Above: Mt Erebus, Antarctica
picture by Sean Brocklesby
A press release today by the University of Washington makes a claim that Antarctica is warming and has been for the last 50 years:
“The study found that warming in West Antarctica exceeded one-tenth of a degree Celsius per decade for the last 50 years and more than offset the cooling in East Antarctica.”
…
“The researchers devised a statistical technique that uses data from satellites and from Antarctic weather stations to make a new estimate of temperature trends.”
…
“People were calculating with their heads instead of actually doing the math,” Steig said. “What we did is interpolate carefully instead of just using the back of an envelope. While other interpolations had been done previously, no one had really taken advantage of the satellite data, which provide crucial information about spatial patterns of temperature change.”
Satellites calculate the surface temperature by measuring the intensity of infrared light radiated by the snowpack, and they have the advantage of covering the entire continent. However, they have only been in operation for 25 years. On the other hand, a number of Antarctic weather stations have been in place since 1957, the International Geophysical Year, but virtually all of them are within a short distance of the coast and so provide no direct information about conditions in the continent’s interior.
The scientists found temperature measurements from weather stations corresponded closely with satellite data for overlapping time periods. That allowed them to use the satellite data as a guide to deduce temperatures in areas of the continent without weather stations.
…
Co-authors of the paper are David Schneider of the National Center for Atmospheric Research in Boulder, Colo., a former student of Steig’s; Scott Rutherford of Roger Williams University in Bristol, R.I.; Michael Mann of Pennsylvania State University; Josefino Comiso of NASA’s Goddard Space Flight Center in Greenbelt, Md.; and Drew Shindell of NASA’s Goddard Institute for Space Studies in New York City. The work was supported by grants from the National Science Foundation.
Anytime Michael Mann gets involved in a paper and something is “deduced” it makes me wary of the veracity of the methodology. Why? Mann can’t even correct simple faults like latitude-longitude errors in data used in previous papers he’s written.
But that’s not the focus of the moment. In that press release they cite NASA satellite imagery. Let’s take a look at how the imagery has changed in 5 years.
NASA’s viewpoint – 2004
Click for larger image
NASA’s Viewpoint 2007 (added 1/22)
NASA’s viewpoint – 2009
Earth’s viewpoint – map of Antarctic volcanoes
From the UW paper again:
“West Antarctica is a very different place than East Antarctica, and there is a physical barrier, the Transantarctic Mountains, that separates the two,” said Steig, lead author of a paper documenting the warming published in the Jan. 22 edition of Nature.
But no, it just couldn’t possibly have anything at all to do with the fact that the entire western side of the Antarctic continent and peninsula is dotted with volcanoes. Recent discovery of new volcanic activity isn’t mentioned in the paper at all.
From January 2008, the first evidence of a volcanic eruption from beneath Antarctica’s ice sheet has been discovered by members of the British Antarctic Survey.
The volcano on the West Antarctic Ice Sheet began erupting some 2,000 years ago and remains active to this day. Using airborne ice-sounding radar, scientists discovered a layer of ash produced by a ’subglacial’ volcano. It extends across an area larger than Wales. The volcano is located beneath the West Antarctic ice sheet in the Hudson Mountains at latitude 74.6°South, longitude 97°West.
UPDATE 1/22
In response to questions and challenges in comments, I’ve added imagery above and have a desire to further explain why this paper is problematic in my view.
The author of the paper himself (Steig) mentions the subglacial heat source in a response from “tallbloke” in comments. My issue is that they don’t even consider or investigate the possibility. Science is about testing and if possible, excluding all potential candidates that challenge your hypothesis, and given the geographic correlation between their output map and the volcanic map, it seems a reasonable theory to investigate. They didn’t.
But let’s put the volcanoes aside for a moment. Let’s look at the data error band. The UAH trend for Antarctica since 1978 is -0.77 degrees/century.
In a 2007 press release on Antarctica, NASA’s describes their measurement error at 2-3 degrees, making Steig’s conclusion of .25 degrees Celsius over 25 years statistically meaningless.
“Instead, the team checked the satellite records against ground-based weather station data to inter-calibrate them and make the 26-year satellite record. The scientists estimate the level of uncertainty in the measurements is between 2-3 degrees Celsius.”
That is from this 2007 NASA press release, third paragraph.
http://earthobservatory.nasa.gov/IOTD/view.php?id=8239
Also in that PR, NASA shows yet another satellite derived depiction which differs from the ones above. I’ve added it.
Saying you have a .25 deviation over 25 years (based on one-tenth of a degree Celsius per decade per Steig) with a previously established measurement uncertainty of 2-3 degrees means that the “deduced” value Steig obtained is not greater than the error bands previously cited on 2007, which would render it statistically meaningless.
In an AP story Kenneth Trenberth has the quote of the day:
http://news.yahoo.com/s/ap/20090121/ap_on_sc/sci_antarctica
“This looks like a pretty good analysis, but I have to say I remain somewhat skeptical,” Kevin Trenberth, climate analysis chief at the National Center for Atmospheric Research, said in an e-mail. “It is hard to make data where none exist.”
“Africa Cooling according to scientists”. – AP headline.
The continent of Africa has been cooling by 0.0569C per decade (+/-0.123C) over the last several periods ending in the autumn timeframe of the last simulation.
The results have been reviewed by 3 eminent individuals.
Reviewer #1 corrected the improper terminology of siting effects.
Reviewer #2 provided a climate simulation which reproduced the results except for the gridbox defined by -20,25 by -20,30 which was out of sinc on some non-lateral issues.
Reviewer #3 reacted vehemently to the proposition that aerosols forcings had been properly accounted for in the effect of spatial patterns of spring westerlies but this has been compensated for through atmospheric padding.
“The satellite data collected for the study has confirmed our worst fears” said John Holmes of the National African Atmospheric Studies Centre.
The data for this study will be made available (is available at the time of printing) through ftp at the next automation – site ACVS.
Here’s a completely independent study that also shows the MWP to be cooler than today:
http://www.agu.org/pubs/crossref/2008/2008GL034187.shtml
It’s a temperature reconstruction made using geothermal heat flux and borehole temperature data.
The “Alarmists” part of the Arctic “warming” is all over the media, from CNN to BBC and most National Broadcasters and News Papers in Europe.
Mission Accomplished!
I agree with Matty way up top. This has made some headlines on Reuters and elsewhere which is troubling. This headline makes a rather bold, one-sided claim. Amazing how easy it is to mislead.
Wow their scientific evidence is about as rock solid as the foundation for the tower of pisa… oh wait didn’t one side of those foundations crumble? Anyway, even if the climate was changing there would be no proof that it was because of polution. I agree polution can be bad and should be reduced with the right intentions, not just so more money can poor into the pockets of Government officials. However, the earth has natural cycles it goes through, we cannot really expect the climates to stay the same for all of eternity can we? I mean was the Ice Age because the humans back then weren’t using enough aerosol cans to keep the world warm? The problem with humans is that we think we are so powerful we can do anything and that we are the center of the universe and that every problem and solution somehow comes from amongst our ranks.
foinavon (16:55:45) :
REPEATING MY POST FROM ANOTHER THREAD, AT
http://wattsupwiththat.com/2009/01/17/divergence-between-giss-and-uah-since-1980/#comment-74925
Allan M R MacRae (22:02:29) :
Jan 18 – foinavon (14:31:17) :
I think you are writing nonsense re Spencer and Christy’s UAH LT measurements.
Rather than just quoting all these papers, you should quote the magnitude of the corrections involved.
I think you will find the corrections are practically insignificant.
For plot of UAH LT global temperature anomalies in 2002, see Figure 1 in
http://www.apegga.org/Members/Publications/peggs/WEB11_02/kyoto_pt.htm
For a 2008 plot, see
http://icecap.us/images/uploads/uah7908.JPG
I cannot see any material difference – can you?
Also, UAH and RSS LT temperatures seem to be converging, and the corrections are not all at UAH – many are at RSS.
Please quote the actual numbers if you wish to make a valid point.
Regards, Allan
Is this statement really true….Did this guy say that.
apparently it’s NOT what he said.
E.M.Smith (17:11:36) :
“Odd that you left ‘replication’ off that list… Is that why we have not gotten publication of the raw data and methodology of GISS ?”
GISS temperatures are replicated here:
http://www.cru.uea.ac.uk/cru/data/temperature/
The papers describing the GISS methodology can be found here:
http://data.giss.nasa.gov/gistemp/
That took me all of 30 seconds to find.
Don’t know where the raw data is, but I could probably find it in a few more minutes with Google…
The 2009 pic totally lacks a scale, making it useless and suspicious.
Budahmon,
Prof. Brook did not say that.
He states what he did say over at Jennifer Morhasy’s website on the thread about this same topic.
He was badly quoted.
I’ve read the paper now fairly rapidly. The data was created using odd means of surface satellite measurement not lower troposphere, cutting out portions of the satellite data for what was assumed to be clouds. Ground stations were used in a low influence fashion according to one author and RegEm was used to interpolate the rest.
What I do know is that real data, not interpolated data shows a ring around the antarctic hasn’t warmed!
http://digitaldiatribes.wordpress.com/2008/11/30/2008-update-on-antarctic-temperatures-rss/
I am pretty skeptical about this paper because sat trends and ice have both shown cooling. Keep in mind Michael Mann will use anything as a proxy for temperature, as long as it has an uptick. The fact that Ice isn’t as good a proxy as some tree a hundred miles from the temperature it correlates with is a real head scratcher.
Pieter F (10:13:33) :
“Zeke: Volcanoes? Yes, really.
You are missing a fundamental point of the empirically based skeptics. We do not deny that there was a period of warming late last century culminating in the 1998 El Niño event. Warming trends are exaggerated at the poles. Therefore, a warming in Antarctica late last century is not surprising. However, since 1998 there has been an overall average global cooling and that too has been more profound in Antarctica. The AGW alarmists are having difficulty resolving the new trend (predicted, by the way, years ago by the solar scientists). So they turn to master alarmist computer modeler, creator of the hockey stick that served Mr. Gore so well.
West Antarctic has many very active volcanoes, even several below the ice sheet. It is warmer in the west than the rest of Antarctica where all indications are that it is distinctly cooler there. For a decade now, things are globally cooler. Why is it so difficult to understand that the West Antarctic volcanoes contribute to an anomalous warming in that area?”
Pieter F,
There has been no warming at the SH.
Long term this paper in Nature will only help the skeptic cause as they desperately re-hash old data to prove a point. Nearly all polls are showing that a majority of people just aint believing it (AGW) any more. Only problem.. Journals like Nature may be hit permanently re credibility problem in the future
Chris V. (18:30:00)
Nice try, but it’s not that simple…
See LIMITS ON BOREHOLE-BASED RECONSTRUCTIONS From Surface Temperature Reconstructions for the Last 2,000 Years.
Committee on Surface Temperature Reconstructions for
the Last 2,000 Years, National Research Council ISBN: 978-0-309-10225-4 Page 80.
This identifies a number of problems with borehole records used as temperature proxies. It seems that borehole records are worth the same critical auditing that that has been given by Anthony Watts to surface stations. Perhaps http://www.boreholestations.org is not too far away.
Chris V. (18:30:00) :
Here’s a completely independent study that also shows the MWP to be cooler than today:
http://www.agu.org/pubs/crossref/2008/2008GL034187.shtml
It’s a temperature reconstruction made using geothermal heat flux and borehole temperature data.
Completely independent of what exactly? Doesn’t make it correct does it? Keep on trying as hard as you like you cannot make the MWP disappear. I don’t believe you or the dodgy study you quoted. Next you’ll be calling it the MCP.
265 comments already!! WOW!! People see the words “warming in the Antarctic” and “Michael Mann” together and the fur starts flying!
E.M.Smith (16:37:03) :
Simon Evans (15:23:38) :
E.M. Smith,
This isn’t about ‘calibration’ it is all about “NEVER let your precision exceed your accuracy. – Mr. McGuire”
We have a precision of 0.1 put on data with an accuracy of 1.0.
I think you have misunderstood my point. If a bias in a station reading is consistent, then the trend can be accurately assessed,
And you sir, have completely missed mine. THERE CAN BE NO TREND OF LESS THAN ONE DEGREE. PERIOD.
I don’t care what your calibration error is.
I don’t care how you do the measuring.
I don’t care how you process the data.
I don’t care how biased the data are.
Your accuracy is measured in degrees. There can be no precision that is valid in less than full degree increments. There can be no trend of less than full degrees. ANY claim of a trend IN EITHER DIRECTION of fractional degrees is a mathematical farce.
This isn’t up for debate, it is a fact of mathematics.
Actually it isn’t ‘a fact of mathematics’, you appear to have confused accuracy with resolution.
MarcH (19:57:00) :
Looking for the perfect temperature proxy? Sorry, it doesn’t exist.
Tree rings, speleothems, borehole temps, etc. all have their inadequacies.
But when multiple independent proxies (each with their own different shortcomings) show the same thing, it is strong evidence that the results are real.
Your link also says this (pg 81) regarding the major potential source of errors (percolating ground water): “….. This is further evidence that the groundwater bias is quantitatively small in borehole-based temperature reconstructions on larger scales. The borehole temperature database has been screened to eliminate other sorts of groundwater influences that are more readily apparent”.
Jeff Id (19:30:36) :
I am pretty skeptical about this paper because sat trends and ice have both shown cooling. Keep in mind Michael Mann will use anything as a proxy for temperature, as long as it has an uptick. The fact that Ice isn’t as good a proxy as some tree a hundred miles from the temperature it correlates with is a real head scratcher.
Jeff – if you keep working with MM’s data/techniques and scratching your head – you’ll run out of hair… 🙂
Neil Crafter (21:12:14) :
“Completely independent of what exactly? Doesn’t make it correct does it? Keep on trying as hard as you like you cannot make the MWP disappear. I don’t believe you or the dodgy study you quoted. Next you’ll be calling it the MCP.”
Completely independent of Mann, tree rings… A totally different data set and method.
Have you read the paper? Do you have any technical criticisms of what they did (other than you think it’s “dodgy”)? How did you arrive at that conclusion?
Responses to various points put to me above:
1. regardless of whether or not you believe there has been ozone depletion, the models presume that. Thus this paper does not contradict previous statements suggesting that the modeling matches cooling since the late 70s. By the way, if there had been no ozone depletion then the cooling of the lower stratosphere would be an even stronger indication of GHG warming.
2. E.M. Smith: “Your accuracy is measured in degrees. There can be no precision that is valid in less than full degree increments. There can be no trend of less than full degrees.” Those are your premises and not mine, so there is little point in demanding whether I accept the conclusion you draw from them.
3. JimB: “You can address all the arguments here with word play for ever.” I wasn’t. I was making the point about double standards. This thread is packed with evidence of it. I said that I agreed with the general principle of openness – is that not direct enough for you?
Phil. (15:40:04) :
tetris (11:48:46) :
Anthony:
Has anyone in the Steig, Mann, et. al. team ever sat down and done a “back of the envelope” calculation to “deduce” the calories necessary to get all that ice to melt so that it actually will raise sea levels?
[snip]
REPLY: Phil. It is rude to answer a question posed to the host with a snide remark to the person posing the question. Please don’t do it again. I’ll answer my own questions, thank you. – Anthony
Be my guest, it wasn’t a snide remark it was an answer to his question!
George E Smith: “We have quite a few weak debaters attend here, and attack the messenger…”
Sadly, I have to agree with you. For example: “Keep in mind Michael Mann will use anything as a proxy for temperature, as long as it has an uptick…”
On the matter of AGW scientists appearing at sceptic conferences, it’s not going to happen. The issue has become too highly politicised and polarised. From both the pro- and anti-AGW perspectives, the mere attendance at such a conference would be seen as giving legitimacy to the sceptical viewpoint. For this reason alone, the AGWers are not likely to bite.
The way I see it, relations between pro- and anti-AGW climate scientists have now reached a point where rapprochement is not possible. There’s too much water under the bridge and both sides have staked out a position from which they are unlikely to resile.
The likely outcome, providing the AGW science is correct, will be a completion of the current paradigm shift, as the sceptic position becomes more and more marginal.
At a later date there may well be a degree of convergence between today’s pro- and anti- positions, in terms of both the influencing mechanisms and effects of AGW, but that belongs to the future.
Have a look at the link here, there is a letter contained in the comments section from a NASA Metrologist in the Arctic:
http://co2sceptics.com/news.php?id=2606
Interesting reading.
Anthony,
This is the best scientific blog on the net. Great Stuff and thank you.
There seems to be a mild risk here that the WUWT may mislead readers. Two sets of images, one showing a predominantly cooling Antarctic from captioned ‘NASA Viewpoint 2004’,
another from this year showing an Antarctic dominated by West Antarctic warming, captioned ‘NASA Viewpoint 2009’ are displayed, the title speaks of an ‘evolution of viewpoint’,
the text has … Let’s take a look at how the imagery has changed in 5 years.… strongly implying that the new work contradicts the earlier viewpoint and has brought
about a shift of opinion. It does not.
The two images cover different periods, the 2004 picture is of the period 1982-2004 [Source], the
second is of the 5 decades to present day covered by Steig et al [large version with
scale]. So the two images do not illustrate an ‘evolution’ of view about the same thing at all, (perhaps the captions could be updated to make this clearer, currently they
invite direct comparison of the two images). Nor has the scientific understanding been shifted, just refined. As the lead author says;
Our results do not contradict earlier studies suggesting that some regions of Antarctica have cooled. Why? Because those studies were based on shorter records (20-30 years,
not 50 years) and because the cooling is limited to the East Antarctic. (from RealClimate)
On Mann et al linking this to AGW – doubtful. The earlier studies and the image in particular were widely used as evidence that global warming was not actually ‘global’, for
example by Steve Goddard. Professor Mann’s remark is to the effect that this argument
is inconsistent with the results of this new study. The paper itself speculates about changes in wind patterns drawing more warm air into the region but Steig himself says this
on attribution
“We now see warming is taking place on all seven of the earth’s continents in accord with what models predict as a response to greenhouse gases,” said Eric Steig, a professor
of earth and space sciences at the University of Washington in Seattle, who is the lead author of a paper published Thursday in the journal Nature.
Because the climate record is still short, more work needs to be done to determine how much of the warming results from natural climate swings and how much from the warming
effects of carbon dioxide released by the burning of fossil fuels
Its hard to see how that could be any clearer. A proper scientific expression of what we know and what we do not.