Bishop Hill Lord Stern's squawk box
Feb 3, 2014 Climate: WG2 Climate: Ward Lord Stern's squawk box has made one of his grubby sallies into the media today, sounding off in the letters page of the FT in response to an earlier missive from Lord Turnbull. Ward has several gripes - hasn't he always? - one of which is the trend in Arctic sea ice since its minimum a couple of years ago:
The Arctic sea ice has not been recovering since its record minimum in September 2012, and is still on a clear downward trend.
Here, courtesy of Cryosphere Today, is the recent record of Artic sea ice:
;)
I don't know about you, but that looks very much like a recovery from where I'm seated. It's astonishing that Lord Stern feels his spokesman can behave in this way and astonishing that the London School of Economics tolerates it.
Bishop Hill
Interestingly, Nature has just announced a conference on the very subject of Arctic sea ice.
This meeting explores the recent, rapid Arctic sea ice reduction. We will discuss the evidence for change, the inability of our climate models to predict these changes, the processes responsible for sea ice reduction and improved representation of these processes in climate models, and the impacts of sea ice change on local and global weather and climate.
Reader Comments (33)
Sorry, Your Grace, but two years do not a trend make.
This graph certainly suggests that the 2013 recovery was the biggest single jump in the satellite era but the trend is still down.
The reaction should be to (as Mrs T put it) 'rejoice'! But not to set too much store by it.
And here's the graph for global sea-ice 1979-present: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg.
Forgive me for adding the following excerpt from a Royal Society Report:
If Bob Ward thinks the Arctic is melting I suggest he reads Tony Brown's essay for some context and enlightenment.
Mike Jackson: That sure looks like a hockey stick to me. How long is a trend, 2 years, 30 years, 300 years, 3,000 years?
Come on, Phillip! Where in that link can you find anything that you could honestly call an upward trend.
I hope you're right but at this stage 2013 is only a spike.
I will certainly agree that lapogus' graph is much better since it measures daily variation rather than monthly but I think we are hard pushed to use words like 'recovery' just yet!
Addendum
It's interesting (looking again at lapogus' graph) that the major decline has only been since about 2001 and that the swings between max and min have been considerably larger. Also that prior to that the years where you can "see daylight" on the graph (major swings) have come at about 7 or 8 year intervals. I wonder if there's any significance in that.
Steven Goddard has identified a problem with the trend from 1979 to 2013 - see: Arctic Ice Growth Since 1971
Mike Jackson: "two years do not a trend make."
I quite agree. The letter should have read something like, "Despite a recent increase in Arctic sea ice, the long-term trend remains clearly downward." I would have no objection to that.
But where is the justification for this part of the statement: "The Arctic sea ice has not been recovering since its record minimum in September 2012"? That is very specifically about the short-term history, and does not agree with the observations, for sea ice area and extent, whether comparing September to the following September, or the anomaly more generally.
Lets forget that we know the Arctic ice has been bigger and smaller in the recent and distant past.
Lets forget the 2012 Arctic Cyclone that increase the ice loss.
Lets forget that the supposed polar amplification due to greenhouse gases is meant to affect both the Arctic and Antarctic.
Lets just take the pieces of information that "support" CAGW!
Mike Jackson: "two years do not a trend make."
Of course it does . There is no temporal definition to the word "trend"
Off Topic
The Mail is at it again
http://www.dailymail.co.uk/sciencetech/article-2550951/Global-warming-definitely-caused-humans-UN-report-claims.html
OT - Yeo gone. Oh dear... ;-)
Going big on disappearing Arctic ice was too hard to resist for those who spin the yarns of our self-inflicted climate doom. They saw a suitably attractive trend and claimed it for their own. Just as they did with the cooling trend that ended in the 1970s and the subsequent warming trend that ended before the century did. Of course they have done that with any number of things, from snow in the UK, the ice on Kilimanjaro, a Himalayan glacier or two, etc etc. But Arctic sea ice in the summer is a very variable thing to pin your hopes for despair on. It is not massive like the land-based ice-sheets, and it is vulnerable to the whims of travelling storms and poorly understood ocean currents. It has been reported as dramatically reduced in extent several times before, not least in the first half or so of the 20th century, and as lapogus (2:31 PM) reminds us, even early in the 19th century during the long tail-end of the Little Ice Age. So you wouldn't want to bet your shirt, your grants, your foundation funding, or your credibility on such a temperamental poster-bear carrier. Well, you and I wouldn't, but then we don't have a lucrative cause to support.
lapogus
Thanks for the link.
Less Arctic sea ice in 1971 than today - interesting. Another case of a cheery-picked starting point.
To commenters who are saying that two years is too short, I agree. Whether any of the fluctuations in the Arctic sea ice since the start of the record are statistically significant is a question that I have yet to see properly addressed. Has the sea ice area recovered since September 2012? Undoubtedly yes. Does this signify anything other than natural variation? I don't know.
Bishop Hill
http://tamino.files.wordpress.com/2011/09/walsh.jpg
Perspective please.
This is the average Arctic ice cover from from 1870, compiled by Walsh and Chapman.
The 1 year variation you describe is within the range of normal variation and much smaller than the overall change in average since 1950.
You are also comparing 2013 with 2012, the year with the lowest Summer extent on record. It would be surprising not to see some recovery. Record years are usually outliers, rather than close to the long term trend, and rarely occur in successive years.
Another perspctive, this time the NSIDC daily extent data.
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
The current year went below last year for a month from mid December 2013 to mid January 2014. Should I be excited ? No.
It is too easy to get excited about short term trend variations. Sandy S and I have an informal agreement to avoid such excitement. Would anyone else on Bishop Hill care to sign up?
I'm tempted, EM, as whichever side of the debate one is on, claiming temperatures or weather events prove one's point is a pretty spurious exercise, and usually ends up smearing one's face with egg as the pattern changes and one's ignorance is proven.
What I can't understand though, is why Ward should say that Arctic sea ice hasn't recovered since 2012 when it clearly has. He is entitled to say that this recovery is too modest and short-lived to tell us anything about the longer term, and very few of us would disagree with him, but that is not enough for him. He would also be more likely to be thought of as honest if he made occasional reference to Antarctic sea ice as well.
Entropic man -
I'm happy to agree with you and SandyS. But what of Mr Ward?
By the way, above you wrote "You [BH] are also comparing 2013 with 2012." That was Ward, responding to Lord Turnbull. If you want to complain that Lord Turnbull over-stressed the point, I might agree. But Ward was just flat-out wrong.
I wrote above what I thought was a fair assessment.
Harold W, David S
If I wanted to suggest that sea-ice is continuing to decline I would point out that Arctic sea ice area for this date is lower than for 2013.
http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html
Since this would break my agreement with Sandy S, I would not dream of mentioning it! :-)
Perhaps Ward should have said that there has been no "significant" increase since 2012. Unfortunately such technical precision tends to be wasted on politicians.
I'm not sure that Antarctic ice extent is behaving in a manner which gives clear information either way on climate change. Did you read Dr. Curry's paper suggesting that the increased extent was due to global warming induced salinity changes?
http://journals.ametsoc.org/doi/abs/10.1175/JCLI4136.1
Well, Judy has a nice post and thread about Antarctic Sea Ice which should improve everyone's understanding and confusion, a twofer.
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Entropic: "...I would point out that Arctic sea ice area for this date is lower than for 2013...[but] I would not dream of mentioning it! :-) "
I could quibble that the anomaly for 2/2/2014 seems to be -0.725 (millions of km^2), while 2/2/2013 was -0.749, but that would be merely disputing whether it was the left or the right cheek of the gnat's behind. This winter was running ahead of last winter up to around mid-December; since then this winter has been pretty much the same as last year. But Ward made a comparison not to last year, but to the minimum of Sept. 2012. I wouldn't mind his claiming that there hasn't been a significant recovery -- I suspect that's correct, but I'd want some backing for it -- but to claim there was *no* recovery is astonishing. I expect Ward to spin the figures, but not to be outright wrong.
Perhaps the FT edited his original letter, and introduced the error thereby.
Thank Finagle for a bit of humour. Time to stop dancing on the head of an icicle?
HA HA! "Record years are usually outliers". Well yes indeed but when this single outlier happened all the climate alarmists wailed it was a sign of thermageddon happening even faster than predicted, exactly the same mistake they made with the previous ice minimum. Now of course their tune changes but smart people, ie skeptics, were predicting a rapid recovery and lo and behold we were right again. I've been right with every prediction so far. It's easy - I just listen to the prediction of the consensus climatologists and I predict the exact opposite and it works every single time. So don't seek to preach to us about short-term fluctuations: Physician heal thyself.
JamesG
Physician, heal thy self. You are making the same mistake you complain about.
The evil laugh is another giveaway. :-)
Like the proverbial monkey that gets trapped simply because it won't let go of some nuts in a trap, the Stern gang 'can't let go' of the 2012 sea-ice minimum. They're so glad about it, that they can't resist shouting about it - even when it falsifies their case.
If they had been content to state that, The Arctic sea ice has not been recovering in the long term, it is still on a clear downward trend, I doubt if they could have been challenged.
Alternatively, they could have said in spite of brief downward spikes in 2007, and 2012, the sea-ice trend has continued a steady downward trend of 9% per decade (perfectly illustrated at http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi_range_ice-ext.png ). That couldn't be challenged either - at this point in time.
But like so many in the green movement, they seem to think the truth isn't good enough - they seem compelled to exaggerate, sex-it-up, cry 'wolf' etc.
Something about Stern makes my skin crawl.
"Perspective please. - This is the average Arctic ice cover from from 1870, compiled by Walsh and Chapman."
The Walsh and Chapman graph is based on a computer model of what they think happened to sea ice in the past based on certain global warming theories of what should happen to sea ice. This model is then used as evidence that certain global warming theories of what should happen to sea ice is confirmed.
The time period to observe the trend was set by Lord Stern, not The Bishop. The Bishop merely noted that the statement was factually incorrect..
If the time period chosen offends some people, their attentions should be turned toward Stern. Are any of those people prepared to say that, not only was Stern's statement wrong, it was stupid? Because, it seems like for once, there's a huge common ground here. :)
Feb 4, 2014 at 2:16 AM | Will Nitschke
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Ah yes, that old canard, "model-based evidence". There is no such thing.
Tell you what - let's send Chris Turney to investigate....
It's safe to say that some prefer to see a long term decline whereas others see a mere downslope in a cycle. Who is right? Well looking at the records we see Arctic temperatures being the same now as in the 1930's and the Gisp2 reconstruction showing a much warmer MWP. Against this real data we have unvalidated models which falsely predicted that the Antarctic would warm due to manmade warming. When it became apparent that the Antarctic cooled instead they called it natural variation but failed to connect the logic that pointed to the Arctic may also be varying naturally - as indeed all real data indicated. Pure hubris in other words!
Not that I regard Arctic warming as a necessarily bad thing and neither do the folk that live there. And I don't mind folk being wrong either, but it would be nice if they admitted it now and again, stopped pretending they know things they plainly don't and dropped the unjustified moral superiority.
BTW, the Arctic temperatures still closely match the expectations from the Solanki solar reconstruction. Since the Arctic is seemingly the only pointer to manmade warming that the IPCC can still pretend to cling on to then they might consider that fact.
Has the area of the Earth's surface in which human kind can live and flourish, given accumulated knowledge and material capital, increased or decreased during the last two hundred years? A clue: it has not decreased.
Thermometers don't mind the temperature and existing species have seen and survived it all before.
The Nature conference blurb states "...the inability of our climate models to predict these changes...". Isn't that a bit too honest? How did it slip through the net? I'm sure what they meant to say was something like "...the amazing ability of our models to hindcast the changes when we incorporate arbitrary forcings...".