Just a little something he threw together
Guest Post by David Middleton
First the breath-taking headlines…
- Scientists Report Faster Warming in Antarctica, New York Times (WUWT commentary)
- West Antarctic Ice Sheet warming twice earlier estimate, BBC
- West Antarctica warming much faster than previously believed, study finds, NBC
- Western Antarctica is warming three times faster than the rest of the world, Grist
Oh noes out the wazzoo!!!
What could possibly have caused such an out-pouring of Mr. Bill impersonations?
Apparently this did…
Central West Antarctica among the most rapidly warming regions on Earth
David H. Bromwich,1, 5 Julien P. Nicolas,5, 1 Andrew J. Monaghan,2 Matthew A. Lazzara,3 Linda M. Keller,4 George A. Weidner4 & Aaron B. Wilson1
Nature Geoscience Year published: (2012) doi:10.1038/ngeo1671
Received02 May 2012 Accepted15 November 2012 Published online23 December 2012
Abstract
There is clear evidence that the West Antarctic Ice Sheet is contributing to sea-level rise. In contrast, West Antarctic temperature changes in recent decades remain uncertain. West Antarctica has probably warmed since the 1950s, but there is disagreement regarding the magnitude, seasonality and spatial extent of this warming. This is primarily because long-term near-surface temperature observations are restricted to Byrd Station in central West Antarctica, a data set with substantial gaps. Here, we present a complete temperature record for Byrd Station, in which observations have been corrected, and gaps have been filled using global reanalysis data and spatial interpolation. The record reveals a linear increase in annual temperature between 1958 and 2010 by 2.4±1.2 °C, establishing central West Antarctica as one of the fastest-warming regions globally.
[…]
The manufactured “record reveals a linear increase in annual temperature between 1958 and 2010 by 2.4±1.2 °C.” That’s a 50% margin of error on the reconstruction that supposedly corrected the recording errors.
I haven’t purchased access to the paper (nor do I intend to); however, the freely available supplementary information includes a graph of their reconstructed temperature record for Byrd Station. It looks very similar to the NASA-GISS graph that doesn’t show any significant recent warming trend.
The NASA-GISS data (GHCN & SCAR) for Byrd Station are in two segments: 1957-1975 and 1980-2012. The 1957-1975 series depicts a moderately significant (R² = 0.19) warming trend of about 1.0 °C per decade. The post-1980 series depicts a statistically insignificant (R² = 0.01) trend of 0.3 °C per decade.
Bromwich et al., 2012 get their 2.4 °C of warming from 1958-2010 (0.4 °C per decade) by stitching together the fragmented data sets. If I just combine the two NASA-GISS series, I get a trend of about 0.4 °C per decade…
But, almost all of that warming took place before 1988. And Byrd Station has seen no warming (actually a slight cooling) since 1991.
Furthermore, the corrected temperature record of Bromwich et al., 2012 appears to actually depict more cooling since 1991 than the uncorrected data…
Can anyone please enlighten me? Is the NASA GISS data for Byrd station raw data, or has it already been adjusted in some way?
I found the same things and have a copy of the paper. Essentially, this paper represents an attempt to use the 2011 updated AWS data and paste it onto the manual data to find a trend. Although the initial submission of the paper had effort put into AWS data, in its final form O’Donnell 10 was just a correction to S09 math. If the data changes, it will change the result.
I downloaded the recent AWS and Manual data from Byrd, ran an anomaly calc and subtracted from Bromwich 12 results. I got a perfect match at all points where data existed. I have spent no time on the infilling, but I am very skeptical of the infilled series quality.
I received the old AWS data from Nic Lewis and subtracted from the new, and found that the corrections were about 1 C up and then 1C down later. Basically they are very large. The Bromwich paper discusses some of the rationale behind the corrections but does not provide enough information to replicate them.
The whole point is that if the corrections are reasonable, then the non-infilled result is probably reasonable. The infilling of gaps is questionable at best.
Oh, and the thermometer data (not infilled) shows about 2C over 52 years where the paper reports 2.4 with infilled data.
RealClimate Bore Hole 1126. “What Bromwich at al. have shown is that Byrd Station is actually cooling in the last 2 decades. Warming, if any, happened in the 1980s. It is inconsistent with other studies showing recent warming at the same location.”
Comment by Berényi Péter — 26 Dec 2012 @ur momisugly 4:39 PM
It was a comment to The heat is on in West Antarctica by Eric Steig, boreholed properly as all inconvenient but true propositions are supposed to at that site.
BTW, I have painstakingly re-digitized Figure S10 of the Supplementary Information and the trend mentioned above turns out to be -1.74°C/cy.
If this is how one of the most rapidly warming regions on Earth looks like, the rest should be cooling even faster, should not it? (I am fed up with bloated headlines in scientific journals that contribute nothing to science but are designed to be picked up by MSM zombies disinclined to check the background.)
so Antarctic scare story- false,
Kilamanjaro ice loss- nothing to do with AGW, currently putting on ice,
Himalayan glaciers- another false story currently putting on ice,
Frogs dying in S America- nothing to do with AGW
All James Hansen prediction from the 1980s- wrong.
@ur momisugly Dodgy Geezer
I have complained – although I struggled to get it into the 1500 characters allowed by the BBC to complain online.
Here it is:
The 2.4C increase in average annual temperature 1958 to 2010 is subject to a 50% error margin of + or – 1.2 degrees. Mentioning this takes one more sentence.
See the supplementary information for this paper. Almost all of the warming took place before 1988 and there has been no statistically significant warming (in fact cooling) since 1991. See – http://www.nature.com/ngeo/journal/vaop/ncurrent/extref/ngeo1671-s1.pdf. The BBC reports warming for a period when there is cooling.
The article quotes a co-author – “What we’re seeing is one of the strongest warming signals on earth” – without mentioning uncertainty, without assessing the method of filling in the Byrd station data, (essentially guesswork), giving a statistically insignificant (R2=0.01) trend of 0.03 degrees per decade post 1980.
“The authors say they are confident that the data from Byrd Station is representative of the region …. for a considerable distance.”
Might some perspective be given, say that the WAIS is 8 times larger than the whole of the UK, an area of 765000 sq miles? Is that confidence justified and if so on what basis?
The authors say they are unable to say if any warming is by humans. McGrath quotes these scientists stating that in their “opinion” it is probably human caused and that “some of it IS influenced by human acts”. No comment on how scientific these scientists are being in voicing such an “opinion”?
The paper overall does not say what McGrath reports. This is not about “warmist” or “skeptic”, but an obvious inability to take a science paper, consider it, and give a reasonable and accurate report of its contents and findings with some intelligence applied to them by the correspondent or journalist.
This is not journalism or reporting, but, deliberate or not, advocacy.
@Rob Decker
“After all, O’Donnell et al’s own reconstruction at Byrd was highly questionable, since it was based upon temperature trends from stations a 1000 km away across the Ross sea, which arguably have next to nothing to do with the temperature trends at Byrd.”
What do you think they did in this paper to infill the missing temps? And how do you think NASA-GISS extrapolate temps with their 1200km grids?
Hockey stick graph- gone to AGW heaven,
The post-1980 series depicts a statistically insignificant (R² = 0.01) trend of 0.3 °C per decade.
I hope you mean .03, because .3 is rather significant….
And yet more linear regressions. The only function this field knows apparently. Y=mx+b. I’m sure the real world works that simply.
Rob Dekker,
That will be O’Donnell, 2013. It’s even worserer than we thought!
mitigatedsceptic says:
December 27, 2012 at 2:11 am
“Peer reviewed?”
More like steer reviewed, you know, a bunch of bull with no balls to it.
The derision this “science” deserves is almost more than I can fathom. As Triumph the puppet dog might say, “Another peer-reviewed climate paper… for me to poop on.”
Look, it’s simple. All they’ve got left is catastrophic sea level rise from the Greenland Ice Cap(which sits in a bowl) sliding into the sea, or the WAIS suddenly falling into the sea.
With Catastrophic AGW wisping into willows and plain vanilla AGW being recognized as a good thing, with Climate Change being accepted as normal, with Climate Weirding being disproven statistically, the clandestine coterie of climate have fooled themselves into thinking the people will fall for this. Sure, it is easy to picture, but is it easy to happen?
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David,
In their Supplementary Table S1 they report a post-1980 decadal trend of 0.51+/-0.52C. Although not statistically significant, it is in fact a bit larger than their 0.47+/-0.23C decadal trend for the whole period. Do you know where this discrepancy with your results comes from?
Thanks,
Mikel
BBC puts up these articles and rarely allows any reader feed back comments anymore.
They get way with posting misinformation all the time & there is little anyone can do about it.
It would be nice to see a full page retraction or another major media source take them to task but it never happens
MattN says: December 27, 2012 at 4:22 am
The post-1980 series depicts a statistically insignificant (R² = 0.01) trend of 0.3 °C per decade.
I hope you mean .03, because .3 is rather significant…
Not with R² = 0.01
The BBC article is so misleading… I have complained to the BBC about the presentation…
See complaint below:
The article references a paper detailing how a temperature record from a single weather station in West Antarctica was reconstructed and then showed a significantly higher rate of warming than in the rest of the continent. This is not a critique of that paper which has its own flaws. This is a complaint about the map at the top right of the article which has the following caption: “The data from Byrd Station shows rapid warming on the west Antarctic ice sheet” The map is in fact a contour map showing the correlation coefficient between the temperature record at Byrd and the other stations in Antarctica, by definition, the value of the correlation coefficient at the Byrd station will be 1. Every other station in Antarctica has a correlation coefficient of 0.3 or less… this is a rather moderate level of correlation and suggests that rebuilding the temperature record based on the other weather stations will be unreliable. The fact that there is a massive red bulls eye at the Byrd station is a mathematical certainty, the size of the bullseye is a function of the spacing between the weather stations and the mapping software. The big red bulls eye is wholly unrelated to the warming derived from this reconstruction. To use this map and to then label it with the caption is to deliberately mislead, and shows the bias in reporting of issues relating to AGW.
The R² equaling 0.01 makes the trend insignificant. This essentially means that the 0.3 °C per decade trend only explains 1% of the variation in the time series. All of that 0.3 °C per decade is driven by the 1.0 °C per decade trend from 1957-1975.
Byrd Station almost undoubtedly warmed quite a bit as atmospheric CO2 climbed from 315 to 330 ppmv. Then it warmed a tiny bit as CO2 rose from 330 to the “safe” level of 350 ppmv. It has not warmed since CO2 entered the CAGW zone and climbed above 390 ppmv.
My trend is from the GHCN/SCAR data from NASA-GISS. It’s a simple linear regression. I didn’t calculate a standard deviation; but the R² of 0.01 leads me to believe that the error bar would be pretty large.
I did not have access to B12’s data; but any time the MoE is as large as or larger than the trend, I tend to discount it.
And we’ve got a weather station that’s showing a maximum summer temp below -10C!, and that was in the early 1970s.
Now, when I was at school, we were taught that ice melts at 0C.
A comment in General.
Any, any paper on AGW that is pay-walled should automatically dismissed. We Taxpayers have already PAID for the research and work {cough, cough}, and we should not have to pay again.
Unless there is some reason to assume that a logarithmic, exponential or other type of function would better capture the trend, linear regressions are generally the best choice.
Ideally, it would be great to have about 3,000 years of instrumental data. That way you could take it into the frequency domain and identify the natural cyclicity. Then you could fit a Gaussian filter to it and demonstrate that there are no actual secular trends in the temperature data.
A note on the title of this post: I forgot to include one. The title of “Mr. Fix-it” is really funny because I am totally helpless when it comes to fixing things around the house. My “tool kit” consists of duct tape, bungee cords, zip-ties and rubber bands… 😉
When the warm turns, the bill will come due for these claims they’ve put on their “credit” card–not only the authors, but the journals and the MSM. Who will ever believe them again?