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Discussion > A temperature timeline for the last 22,000 years

Mark Hodgson

As a batsman I always found it difficult to play a bowler who kept sending down no-balls.

You took the GWPF post and stretched it in ways which illustrated your ignorance. If you feel that pointing that out is an ad hom, you should find a site more suited to your delicate sensibilities.

I notice that nobody here cares about my sensibilities. One law for the contrarians and another for the consensus?

My spell checker thinks your name has an e and is difficult to persuade otherwise.

Sep 25, 2016 at 9:32 AM | Unregistered CommenterEntropic man

Entropic Man:

"Your quote about statistics summed up your ignorance of statistics.
Every point you made illustrated that you do not understand the difference between short term variation and long term trend. It is a typical contrarians propoganda trick to highlight every short term rise in sea ice and pretend that it is a long term trend."

And: "I repeat. Stop cherrypicking short term variation and pretending that it represents the long term trend."

I repeat, the points you refer to were not points I made, they were a direct quotes from a GWPF report. Read what people say, and don't jump to conclusions. But while we're at it:

"Load the NSIDC October 2015 archive . Scroll down in the review to the graph headed "Average monthly Arctic Sea ice extent September 1979-2015".
The graph shows two things of interest. The long term trend shows a decline of 13.4%/decade."

Really? What was that about cherry picking? The wording under your precious graph actually says "Monthly September ice extent for 1979 to 2015 shows a decline of 13.4% per decade relative to the 1981 to 2010 average." That's "relative to the 1981 to 2010 average" rather than the absolute statement you make. And guess what? 1981 was a low ice reading year and 2010 a high ice reading year (or rather 1981 was a downtick on the graph and 2010 was an uptick). In other words, the carefully chosen (cherry picked, one might even say) years of 1981 to 2010 to provide an average have the effect of massively exaggerating the stated rate of ice decline, relative to that average.

Be careful regarding the insults you throw around - they might come back to haunt you. Hypocrite!

Sep 25, 2016 at 9:34 AM | Unregistered CommenterMark Hodgson

Entropic Man:

"You took the GWPF post and stretched it in ways which illustrated your ignorance."

No I didn't. Stop telling lies.

My words were:

"As Disraeli said, there are lies, there are damned lies, and there are statistics. In the modern age, one might add to that list political spin. Given the difficulty of discerning the truth in the conflicting stories put out there, I'd be interested to read what Entropic Man makes of this from David Whitehouse at GWPF: http://www.thegwpf.com/a-ten-year-hiatus-in-arctic-ice-decline/
Follow the link to see the graphs referred to - words cut & pasted below:"

The rest was a cut & paste from the article I referred to, with no extra verbiage from me. I didn't stretch the GWPF post in any way at all. I repeat, stop telling lies.

A simple apology for your error would suffice. Failure to make it will mean I can no longer take you seriously.

Sep 25, 2016 at 9:51 AM | Unregistered CommenterMark Hodgson

EM. You wrote :
"I notice that nobody here cares about my sensibilities. One law for the contrarians and another for the consensus?"
At several times I have indeed cared about your sensibilities and defended you against what I considered unfair comments against you. And you have repaid me how?

Sep 25, 2016 at 9:52 AM | Unregistered CommenterACK

Longer trend

Source

The Sea Ice Index starts in 1979 because that is the start for data from satellite passive microwave sensors. These can see through cloud, operate during the Arctic night and provide global coverage.

Sep 25, 2016 at 10:58 AM | Unregistered CommenterPhil Clarke

Tag team time. EM gets a battering, so his replacement steps forward, fully refreshed.

Sep 25, 2016 at 11:09 AM | Unregistered CommenterACK

Ah, of course, EM – anything that supports your theory is to be considered; nothing that contradicts it. Silly me. I shall try to remember that, in future: in this case, it is far more important to consider the “low” summer ice extent following an average winter than the abnormally high extent (from which a summer high extent follows) with which today’s extent is compared. Ri-i-i-i-ight…

Do note that the 1973 extent given in the IPCC 1990 WG1 report (surely, something that you give greater credence than you give other “non-peer-reviewed” articles) is very low, and this after decades of cooling. Though you will, no doubt, vehemently deny it, this was data used to “prove” the onset of a new ice age – thought that is now being rabidly air-brushed of history. Oh, how the mantra changes; how will you cope should a rapid cooling become undeniable?

My spell checker thinks your name has an e and is difficult to persuade otherwise.
A stark admission of your own failings, I’m afraid, EM, especially as I have no problems, whatsoever, with getting my computer to do what I it to do, not what it thinks is a good idea.

Sep 25, 2016 at 1:21 PM | Registered CommenterRadical Rodent

And I stand with ACK on your plea for consideration – I, too, have defended you when others have lathered on the ad homs against you. I do try to assault your arguments, not your person, though there are many times when your rigidity of thought, your refusal to acknowledge evidence that is contrary to your beliefs, your intractable failure to consider that you might be mistaken, such that you seamlessly deviate onto another train of argument, all these can severely test me.

Sep 25, 2016 at 1:32 PM | Registered CommenterRadical Rodent

Interesting, Mr Clarke. Please tell me, from where is the data prior to the satellites gathered? If, as I suspect, it is from local observations, how widespread were these observations in any one year? Do give some indication of the reliability of historical local observations, and how present local observations compare with the satellite data. And, if local observations are acceptable, why has the term of the graph not been extended further back, to, say, the 1920s? Surely, the longer-term data gained would be more valuable in the determination of trends and cycles, thus far more useful for extrapolation into the future? Mind you, as the observations from the 1920s and 30s might give ice extents even lower than present, it would upset a lot of the rhetoric that you seem to promulgate.

Sep 25, 2016 at 1:48 PM | Registered CommenterRadical Rodent

Ravishing Rattie. I must defend EM against the depredations of his spellchecker. I too have a particularly evil one that this morning over on Unthreaded behaved shamefully. Even yours may have swallowed a "want" (or you may have been making a joke).
Anyway you may be too late. EM may have been relieved by his tag partner - although this could be a ruse.

Sep 25, 2016 at 1:55 PM | Unregistered CommenterACK

Thank you for pointing that out, Minty. All errors are entirely of my own making, I’m afraid – I don’t need no machine to do nuffink for me in typos, not never!

Sep 25, 2016 at 2:33 PM | Registered CommenterRadical Rodent

But, but, but, RR you never ever admit to error. Are you ill?

Sep 25, 2016 at 3:14 PM | Unregistered CommenterACK

What error?

hehehehe...

Sep 25, 2016 at 3:16 PM | Registered CommenterRadical Rodent

RR. Short-term memory problems?

Sep 25, 2016 at 3:38 PM | Unregistered CommenterACK

EM writes

"I repeat. Stop cherry picking short term variation and pretending that it represents the long term trend."

No serious student of climatology would consider a period of less than four decades of records of Arctic ice extent adequate to exhibit a long term trend. In the context of climate change even in a single Interglacial it would require a record of at least a millennium to give any substance to a "long term" trend.

The satellite record from 1979 to date is a short term "cherry pick " that does not give observational substance to a long term trend

Sep 25, 2016 at 4:26 PM | Unregistered CommenterSpectator

Spectator & Radical Rodent

I think the Cherry Picked year of 1979 was to avoid cross contamination with the previous Ice Age Scare stories that Climate Scientists and associated computer tricksters would rather pretend never happened, for fear it would make them all look like a load of confidence tricksters.

Better luck in another 50-70 years, or maybe 200, when the cycle comes round again. I could be more precise, if Climate Science had used their research funding more wisely.

Sep 25, 2016 at 6:05 PM | Unregistered Commentergolf charlie

Even longer term

Then there's Polyak et al. 2010

Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This information can be provided by proxy records from the Arctic Ocean floor and from the surrounding coasts. [...] The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities.

Sep 25, 2016 at 7:08 PM | Unregistered CommenterPhil Clarke

While I wait for Entropic Man's apology, for maligning me unfairly, and for playing fast and loose with the facts, I decided to follow Phil's link in his first response. The 2 paras above the graph to which he links read as follows:

"Passive microwave satellite data reveal that, since 1979, winter Arctic ice extent has decreased about 3 to 4 percent per decade (Meier et al. 2006). Antarctic ice extent is increasing (Cavalieri et al. 2003), but the trend is small.
Satellite data from the SMMR and SSM/I instruments have been combined with earlier observations from ice charts and other sources to yield a time series of Arctic ice extent from the early 1900s onward. While the pre-satellite records are not as reliable, their trends are in good general agreement with the satellite record and indicate that Arctic sea ice extent has been declining since at least the early 1950s."

So much for Entropic Man's 13.4% per decade!

Also, if you look at the graph (and it's their graph, after all) the final sentence is patently untrue. It looks difficult to get a gnat's whisker between the Arctic sea ice readings in 1953 (at the start of the graph) and 1983.

Sep 25, 2016 at 7:46 PM | Unregistered CommenterMark Hodgson

Take another look at the graph. Doesn't the downward trend look alarming? Then look at the heading - "Arctic Sea Ice Extent Standardized Anomalies". Look at the scale - not an absolute one, but "Anomaly (# St. Dev. from 1981-2010 Mean)". That old trick! Choose an average that will guarantee to show maximum exaggeration on the graph, and use that. Why do that if you have a strong case to show, which stands on its own merits?

I've had a look at Phil's later link and graph but couldn't really take it seriously, given the remarkable fall-off it shows at the end, which is not consistent with the first graph he links to. The link to Polyak et al 2010 took me only to an abstract (from which I am unable to decide whether or not it represents good science), and attempts to go further were met by a refusal, as I'm not registered with the site.

Sep 25, 2016 at 8:00 PM | Unregistered CommenterMark Hodgson

Spectator, Radical Rodent.

Walsh et al (2016) published a new dataset of Arctic sea ice extent based on a variety of sources. It starts in 1850 and shows stable September minima around 8 million sq km up to the 1970s and a drop to 4 million sq km at present.

Go here for more details and scroll down to the last graph for the numbers.

Sep 25, 2016 at 9:05 PM | Unregistered CommenterEntropic man

The 13.4% was I believe the trend in the annual September minimum. The Arctic is basically a basin almost surrounded by land, which freezes over completely each winter, thus the rate of decline in the maximum is less than that in the minimum.

Sep 25, 2016 at 9:14 PM | Unregistered CommenterPhil Clarke

Mark Hodgeson

Dissociate yourself from the David Whitehouse post, his unscientific approach and his statistically invalid comments.

Once you recognise that he is wrong you may consider yourself apologised to. If you agree with him, my poor opinion of you both stands.

Sep 25, 2016 at 9:20 PM | Unregistered CommenterEntropic man

EM 9:05 before I look at your link, I note the start date of 1850.

History books have been able to confirm that sea ice retreated in the 1830s 40s so much that William Franklin went looking for the North West Passage in 1845, never to be seen again. The ice then started to advance again.

One of his ships, HMS Terror has just been found, coincidentally in a place known as Terror Bay.

HMS Investigator, one of the search ships abandoned in 1855, was found on the sea bed, , exactly where she got stuck in ice.

Will I learn anything about sea ice extent from Walsh et al 2016, that alters historical facts, that are confirmed by modern archaeological evidence?

The North West Passage has been the graveyard of Victorian adventurers, and over a century and a half later, is turning into a graveyard for Climate Scientists and their unscientific claims.

Sep 25, 2016 at 9:40 PM | Unregistered Commentergolf charlie

https://www.theguardian.com/world/2016/sep/12/hms-terror-wreck-found-arctic-nearly-170-years-northwest-passage-attempt

https://en.m.wikipedia.org/wiki/HMS_Investigator_(1848)

https://en.m.wikipedia.org/wiki/HMS_Erebus_(1826)

Climate Science doesn't do history, if it reveals Inconvenient Truths.

EM, I seem to remember you telling me that HMS Investigator had a "powerful 20hp engine". How is 20hp "powerful" in a ship over 115ft long? " Northabout" the yacht which has just done the polar circumnavigation had an 80hp engine in a 50ft hull, and Northabout had refuelling stops planned in advance and large diesel tanks to hold it.

Sep 25, 2016 at 10:02 PM | Unregistered Commentergolf charlie

Entropic man: very good. However, it would appear that Walsh et al are totally ignoring reports from the 1920s and 30s which talk about very low ice extent, and the prospect of the Northwest Passage opening up (again? – was it ever, despite Franklin’s doomed expedition in the 19th century?). It would be interesting to know if a submarine could safely surface at the North Pole, now, as USS Skate did, in 1959. If not, why not? Ice too thick, or modern subs too thin?

As the Northwest Passage is still not open, despite much hyped attempts to find it, all of which have ended as Franklin did, though (thankfully) none so tragic, I would moot that you are being misled. What is happening in the Arctic, now, is nothing more than what has happened in the past; I doubt it will be too long before we are in a panic (led by you, perhaps? – in which case, probably with human-produced CO2 as the culprit) about the encroaching ice.

Sep 25, 2016 at 10:17 PM | Registered CommenterRadical Rodent