Phil Clarke 7:08 can we assume that Polyak did not do history, only computer modelling at school? How did he calibrate his proxies to fit the models, and end up being so wrong?

In proper science, you do not start with a fabricated conclusion, and work backwards adjusting modelled evidence to fit.

EM

1. I suggest you switch off your spell checker.

2. Please try to learn to read and understand simple English. I did not associate myself with the David Whitehouse post. I mentioned it without either approval or disapproval. I simply quoted it, provided a link, and asked for your comments. You responded with abuse (based on your failure to read carefully and understand what I wrote), lies and hypocrisy.

3. Before you accuse David Whitehouse of "his unscientific approach and his statistically invalid comments" I suggest you re-examine your own behaviour.

4. Given your lack of humility and failure to apologise for uncalled for abuse, lies and hypocrisy, I can no longer take you remotely seriously.

Phil Clarke:

"The 13.4% was I believe the trend in the annual September minimum. "

Wrong. It does relate to the September minimum, but it's not 13.4% per decade in absolute terms. The full quote is ""Monthly September ice extent for 1979 to 2015 shows a decline of 13.4% per decade relative to the 1981 to 2010 average." However, EM chose to omit the weasel words "relative to the 1981 to 2010 average" when claiming, dishonestly, that Arctic sea ice is declining by 13.4% per decade in absolute terms. The same website on which you both rely says this:

""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."

Please do not associate yourself with EM. I am a seeker after truth, as I believe are you. EM, by contrast, is a true believer. There's a big difference.

Mark Hodgson

When you describe a % trend you have to define what the trend is a % of.

In this case the reference is the 1981-2010 average, which is about 6 million sq km and represents the midpoint of the dataset. In numerical terms it represents a drop of 800,000 sq km/decade.

You have made the mistake of thinking that the fig 3 graph shows sea ice extent anomaly. It actually shows extent.

And for trend purposes the baseline is utterly irrelevant.

EM

Thank you for spelling my name correctly.

However, as for this: "When you describe a % trend you have to define what the trend is a % of.
In this case the reference is the 1981-2010 average, which is about 6 million sq km and represents the midpoint of the dataset. In numerical terms it represents a drop of 800,000 sq km/decade."

Wrong, both for the reason explained by RR and for the fact that the graph covers the period 1979-2015. Why not, then, take the average of 1979-2015 to define your trend? Answer, as I have already pointed out -

"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"

Great news! Climate science has new scares, and scary numbers. Actually, they are not very scary really

https://wattsupwiththat.com/2016/09/26/claim-greenland-ice-melt-worse-than-previously-thought/

Radical rodent

Wrong graph. Mark Hodgson and I were discussing Fig 3 of the NSIDC 2015 melt review. This shows the September average extent from 1979 to 2015, is the summer minimum..

Since you were talking about changes from 12million sq km to 10 million sq km. I presume your graph is showing the Arctic sea ice maximum.

Mark Hodgson

GISS use the 1951-1980 average as the basis for their anomalies. The Met Office use 1961-1990. NSIDC use 1981-2010.

I would guess that it has become standard practice to use the three decades around the midpoint of the years for which you have data, You start counting at the beginning of the first decade of the three.

EM:

"GISS use the 1951-1980 average as the basis for their anomalies. The Met Office use 1961-1990. NSIDC use 1981-2010.
I would guess that it has become standard practice to use the three decades around the midpoint of the years for which you have data, You start counting at the beginning of the first decade of the three."

Thank you for the explanation. However, "I would guess that it has become standard practice..." is a little vague. Is there any good reason why you wouldn't use the average of the years you are studying? Is there any GOOD reason why GISS, Met Office and NSIDC all apparently use different averages as the basis for their anomalies? It strikes me as unhelpful, to say the least.

Mark Hodgson

I'm a retired teacher, not a climate science professional. AFAIK each of the groups generating historical climate data can use whatever baseline they think best. Nobody enforces a common baseline, though those producing comparison graphs have tended to choose 1981-2010.

There are a number of graphs comparing different analyses. For example, moyhu maintains graphs comparing the monthly figures for the last 5 months and the last 4 years. The different datasets have all been recalculated to a common 1981-2010 baseline. The Met Office have a similar graph comparing Hadcrut4, NOAA and GISS.

Alternatively, you can use the baseline value for each dataset to calculate actual values for the global average. For example, the actual GISS 1951-1980 average is 14.0C. This makes the 2015 anomaly of 0.86C an actual value of 14.86C.

The Paris Conference focused interest on the amount of warming due to industry. The pre--industrial baseline used is 1851-1880 (13.8C).

Thus the 2015 global anomaly becomes 1.06C above pre-industrial.

Converting back, the Paris 1.5C target becomes GISS anomaly 1.3C and the Paris 2.0C target becomes GISS anomaly 1.8C.

This was never designed to be easy for the layman, but it gets easier with practice.

This was never designed to be easy for the layman, but it gets easier with practice.

Sep 26, 2016 at 9:55 PM | Entropic man

No, it was designed for the gullible, by the gullible. If it was real science, why the dependency on the 97% Consensus? You need to start saving the good bits of climate science before it is all flushed away.

EM

Thank you for your helpful explanation. I understand it, and can see how it works. I accept that if you're going to talk about % increases or declines you need to be comparing against something.

I remain uneasy about the rather casual-seeming basis to the dates selected. For instance:

"The pre--industrial baseline used is 1851-1880 (13.8C)."

Why? It is true that the industrial revolution got into its stride in the mid-late 19th century, but it started in the 18th century. So why regard 1851-80 as pre-industrial, when clearly it wasn't? Rightly or wrongly (and possibly wrongly - it's possible the anomaly would be bigger if an earlier date was chosen) I can't help feeling that dates are cherry-picked for presentational purposes, though if I get time later today, I will follow your latest links to check it out further. In the meantime, it all just lacks a "scientific" feel.

Mark Hodgson, judging by failure of the Franklin Expedition, the mid 1850s is when deep frozen cherries became unexpectedly available again for picking. From the 1830s to about 1850 there were wonderful crops of cherries grown in the warmer climate.

Mt Tambora blew it's top in 1815, causing the "Year without a Summer" in 1816, which according to modern Climate Science must have reduced sea temperatures and air temperatures for a number of years, but for reasons unknown to Climate Science it warmed again into the 1840s before cooling off again in time for EM to select his start date.

The Year Without a Summer caused mass starvation due to crop failures, recorded across Europe. Climate Scientists don't do history, which is why they don't understand the dangers of a cooling world. Unless you only want to pick frozen cherries.

How did the world recover so quickly from the "Year Without a Summer" in 1816, to start opening the North West Passage up to adventurers by the 1840s, only to cool down close the NWP and kill the misguided fools who mistook a few warmer years for a natural progressive trend and new equilibrium? I don't know, nor do Climate Scientists. So Climate Scientists have to pretend it never happened.

Golf Charlie

In the Victorian Royal Navy, with nobody to fight, one got reputation and promotion by deeds of exploration. Franklin gave the Admiralty the same warming Arctic bullshit you give here. He was trying to persuade then to give him ships to seek the NW Passage.

Easier cherry picking does not scientific data make. If the Arctic was milder in the 1830s it would show in ice melt. Companies like the Hudson's Bay Company would have noticed and recorded the early melt and later freezing. Besides, how do you get a warming Arctic and good cherry harvests during the LIA?

You keep talking about Arctic warming in the 1830s.Show me numbers.

The 1815 Tambora reduced temperatures and insolation right around the Northern Hemisphere. Crop failures occurred in North America, Europe, India and China. Its effect on Ireland in 1816 is recorded, in the big increase in the price of grain and the number of people seeking poor relief. It was also transient. Within 3 years conditions returned to normal.

The Pinatubo eruption in 1991, though much smaller, also produced widespread cooling. Again the temporary decrease returned to normal after 3 years.

It is not reasonable to suggest that temporary warming in the 1830s Arctic, if it even took place, could be blamed on an eruption thirty years earlier

Mark Hodgson

Historically the Industrial Revolution probably began with Abraham Darby,'s coke fired blast furnace in 1709 and Newcomen's atmospheric engine in 1712. From a climate viewpoint the Industrial Revolution became significant when it's emissions became large enough to change the CO2 content of the atmosphere.The Law Dome ice core shows atmospheric CO2 increasing the interglacial 280ppm from the mid 1800s.
Look at Figure 2 here.

Robert Fitzroy established the Met Office in 1845. This makes the 1850's the first decade for which systematic temperature data is available.

With the onset of increasing CO2 and the availability of accurate temperature data both occuring around this time an 1851-1880 baseline looks reasonable.

EM. Are you sure preIndustrial CO2 values were 280ppm, or was it 270ppm or even 260ppm? 0r could it have been, at times, much higher?
The problem summarized here:
http://drtimball.com/2012/pre-industrial-and-current-co2-levels-deliberately-corrupted/

Beck's measurements are problematic (and physically implausible) , Jaworowski's claims have been discredited:

In Dashiell Hammett’s story The Golden Horseshoe, much of the action takes place in a bar of that name in Tijuana. At one point the narrator, an operative for the Continental Detective Agency, kills a few strategic seconds by studying the decorations:

I was reading a sign high on the wall behind the bar:
ONLY GENUINE PRE-WAR AMERICAN AND BRITISH WHISKEYS SERVED HERE
I was trying to count how many lies could be found in those nine words, and had reached four, with promise of more …

Sometimes I come across an article, web posting, advertisement or other statement that makes me feel when I read it just as I imagine the Continental Op did in that Tijuana bar. How can they possibly pack so much misinformation into such a small space?
To honor exceptional achievement in mendacity, I would like to present the Golden Horseshoe Award to that writer who has out-performed his or her peers in density of false statements per column-inch. To receive the first Golden Horseshoe Award, I can think of no more worthy recipient than Zbigniew Jaworowski.

Read on

Dr Tim Ball of course, launched a libel action during which he was accused of being ' a paid promoter of the agenda of the oil and gas industry rather than as a practicing scientist'. He later folded, perhaps because truth is a valid defence against a libel claim.

https://en.wikipedia.org/wiki/Timothy_Ball#Controversies_and_lawsuits

I humbly submit that a 'seeker after truth' is unlikely to get much from the likes of Beck, Jaworowski or Ball.

A little more actual scepticism, pls.

ACK

Reading the post, my antennae quivered at the immediate mention of climate conspiracy, cherrypicking and evidence to a Senate Committee. This suggests a definite bias in the writer, which then taints anything he writes later.

I cannot check the data without reference to the sources, but two cientific points did jar.

The post shows Callender data and mentioned 90,000 data points. On the graph there is a scatter of individual points and a number of clumps. Lacking more detail I assume that most of the data points are within the clumps, which follow the generally accepted curve.

You know yourself that any such analysis will generate outliers, but that they are indicative of local variation or experimental error (bacterial contamination was mentioned). Unless they are numerous enough to create large confidence limits they do not affect the main analysis.

You may remember that gas bubbles tend to migrate upwards in firn Thus a layer of ice dated by volcanic ash will contain bubbles of CO2 trapped at an earlier date. The difference is consistent and is corrected by moving the whole CO2 curve to the right, bringing the age of the bubbles in line with the age of the ice.

Jaworowski shows the shift in his own paper, but claims that it was deliberately moved to fraudulently create a pattern. . Ball mentions the firn, but spends most of his words trying to stress the size of the errors.

Overall I found the claim of conspiracy unconvincing. Ball telegraphied his bias from the beginning Jankowski's selective analysis was apparent even to an educated layman like myself.

EM, phil Clarke. Perhaps antennae should have kept twitching EM and you should have persisted with your researches into Callender's cherry picking - eliminating any data points that did not fit the result he wanted or expected. Jaworowski is one of the few who did original work on gas trapping and integrity. His work on lead in ice cores is still acceptable, why not his critique of gas contents within bubbles? His experimental work can be replicated. Tim Ball has a PhD in climatology, does anyone here? So he backed down in pursuing a libel case. Do you know why? You seem yourself to be spreading libel. If you have genuine information about the case, do share.
The point I'm making is not what the pre Industrial CO2 value was, but like so many other things in climate science, there is dispute, commonly ignored and buried by the consensus. Calebrated stomatal values certainly do not suggest values were uniformly low.

Good story PC, pity it was all innuendo.

ACK

What cherry picking? Callender's data, according to Ball includes data points as high as 550ppm and as low as 200 ppm.

EM. Before responding in ignorance, read up on the subject. Only the low CO2 values were used, the high values were discarded, commonly on somewhat spurious grounds. Callender found the result he wanted to find.

ACK

Link please, preferably to something peer reviewed.

I am disappointed in you. It is sad to see a retired scientist decline into just another conspiracy theorist.

Ball asserts that 'Ernst-Georg Beck confirmed Jaworowski’s work.'

On planet Ball perhaps, elsewhere Beck's measurements have been shown to be subject to pollution from urban areas and observed with equipment that did not give the claimed level of accuracy. If the claimed CO2 flux were real, it implies the emission of gigatonnes of carbon …. No source for which has ever been given.

The problems with Jaworowski's work are admirably documented in the blog post I linked. The unconvinced can turn to this letter by Hans Oeschger (honoured by the creation of the Oeschger Medal) which ends

 I find the publications of JAWOROWSKI not only to be incorrect, but irresponsible.

Not innuendo.

 Tim Ball has a PhD in climatology, does anyone here? 

That's a bit of a stretch, his thesis was on the historical climate of a little bit of Canada and his Doctorate was in historical geography; he was employed as a professor of Geography until he retired some 2 decades ago. As you bring up his credibility, here is the statement of claim against which he declined to defend himself:

"...that the Plaintiff never held a reputation in the scientific community as a noted climatologist and authority on global warming....

"The Plaintiff has never published any research in any peer-reviewed scientific journal which addressed the topic of human contributions to greenhouse gas emissions and global warming;

"The Plaintiff has published no papers on climatology in academically recognized peer-reviewed scientific journals since his retirement as a Professor in 1996;

"The Plaintiff's credentials and credibility as an expert on the issue of global warming have been repeatedly disparaged in the media; and

"The Plaintiff is viewed as a paid promoter of the agenda of the oil and gas industry rather than as a practicing scientist."

Phew!

http://www.desmogblog.com/dr-tim-ball-the-lie-that-just-wont-die