NOTE: Another related story posted here
By Steve Goddard
A popular AGW cottage industry from 2003-2007 was to make press releases warning that the Greenland ice sheet was melting down. Some fine pieces of journalism were produced, like this one from the BBC.
The meltdown of Greenland’s ice sheet is speeding up, satellite measurements show. Data from a US space agency (Nasa) satellite show that the melting rate has accelerated since 2004. If the ice cap were to completely disappear, global sea levels would rise by 6.5m (21 feet).
This one from New Scientist
The Greenland ice sheet is all but doomed to melt away to nothing, according to a new modelling study. If it does melt, global sea levels will rise by seven metres, flooding most of the world’s coastal regions.
NASA’s Earth Observatory even has a regular section named “Greenland’s Ice Alarm.” In their August 28, 2007 edition they included the map below, which shows Greenland warming at 3°C per decade.
One has to wonder where their data comes from, because GISS shows that Greenland has not warmed at all over the last 90 years.
GISS temperature trends since 1920
Below is the GISS temperature graph for Godthab, Greenland. It was warmest around 1940, and the only recent warm years were from (you guessed it) 2003-2007. The Godthab pattern is fairly typical for Greenland and Iceland.
NASA’s Earth Observatory generated their 3C/decade trend by very carefully cherry-picking their start and end points. Tamino must be incensed by NASA’s behaviour, because he hates cherry-picking.
But you don’t hear so much about Greenland melting down any more.
Vol. 323. no. 5913, p. 458
FALL MEETING OF THE AMERICAN GEOPHYSICAL UNION:
Galloping Glaciers of Greenland Have Reined Themselves In
Richard A. Kerr
Ice loss in Greenland has had some climatologists speculating that global warming might have brought on a scary new regime of wildly heightened ice loss and an ever-faster rise in sea level. But glaciologists reported at the American Geophysical Union meeting that Greenland ice’s Armageddon has come to an end.
Greenland warming of 1920–1930 and 1995–2005
Petr Chylek
M. K. Dubey
Los Alamos National Laboratory, Earth and Environmental Sciences, Los Alamos, New Mexico, USA
G. Lesins
Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
We provide an analysis of Greenland temperature records to compare the current (1995–2005) warming period with the previous (1920–1930) Greenland warming. We find that the current Greenland warming is not unprecedented in recent Greenland history. Temperature increases in the two warming periods are of a similar magnitude, however, the rate of warming in 1920–1930 was about 50% higher than that in 1995–2005.
Below is a video I took flying over Greenland from east to west on August 10, 2008 (peak melt season.) On the east side there were lots of icebergs and little evidence of any melt. As you traverse to the west side, you see a few melt ponds.
Temperatures have been running well below normal in Greenland this summer.
It is mid-summer and temperatures in the interior of the Greenland ice sheet are currently minus 16F. Temperatures never get above freezing for more than a few minutes there. Meanwhile temperatures in the interior of the East Antarctic ice sheet are close to minus 100F.
Every good citizen knows that the poles are melting – because they have been fed a continuous stream of gross misinformation. The press loves to print this stuff, but never makes any serious attempt to set the record straight later.
They can always recycle the ice shelf fracturing melting story a few more times.
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Matthew L
Everything in this article is documented from standard sources like GISS, NOAA, etc. Your claim that I “made stuff up” is nonsense.
Produce some evidence or stop making ad homs.
As a professional statistician, I find this story completely misguided and to be honest, irresponsible. I am not invested in whether Greenland is melting or freezing. However, looking at your plot of your Gothab data, I see a definitive trend upwards. It looks to be on the order of 2 to 3 degrees centigrade per century. Why would anybody be quoting +3 degrees C per “DECADE”. That is 30 degrees C per century and is blatantly wrong.
Your arguments about endpoints are well taken, but then I see the same mistakes in your conclusions about recent behavior. Let the number cruchers crunch the numbers……a trend is not a short period!
Robert,
Since the Himalayan glacial retreat has been revised from 2035 to 2350 the Greenland glaciologists can now take that mass contribution to sea level rise and apply it to Greenland. It must be very funny to see the various group of AGW alarmists fighting over their contribution to sea level. Of course NASA would like most of it assigned to rising temps (steric contribution) leaving the glaciologists out in the cold.
Anyone who doubts that the Greenland icecap owes its continued existence mostly to the underlying terrain, might want to explain why most other land masses at the same or similar latitudes have not had permanent icecaps within recorded history.
[A gratuitous plug for another blog is acceptable. Repeated plugs in the same thread for the same blog is not. ~dbs, mod.]
GeoFlynx
Glacial rebound is not slow at all. There are places in Canada that have risen 1000 feet just since the last ice age!
http://www.homepage.montana.edu/~geol445/hyperglac/isostasy1/
Robert Lund
You don’t plot one leg of a wave and call it a trend.
Temperatures were higher in the 1940s, period.
Sorry, but this is the N th. ice post WITHOUT WHISKEY!!
Remember last week how I plotted eight complete cycles of Arctic ice, and people were complaining about the trend – based on shape of the start/end half cycles?
Well, NASA’s cherry-picking is infinitely more egregious, yet the same people come to their defense. Pretty lame.
Make up your mind folks, you can’t have it both ways.
Jeff P
I am talking about rates of sea level rise. If the rate of ice loss has doubled, then sea level rise would also have to double.
This tendency towards hype is now apparently starting to affect honest to god science — by which I mean physics.
Recently Rhianna Wisniewski, spokeswoman for the Fermi National Accelerator Laboratory in Batavia, Ill. had to respond to rumours that they had discovered the “God Particle. According to CBC.ca (“‘God particle’ rumour wrong, Fermilab says<“), the rumour was started on a blog by Tommaso Dorigo, “an experimental particle physicist who works at the European nuclear research centre and on an experiment at Fermilab.” Dorigo wrote that “it reached my ear from two different, possibly independent sources, that an experiment at the Tevatron (part of Fermilab) is about to release some evidence of a light Higgs boson signal.”
While Dorigo admitted that he could go through the research to find out the truth of the rumour, he decided it was “too much work — while wild speculation is more fun!” He also admitted that some scientists were bothered by his “carefree attitude” towards truth and rumour, but excused it saying, that physics needs publicity.
“Suffices to say that, in a nutshell, keeping particle physics in the press with hints of possible discoveries that later die out is more important than speaking loud and clear once in 10 years, when a groundbreaking discovery is actually really made, and keeping silent the rest of the time.”
No. No it doesn’t. The Boy Who Cried Wolf. The Climatologist Who Cried It’s Worse Than We Thought. All of this shows quite strongly that if you keep spouting off things that later turn out to be false, it will eventually lead to people distrusting and ignoring you.
What is happening to science!?
Dave Wendt says:
July 13, 2010 at 2:01 am
“The abstract of the second paper you cite second indicates that the GRACE data suggest an accelerated decline in the ice mass in 2007-2009. If you go to this site for the global drought monitor and click through their maps for 12,18,24, and 36 months from the present, they indicate that large portions of Greenland were experiencing severe to exceptional drought conditions over the period referred to in the paper, which would suggest an explanation for the larger decline in mass loss unrelated to the melting rate.”
*****************************************************************
VILLABOLO:
Dave, the explanation you pose for Greenland’s continuous ice lost in the past decade has the following shortcomings:
1) First, you are incorrect in stating that the abstract I cited indicates an acceleration from 2007-2009. It was between 2002-2003 and 2007-2009. I’ve reposted the link below with a quotation:
http://www.agu.org/pubs/crossref/2009/2009GL040222.shtml
“We use monthly measurements of time-variable gravity from the GRACE (Gravity Recovery and Climate Experiment) satellite gravity mission to determine the ice mass-loss for the Greenland and Antarctic Ice Sheets during the period between April 2002 and February 2009. We find that during this time period the mass loss of the ice sheets is not a constant, but accelerating with time, . . .”
2) The drought maps do not totally overlap with Greenland’s ice melt in time or space as measured by GRACE satellites. You would need to compare the drought maps side by side with GRACE’s satellite maps of Greenland’s ice gain/loss on a yearly basis to make a correlation.
a) The drought maps only go back 3 years, which is insufficient time to make a correlation with Greenland’s longer history of ice loss.
b) The ice loss mentioned in both the abstract and NASA’s article predate the drought period that you indicated was accelerating since 2007. GRACE satellites begin to detect increasing ice loss since their first full year of measurements in 2002. There was ice loss detectable even before then.
Irrespective of any acceleration that one may wish to fit into the limited time frame of the drought maps you linked to, there is the fact that the 2002 ice loss (137 billion metric tonnes) was half of 2009 (286 billion tonnes).
c) The drought maps for the past 36 months, which start in July of 2007, indicate very little drought in comparison to the maps of 24 months ago, which start in July 2008. This implies that the period from 7/2007 to 7/2008 would have had little impact on the acceleration. And the year/s before?
Again, the very limited span of time precludes any meaningful comparison.
d) What would a 2006 drought map look like in comparison to Greenland’s major ice loss of 2003-2005 at the edges as monitored by GRACE?
http://www.google.com/imgres?imgurl=http://www.nasa.gov/centers/goddard/images/content/160991main_mass_trend_greenland_lg.jpg&imgrefurl=http://www.nasa.gov/centers/goddard/news/topstory/2006/greenland_slide.html&h=1171&w=1800&sz=250&tbnid=Nmij6hqFLO-i6M:&tbnh=98&tbnw=150&prev=/images%3Fq%3Dgreenland%2Bgrace%2Bimages&usg=__rfFyA1DTRnpoc3t1yPtsHoPadPk=&sa=X&ei=ALU8TPK1I46osQPB8IDbCg&ved=0CBgQ9QEwAA
Greenland appears to be an up & coming tourist mecca!
http://www.greenland.com/content/english/tourist
Steve,
What the hell? Whats with the technobabble? Leg of a wave? You do not seem to understand the slightest about chance variation and statistics. Fit a least squares line to the series and test the hypothesis that the trend slope is positive.
“I am talking about rates of sea level rise. If the rate of ice loss has doubled, then sea level rise would also have to double.”
—————
This is false.
This would only be true if the cause of sea level rise was ONLY from ice loss. Clearly this is not the case.
If ice loss has gone from something like 50 Gt a year to 100 Gt it has doubled but the impact on sea level rise would be tiny and far below the margin of error for the measurement of sea level rise. A 50 Gt increase in Ice loss would be less than 0.1 mm increase.
If you’re saying that ice loss could not have possibly doubled (or even increased) because we aren’t seeing a 3+mm increase in the rate of sea level rise you’re way off base.
Interesting thread. I like the dissection of Greenland temperature data, probably because I’ve done a great deal of that myself over the last few years. What I recommend to anyone who has the facilities to carry out simple regression analyses to fit trend lines is to collect Greenland data (Any actual station, or combinations of stations, as published by Vinther et al) but do some deliberate cherry picking. The reason for this is possibly unethical approach is that it is possible (and simple) to show that in 1922 (I could specify a period of two or three months, but you’d not believe it!) a large step change in the North West Atlantic measured air temperatures occurred. Its magnitude was at least 1 deg C. It was preceded by a long period of temperature stability – at least back to 1860 – and followed by another period (to about 1970), which both show “slopes” that lack any statistical significance. I could quote confidence intervals etc, but won’t. It gets a bit boring and many would not be sure exactly what they mean. If one substantially relaxes the usual standards for statistical significance one might be tempted to hypothesise slight negative slopes! Further time periods are less simple to describe, but seem to show marked downward trends in general.
Anyway, please try looking at the data subsets “earliest data” to 1922, 1923 to 1970 and 1970 to the present, and see what you make of them.
If I knew how to post GIF files to this site I would do so (advice, anyone?). These diagrams make things very obvious.
I am convinced that Greenland did NOT experience a general warming over the period 1920 to 1930 – something that has often been stated in post in this thread. Instead, West and East Greenland, and Iceland, all underwent a step change in late 1922. You can readily verify this for yourselves!
What would be very interesting is a plausible mechanism for such an occurrence.
Robin
Jeff P
Uhhmm… You might want to think your sea level argument through a little more carefully. Increasing ocean heat content will also tend to raise sea levels, and makes the the ice melting argument even less tenable.
Jeff P says:
July 13, 2010 at 12:36 pm
“I am talking about rates of sea level rise. If the rate of ice loss has doubled, then sea level rise would also have to double.”
—————
“This is false.”
“This would only be true if the cause of sea level rise was ONLY from ice loss. Clearly this is not the case.”
*****************
VILLABOLO:
I would also factor in thermal expansion.
stevengoddard says:
July 13, 2010 at 1:25 pm
Jeff P
“Uhhmm… You might want to think your sea level argument through a little more carefully. Increasing ocean heat content will also tend to raise sea levels, and makes the the ice melting argument even less tenable.”
*****************************
VILLABOLO:
Ahhhh . . . Steve, with all due respect. Thermal increase would simply be a CO-FACTOR with ice melt. And where would both come from?
villabolo says:
July 13, 2010 at 11:59 am
1) First, you are incorrect in stating that the abstract I cited indicates an acceleration from 2007-2009. It was between 2002-2003 and 2007-2009. I’ve reposted the link below with a quotation:
http://www.agu.org/pubs/crossref/2009/2009GL040222.shtml
“We use monthly measurements of time-variable gravity from the GRACE (Gravity Recovery and Climate Experiment) satellite gravity mission to determine the ice mass-loss for the Greenland and Antarctic Ice Sheets during the period between April 2002 and February 2009. We find that during this time period the mass loss of the ice sheets is not a constant, but accelerating with time, . . .
The abstract also says this
“In Greenland, the mass loss increased from 137 Gt/yr in 2002–2003 to 286 Gt/yr in 2007–2009, i.e., an acceleration of −30 ± 11 Gt/yr2 in 2002–2009”
“a) The drought maps only go back 3 years, which is insufficient time to make a correlation with Greenland’s longer history of ice loss.
b) The ice loss mentioned in both the abstract and NASA’s article predate the drought period that you indicated was accelerating since 2007. GRACE satellites begin to detect increasing ice loss since their first full year of measurements in 2002. There was ice loss detectable even before then.”
The implication of the paper is that melting is responsible for the recent acceleration of ice mass loss, which is what I question. Neither the drought maps nor the GRACE data are of sufficient length to speak meaningfully to any long term trends.
“Irrespective of any acceleration that one may wish to fit into the limited time frame of the drought maps you linked to, there is the fact that the 2002 ice loss (137 billion metric tonnes) was half of 2009 (286 billion tonnes).
c) The drought maps for the past 36 months, which start in July of 2007, indicate very little drought in comparison to the maps of 24 months ago, which start in July 2008. This implies that the period from 7/2007 to 7/2008 would have had little impact on the acceleration. And the year/s before?”
Droughts are not an instantaneous phenomenon,. The fact that large areas of northern Greenland went from no drought to severe to exceptional drought from the 36 mo map to the 24 mo map would seem to indicate that precipitation was in seriously short supply for the intervening 12 months. I don’t know how much of the measured ice mass loss this would account for and I don’t know that anyone else has done that calculation. Since this was another paywalled link I haven’t read the paper, so I can’t say if the authors actually took this factor into consideration or not, but if they didn’t it suggests to me a serious hole in their analysis.
stevengoddard says:
July 12, 2010 at 11:56 pm
richard telford
I have written about GRACE in the last two weeks. How strange that you forgot to mention that.
GRACE measures gravity, not ice thickness. Greenland is subject to large changes in elevation due to post-glacial rebound, and there are very few calibration points available away from the coast.
There is little reason to believe that some interpretations of the GRACE data wrt Greenland ice mass have much validity.
###########################################################
http://www.skepticalscience.com/Watts-Up-With-That-concludes-Greenland-is-not-melting-without-looking-at-any-actual-ice-mass-data.html
GPS receivers have been placed at selected locations around Greenland to measure how much the bedrock is lifting in response to thinning ice sheets. These find the land is now rising up at an accelerating rate. An overall picture is obtained by satellites measuring the change in gravity around the ice sheet. As the ice sheet loses mass, the gravity around Greenland changes, as measured by the GRACE satellites. These measurements find accelerating ice loss.
Gravity measurements by the Grace satelites are evidence of a change in gravity for the less. This is due to loss of ice.
If you truly believe what you say about Grace, possibly you should let NASA know they have it all wrong.
The back and forth on melting/not melting, rising/not rising, etc. is fascinating and great reading. However, I have seen several posts point to artifacts (human, vegetation, etc.) found underneath ice sheets, once melted, that none of the “pro-AGW” crowd seems to respond to.
Clearly there are many challenges to using data on ice mass, ice melt, sea level rise, etc. These include the simple fact that even if our current measurements are perfect, they haven’t been gathering data nearly long enough for anyone to draw any trend conclusions from.
On the other hand, we have INDISPUTABLE evidence that the world was warmer many, many years ago in the form of these artifacts.
To me, this PROVES that the current climate is NOT unprecedented in history.
Where am I wrong?
Does anyone know how many miligals change the lost in ice represents? How big was the isostatic correction in milligals and finally what is the degree of error.
Jeff Green
Good luck finding bedrock in the interior of Greenland. There are only a few mountain peaks poking through the two mile deep ice.
villabolo
Oceanic heat content has been increasing, causing sea level to rise. This further undermines the melt argument.