Bishop Hill Inside mathematics
Jan 10, 2014 BBC Climate: Surface The BBC's Inside Science programme looked at the Ship of Fools expedition yesterday. We were treated to the unedifying sound of presenter wondering about whether what he called "deniers'" views on sea ice extent in the Southern Hemisphere carried any weight. We were led to beleive that they did not. Normal BBC fare I hear you say.
Some of what was said was bizarre though. Interviewee Professor John Turner of the British Antarctic Survey said the rise in Antarctic sea ice extent was less than 1% and was therefore well within the bounds of natural variability. I have no problem with the second part of that statement, but 1% seemed very low to me. Here is the relevant graph from the Cryosphere Today website.
The Antactic sea ice has an annual mean of 9 million km2 or so and the current anomaly is 1.395. So we are at 14 or 15% above normal, not less than 1%. Am I missing something, or does Prof Turner have a problem with his mathematics?
The audio is attached below.
Bishop Hill
Prof Turner emails:
Based on the Bootstrap version 2 passive microwave sea ice data the annual mean Southern Hemisphere sea ice extent increased at a rate of 147 × 10**3 km**2 per decade (1.2% per decade) over 1979-2011, which is significant at p<0.01.
I think that's him agreeing that the figure he gave on the BBC was wrong, but I've emailed back asking for clarification. Remember folks, there is nothing wrong with errors if they are corrected.
Bishop Hill
The British Antarctic Survey Twitter account just pointed me to this paper.
@etzpcm Here is a paper you might find useful with 1% per decade fig: http://t.co/q4E0lcUJh2. Thanks to you and @aDissentient for contact.
— BAS_News (@BAS_News) January 10, 2014
I'll see if I can get a copy, but the tweet makes it clear that when Prof Turner said there had only been a 1% increase in sea ice, he meant 1% per decade. Moreover, the paper was submitted to the journal in January 2009 and was published a few months later. It is therefore unlikely that it includes data beyond 2007.
Here's the longer term record of the Antarctic sea ice anomaly:
As you can see, things have moved on quite a bit since that time. That said, his original email said 1.2% up to 2011, so I'm still not entirely clear.
Bishop Hill
Another email from Prof Turner
- the trend was calculated from the annual mean total Southern Hemisphere sea ice extent.
- the percentage increase was based on the average annual SIE for 1979-2011 since there is no reliable whole Antarctic sea ice data before 1979.
If you include the 2012 data the trend increases to 157 × 10**3 km**2 per decade (1.27% per decade).
2012 didn't have the largest annual mean in the record, but it did have the largest daily ice extent, which occurred on 24 September. Our paper on this event is attached. In 2013 there was an even greater extent of Antarctic sea ice in September, so many people are trying to understand the mechanism or mechanisms responsible for the changes we are seeing.
Reader Comments (119)
There's now a transcript of this interview here:
https://sites.google.com/site/mytranscriptbox/home/20140109_is
Here is what IPCC AR5 SPM says:
"It is very likely that the annual mean Antarctic sea ice extent increased at a rate in the range of 1.2 to 1.8% per decade (range of 0.13 to 0.20 million km2 per decade) between 1979 and 2012."
So John Turner's claim of less than 1% is false.
That looks like a good opportunity to formally request an apology from the BBC, both for using the d-word and for distributing incorrect data?
Good Luck with that!!
If 1.395 million km^2 is 1% of the total, then the total sea ice would be 139.5 million km^2.
Obviously patent nonsense. Surely that obvious trivial mathematical sense check would have been suggested by a "maths" program on the BBC?
No? It wasn't??
Andrew, you should know by now that it is the extent of summer sea ice that is all important to understanding global warming ;-) We are fast approaching the summer sea ice minimum in S hemisphere. I think one would be entitled to take current sea ice area of 5.5 million sq kms as the reference and deduce 1.4/(5.5-1.4) * 100 that summer sea ice is currently 34% more than datum. You should write to the BBC.
Totally off topic, this weeks offerings on Energy Matters:
The Primary Energy Tale of Two Continents
Correlated wind and incoherent energy policy
But of course the only relvant question is:
How have actual sea ice trends compared with IPCC, Alarmist model based, predicted changes.
Simply, in 2001 the IPCC predicted a 25%-40% reduction in Antarctic sea ice for a doubling of CO2. (see Assessment Report 3 Chapter 16)
So far, well down the road to our double (normally accepted to be c. 550 ppm) at 400 ppm CO2, the sea ice trend has been positive.
As a falsification test of their models and underlying theory, I reckon that leaves the current temperature "pause" for dead.
It is the BBC after all so no chance of objective reporting.
Also from John Turner's page
"My group uses a wide range of data to study how the climate of the Antarctic has changed over the last 50 years and how it will change during the next century. We make extensive use of the output of the atmospheric models run by the UK Meteorological Office"
Clearly a fully paid up member of the Team. Anyone depending on grants will certainly be singing the same AGW hymn.
Who's that Antarctica "expert" in the program who said a lot of pure garbage before Turner, trying to argue it was an unforeseeable "cataclysmic event" and that the Akademik S was going to remain trapped for a long time?
The ship has been free since Jan 7th.
"Inside Science" is a total fail.
Euan, I am not so sure the summer sea ice areal extent is all important to anything. Less sea ice at the end of the summer just means there will be much more heat loss to space from the open ocean through the autumn and early winter (sea ice and snow is a good insulator of the relatively warm oceans). The quick re-freezing and recovery (from summer minima) of the Arctic sea ice in recent years suggests that overall the sea ice has a net negative feedback role, not positive (from lower albedo) as climate scientists like to suggest.
Update - sorry, just seen your ;-)
Normally the global warming alarmists grossly over-estimate changes. In this case John Turner has underestimated a change. I wonder what the reason for that could possibly be? No prizes for guessing the answer!
More from IPCC AR5, Chapter 4, verse 4.2.3.1:
The regression trend in the monthly anomalies of Antarctic sea ice extent from November 1978 to December 2012 is slightly positive, at 1.5 ± 0.3% per decade (very likely) (see FAQ 4.2) as updated from Comiso and Nishio (2008). The seasonal trends in ice extent are 1.2 ± 0.5, 1.0 ± 0.5, 2.5 ± 2.0, and 3.0 ± 2.0% per decade (very likely) in winter, spring, summer and autumn, respectively, as updated from Comiso et al. (2011). The corresponding trends in ice area (also updated) are 1.9 ± 0.7, 1.6 ± 0.5, 3.0 ± 2.1, and 4.4 ± 2.3% per decade (very likely). The values are all positive with the largest trends occurring in the autumn. The trends are consistently higher for ice area than ice extent, indicating less open water (possibly due to less storms and divergence) within the pack in later years.
A suggestion - rather than go through the pointless BBC complaints procedure, would it not be more fruitful if a suitably qualified mathematician or statistician just emailed the presenter / producer directly and ask for an opportunity to put the record straight?
What? The BBC getting its science wrong and then unwilling to fix it?
Surely not?
Almost from the start, the programme is wrong: Andrew Luck-Baker announces that the helicopter has landed on the heli-deck, then Adam Rutherford says: “Andrew, that's you being winched onto the deck…” Ooops. Landing is not the same as winching. (Landing would have been the preferred method, what with all the personnel involved, and the risks associated with winching.)
While John Turner managed to avoid the “D-word” (which the BBC man did not), he still managed to give us some dodgy stats, other than that already mentioned: “…in the Arctic, we've had a remarkable loss of sea ice, over the last 34 years or so.” Well, yes. But 34 years or so ago, we were assured that we were heading towards another ice age; just a shot in the dark, but could it be possible that the ice back then was abnormally extensive?
Not bad, for a 9-minute article to be so shot full of holes even I can spot them!
I gave up trusting anything coming out of the BAS quite some time ago. It's just more of the same lies to keep the global warming trough filled to the brim.
Maybe Tim Harford, who presents More or Less would be interested in having a look...
lapogus: The feedback to the programme that is presented the following week is always carefuly edited. I doubt if anyone will get a correction broadcast, but worth a try from lots of people.
Alex: I've emailed More or Less to try to get Tim Harford to look at climate change statistics, but no success so far. Still, worth a try.
Iapogus, I'm sure the variations in the melt cycles of sea ice is enormously complex. I have been wanting to write a post on this to pull together various threads of ideas but find so much contradiction in the literature, it is extremely thin ice to go skating upon. For example, I came across a paper that found less Arctic Sea ice during the LIA.
Take a look at Judith Curry's assessment of what the AR5 WG1 report actually says...
http://judithcurry.com/2014/01/06/ipcc-ar5-weakens-the-case-for-agw/
...and look at the part about 'Sea ice', especially the bit about attribution.
You'd assume and expert scientist like Prof. Turner would be aware of this?
Lapogus, the presenter writes for the Guardian and studied under Steve Jones. Bish has tweeted him but don't hold your breath.
I already complained last night on the basis that the term denier is offensive to a third of the BBC's listeners. I also mentioned that my wife's uncle was in Buchenwald, falsely suspected of being in the Belgian resistance. We should all complain.
I guess when talking about the amount ice has risen they use the total amount of ice on the Antarctic.
... or is this percentage a fraction of total water on the planet?
In which the total sea ice will be never more than 0.00...001%
Alternatively, ... since its hydrogen monoxide - they could just use the mole fraction of hydrogen in the solar system tied up as Antarctic ice.
... or they could be honest?
I already complained last night on the basis that the term denier is offensive ... we should all complain.
I will get onto this.
It's probably that 1% that the good ship 'Kevin Turvey' got stuck in. Par for the course, unfortunately. If BBC journalists had a better science & maths background then they would be able to quickly and confidently call BS in these situations.
Then, of course, the "bounds of natural variability" are something the catastrophists are so cock sure about, until they choose to decide otherwise. Hence the cause of the "pause" in their global warming.
I don't know exactly what Mr. Turney said, but from a quick glance at the chart, it seems that sea ice extent in the Antarctic is at present about 25% over mean from the base period. Someone should let BBC know. I am sure they will correct or at least follow up on such blatant misinformation - no?
Does anybody know what the Bootstrap version 2 passive microwave sea ice data have to say about Summer mean Southern Hemisphere sea ice extent?
At my slimiest and most devious I can get the increase down to 3%. If one equates extent with distance from the centre of Antarctica the sea ice is a thin ring around the continent. based on assuming Antarctica is a circle with a ring of sea ice then with a little help from Wikipedia and Archimedes
Area of Antarctic is 14,000,000 Sq KM so if circular this would give a radius of 2,110.9 KM
Adding 9,000,000 Sq KM od sea ice gives a radius of 2,705.6 KM for average extent
Adding a further 1,395,000 Sq KM gives a radius of 2,786.4 KM and increase over normal of 80.8 KM
80.8/2705.6*100 = 2.98%
One could equate extent at a point where the increase is least which would bring down the increase extent % but that would be really extremely slimy.
Or one could be completely wrong and just spout any old crap (pardon my French)
I think we should congratulate Professor Turner for at least engaging and having at least some rationale for his claim. If he wasn't able to skew the figures at least a bit, the BBC would never have used him.
Lord Deben, chair of the .Climate Change Committee said recently that without challenge that 30% rising soon to 50%of Germany''s electricity was from renewables. In. fact last year it was 8% and last month less than 5%.
Progress Report
Although I did not hear the program as a result of the comments above and as Chairman of the Scottish Climate & Energy Forum I have had a telephone call with a member of the program team who listened politely and intelligently and said they would pass on my details to the producer who I asked to call me back.
In the conversation I made it very clear that the use of the word "denier" did not in any way represent our views and as such it was a serious lie which was damaging people's reputations. As such I made them aware that if they continue using this lie, then it is likely to result in court action - if not by us - then by some other sceptic who has lost financially as result of this type of malicious comment.
However, the real culprit is Prof John Turner. I have phoned him but have not so far been able to talk to him.
The Sceptic View
Just to reiterate the point for anyone who is not already aware. When we formed the Scottish Climate & Energy Forum, we had a consultation on sceptic views. This is available on the web: http://scef.org.uk/index.php/climate/the-sceptic-view
I am very confidence that we have the evidence that we are not "deniers" as nothing in this document supports the label "denier". We agree that global warming has occurred, that CO2 is a greenhouse gas, that climate changes. As such the use of the term "denier" is a malicious lie intended to damage our reputations.
People who continue with this malicious action calling us "denier" should be made aware that this is actionable in a court of law and believing it to be true is no defence when it is not.
I think he may be talking about the gradient, rather than the amount. If sea ice rises 12% over a period of 10 years, that's roughly 1.2% per year.
TRUST ? - can we trust the sc-activists (activist scientists) ?
COMPETENT ? - are people like Turner and Turney on top of the game ?
.. Well with Turney not understanding real life ice conditions and getting his ship stranded, and Turner not knowing the difference between "less than 1% (all ice)" and "1.2% per DECADE sea ice".. it doesn't look so, does it ?
- Buy a used car from them ?
No I am sorry the prog is criminally misleading
1. "sea ice" - no they said ICE
2. "1%" - no Turner said "less than 1%"
3. "1.2% per DECADE" - no they said 1%, not qualified by saying per decade
the figure 1% appears in the transcript 4 times
John Turner :sea ice around the Antarctic. ..late '70s. ..slight overall increase in ice - not a huge increase, less than 1%.
..Arctic, we've had a remarkable loss of sea ice, over the last 34 years or so. But in the Antarctic ..within the bounds of natural variability of the Earth system." - implying Artic ice loss is NOT within natural variation (wrongly I think)
Adam Rutherford: "A 1% increase in sea ice... You .."
John Turner: Yes, but a 1% increase in the extent of sea ice is really a very small amount. ..ozone hole, which we know has had a big impact on the Antarctic, or without increasing greenhouse gases.
People think that really the human impact of increasing greenhouse gases only started in the 19th century, ..
And a 1% increase, I believe, is within the bounds of natural variability. So we can't really infer global change from a measurement like that."
Other quotes
AR : "it has been used by climate change deniers in the press, as a brickbat to beat scientists and the science" - using the denier word is DEFAMATION & a misframing psychological trick .. normal for AR though
JT : "What we've had here was a weather event (not climate)"
John Turner: "Well, no-one questions the data more than scientists. " (seems to me Sc-activists only question data if its against their dogma)
JT : "we're only too aware of the sparseness of the data that we have" - well why the certainty in your PR statements ?
AR : "special documentary here on Radio 4, on the 29th January
" .. a form of the special Luck Baker documentary was already broadcast on the World Service I listened to Discovery last night
AR : "Expedition Leader Chris Turney" - Luck Baker calls him one of 3 joint leaders (in that prog)
I checked Turner's calculation using the NOAA sea ice index ftp://sidads.colorado.edu/DATASETS/NOAA/G02135 product (for which I already have a collation script.) Turner said that he used G02202_v2. I'll try to look at that some time.
Note that Turner's results end in 2011, though data is available through 2013 and there has been an increase in 2012 and 2013.
Using the G02135 product to end 2013, the trend in SH extent anomaly is 170 × 10**3 km**2 per decade (rather than Turner's 147 × 10**3 km**2 per decade). The average SH sea ice extent in this period is 8.7 million sq km, which would appear to yield a percentage increase of more like 1.9% than under 1%.
Curiously, using AR1 significance tests, the t-value of the SH increase is greater than the t-value of the NH decrease, so it is not obvious that the NH decrease is "more significant" than the SH increase.
(1.2% per decade) over 1979-2011, which is significant at p<0.01.
Why don't you ask him for the data and a detailed description of what he has done. I am involved in much simulation including bootstrap methods, the detail is no way sufficient to understand what on earth he's done. If you can figure it then let me know where to get data and I'll have a go at recreating.
The phrase 'per decade' is not mentioned. The 'less than 1%' statement comes after a mention of the 1970s and before a reference to 34 years, so most listeners will have got the impression that this is the change over that time period.
[Snip - venting]
Antarctic sea ice extent is ABOVE 2 (two) standard deviations of the 1981 - 2011 average.
How is that for natural variability?
http://nsidc.org/data/seaice_index/images/daily_images/S_timeseries.png
OK The Luck Baker Discovery documentary programme I listened to was not a complete whitewash disaster you expect from the BBC (mp3 download )
- Climate Science to me is 90% PR and 10% Science.. and in this prog the PR wasn't as slick as it normally seems
1. Chris Turney's incompetence does shine through : we can hear his making promises about rescue , which don't turn out etc.
2. In a lengthy speech Greg Mortimer one of the other 2 co-leaders * says he has been coming to Antarctic every summer for 20 years.
Yet he doesn´t come across as competent . He didn't help predict the ice and then we hear him say it is likely the ship will be stuck a long time.. yet we know the ship was released when the weather changed and the wind died down.
* ALB calls Greg Mortimer one of 3 joint expedition leaders in that prog
funny nothing comes up when I type into Google
Shokalskiy "joint leader" Antarctic
- They did imply a GOOD GET OUT ..but weren't as good as usual about being "on-message" : This was of the form of Greg Mortimer saying " ah you see there was a kind of ice earthquake caused by global warming, suddenly these chunks of old ice broke off and got blown into our area." paraphrased
- I could buy that, but hey didn't sell it very well (afraid of getting caught out ?)
......
- Mentions ship was holed above the ice line and they welded a plate over it . (how do you get a hole above the ice line ? surely it was made by the ice ?)
..............
- There was an Australian female speaking much more like a dizzy giggling activist rather than a scientist (Tracy Rogers marine ecologist)
- My paraphrasing as I don't have an Alex Cull transcript yet
TR : "sea of multi-ice.. that's basically why we are here.. it's so iced-up" (em sounds like post hoc justification to me ..they never mentioned that before)
.. "layer upon layer ..been growing rather than receding ..it's quite unusual.. probably changed the environment here"
- Luck Baker doesn't play the role of a journalist but rather that of a good cop on the subjects side, saying their words for them. An activist interviewing a fellow activist
ALB :"So this tells us ho East Antartica is changing .. I know you work a lot in the west where there has been been warming, I guess something else has been happening here ?"
TR : "Global warming ..really it's climate change ..some areas of warming ..and err (can't bring myself to say cooling) are experiencing different things ..sea ice in the west the trend is ALL receding..but here it's growing.."
ALB "I guess the message isn't that Antarctica is fine..it might melting on one side, but growing on the other..that's not necessarily a good sign a balance is it ?"
TR : "no, not at all ..system is changing ..not like this before .. some areas of the world we are seeing FLOODING, IN OTHERS CYCLONES, HERE IT'S....." (see sc-activist broadcasting UNVALIDATED opinions as if they were facts.. not professional at all for a scientist)
...............
ALB "This is not newly formed ice, but ice that has been hanging around for years, Greg Mortimer says he has never seen anything like that before"
- next get Greg Mortimer's explanation
.....
- We then move on to a 4 minute footage of the rescue, without a real full explanation of the many changes in Turney's promises and plans
.....
Competent ? - FLAILING is the word to me
- failed predictions, post hoc excuses, relying on activist journalists to help them .. etc.
Well, I'm coming late to this thread, and folks have already pointed out that "1%" is not the same as 1.5%/decade.
And Geckko has compared the observations to a prediction of the TAR. Adding onto that, AR4 WG1 shows model-mean prediction of Antarctic sea ice extent in the (austral) summer and winter in Figure 10.13, panels c and d respectively. Both show strong decreases over time. I'll make a stab that the rates are about -5%/decade and -2%/decade resp.
I was curious to compare the IPCC graph with actuals. I couldn't locate an Antarctic sea ice extent anomaly chart, although NSIDC hosts a graph of sea ice area anomaly. So, I downloaded the actual sea ice extent figures from NSIDC. The "historical" (pre-2000) portion of AR4 WG1's Figure 10.13 shows the beginning of a gradual decline (which is projected into the future). Interestingly, that decline isn't present in the observations. However, it was not thought important enough to point out that models could already be seen to be diverging from reality.
hey stop I just went back to the previous episode - scientist mentioned a nearby big block of ice being a problem and that it would surely not break up for next 4 years.
ep3 mp3 with Guardian "journalist" Ashok Jha presenting this ..now interviewing the penguin woman about them abandoning their chicks too early, earlier than ever (obviously due to warming not cooling), but she says
- So they did know there was a huge sea ice block in the area which are likely to send bergs off sometime ..is it from this very same block that bergs broke off and that they got trapped in ?
.. the same ice she said will be firm for another 4 years ? or just a coincidence ?
Turner: "Yes, but a 1% increase in the extent of sea ice is really a very small amount... ."
Yes, comparative to the area of the Antarctic it is small, but it is still a fair-old lump of ice. It's larger than the land area of Greece.
2 tweets from BAS, in response to mine:
Paul Matthews @etzpcm 2h
Prof John Turner of the British Antarctic Survey @BAS_News gives false information to @BBCRadio4 about sea ice. http://www.bishop-hill.net/blog/2014/1/10/inside-mathematics.html
BAS_News @BAS_News 20m
@etzpcm From 1971-2011 it is 1.2 per cent increase per decade - based on the "Bootstrap version 2" passive microwave data. @bbcradio
BAS_News @BAS_News 6m
@etzpcm Here is a paper you might find useful with 1% per decade fig: http://ow.ly/ssqZT . Thanks to you and @aDissentient for contact.
and my reply
Paul Matthews @etzpcm 24s
@BAS_News There was no mention of 'per decade'. False impression given was less than 1% since 1970s. @BBCRadio4
BTW Greg Mortimer is a Greenpeace guy in the 2009 ABC article it quotes indirectly "The whole idea of the exercise was to bring attention to the Greenpeace aims. "
and directly "Ah, yes. I think Greenpeace was aware of that potential more than we were. For Lincoln and Andy and I, I think it was more - it would be fun to climb Centrepoint, and that Greenpeace cause was a worthy one.
- hey, it's not the first time he's been ill prepared and got rescued 2010 he was rescued on a mountain in Greenland
and the he is used in a June 2013 History Channel TV prog to teach children about The failure of a modern expedition to re-enact Ernest Shackleton’s crossing of South Georgia Island in May 1916.
The children are asked "Note the credentials of expedition leader Greg Mortimer."
I think a half reasonable test for an activist/scientist would be whether they use the same definition when referring to both the Arctic and the Antarctic sea ice.
Funnily enough I did a post on this earlier this afternoon on WUWT.
The actual sea ice area as at yesterdays published figures were 5.525 million sq km against the 79-08 mean average for this time of year being 4.131 million sq km.
I calculated the anomally as plus 33.74%....one of the above postings said 34% so appears I am on
the right track and Mr Turner has clearly "miscalculated".
I too emailed the BBC...well you have to...don't you?...even is it's just for a laugh!!
My impression from a number of interviews like this is that the "expert" knows he/she will not be challenged which makes it easy to play fast and loose with the facts. In addition they can usually rely on the partisan interviewer to summarise in a way which highlights the propaganda they are promoting.
If only Andrew Neil could spend more time on these issues....
Is it credible that this man:
http://www.antarctica.ac.uk/met/john.turner/
cannot distinguish between rate of change of extent of Antarctic sea ice and extent of Antarctic sea ice?
Is it credible that he does not know accurate figures for the current extent of Antarctic sea ice?
Is it credible that he doesn't know that the Antarctic sea ice extent (>15% sea ice) has been greater than 2 SD's above the 1981 - 2010 average for some time (many months)?
I think he has chosen to be 'effective' in a Stephen Schneider way, cherry-picking an out-of-date figure with which to obfuscate on a national radio programme.
The BBC should be required to broadcast an on-air correction and a fulsome apology for misleading listeners at the start of the next Inside Science.