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.”
If there’s something weird
with your dataset…..
Who ya gonna call?
Michael Mann!
If your history
don’t match the faith….
Who ya gonnal call?
Michael Mann!
He ain’t fraid of no facts….
He ain’t fraid of no facts…..
If your temperature….
don’t match dogma
who ya gonna call
Michael Mann!!!!
Has anybody visited http://climate.jpl.nasa.gov/keyIndicators/index.cfm#CarbonDioxide and looked at the monthly CO2 (the last 8 months of 2008) from Mauna Loa. If you average out it’s flat; no significant increase
I always find it hard to swallow that while the actual measurements show one thing, crunching the numbers show something else.
There’s a reason Mark Twain is famously quoted about lies, damn lies and statistics. Slice and dice the numbers any way you want until you get the results you want.
Who gets credited with the quote about global warming is created by computers?
In looking at the CRUTEM, GISS, and NCDC Surface Temperature data (January 1950 to Dec 2008) for the West Antarctic (available through the KNMI Climate Explorer website)…
http://i40.tinypic.com/vp7pdt.jpg
…there are a number of things that stand out:
1. The NCDC and CRUTEM anomalies have increased since 1969 (period referenced in the study), while GISS remained relatively flat. The study wouldn’t deal with this, just an observation.
2. There appears to be a difference in the number of sampled surface stations between NCDC and the other two from the 1960s to the early 80s. Also not related to the study.
3. But, related to the study, during periods of volcanic activity (excluding El Chichon), year-to-year variability appears to decrease.
4. And the NCDC and CRUTEM data appear to have step changes that could be linked to the 1982/83 and 1997/98 El Nino events.
Did the paper discuss these, especially the ENSO-induced step changes?
If you’ve never heard of ENSO-induced step changes, there are discussions of it here in a two-part series:
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of.html
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of_11.html
And another thing — let’s suppose Antarctica is warming. So what? Does that mean it’s man made? Does that mean it’s caused by too much CO2 in the atmosphere?
We all know the climate is changing and we all should know the climate is supposed to change, that change is natural and expected. The fact the climate in Antarctica may also be changing should come as a surprise to no one.
I am from Missouri, so you’ll have to show me. Anything from the inventor of the “hockey stick” (not the “discoverer”, the “inventor”) needs to be scrutinized with extra care. First, let’s attempt to establish what’s really happening and then why.
Hmm…could someone please point to any respectable definition of ‘Interpolate’ that does not mean ‘we made it up’? Furthermore, whenh was Interpolation accepted as a legitemate scientific method? Isn’t Interpolation completely at odds with Empirical Obsevation?
“We’ve really filled in a huge gap.”
So very telling.
Please see the insightful comments by Roger Pielke Sr. @ur momisugly climatesci.org.
He concludes:
“In terms of the significance of their paper, it overstates what they have obtained from their analysis. In the abstract they write, for example,
“West Antarctic warming exceeds 0.1C per decade over the past 50 years”.
However, even a cursory view of Figure 2 shows that since the late 1990s, the region has been cooling in their analysis in this region. The paper would be more balanced if they presented this result, even if they cannot explain why.”
When I interpolate or “stretch” my photographs, they get fuzzy. Perhaps these guys are a little “fuzzy”.
This seems a little like the early settlers pulling up the the Carolina shores and proclaiming that the entire continent is swamp and forest. You can’t tell what the margarita tastes like by sampling the salt on the rim of the glass.
This sounds like a job for McIntyre, and fortunately, it looks like he’s already on it.
You shouldn’t all be paranoid abou this study. The authors themselves remain quite cautious about the reasons behind the warming
“We’re almost certain that greenhouse gas increases are contributing to this warming, but what’s difficult is to attribute this warming and so say how much is down to natural warming and how much down to anthropogenic causes.”
Drew Shindell from Nasa’s Goddard Institute for Space Studies (Giss) in New York. (in the BBC press coverage)
It’s disturbing that the ‘margin of error’ (whatever that actually means) is more than 60% of the claimed average. It seems to me that this makes the claim virtually useless.
Clearly a threat if the temperature in Antarctica goes from -20C to -19C over the next 100 years.
Correct me if I am wrong but I thought that satellite data was incomplete over the poles. The last satellite picture that I saw showing icecap depth covered only 78% of Antarctica (there is a similar “hole” in coverage in the northern icecap also). The article states that satellites “have the advantage of covering the entire continent”. Are there satellites that completely cover the Antarctic continent?
“Steig’s team used mathematical models to establish the relationship between the ground and satellite measurements between 1979 and 2006 and then used the correlation they found to calculate temperatures for the interior going back to 1957.”
Mathematical models are a good substitution for actual measurements. /sarc off
“Using airborne ice-sounding radar, scientists discovered a layer of ash produced by a ’subglacial’ volcano”
How does this affect the albedo of the ice/snow in that area? Isn’t there going to be more meltoff and warmer termperature due to the ash as well as the increase in meltoff from the volcano?
I am easily reminded of those blokes walking up and down public roads wearing sandwich boards stating:
PREPARE THYSELF:THE END IS NIGH
This is a new religion. They have an inquisition, burn skeptics (scientists) at the stake (lose their jobs), They have this profound faith in the future heaven and hell (heaven is an atmosphere without CO2, hell being an atmosphere with CO2). They even have an afterlife: Antarctica; after the global warming, Antarctica will be the only habitable place on the planet and only a certain number of human beings will be let in, the others will die burning.
That’s it ! I finally discovered how some “skpetics” do to have those famous petitions of “scientists” agains AGW. They actually… pay them!
I’m not kidding, check this link http://www.guardian.co.uk/environment/ethicallivingblog/2009/jan/19/1
Scientists who attend the International Conference on Climate Change to be held in New York, 8-10 March 2009 (organized by the Heartland Institute) get a $144 reward if and only if they sign the petition claiming skepticism against AGW.
Ahhh, this is science as we like it, isn’t it? Can we also receive a Macy’s card, please?
Perhaps the Steig did not communicate well as he explained what he did in the study, but he is not doing interpolation — he is doing extrapolation. When one knows the end points and fills in missing some values in the middle, that is interpolation. Steig explains that they established a relationship between two sets of variables in the last twenty five years and then based on that relationship estimated temperatures in areas of the continent without weather stations for the previous 25 years. That is extrapolation which is more prone to error than interpolation.
The alarmists really are getting desperate now. Their arguments are so frequently contradictory and so utterly unscientific one wonders what sort of insane, twisted world we must live in for them to be taken seriously. All they’ve done here is fudged a few figures to suit their agenda. This isn’t science, it’s politically driven rubbish.
We simply have to hope that nature continues to fly in the face of these idiots. There’s only so many times they can cry ‘wolf’ before even the mainstream media see them for the disgraceful crooks they really are.
“To identify causes of the warming, the Team turned to Dr Schwindle of ORACLE’s Institute for Space Studies in Delfoi, who has used cristal balls to identify mechanisms driving Antarctica’s enigmatic temperature trends.”
Volcanos? Really? Surely with a claim like that, you will shortly be providing us with some evidence that there has been a -trend- in vulcanism in West Antarctica over the past 50 years. The argument that West Antarctica is hotter because there are lots of volcanoes there is completely irrelevant (and rather misguided given the limited effect of volcanoes on local temperatures over the long-term) IF there is no trend in vulcanism. Stieg et al are not arguing that West Antarctica is warmer or colder than East Antarctica, rather that it has warmed faster over the past 50 years.
For those hoping that this paper will be proven wrong, don’t hold your breath. They seem to have crossed their Ts and dotted their Is on the analysis this time around, and others who have produced studies of Antarctic temperature (e.g. Monaghan) concede that they are revising their position on long-term temperature trend in light of the evidence presented.
It is interesting how these guys insist on averaging averages of averages of non-existent data, which they have “in-filled” with more averages that they have deduced.
I believe I was taught the error of averaging averages in grade school. I guess statistics have changed over the last 40 years?
Since we are told that WEATHER is not predictable, and what we measure IS the weather, how can they put any reliance on this deduction??
HAHAHAHAHAHAHAHAHAHAHAHAHA
Just what models were used to determine these NEW temperatures. Surely they did not use the same types of modelling that was projecting non-existent warming before this exercise?
Tell me it’s not ture.
New Opportunity….beach front property
Antarctica is warming! Buy Now!
Last fall, before the Arctic desended on the Midwest, I was fortunate enough to go golfing. Unfortunately I lost my scorecard, and I have no memory of what my score was. I am suposed to enter my scores into the handicap system, in order to play fairly against others who keep a handicap.
I do remember playing the last two holes. I made a birdie on 17 (unusual), and a par on 18 (not unusual).
Now if I use the method employed by the scientist in the above study, do I extrapolate the known data, to the unknown holes and post a -9, for the round? Or do I take my average scores for each missing data point, and then add the two relatively good scores at the end?
Missing data is data which is not known, and therefore no amount of “deductive reasoning” will contain a useful trend to analyze. Too much of it is reduced to an average, and what you care about is the departure from the average.
Steve M.,
“Using airborne ice-sounding radar, scientists discovered a layer of ash produced by a ’subglacial’ volcano”
How does this affect the albedo of the ice/snow in that area? Isn’t there going to be more meltoff and warmer termperature due to the ash as well as the increase in meltoff from the volcano?
The volcano in question erupted 2,000 years ago The ash layer from it is now below ice and therefore has no relevance to recent albedo. As for “increase in meltoff from the volcano”, it seems possible that any current activity may affect ice sheet flow in that specific region, but if there are those who think that sub-ice vulcanism is contributing significantly to surface temperature trend then I look forward to their figures on the matter.
“Stieg et al are not arguing that West Antarctica is warmer or colder than East Antarctica, rather that it has warmed faster over the past 50 years.”
Warmed faster than what?