This is a continuation of a remarkable thread that has now received 10,000 comments running to well over a million words. Unfortunately its size has become a problem and this is the reason for the move.
The history of the New Statesman thread goes back to December 2007 when Dr David Whitehouse wrote a very influential article for that publication posing the question Has Global Warming Stopped? Later, Mark Lynas, the magazine’s environment correspondent, wrote a furious reply, Has Global Warming Really Stopped?
By the time the New Statesman closed the blogs associated with these articles they had received just over 3000 comments, many from people who had become regular contributors to a wide-ranging discussion of the evidence for anthropogenic climate change, its implications for public policy and the economy. At that stage I provided a new home for the discussion at Harmless Sky.
Comments are now closed on the old thread. If you want to refer to comments there then it is easy to do so by left-clicking on the comment number, selecting ‘Copy Link Location’ and then setting up a link in the normal way.
Here’s to the next 10,000 comments.
Useful links:
Dr David Whitehouse’s article can be found here with 1289 comments.
Mark Lynas’ attempted refutation can be found here with 1715 comments.
The original Continuation of the New Statesman Whitehouse/Lynas blogs thread is here with 10,000 comments.
PeterM
Even your statement below is not correct:
The Wiki blurb you cite does not tell us this at all. In fact, it tells us
and
The temperature curve from Vostok (shown by Wiki) shows a warming from around 20,000 YBP to essentially the current level by 10,000 YBP, which has been fluctuating up and down since then.
You are off by 11,000 years, Peter.
Max
Peter follows the credo “close enough for government work”……which, loosely translates (from American to English), “I don’t give a damn because it isn’t my money and it’s almost time for my coffee break”.
Glad to hear that Peter finally agrees that the ice caps have been melting since well before the industrial age………well before the invention of the internal combustion engine or the light bulb.
You’re making progress Pete.
The global warming fraud perpetuates additional fraud….
Red flag on green-jobs numbers
http://hotair.com/archives/2010/09/24/red-flag-on-green-jobs-numbers/
Questioning the Arctic Ice Melt and Temperature Scare
http://www.hawaiireporter.com/questioning-the-arctic-ice-melt-and-temperature-scare
Yes you are correct. The last glacial maximum was 20k years ago not 10k years ago. Nevertheless sea levels were still over 20mtrs higher then than they are now. And why was that? Yes, because that amount of water was locked up as extra ice at the poles.
We can probably excuse Brute for not looking at the wording in the scientific paper itself. Readers of Wattsupwiththat will have seen the sentence:
“Peer reviewed study says current Arctic sea ice is more extensive than most of the past 9000 years”
and not
“there have been times when sea-ice cover was less extensive than at the end of the 20th century.”
So the question arises: Is Anthony Watts incapable of reading a scientific paper too? The only other possible explanation is that he is deliberately engaging in misrepresentation. But, surely, Anthony watts is a person of integrity. He wouldn’t do anything quite so underhand. Or, would he?
This is a curious story. I’m not sure I have any real explanation for it. Maybe you can tell me how a guy who believes the Earth to be no more than a few thousand years old can write his PhD on “marine reptiles that… vanished at the end of the Cretaceous era about 65 million years ago”
http://www.nytimes.com/2007/02/12/science/12geologist.html
He’s obviously intelligent enough to know one thing but yet still believes another.
I wonder how long it will be before we see a climate change denier doing the same thing?
PeterM
You agreed (1882) that
Correct. That’s what the paleo-climate record shows for the glacial maximum 20,000 years ago according to the Wiki curve you posted (1757).
This curve also shows that sea levels were essentially at today’s values 8,000 years ago.
Of course, Arctic sea ice extent does not have any direct influence on sea level (since this ice is floating), but still this record confirms that the study Brute cited makes sense.
Case closed.
Max
PeterM
Interesting story (1883) about Marcus Ross.
Religious belief of a scientist is a strange thing when it conflicts with scientific data.
I would suggest that there are “dangerous AGW” believers who fall into the same trap as Ross has done, as there may be (what you call) “deniers”, as well.
As we have discussed before on this thread, the scientific method is based on rational skepticism, which in turn is based on the insistence on empirical data to falsify (or validate) a hypothesis.
Curiously, it appears that Ross is fully aware of the “empirical data” (at least as close as you can get with paleo-climate reconstructions), which falsify his religious belief that the Earth is only a few thousand years old, yet despite these data he clings to the religious belief.
Can this be compared to scientists (or other individuals) who have the political (or pseudo-religious) belief that humans in the developed world are (guilty of) living excessively by overconsumption of fossil fuels, for which they will be punished (unless a global effort is made to force a reduction in this consumption), despite the fact that the empirical data to support this belief is lacking?
What do you think, Peter? Is there a valid comparison here? Or am I off base?
Max
PeterM
Stop flogging a dead horse (1882).
The study Brute cited does, indeed, show that the Arctic sea ice extent was lower than today over most of the past 9,000 years (as Watts has correctly stated).
Just look closely at the curve (a) plotting months per year where sea ice extent exceeded 50% of the maximum versus calendar age in thousands of years BP.
“Today’s” value is around 9 (confirmed by NSIDC data).
Over the 9,000 year period, this rarely exceeded 9, and was mostly in the range of 6 to 8.
You may disagree with the statistical method used, but you cannot disagree that the study does show that over most of the past 9,000 years Arctic sea ice was at a lower extent than today, as Watts has also stated.
Max
Max
I agree on power front, it has to come from somewhere, my guess is that running a compressor for 2 minutes to get a full charge compared to plugging an electric car into the mains overnight is a significantly more efficient option :) Though i can’t say i’ve tried working it out.
One big advantage though is they don’t require rare metal power cells, which are likely to become quite pricey now china has cornered the market.
As you say, be interesting to see how it develops
Max,
I don’t understand your reasoning. How can “plotting months per year where sea ice extent exceeded 50% of the maximum versus calendar age in thousands of years BP.” be related to the total extent of ice cover? Either now or 9000 years ago?
Max, If you mean by “essentially at the same level” you mean they were only 15 mtres less 8,000 years ago than they are now, then yes you are correct.
Was sea level at any time higher? Well, possibly but not but by much. Maybe cm but not metres.
You don’t like explanations along the lines of “the only explanation for” but there is no other explanation for varying sea levels which aren’t based on the Earth’s overall average temperature. Higher temperature = Less polar Ice.
Peter #1889
It is clear that you have still not fully read the article about sea ice if you make those interpretations.
As for sea levels can I remind you that sea level fluctuates by around a metre either side of the Holocene level shown and that;
“The highest global sea level of the past 110,000 years likely occurred during the Medieval Warm Period of 1100 – 1200 A.D., when warm conditions similar to today’s climate caused the sea level to rise 5 – 8? (12 – 21 cm) higher than present. Image credit: Grinsted, A., J.C. Moore, and S. Jevrejeva, 2009, “Reconstructing sea level from paleo and projected temperatures 200 to 2100 AD”, Climate Dynamics, DOI 10.1007/s00382-008-0507-2, 06 January 2009.”
By the way have you seen the latest study from New Scientist which shows that the sun is back in fashion as a climate driver?
http://wattsupwiththat.com/2010/09/24/climate-science-solar-shock-and-awe/#more-25332
So, sea levels not at unprecedented highs, sea ice not at unprecedented lows and the sun making a comeback. Have a good weekend Peter.
tonyb
TonyB,
Op-ed articles are one thing. Scientific references are another.
Incidentally there are ‘around’ 100cm in ‘around a metre.’ Your reference, even taking the highest figure of the range, still doesn’t account for ‘around’ 79cm of your claim.
Lets say (purely for argument sake) that today its 79cm higher than the average-which includes periods below the average-then add 21cm to it during the mwp and you get…?
So now we can dismiss certain categories of articles you don’t like can we?
tonyb
PeterM
The Wiki sea level chart for the past 8,000 years, which you cite tells us nothing about Arctic sea ice extent (the topic of Brute’s study and our discussion).
First of all, floating sea ice has no influence on sea level.
Secondly, the massive grounded ice sheet that melted since 20,000 YBP is believed to have caused a total sea level rise of 120 meters to today (your earlier Wiki chart). Most of this melting apparently occurred before 8,000 YBP. Your latest chart appears to show that another 10-11 meters increase occurred in the 1,000-year period from 8,000 YBP to 7,000 YBP, with another 4 meters or so occurring gradually over the 7,000 years from then until today, with some minor “starts and fits” as the scientific study on slightly higher MWP sea level cited by TonyB points out. The individual data points on your latest curve also seem to show some sea level data points higher than today 1,000 to 2,000 YBP.
Interesting, but not directly relevant as far as Arctic sea ice trends over the past 9,000 years are concerned.
To repeat (since we seem to be drifting off topic): over most of the past 9,000 years, Arctic sea ice extent was lower than it is today, as the study cited by Brute shows.
Or do you want to “dismiss” this study since “you don’t like” its conclusions?
Max
PeterM
You wrote (1888):
First of all, it is not “my” reasoning. Take it up with the authors of the scientific study.
However, I think I can understand the logic.
Each year by late summer the sea ice shrinks down to a relatively small fraction of its maximum late-winter extent, and then freezes back again. These seasonal changes are several orders of magnitude greater than the changes between years or even centuries.
The number of calendar months during which the net sea ice extent exceeds 50% of its maximum late-winter extent gives an indication of how stable the sea ice was during the warmer months.
If, for example more than 7 or 8 months of the year have less than 50% of the maximum late-winter sea ice extent, then it is quite likely that the late summer could be essentially ice-free.
If, however, there are only 3 months with less than 50% of the maximum extent, the likelihood of having an ice-free late summer are much lower.
In the first case, it is most likely that the annual ice extent averaged over all 12 months will be lower than in the second case.
So I can follow the authors’ logic.
BTW, you can run a check using NSIDC data since 1979.
Since around 2005 we have been at 9 months per year exceeding 50% of the maximum extent, while in the early 1980s (and over the entire period) this was 10 months.
Max
Max
As you may have heard Ernst Beck has died of cancer.
Here is an obituary
http://wattsupwiththat.com/2010/09/23/obituary-ernst-george-beck/
Here is a continuation of Ferdinands series of articles on co2 in which Beck features prominently-lots of good comments
http://wattsupwiththat.com/2010/09/24/engelbeen-on-why-he-thinks-the-co2-increase-is-man-made-part-4/
I am very saddened with this news for as you may remember I became very interested in his work after finding out about the historic Co2 measurements and subsequently corresponded frequently with him
tonyb
Max,
This all seems a bit convoluted.
So if 10 million square km of winter ice shrinks back to 4 million square kilometers of summer ice, this shows that the sea ice extent is less than if 2 million sq km had shrunk back to 1 million?
Is this the basis for Anthony Watt’s claim that “over most of the past 9,000 years, Arctic sea ice extent was lower than it is today”?
PeterM
Sorry you are unable to grasp the logic used by McKay et al. to determine Arctic sea ice trends over the past 9,000 years and to conclude that the extent over this period had frequently been lower than it is today.
NSIDC tell us that this year’s maximum extent occurred on March 31 at 15.25 million square km.
http://nsidc.org/arcticseaicenews/2010/040610.html
The 1970-2000 mean (baseline) end March extent is 15.70 million square km and the average of all years since 1979 is 15.54 million square km.
So there is hardly any change in the maximum extent.
There are no periods such as those you describe in your hypothetical question:
The Arctic Ocean itself has a total surface are of around 14 million square km. This includes the East Siberian, Chuchki, Barents, Laptev and Kara Seas. The adjacent Bering Sea has a surface area of 2.2 million square km, and the Greenland Sea on the other side has a surface area of 0.46 million square km. So the total surface area is around 17 million square km. So you can see that a major portion of this total area is covered by sea ice at its maximum extent today.
The minimum extent usually occurs around end-September. Last year the extent was 5.36 msk or around 35% of the maximum extent. End-September 2010 data are not yet in, but NSIDC tells us it is expected to be around 0.3 msk below the 2009 level.
Your hypothetical cases do not make sense, Peter. Both the maximum and minimum extents are much greater than you state.
I think it is fair to assume that McKay et al. knew what they were talking about when they concluded that the current Arctic sea ice extent is not at all unusually low, but rather on the high side when compared with the past 9,000 years.
But if you have problems understanding their methodology or statistical approach, I suggest you contact them directly.
Max
TonyB
Sorry to hear about Ernst Beck. The comments to his obituary on WUWT are interesting.
Max
TonyB and PeterM
Am just reading “Climategate – The CRUtape letters” the new book by Steven Mosher and Thomas W. Fuller.
It gives a very good summary of how this all developed with a good description of the roles of the main players.
The authors describe themselves as “lukewarmers” (believe Judith Curry also used this expression for herself).
In other words, they agree a) that human GHGs have had an impact on our climate, along with a lot of natural forcing factors, the UHI effect, land use changes, etc., but b) that AGW does not pose a catastrophic threat to civilization and c) that any policy actions should be taken based on the certainty of the science rather that on the precautionary principle following a vague notion of “post-normal science” (i.e. “if there is a threat, which is uncertain, but the impact is potentially very large, then some kind of action is mandatory”).
The authors cover the events in excruciating detail.
They come to an interesting conclusion on “the real crime in Climategate”, which I will quote partially:
and to the process:
The authors have put together a very informative account (also a “good read”), which anyone on either side of the AGW argument should take the time to read.
Max
Max,
You say “Sorry you are unable to grasp the logic used by McKay et al.” It doesn’t sound like you do either , otherwise you wouldn’t be referring me to the paper’s authors for clarification.
Yes, there certainly are technical reasons for looking the ratio of the maximum to minimum ice cover in any one year. What I don’t understand is how Wattsupwiththat have used these technicalities to justify their claim of:
“Arctic sea ice extent at the end of the 20th century was more extensive than most of the past 9000 years”
rather than the much more measured statement in the paper itself. Do you understand it or are you going to refer me to Anthony Watts on that one too?
Of course, if I was being slightly more cynical than I am, I would be accusing Anthony Watts of using attention grabbing headlines to mislead simple souls like Brute!
PeterM
Yes. I think I can follow the authors’ logic on the Arctic ice trend over the past 9,000 years, even if you are apparently having difficulty doing so.
But let’s see if we can wrap this up.
It’s not about Anthony Watts, Peter.
Quoting from the McKay et al. study cited by Brute:
http://bprc.osu.edu/geo/publications/mckay_etal_CJES_08.pdf
OK. What does this mean?
Present day sea surface temperature in August averages 1.1 ± 2.4 °C. Over the 9,000-year Holocene this averaged considerably warmer at 3 to 7.5 °C. So it is cooler in the Arctic today (late summer, when sea ice melts to a low extent) than it has been over most of the past 9,000 years.
The average number of months/year with >50% coverage averaged 10.6 ±1.2 months/year over the period 1954–2001, based on data from NSIDC (for the record from 1979 to 2009, I calculated a figure slightly above 10 months, and last year it was 9 months). Over the 9,000-year Holocene the study shows that this ranged between 5.5 and 9 months, so considerably lower. This is not surprising: it’s colder today than over most of the 9,000-year Holocene, so the sea ice extent is a bit greater.
All this simply shows that the current Arctic temperature and sea ice extent are not unusual at all; in fact the temperature is a bit cooler and the sea ice extent a bit greater than the average of the past 9,000 years.
Got it this time?
(Let’s wrap this up now. It is getting repetitive and boring.)
Max
PeterM
You wrote:
I think you may be making a mistake in classifying Brute as a “simple soul”. You (or even I) may not agree with all of his views, but he has definitely not left that impression with me, for example.
Besides, “ad homs” have a way of boomeranging: someone here might return the favor to you.
Max