012, that would be a sea level rise of +32 mm.
Which would mean that the contribution from the Greenland ice sheet would be 8mm/32mm or only 25%.
Not the 250% he claims.
I love this branch of science….I call it Phallusy Science. Always over exaggerating the size or the impact. But once exposed, we get to see how big…..I mean how really small it is.
Greenland’s contribution to the rate of change in mean sea level rise over the same time period (2002-2012) would be 8mm/10 = 0.8mm/yr
Using Kevin’s [source 1=”http://manicbeancounter.com” language=”:”][/source] calculated rate of sea level change per year: 3.2mm/yr
The contribution to the rate of change in sea level rise for the past 10 years would still be 25%, not the 250% he claims.
Once again… the models are broken.
I get it. Modelling is fun and, in some cases, even useful. But, folks, we gotta stop going crazy and formulating public policy and spending billions or even trillions of dollars based upon models which have not been validated to at least a reasonable degree.
Shame about the error.
Still, it is interesting to note that if sea level is allegedly rising at say 3.2mm per year and the Greenland Ice melt is 8mm over ten years (thats 0.8mm/year) – this still leaves about 2.4mm of SL rise to be accounted for from ‘other’ sources. Whether this is part thermal expansion or other glacial/ice sheet melt, reduced atmospheric water vapour, tectonic movement, etc, etc, is what actually raises my interest.
For the warmists – this kind of discrepency, especially when trying to claim the SL rise is mostly due to ice melt (and drowning polar bears) – needs to be answered?
Maybe less manic and more counting would be in order.
At last !!
It really is worse than we thought !!!