I really like to write a bit more about such articles, but I just don’t have the time right now. So I will simply recommend you read this guest post at WUWT on Steig’s 2009 Antarctica temperature study. The traditional view has been that the Antarctic Peninsula (about 5% of the continent) has been warming a lot while the rest of the continent has been cooling. Steig got a lot of press by coming up with the result that almost all of Antarctica is warming.
But the article at WUWT argues that Steig gets to this conclusion only by reducing all of Antarctic temperatures to three measurement points. This process smears the warming of the peninsula across a broader swath of the continent. If you can get through the post, you will really learn a lot about the flaws in this kind of study.
I have sympathy for scientists who are working in a low signal to noise environment. Scientists are trying to tease 50 years of temperature history across a huge continent from only a handful of measurement points that are full of holes in the data. A charitable person would look at this article and say they just went too far, teasing out spurious results rather than real signal out of the data. A more cynical person might argue that this is a study where, at every turn, the authors made every single methodological choice coincidentally in the one possible way that would maximize their reported temperature trend.
By the way, I have seen Steig written up all over, but it is interesting that I never saw this: Even using Steig’s methodology, the temperature trend since 1980 has been negative. So whatever warming trend they found ended almost 30 years ago. Here is the table from the WUWT article, showing the Steign original results and several cuts and recalculating their data using improved methods.
1957 to 2006 trend
1957 to 1979 trend (pre-AWS)
1980 to 2006 trend (AWS era)
|Steig 3 PC||
+0.14 deg C./decade
+0.17 deg C./decade
-0.06 deg C./decade
|New 7 PC||
+0.11 deg C./decade
+0.25 deg C./decade
-0.20 deg C./decade
|New 7 PC weighted||
+0.09 deg C./decade
+0.22 deg C./decade
-0.20 deg C./decade
|New 7 PC wgtd imputed cells||
+0.08 deg C./decade
+0.22 deg C./decade
-0.21 deg C./decade
Here, by the way, is an excerpt from Steig’s abstract in Nature:
Here we show that significant warming extends well beyond the Antarctic Peninsula to cover most of West Antarctica, an area of warming much larger than previously reported. West Antarctic warming exceeds 0.1 °C per decade over the past 50 years, and is strongest in winter and spring.
Hmm, no mention that this trend reversed half way through the period. A bit disengenuous, no? Its almost as if there is a way they wanted the analysis to come out.
31 thoughts on “Worth Your Time”
In the initial press releases announcing Steig et al, he was specifically quoted to say something along the lines that this result didn’t contradict other existing findings of cooling during the last 30 years. I’ve been wondering why no one has been highlighting that fact. If anything, Steig et al. seems to weaken the AGW hypothesis a little, since it further confirms 30 years of Antarctic cooling during a time of “rapidly” increasing CO2.
You might want to check out this interesting piece from down under.
What do you think?
Perhaps close to nit-picky, but the sentence “…Steig gets to this conclusion only by reducing all of Antarctic temperatures to three measurement points” is a little bit off. Actually, Steig maximizes the increase in Antarctic temperature by choosing three points. [By points, we are referring to a complicated statistical term.] The result would have been a negative trend if the # of points was 1, and the positive trend would have been lower if any # other than 3 had been chosen.
(On this post, you are discussing only one statistical issue. There are others which make his conclusion more suspect.)
One more note before ending: as you point out, if 30 years had been the time frame, the result apparently would have been a cooling trend. Also, if 60 years had been the time frame, the result again apparently would have been cooling. But the time frame of 50 years gives warming.
OK, let’s get this straight. Climatologists keep telling us we need 30 years of data to detect a ‘current’ trend. The last 30 years of data for Antartica show a negative trend (cooling) even when done by an AGW hypothesis supporter, and this exciting research finding makes the cover of the journal Nature as ‘further proof’ of AGW.
A cynical reader might observe that finding proof for AGW is getting increasingly more desperate over time, otherwise such a study, which really is proof against AGW, would never have been presented as evidence.
OK deniers, to paraphrase Steve McIntyre “due to the unique circumstances of Antarctica, whether it is cooling or warming says nothing about the overall theory of AGW”.
This topic is an excellent demonstration of flawed science, flawed methods, an arguement for archiving and transparency and an example of alarmists torturing data to find what they want to see.
In short, it doesn’t say anything about AGW theory in general. Don’t go “a bridge too far”. Making the arguement that AGW is hogwash because Antartica is cooling is a week point to make. Focus on the good arguements (like positive feedback).
that is a fair point. the antarctic is not the world. but who are you addressing? i don’t see anyone here making the claim that “AGW is hogwash because Antartica is cooling”, just that it is not the confirmatory evidence it was trumpeted as, but rather, the converse. antarctic cooling is certainly not what the GCM models predict.
additionally, given the number of scare scenarios that have been laid out in which warming will cause massive antarctic ice melt and lead to “catastrophic” sea level rises that will sink all of our coastal cities, it does bear watching and has taken on a unique importance as the only repository of ice big enough do cause such an effect.
it also bears remembering that the increased global albedo created by a polar continent is big part of what is keeping earth in an ice age (and in fact triggered it along with the closing of the isthmus of panama.) so as continental temperatures go, it’s a key one.
“Making the arguement that AGW is hogwash because Antartica is cooling is a week point to make.”
It’s not a weak point to make because the climate models predict maximum warming at the poles. For there to be cooling instead of warming… that is a major problem. This is why the study has garnered so much attention in the first place. It’s also why Arctic warming is quoted so often as the best evidence for AGW. Which is why Antarctic cooling is a thorn in the side of the AGW hypothesis at present.
Will Nitschke – as always, you are selectively ignorant. There is a wealth of literature on why Antarctica is expected to be the last place to respond to external forcings, not the first as you seem to think. Surrounded by ocean = slow to respond. Surrounded by land = fast to respond. Which one of those is the north pole? Which one of those is the south pole?
You mean the “wealth of literature” you refer to being an article posted on the subject by the Realclimate website. Which was an extended apology for why the models aren’t predicting what they should. Yet as soon as the dubious Steig paper got published, they were quick to downplay their own ideas.
How slow is slow to respond? 30 years of cooling – even according to Steig who is trying to prove the opposite – very slow indeed. In fact so slow, Antarctic is going backwards. LOL.
north america is surrounded by ocean. should it be slow to respond? what about australia?
the north pole ice is all FLOATING on water. are you arguing that being near continents swamps this effect? where will temperature change more quickly in the evening, on the beach, or on the surface of the water just offshore?
Will Nitschke – thanks for the nice confirmation that you don’t read the literature.
morganovich – you do have to try quite hard to be so dense. You must be determined not to understand. Look up “polar cell” and “antarctic circumpolar current”, learn how to have an open mind, and you might potentially, with a bit of hard study, be able to understand how Antarctica is substantially isolated from the rest of the climate system.
once more, our troll makes a nitpicky dodge and fails to respond to the substance of the criticism and descends into name calling.
you are an utter charlatan. i have serious doubts that you understand the phrases you use. look up “antarctic bottom water” and you’ll see that the antarctic is constantly recycling colder water north and sucking in warm water.
i’m sure that you will have a typically puerile and off topic response, but i am discontinuing our dialogue until you actually provide some data.
sorry to have fed the troll. my mistake.
In Will’s comment prior to mine
Subsequently, hunter responds to the weak arguement. If it hadn’t been made, maybe he/she would be forced to address the sloppy science, flawed methods and lack of transparency issues instead. Your debating opponent always seizes on your weakest point and ignores the strong points you made.
i don’t see anyone here making the claim that “AGW is hogwash because Antartica is cooling”
I’ll make that claim.
Antarctica is a special test case for global warming. We have been told that co2 is well mixed and rising. Antarctica receives the same amount of insolation as the tropics because the air is thinner with few if any aerosols or clouds to reflect the sunlight away.
Since it is the dryest place on Earth it has very little water vapor to confuse the “which GHG is absorbing what” question. Weather flux is almost nonexistent inside the circumpolar wind current
By rights we should see the effect of co2 GH temperature rise over the Antarctic nakedly, or in as close to isolation as is possible on Earth.
Instead we see cooling.
Mr. Gore you lose. Pick up your remaining chips and make your way to the cashier booth.
You don’t have to go home, but you can’t stay here.
“I don’t see anyone here making the claim that AGW is hogwash because Antartica is cooling”
Oh, the nuances. Skeptics do not stake their opposition to catastrophic AGW solely – or even mainly — on the direction of Antarctica temperature trends; but GW pessimists did much media and blog play on the Steig study, saying that Antarctica is actually warming. So flaws in the Steig study are quite relevant because GW pessimists latched onto it. Nevertheless, GW pessimists could claim that short-term Antarctica cooling (or no trend) is consistent with catastrophic AGW. I have been studying GCMs for over 20 years. There is no doubt that the GCMs were initially predicting similar warming at both poles. However, models twenty years ago were quite crude compared to today’s, and some models now allow for differentiated responses at the poles, and they have been parameterized / fitted for geographical differences that have developed in the last twenty years. (This process makes a mockery out of claims that GCMs are based soley on known physical relationships.)
Just because a model can be adjusted to allow divergent polar trends does not mean that it is a reliable model. With sufficient “dummy” variables, a model can be fitted for a wide range of historic trends.
Developments in the Antarctica should not be dismissed lightly. Antarctica weather stations are less subject to micro siting issues than Arctic stations. They also are less subject to the black carbon warming impact of northern hemispheric pollution. Meanwhile, CO2 is viewed as a well-mixed global gas. (Please note: I did not say that UHI is affecting Arctic station readings — but micro siting issues exist independent of UHI.)
Another thing that has always bugged me, the global temperature maps. You’ve seen them. The satellite maps leave the poles out. NOAA has their own satellites.
The warmer scientists always claim that the poles are where they expect to see the results of global warming first.
So whay is it that the temperature maps end at the tip of the Antarctic penensula and the tip of Siberia, Canada’s Sverdrup Islands, and Point Barrow, with those stations microsite warmings smeared peanut butter style to cover the whole Arctic and Antarctic in a glowing red?
Polar orbit is one of the easier methods of flying satellites, witht he advantage of using the Earth’s rotation to allow the sensor sweep to be provided fresh land on each loop, and yet these scientists don’t have a polar orbiting temperature monitoring satellite.
It may be that polar orbit requires a larger rocket for the same weight satellite, thus making it more expensive. Polar satellites are launched from Vandenburg from military launch sights. KSC does not launch true polar orbits without an incredibly expensive “inertial upper stage” that changes the orbit after release.
All in all, polar orbits are expensive and somewhat rare as a result. This may be the complete explanation, or there could be more to it.
To be clear, I agree with Warren that CO2 be the cause of some significant fraction or 1.0 of warming for a doubling of CO2.
Making the arguemments that James and Inquirer make above, although very likely true, are pointless. When was the last time you made these points to an alarmist and they “converted”? If you manage to pin down a casual climate alarmist and make the same points he’ll turn to RealClimate and look up “The Antartic is cooling? Yeah, we knew that” or “The Antartic is warming? Yeah we knew that” (which ever it is at the moment) and you won’t have gotten anywhere. Try talking about this to a casual observer and they will be confused and stop listening.
If there’s anything to be gained from this line of attack, it will be from PhD’s publishing in scientific journals (if the editors let it in).
On the other hand, talk about authors of government funded studies not releasing their data and code, talk about transparency, focus on the fact that a condition of using scientific studies as a basis for public policy should be that all data, methods and code should be released and the study replicated. You don;t need to have a PhD next to your name to be credible and everyone understands what you’re talking about.
Even Gavin Schmidt is having problems fending off those arguements.
I don’t try to convince alarmists. They are liars and charletans operating to confuse and befuddle the public into surrendering their freedoms. The last thing on their minds is ecology.
What I do is endeaver to expose their fraud for the casual alarmist, and give that person a handle to reach for when the gas tax hike is being debated in State Assembly.
You would be surprised how an extra 12 cents a gallon changes heads.
I’ve never noticed Gavin having trouble fending off an arguement, when the delete key is so handy.
BillBodell: “it doesn’t say anything about AGW theory in general>”
AGW is a hypothesis, not a theory. It has not yet been falsified and most of the peer reviewed AGW garbage has not been replicated because the so-called climate scientists refuse to release and archive their data and methods.
Climate science as it stands today is nothing more than a political and economic movement designed to destroy western civilization by reducing it to poverty.
True, a carbon tax would cause problems and the public would never go for it (unless they were truly convinced of the magnitude of the problem, which the public isn’t).
The problem is, they’ll implement cap & trade trade which will hide the cost from the consumer (and add layers of bureauratic inefficiencies and corruption). Consumers won’t see it coming.
i took “proof” in that sentence as being used in the colloquial sense as a synonym to “evidence” rather than in the strict logical sense of “proven”.
by your read, i can see your point, and you are certainly correct about the behavior of our troll, but it still seemed to me that no one was making the claim that all of AGW theory was (or could be) invalidated by this result.
now, for a really interesting result that could well totally invalidate all the existing GCM’s, i would recommend having a look at this:
if water vapor is providing a long term NEGATIVE feedback, then the GCM’s all have the worng sign on their largest feedback component.
i have no idea what the quality of this radiosonde data is (and there seems to be some debate), but the guys calling it “iffy” have some of the “iffiest” data around and i have not yet seen a concrete reason for their opinion, so likely worthy of investigation.
satellites are launched from as near the equator as possible to gain the most rotational momentum and allow for greater payloads. as this momentum goes with the earth’s spin, that is the easy orbit for a satellite. achieving an orbit across the poles is very difficult and requires much more energy and a great deal of orbital maneuvering.
“Climate science as it stands today is nothing more than a political and economic movement designed to destroy western civilization by reducing it to poverty.”
Of course it is! And saying so doesn’t make you look mental. Not at all.
“Of course it is! And saying so doesn’t make you look mental. Not at all.”
You mean like walking from North Carolina (because using a car causes co2) through a snow storm, to Washington DC, to hold up a sign, which you have to study up to find out if the cause is called the war on “global warming”, “climate change”, “extreme weather”, or “weather weirdness” this week, and stand out in the freezing snow, to picket a coal plant that burns natural gas?
You mean that kind of mental?
Hmmm, that’s a good point. It does make me look like a retard, doesn’t it?
Observing that other people are mental of course means that you yourself are not mental. Of course!
Paltridge, G., et al., 2009 – the paper under discussion on climate audit’s current post;
“Trends in middle- and upper-level tropospheric humidity fron NCEP reanalysis data” – uses weather balloon data to show upper level humidity has been dropping since the 1950’s.
Changes in specific humidity in the upper troposphere (300 – 700 mb) may be very significant for temp readings in Antarctica. Because of the Earth’s spin the 300 – 700 mb readings are much closer to the surface, (in fact I think at the pole the ground level pressure is in the 700 mb band).
The gradual trend to lower temps in Antarctica could be independent confirmation of Paltridge.
Hmmm, that’s a good point. It does make me look like a retard, doesn’t it?”
Will, was that you?
It’s nothing to do with the Earth’s spin, James Mayeau – the low pressure at the South Pole is a simple consequence of it lying on a plateau about 3,000m above sea level.
“low pressure at the South Pole is a simple consequence of it lying on a plateau about 3,000m above sea level.”
2860m to be exact.
It’s a fair point. 2860 is higher then Donner Summit.
But I’m kind of enamoured of the low pressure/relative humidity theory because it fits so well with Antarctic cooling.
So I figured I’d find a city or town at or above 2860 then check out it’s barometric pressure.
Telluride Colorado elevation 9078 feet at the airport. http://www.wunderground.com/US/CO/Telluride.html
And guess what. It’s BP is 29.83 inches, which equals 1010.5 millibars.
And as much as I liked that result, because it tended to prove my point, I couldn’t help noticing that this is near the same as our barometric pressure here in Sacramento.
Somethings not right. I’ll get back to you.
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