How long before we reach the catastrophic 2°C warming?

Guest essay by Neil Catto

The other day I conducted a presentation using the UK CET, like I have on several occasions. Along with explaining it as the longest recognised instrumental record of historical temperature anywhere on Earth, it is the best record we have to understand long the past.

clip_image002

Fig 1 Central England Mean Monthly Temperatures 1659-2012

As part of this presentation I point out that the temperature from 1659 to 2012 has only increased 0.87 Deg C in 353 years, or equivalent to 0.025 Deg C/decade. Considering this is a recovery period from the Little Ice Age it is hardly surprising and just part of natural variation. At this stage I normally get a few “really?” questions.

“The UK MetOffice’s own figures”, I reply.

The other day however was a bit different, someone in the audience asked “so how long will it take to get to the dangerous 2 Degrees C?”

Pause, why hadn’t I worked that one out before? Quick calculation done, 800 years I replied.

“Say again?”

I recalculate, and say “800 years given the current trend”. Gobsmacked audience!

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J. Philip Peterson
October 30, 2013 10:46 pm

We probably had 2C warming in the 1930s but that has been adjusted and hidden. That’s when most of the high temp records were recorded, in the US at least.

Janice Moore
October 30, 2013 10:47 pm

Hear, hear!
Well done. Thank you for all the time and effort you have dedicated to prevent Envirostalinist tyranny. John Milton would have written a sonnet in your honor, O Valiant Defender of Our Liberties.

Crispin in Waterloo
October 30, 2013 11:06 pm

Heh-heh. Well done. And the time will be extended further by 2016. At some point late in my lifetime it may reach the point of ‘never’.

Steve Cords
October 30, 2013 11:21 pm

One can also ask, “Just what is the right temperature?” or “What is the temperature supposed to be?” Sea levels have risen 5 feet in the last 8,000 years (times and elevations approximate for discussion) and we are suddenly concerned about the last few inches.

October 30, 2013 11:31 pm

Good answer.
Also, follow it up with other questions?
2 degrees… from where? (why pick that spot?)
What is the most alarming period of warming on the chart? (1680-1750).
That was more than two degrees from trough to peak.
What sort of catastrophic climate change happened in 1750? From my history, i think it was party time in Brittan

gbaikie
October 31, 2013 12:27 am

“I recalculate, and say “800 years given the current trend”
Yeah, but probably have some warming effect from higher CO2 levels.

October 31, 2013 12:38 am

Thank you for this. That this is the met Office’s figures is surely damning!

James Bull
October 31, 2013 12:45 am

It never hurts to recheck your figures, as I was told many years ago and have passed on to others measure twice or thrice cut once, and nowadays don’t “model” it on made up numbers.
I was once in a workshop where one of the drawing office guys was known as “do it to the drawing” after being told that if you followed the dimensions on the drawings he did things ended up on sky hooks or on another drawing the internal dimensions were greater than the overall measurement. Boy was that hard to make!!!!!!!!
James Bull

Cheshirered
October 31, 2013 1:02 am

Only 800 years? Oh my, it’s worse than previously thought.

October 31, 2013 1:17 am

Stephen Rasey says: October 30, 2013 at 11:31 pm

What sort of catastrophic climate change happened in 1750? From my history, I think it was party time in Britain

Well, yes, relative to France. We were preparing to win the 7 Years War that was brewing. Paris had riots (again) and Prussia was being expansionist (no comment).
If this relates to climate (and it might) then the nation surrounded by water may well be slowest to be affected.
Of course, I don’t know if catastrophic climate change happened in 1750 but the fact that Britain was on the way up is not proof that there wasn’t.

Peter Miller
October 31, 2013 1:24 am

I hope someone is hanging on to the original data here, as it sure looks like someone in the Establishment overlooked doing the usual ‘adjustments’.

John Law
October 31, 2013 1:38 am

I’ll be 867 years old then, I ‘m not sure my constitution will be up to that sort of temperature rise.
Something must be done!

Jquip
October 31, 2013 1:42 am

In 17 817 years.

Olaf Koenders
October 31, 2013 1:44 am

At the rate over the last 17 years? Hmm.. I calculate approximately ∞ years.. ¯\ (ツ) /¯

Tim welham
October 31, 2013 1:53 am

Anthony: I believe the CET published figures are ‘adjusted’ before release. Are they any more reliable?

Editor
October 31, 2013 2:03 am

The actual temperature rise might be less because of the enhanced heat island effect that relatively speaking is a fairly recent phenomena. In the 1701 century the population of Britain was 5.5 million, 100 years later it was 9 million, with most people living in the countryside. Now the population is 60 million with most people living in cities with airports which is where many of the air temperatures are measured.

William Astley
October 31, 2013 2:06 am

It gets better or worse depending on one’s view of whether lukewarm warming is or is not beneficial. It will take 800 years for the planet to warm 2C assuming 100% of the past warming was due to the increase in atmospheric CO2. Now if Shaviv’s calculation is correct (see attached link for details) and 75% (0.54C ± 0.12C) of the warming in the last 100 years was caused by solar magnetic cycle changes then the planet will cool roughly 0.5C if the very recent grand maximum of solar magnetic cycle activity is followed by a grand minimum. The cooling will last for 80 to 120 years.
http://wattsupwiththat.com/reference-pages/solar/
http://www.solen.info/solar/images/comparison_recent_cycles.png
Spoere-type minima have a duration of about 120 years, and Maunder-type minima have a duration of about 80 years. The decadal C14 record in recent 10,000 years shows about 20 events of increase in C14 content, indicating there were 20 grand solar minima in the last 10,000 years or one grand minimum every 500 years. Following analysis of the data, Lockwood believes solar activity is now falling more rapidly than at any time in the last 10,000 years.
http://www.eike-klima-energie.eu/uploads/media/Shaviv.pdf

Dario from Turin
October 31, 2013 3:03 am

Here in NW Italy we have the historical proofs (i.e. written records, mainly by official fiscal autorities of that time) of the production of olive oil referring to the X – XI – XII centuries. From an agricultural point of view, this fact demostrates that the climate was AT LEAST 1° C WARMER than today, with no frost episodes during the winter. So, we have had a catastrophic DECLINE of 1° C….

H.R.
October 31, 2013 3:14 am

Uhhh… 800 years, assuming the warming continues. If you had given that presentation a few hundred years before the Little Ice Age, I suppose your audience might have been asking how many years before the glaciers would return. Global temperature, she goes up. Global temperature, she goes down. Up, down. Up, down.

GeeJam
October 31, 2013 3:20 am

Given that the last one hundred years has been utterly void of any kind of noticeable technological advance or revolutionary invention or any life-changing scientific breakthrough, then in eight centuries time (about 70 x family generations), no doubt humans will be completely incapable of thinking of ways to adapt – given the current trend – to TWO whole degrees of warming. However, I hear that if we spend everyone’s money on filling our planet with millions of wind turbines whilst removing every last drop of man-made CO2 from the air before 2020, it will solve their problem for them. We need to help them get through it. They’ll never cope. We need to act now before it’s too late. (sarc off).

CRS, DrPH
October 31, 2013 3:26 am

…I’m inspired to form a new not-for-profit corporation, 800.org! /sarc

Luigi Mariani
October 31, 2013 3:29 am

If we consider the CET time series of the last 100 years, al the warming is centered in two steps. The first step is perhaps in 1935 and the second (the main) is centered in 1987. This latter is the result of a well known abrupt change of phase of the NAO. The abrupt character of these changes make difficult the adoption of a generalized approach bases on trends (more specifically the trend analysis should be limited to the homogeneous sub-periods) and gives the idea that an approach based on the analysis and forecast of the discontinuities determined by changes in macroscale circulation is the most suitable for this kind of time series.

H.R.
October 31, 2013 3:38 am

@CRS, DrPH says:
October 31, 2013 at 3:26 am
“…I’m inspired to form a new not-for-profit corporation, 800.org! /sarc”
Leave the ‘/sarc off.’ I like it! Set up a little site and I’ll join. If 4-5 others here are of the same mind, you’ll have more members and traffic than 350.org.

Nick luke
October 31, 2013 3:40 am

Just a small quibble…0.87Deg/353years = 0.00246 X 100 = 0.246deg/century. Not 0.025deg/cent. Small typo, I know, but we moan at inaccuracies by the AGW proponents. It makes the difference between your, correct, 800 years and 8000 years…

Kevin Hearle
October 31, 2013 3:42 am

Mmmm so by 2650 we will see all the benefits of increased temperature provided we aren’t falling into a Maunder Minimum or worse which might be worth it to see the shock and horror on the face of Warmists
[2065 ? ]

October 31, 2013 4:15 am

Noticed interesting year of 1740(deep fall of temps) and the preceding warming of more than 2 degrees in 15 years. What happened? Well, its not the sun and it aint volcanoes according to David Archibold in a previous blog here on WUWT(JUNE 2013). He proposes a potential 1740 event occurring in the next 2 years based on a statistical methodology. Baring in mind this is a central england/ north european event of 1740 it is not therefore a record of world temps which may hint at a local mechanism? unfortunately most other records dont go back this far.
smiffy

October 31, 2013 4:17 am

Nick luke says:
October 31, 2013 at 3:40 am
In the post, the figure was for decadel rate of increase, not per century.
cheers,
gary

Chris Wright
October 31, 2013 4:40 am

If you zoom into the CET graph, it shows that the English climate has been rapidly and consistently getting colder since 2000. And it certainly feels colder.
Recently the Daily Telegraph had a headline claiming that the British climate is getting warmer faster than the rest of the world. Clearly, climate scientists have a strange idea of the present tense. It was actually true during the 1990’s, CET shows a rise of about one degree C in little over a decade, which is extremely rapid. But to say that our climate is rapidly getting warmer now is a lie, pure and simple. Right now, and for the past 13 years, it’s been getting colder.
That’s why I often find myself wearing a sweater at the height of summer. And staring out at thick snow in the winter.
How much longer will our politicians be taken in by this nonsense. Quite a long time, I suspect, with outrageous lies like this to keep them going.
Chris

Martin McPhillips
October 31, 2013 5:31 am

Here’s the Wikipedia Holocene temperature chart. Can someone explain why this doesn’t simply end the debate? What’s the problem here? I understand that there’s nuance upon nuance, but ther is nothing dramatic or unprecedented about current temperatures. Is that correct?
http://upload.wikimedia.org/wikipedia/commons/c/ca/Holocene_Temperature_Variations.png

Bruce Cobb
October 31, 2013 6:26 am

Since we’ve been gradually cooling over the past 7k years, by perhaps 0.5°, there’s no reason to think that trend won’t continue, and certainly no reason to think we’ll be warmer. We are after all, headed for another ice age eventually.

Stacey
October 31, 2013 6:32 am

Our friends at the MET office I believe ably assisted by [fragrant] Phil still manage to create a Hockey Stick Graph?
http://www.metoffice.gov.uk/hadobs/hadcet/graphs/HadCET_graph_ylybars_uptodate.gif

Jim Cripwell
October 31, 2013 6:43 am

I may be wrong, but your 800 tears is valid if, and only if, the data is ergodic. Since the data is almost certainly not ergodic, then the 800 years is meaningless.
[Wasn’t there a song a while back about “800 teardrops” ? Or was that “800 teargodics”? .. 8<) Mod]

Jeff Alberts
October 31, 2013 7:19 am

As part of this presentation I point out that the temperature from 1659 to 2012 has only increased 0.87 Deg C in 353 years

Which “the temperature” would that be? There is no “the temperature” when it comes to climate. Averaging temperatures over disparate areas gives you nothing physically meaningful. You’re playing the same silly shell game as alarmists.

herkimer
October 31, 2013 7:19 am

800 Years to raise temperatures by 2 degees C
One can now see how absurd the past MET OFFICE forecasts were when they projected 4 degrees C by just 2060 . Yet IPCC is still projecting in their A1FI scenario a rise of 4 degrees C by 2100 in their latest report. AR5

October 31, 2013 7:20 am

So what now?
Western civilization must reduce its standard of living so that children, 800 years from now, will know what snow is.

janama
October 31, 2013 7:20 am

In 1996 when the Australian temperatures were homogenized/adjusted Sydney Observatory Hill data had adjustment made where due to the addition of a Stevenson Screen all previous data was adjusted down .5C and because the thermometer was moved the 10m to where the new box was all previous data was adjusted down by .7C – that’s a total of 1.2C.
Can you believe it?

October 31, 2013 7:45 am

H.R. says:
October 31, 2013 at 3:38 am
@CRS, DrPH says:
October 31, 2013 at 3:26 am
“…I’m inspired to form a new not-for-profit corporation, 800.org! /sarc”
Leave the ‘/sarc off.’ I like it! Set up a little site and I’ll join. If 4-5 others here are of the same mind, you’ll have more members and traffic than 350.org.

Agreed. Do it! I believe WordPress hosting is free?

October 31, 2013 8:06 am

Guest essayist Neil Catto said,
The other day however was a bit different, someone in the audience asked “so how long will it take to get to the dangerous 2 Degrees C?”
. . . 800 years I replied.
“Say again?”
I recalculate, and say “800 years given the current trend”. Gobsmacked audience!

– – – – – – –
Neil Catto,
A anectodatal sign of the times. Good news I think because it implies some awakening from the ‘settled’ alarming climate mythos.
Hey, I am trying to track back to the root source / fundamental basis of the claim of there being a “dangerous 2 Degrees C”.
It crops up frequently in dialog on climate. I want to critically review it for premise detection and analysis purposes.
Anyone, a few pointers to primary sources of the basis of the idea of a “dangerous 2 Degrees C” would be appreciated.
John

October 31, 2013 8:07 am

Is the Global temperature record correct?
Looking at the CET you would expect to see the large increase in global temperatures showing to some degree but it hasn’t.
Check this graph of temperature vs monitoring stations.
http://www.uoguelph.ca/~rmckitri/research/nvst.html
Perhaps this can explain the standstill. The cull takes out stations in the colder regions so the global temperature record rises. After the cull the situation is stable and the stations are reflecting the true global temperature which is not rising. This would explain why we had a massive step in the global temperature record and the current pause.
Apologies to anyone who tried contacting me via my website, Gmail would not accept the autoforwards set up, but they seem to be working now.

Bruce Cobb
October 31, 2013 8:12 am

Regarding an 800.org, I assume we’re talking ppm, not years. A good motto might be “Do it for the plants!” Yes it would be the perfect antidote to the 350.org idiocy.

Richard Barraclough
October 31, 2013 8:29 am

Most of the hysteria over global warming does not concern itself over what are seen as purely natural fluctuations over the 300 years from 1650 to 1950. The trend of the CET data over this period is even less, at 0.18 degrees per century, or about 1100 years to increase by 2 degrees.
Since 1950, which is the focus of the anthropogenic scare, the trend in CET has been almost 10 times as much, at 1.7 degrees C per century. Even at this rate, it’s about 120 years to increase by 2 degrees. I realise one cannot really extrapolate a linear trend in something as chaotic as temperature, but that was the gist of this post, and , yes, it has been dropping for a few years, so perhaps 120 years is too short.
Some commentators have attributed the sudden fall in temperature in 1740, after the benign 1730’s to a volcano or two on the Kamchatka peninsula. The cold weather and associated crop failures killed 20 per cent of the population of Ireland.

David S
October 31, 2013 8:57 am

OK this is not a criticism. I’m just curious. What kind of thermometer was used to make those early measurements? The modern thermomether wasn’t invented until the early 1700’s.

Steve Oregon
October 31, 2013 9:31 am

Steve Cords says:October 30, 2013 at 11:21 pm
…”Sea levels have risen 5 feet in the last 8,000 years (times and elevations approximate for discussion) and we are suddenly concerned about the last few inches.”
The difference is no one knew about the 5 feet as it rose. No one was telling the folks about it or what it meant.
Now we have mad scientist alarmists measuring everything and purposefully interpreting every change as a worrisome indicator in order to justify their continued monitoring,.
Monitoring change has become the ticket to ride for every lazy and nonproductive academic wishing to be a legitimate scientist.
It’s the easiest pitch possible for those needing to gin up reasons to make their hobby time look like work.
They’ve managed to turn their endless observation gibberish into deliverables.
They monitor, speculate and report whatever they can dream up.
It’s limitless and thousands upon thousands are using this gig.
A fine example is Oregon State University academics (Lubchenco, Barth and Chan) engaged in their perpetual and expensive monitoring of oxygen levels in our sea water off the Oregon coast. Every single new reading delivers another layer of speculation about how something very serious MUST be occurring. Accompanied with declarations of how useful their work and information gathering is.
http://www.piscoweb.org/research/science-by-discipline/coastal-oceanography/hypoxia/hypoxia-updates
It’s all as useless as counting grains of sand on our beaches.
Just Google “Oregon ocean dead zones” and see how massive the ruse has become.
It’s an entirely baseless problem, falsely connected to global warming and embellished over many years into being accepted by RealClimate types as “established science”.

BioBob
October 31, 2013 9:48 am

David S says:
October 31, 2013 at 8:57 am
OK this is not a criticism. I’m just curious. What kind of thermometer was used to make those early measurements? The modern thermomether wasn’t invented until the early 1700′s.

——————————————–
see http://www.rmets.org.uk/sites/default/files/qj74manley.pdf
but if you are lazy, the data is pretty bad, sometimes consisting of reconstructions employing dubious techniques like temps taken from unheated rooms inside, etc.
For what it’s worth, this data is what it is….not very useful but of some interest.
This IS criticism:
Most importantly, there were no replicates, no random sampling, questionable adjustments, etc. just as is the case in essentially ALL temperature records globally.
The data is crap; It always has been crap, and it likely always will be crap if history to date is any indication.

October 31, 2013 10:06 am

M Courtney at 1:17 am
I don’t know if catastrophic climate change happened in 1750 but the fact that Britain was on the way up is not proof that there wasn’t.
But it is counter evidence to the notion 2 degrees of warming is catastrophic.

NeilC
October 31, 2013 10:17 am

A few reasons for this this post;
a. to show how little warming there has been (on record) over the length of instrumental data (I agree the data has been adjusted in all manner of ways especially the very small adjustment for UHI, which I believe is ~1.6 Deg C) In a post from earlier this year.
b. I thought 800 is as nice a number as 97% or 95% or 100% settled
c. yes it was done in fun – but from a serious point I would like this 800 years spread wide and clear to remove the fear of CAGW from as many as possible ( I get phone calls from people genuinely frightened and wanting to make life changing decisions)
d. I’ll bet Auntie doesn’t mention this, any bets?
In late 1739 mt Tarumae erupted: temp went from 9.2 Deg C in 1739 to 6.84 Deg C in 1740 and back to 9.30 Deg C in 1741
thanks for all your comments

Marcos
October 31, 2013 10:26 am

iirc, the 2 degrees C ‘limit’ was a number pulled out of thin air by some German climate scientists. they looked at what historical temp variations had been, saw that a difference of 2 degrees C had happened with no catastrophic results and declared that to be the ‘safe’ range.
a link to this story was in the comments here in the last month or two

John Finn
October 31, 2013 12:57 pm

Regardless of whether one accepts AGW or not, it’s time readers of this blog were a bit more critical of some of the WUWT posts. Neil Catto concludes that it will take 800 years for the 2 deg C threshold to be breached – presumably based on the 353 year trend since 1659.
This is a ridiculous conclusion. As far as AGW is concerned the first 300 years of the record are largely irrelevant. The relatively shallow trend since the 1650s is simply due to the fact that the trend in the first 200-300 years was more or less flat (which pretty much puts the kibosh on the LIA at least as far as Central England is concerned). Analysis of CET trends show the following
1700-1900 -0.05. degrees per century
That’s about as flat as you can get. Now what about the trend since 1900
1900-2012 0.81 degree per century
So virtually ALL the warming in the CET record is in the last 100 years or so – but even that trend is dwarfed by the last 50-60 years.
1950-2012 1.7 degree per century
or warming of about 0.85 degrees per 50 years. There was essentially NO warming trend for at least 250 years . All the warming has taken place in the last few decades. The CET record doesn’t provide much support for either natural variability or LIA recovery.

October 31, 2013 1:11 pm

John Finn,
That is only on your planet. Here on Planet Earth, the natural recovery from the LIA has been ≈0.25 – ≈0.35º/century.
I don’t know where you get your assertions, but even über-alarmist Phil Jones shows that global warming did not just happen recently.

richardscourtney
October 31, 2013 1:15 pm

John Finn:
re your post at October 31, 2013 at 12:57 pm.
If I need a cherry picker then I now know who to contact.
Scroll up and look at the graph.
It shows a clear linear trend (that is the straight red line in the graph) with variability of the actual data (that is the wiggly blue line in the graph) providing variation around that trend.
There is no indication of any change to the trend. However, because of the wiggles it is possible to pick periods of warming or cooling of the actual data to fit whatever one wants to (mis)represent.
Richard

Aussiebear
October 31, 2013 1:26 pm

Oregon,
Your post has got me thinking. Is Global Warming/Climate Change really just an artefact of all of this high and low resolution monitoring of literally everything, and NOT knowing what it means? For example, there is some discussion that there has been an increase in tornadoes in The US. Is this because there is a legitimate increase, or because of better monitoring, we see all of them? Are we being “hypochondriacs” because we fuss over every little change?

DennisA
October 31, 2013 2:34 pm

For more on the CET and Met office projections, read this:
“Global Warming – The Social Construction Of A Quasi-Reality”
http://scienceandpublicpolicy.org/reprint/social_construction.html
Original Paper at http://multi-science.metapress.com/content/v84152h64m5r36t5/
GLOBAL WARMING: THE SOCIAL CONSTRUCTION OF A QUASI-REALITY?
Journal Energy & Environment

dennisambler
October 31, 2013 2:38 pm

H.R. says:
October 31, 2013 at 3:14 am
Global temperature, she goes up. Global temperature, she goes down. Up, down. Up, down.
DUH!
Homer Simpson

RossP
October 31, 2013 2:40 pm

John Whitman and Marcos
The following link gives the “history” of the 2 degree C figure. As Marcos says it was invented by the Germans and like alot of these issues had a large dose of politics in it.
http://www.spiegel.de/international/world/climate-catastrophe-a-superstorm-for-global-warming-research-a-686697-8.html

October 31, 2013 2:57 pm

RossP on October 31, 2013 at 2:40 pm said,
Whitman and Marcos
The following link gives the “history” of the 2 degree C figure. As Marcos says it was invented by the Germans and like alot of these issues had a large dose of politics in it.
http://www.spiegel.de/international/world/climate-catastrophe-a-superstorm-for-global-warming-research-a-686697-8.html

– – – – – – –
RossP & Marcos,
Hey, thanks for the linked reference and the idea of where to look for source of the claim of a 2 degree C danger threshold / limit. I am very very skeptical of such a claim.
I owe you two a brew or two. Are you ever in Northern California or the Adirondack Mtns in New York State or in Taipei Taiwan? I spend pretty much all my time among those three locations. : )
John

Jimbo
October 31, 2013 3:06 pm

Stacey says:
October 31, 2013 at 6:32 am
Our friends at the MET office I believe ably assisted by [fragrant] Phil still manage to create a Hockey Stick Graph?
http://www.metoffice.gov.uk/hadobs/hadcet/graphs/HadCET_graph_ylybars_uptodate.gif

Look at the red line.

John Finn
October 31, 2013 4:03 pm

dbstealey says:
October 31, 2013 at 1:11 pm
John Finn,
That is only on your planet. Here on Planet Earth, the natural recovery from the LIA has been ≈0.25 – ≈0.35º/century.

1. There is no CET data which extends back to 1538.
2. The small scale of the y axis has been chosen deliberately so as to obscure the detail in the fluctuations.
3. Whether or not there has been a recovery from the LIA, it is not obvious in the CET record.
The trend between 1700 and 1900 is flat (-0.05 degrees per century)
The trend since 1900 is 0.81 degrees per decade.
If you disagree with these figures then please tell us why.

John Finn
October 31, 2013 4:04 pm

richardscourtney says:
October 31, 2013 at 1:15 pm
John Finn:
re your post at October 31, 2013 at 12:57 pm.
If I need a cherry picker then I now know who to contact.

I cannot see how I can possibly be accused of cherry picking. The author of the article cites a trend extending back to 1659. I have split the last 300 years into one period of 201 years (1700-1900) and another period of 113 years. The trend for the first period (1700-1900) is essentially flat at -0.05 degrees per century . The trend for the second period is 0.81 degrees per century .
If you disagree with these figures then please show me where I have gone wrong. That goes to anyone out there who thinks I may have made an error. Let’s do the science the way it should be done. If Bob Tisdale or anyone else who is competent at calculating statistical trends would care to check my numbers – I’d be grateful.
Re the graph: The author has used an old trick of using large y axis increments and compressing the axis to mislead the reader. The CET temperature data as displayed on the Hadley web-site gives a clearer indication of the different period trends.
http://www.metoffice.gov.uk/hadobs/hadcet/

gbaikie
October 31, 2013 4:27 pm

“This is a ridiculous conclusion. As far as AGW is concerned the first 300 years of the record are largely irrelevant.

1700-1900 -0.05. degrees per century
That’s about as flat as you can get. Now what about the trend since 1900 ”
If choose to draw the line from 1679 to 1700, you get very steep increase.
You drawing line from peaks in temperatures to valleys in temperature and
deluding yourself. You are cherry picking [perhaps in your mind, fairly].
“1900-2012 0.81 degree per century
So virtually ALL the warming in the CET record is in the last 100 years or so – but even that trend is dwarfed by the last 50-60 years. ”
Though glacier have been retreating since 1850. And as we know it takes prior warming to cause
glacier retreating.
Or the present warming will take time to cause glacier to melt.
And the temperature record given, indicates such prior warming.
Also what takes time to warm is the ocean which again have rising for more than last 100 years.
“The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cool temperatures compared to the present. Subsequently, until about 1940 glaciers around the world retreated as the climate warmed. Glacial retreat slowed and even reversed, in many cases, between 1950 and 1980 as a slight global cooling occurred.”
http://water.wikia.com/wiki/Retreat_of_glaciers_since_1850
” 1950-2012 1.7 degree per century
or warming of about 0.85 degrees per 50 years. There was essentially NO warming trend for at least 250 years . All the warming has taken place in the last few decades. The CET record doesn’t provide much support for either natural variability or LIA recovery.”
It shows that during the LIA there were cycles of warming in which the natural variability in temperature peaked at warmer temperatures and dipped to lower temperature which appear to be greater than we seen in last century.
The coolest of dips in temperature has not come close to being matched in the last 100 years, but steepest warming may have been greater though not reaching as warm as in last century.
It add to the period after 1900 the warming of 0.025 Deg C/decade for 2 centuries: .5 C, then
warming peaks in temperature for the last 100 years is not significantly warmer as compared to past warmer periods during LIA. Though if add ,5 C to LIA dips in temperature, these declines in temperatures are still more severe than any we seen in last 100 year.
So in terms yearly changes in global climatic temperature, they were more severe during the LIA with most significant feature being the extent in which one got many periods with years having cooler average temperature.
This is in agreement with historical records indicating more severe weather during the period prior to 1900.

richardscourtney
October 31, 2013 4:34 pm

John Finn:
I refuse to believe you can be as stupid as you pretend in your reply to me at October 31, 2013 at 4:04 pm.
Your reply says to me

I cannot see how I can possibly be accused of cherry picking.

I explained that in my post you claim to be answering. It is at October 31, 2013 at 1:15 pm. To save you needing to find it I copy it to here.

John Finn:
re your post at October 31, 2013 at 12:57 pm.
If I need a cherry picker then I now know who to contact.
Scroll up and look at the graph.
It shows a clear linear trend (that is the straight red line in the graph) with variability of the actual data (that is the wiggly blue line in the graph) providing variation around that trend.
There is no indication of any change to the trend. However, because of the wiggles it is possible to pick periods of warming or cooling of the actual data to fit whatever one wants to (mis)represent.
Richard

I do not know how to put that more simply. If – as you claim – it really is beyond your reading comprehension skills, then I suggest that you ask a typical 11-year-old school child to read it for you and explain it to you.
Richard

October 31, 2013 4:44 pm

John Finn says:
“The trend for the first period (1700-1900) is essentially flat at -0.05 degrees per century…”
You presume to know the trend, and give a specific degree/century rise?
So therefore, you can specify a number — but others cannot, because you say there is no record??
Take an aspirin and lie down before you hurt yourself.

gbaikie
October 31, 2013 4:48 pm

“The CET temperature data as displayed on the Hadley web-site gives a clearer indication of the different period trends.
http://www.metoffice.gov.uk/hadobs/hadcet/
It seems Met graph indicates we going to freeze to death.
Whereas Bob Tisdale’s graph shows we actual still in a warming period and a continuation of the pause in temperature, no need of alarm. Or it would need a much longer or steeper decline in temperature before we begin to approach the climatic conditions of LIA.

John Finn
October 31, 2013 4:56 pm

richardscourtney says:
October 31, 2013 at 4:34 pm
John Finn:
I refuse to believe you can be as stupid as you pretend in your reply to me at October 31, 2013 at 4:04 pm.

Oh dear, Courtney’s losing the argument so he resorts to name calling. This is totally unacceptable and I’m surprised the moderators have allowed your comment.
I have no problem with people disagreeing with me. In fact I’ve invited anyone whose competent enough to check my figures. I can only assume you have no competence or knowledge of statistical analysis else you would have made some attempt to counter my original argument.
I’ll repeat the points again……
1. There is effectively no trend between 1700 and 1900 in the CET record.
2. There is a trend of 0.81 degrees per decade since 1900.
Get the data and calculate the trends – or get someone to do it for you if you’re not capable.

I do not know how to put that more simply. If – as you claim – it really is beyond your reading comprehension skills, then I suggest that you ask a typical 11-year-old school child to read it for you and explain it to you.

I’ve explained to you why the graph is misleading. I’ve also – more than once – explained that most of the warming (in fact ALL of the warming) in the CET record has happened since 1900 – and more likely since 1950. Check out the Hadley graph which provides a better perspective.
http://www.metoffice.gov.uk/hadobs/hadcet/

John Finn
October 31, 2013 5:00 pm

dbstealey says:
October 31, 2013 at 4:44 pm
John Finn says:
“The trend for the first period (1700-1900) is essentially flat at -0.05 degrees per century…”
You presume to know the trend, and give a specific degree/century rise?
So therefore, you can specify a number — but others cannot, because you say there is no record??

I didn’t say there was no record. I said there was no data which extends back as far as 1538 – as shown in on of your links.
I am very familiar with the CET record. I live in the region covered by the record and have had a special interest in it for some time.

October 31, 2013 5:10 pm

John Finn says:
“I said there was no data which extends back as far as 1538…”
John, apparently you did not read the comments regarding real world data such as glaciers, olive trees, and other evidence showing that the MWP was warmer than the current global climate.
The alarmist crowd has contorted themselves int pretzels trying to erase the MWP. They have been unsuccessful. But supposing they found convincing evidence. Then they would just be facing the fact that the MWP and the current global temperature is cooler than the various other warming episodes during the Holocene.
You are fighting a losing battle trying to convince people that we face runaway global warming and climate catastrophe — when the much more likely threat is global cooling.
The planet has been much warmer, and much cooler in the past. CO2 had nothing to do with it.

John Finn
October 31, 2013 5:15 pm

gbaikie says:
October 31, 2013 at 4:27 pm

You’ve made some attempt to counter my main points but to be honest your argument is muddles.

You drawing line from peaks in temperatures to valleys in temperature and
deluding yourself. You are cherry picking [perhaps in your mind, fairly].

This is a silly argument. I’ve used a period of 200 years, for crying out loud. The odd peak or trough is going to make a great deal of difference over that length of time. But, ok – I’ll play the game. You choose the period. We need one which starts in the 17th or early 18th century and finishes some time in the late 19th or early 20th century.
Incidentally, are you aware that the early pre-1700 CET record only records mean temperatures to the nearest degree and later to the nearest half degree so there has to be some doubt about the reliability of 17th century measurements.

October 31, 2013 5:31 pm

John Finn,
You stated that there was no data which extends back as far as 1538, but your argument depends upon such data. You don’t see a problem with that?
In fact, there is ample data that extends much further back in time, as you can see here. Notice that natural variability encompasses extremes of both warming and cooling.
Our current climate is not unusual or unprecedented. In fact, the planet is on the cool side of the Holocene. And again, CO2 has no corellation with temperature.
That being the case, how can you justify the widespread demonization of “carbon”? Because without that unfounded belief, the whole AGW scare collapses.

richardscourtney
October 31, 2013 5:33 pm

John Finn:
gbaikie had said to you

You drawing line from peaks in temperatures to valleys in temperature and
deluding yourself. You are cherry picking [perhaps in your mind, fairly].

In your reply to that at October 31, 2013 at 5:15 pm you say

This is a silly argument. I’ve used a period of 200 years, for crying out loud. The odd peak or trough is going to make a great deal of difference over that length of time.

No! The silliness is yours.
In your post at October 31, 2013 at 12:57 pm you actually said

The trend between 1700 and 1900 is flat (-0.05 degrees per century)
The trend since 1900 is 0.81 degrees per decade.

So, you compared a period of 200 years to a period of 113 years. That is cherry picking.
And your use of different units is not good practice. You should have reported your cherry picked periods as follows:
The trend between 1700 and 1900 is flat (-0.05 degrees per century)
The trend since 1900 is similarly flat (+0.081 degrees per century).
And if you wanted to assert that they are not similarly flat then you should have provided confidence limits on the stated linear trends.
Richard

gbaikie
October 31, 2013 6:02 pm

“Incidentally, are you aware that the early pre-1700 CET record only records mean temperatures to the nearest degree and later to the nearest half degree so there has to be some doubt about the reliability of 17th century measurements.”
One could same argument about the vast majority temperature reading prior digital age, which is not to say CET had improved their measurement accuracy prior to digital age, but rather most temperature reading as rule even at present [post digital] is inaccurate.
And at CET we didn’t same or worse problem with global siting which can have error 1 to 5 C or worst.
So only problem in terms of accuracy with CET in it’s limited regional location. And compared to using trees as thermometers, we assume with much more confidence that a 17th measurement is the more accurate.
“But, ok – I’ll play the game. You choose the period. ”
My choice is much longer period. Unless you are interested in natural short period [less than century] variability. This way you focus on global climate rather weather or global weather.
But you concerned about last 50 years. Therefore the only way to address your concern is understanding short term variability. And this is not understood at this point in time.
But if you understand global climate, you would have to know that we are in Ice Age which started around 50 million year ago. This is called Ice Box climate.
And you would also know that there is no danger from CO2 having a significant impact upon this Ice Box climate.
In terms short term variability, in my opinion, Stadium Waves, might be useful:
http://judithcurry.com/2013/10/10/the-stadium-wave/
So could be useful approach in understand short term variability. Which not to say I think it’s the answer or that we now understand short term variability- but seems like it could be the right direction.
But everyone admits there is no system to accurately predict short term variability- meaning a proven and dependable way to predict it. Of course predict volcanic eruptions may not be available until we get much understanding about Earth’s dynamics, but perhaps if we exclude volcanic eruption [anything more than 10 Km cubic km of ejecta- would only be somewhat significant] then we might get to this point within say 10 years.

H.R.
October 31, 2013 6:07 pm

says:
October 31, 2013 at 2:38 pm
Re: “DUH”
Some people think global temperature, she go only up. To those people, up and down is a revelation.

Brian H
October 31, 2013 8:26 pm

So few seem to get the point(s).
1. Warming has been mild to moderate, on average.
2. Extrapolations are generally wrong.
3. Any assumption we can’t adapt to 2K in 800 yrs., or much less, is laughable.
4. Alarmists have been prevaricating through their incisors.

RoHa
October 31, 2013 10:44 pm

800 years! We’re doomed. Eventually.

BioBob
November 1, 2013 12:01 am

I have to laugh at heated posts from John Finn, richardscourtney, and others arguing about how many angels dance on the head of a pin !!
You are all silly. The CET data is ALL sh*t, likely not accurate to plus/minus 2 to 5 degrees Celsius over long periods. You got that ?
We have, in CET, reconstructed temperatures, temps taken inside buildings, temperatures essentially taken with a wet finger, bogus adjustments, calculations of means based on observation sets with different internal time periods. We have instrument error, observational error, adjustment error, statistical error, yada yada, yada. There are no replicates at ANY POINT IN TIME, no random samples, no observational consistency. The data is just SH*T.
ANY data with ONE observation has a standard-error of infinity !! Do the math – typical northern hemisphere daily data needs 20-40 observations per data point to yield a reliable single datum point with a decent standard error of the mean. SHEESH – this is not rocket science !!! Look up how to do field sampling and how to calculate a statistically reliable mean.

richardscourtney
November 1, 2013 3:22 am

BioBob:
re your post at November 1, 2013 at 12:01 am.
We are discussing the CET data and what it is claimed to indicate. John Finn made some demonstrably untrue statements. You seem to be saying that untrue statements should not be corrected: I do not agree.
And I have been fully aware of the nature of climate temperature compilations for a long time. Clearly, you have not read this, especially its Appendix B.
http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/memo/climatedata/uc0102.htm
Richard

John Finn
November 1, 2013 3:39 am

dbstealey says:
October 31, 2013 at 5:10 pm
John Finn says:
“I said there was no data which extends back as far as 1538…”
John, apparently you did not read the comments regarding real world data such as glaciers, olive trees, and other evidence showing that the MWP was warmer than the current global climate.

What are you on about? I was commenting on THIS thread about the way the CET record was being used. Why would I bring up evidence (or otherwise) about the MWP. The MWP is irrelevant as far as the CET record is concerned.

John Finn
November 1, 2013 3:51 am

richardscourtney says:
November 1, 2013 at 3:22 am
BioBob:
re your post at November 1, 2013 at 12:01 am.
We are discussing the CET data and what it is claimed to indicate. John Finn made some demonstrably untrue statements. You seem to be saying that untrue statements should not be corrected: I do not agree.

You have haven’t corrected anything. I made 2 key statements, i.e.
The CET 1700-1900 trend is -0.05 degrees per century
The CET 1900-2102 trend is 0.81 degrees per century.

If you think either of those statements is wrong or “demonstrably untrue” then please show me where I’ve gone wrong. It’s time to put up or shut up, Richard.

richardscourtney
November 1, 2013 4:03 am

John Finn:
At November 1, 2013 at 3:51 am you again demonstrate your lack of ability to read.
You say to me

If you think either of those statements is wrong or “demonstrably untrue” then please show me where I’ve gone wrong. It’s time to put up or shut up, Richard.

I did “show {you} where {you’ve} gone wrong” with my post at October 31, 2013 at 5:33 pm. This link jumps to it
http://wattsupwiththat.com/2013/10/30/how-long-before-we-reach-the-catastrophic-2c-warming/#comment-1462862
It’s time for you to shut up, John. And an apology for disrupting the thread with your nonsense would be good.
Richard

John Finn
November 1, 2013 4:04 am

BioBob says:
November 1, 2013 at 12:01 am
I have to laugh at heated posts from John Finn, richardscourtney, and others arguing about how many angels dance on the head of a pin !!
You are all silly. The CET data is ALL sh*t, likely not accurate to plus/minus 2 to 5 degrees Celsius over long periods. You got that ?

The CET data is unreliable before about 1700 – and is perhaps not too clever before 1780 but after that it provides a reasonable record of Central England temperatures. It is consistent with other European long term records, e.g. Armagh.
Tell me, do you agree that there was an LIA period between the 15th-19th centuries when temperatures (global or otherwise) were 1 to 2 degrees below to-days. If so, on what do you base this conclusion?

John Finn
November 1, 2013 4:12 am

richardscourtney says:
November 1, 2013 at 4:03 am
I did “show {you} where {you’ve} gone wrong” with my post at October 31, 2013 at 5:33 pm. This link jumps to it
http://wattsupwiththat.com/2013/10/30/how-long-before-we-reach-the-catastrophic-2c-warming/#comment-1462862
It’s time for you to shut up, John. And an apology for disrupting the thread with your nonsense would be good.

Ok perhaps I need to make it easier for you Richard.
I made this statement
The CET 1700-1900 trend is -0.05 degrees per century
Q1 Do you disagree with this statement and if so – why?
I also made this statement
The CET 1900-2102 trend is 0.81 degrees per century.
Q2 Again do you disagree with this statement and if so – why?
No need for any arm waving – just respond to the questions.

November 1, 2013 4:41 am

John Finn obviously believes, like Michael Mann, that the climate never changed prior to the industrial revolution. No MWP, no LIA, just a flat, unchanging hockey stick shaft.
In reality it is scientific skeptics who know that the climate always changes. Finn is a True Believer who is desperately looking for proof that human activity is causing climate change.
But it is just natural variability. The Null Hypothesis has never been falsified. And CO2 makes no measurable difference to global temperature.

richardscourtney
November 1, 2013 5:43 am

John Finn:
I am replying to your post at November 1, 2013 at 4:12 am.
I am NOT John Finn so I do not “arm wave”.
Your two questions can be answered “yes” but both of them are MEANINGLESS.
You have demonstrated that you are incapable of understanding why they are meaningless, but I will try to explain it in case there are any onlookers with average intelligence who want to know. This will help them when confronted with similar twaddle to yours from other warmunists.
Firstly, as I said, you are comparing different lengths of time. Your two periods are samples of the data from the complete CET data set. The samples are of different amounts of the data so they are not similar samples. Hence, you are comparing ‘chalk and cheese’.
Secondly, choosing samples which fit what you want to say is a form of cheating called ‘cherry picking’: it provides misleading results. And, as I and others have told you, it is what you have done.
Indeed your cherry picking is extreme. Why did you not compare ‘1900 to present’ with ‘1690 to 1803’? Could it be that such comparison would show the opposite of what you are claiming?
Thirdly, assuming your model of linear trends is correct (it is not, but I am ignoring that) each of the two numbers you provide is incomplete. At issue is whether either or both of them differ from the long-term trend and, if so, with what confidence that difference is expressed. ‘Climate science’ expresses confidence to 95%. Thus, the statement

The CET 1700-1900 trend is -0.05 degrees per century

has no meaning because its confidence is not defined.
Or, to be pedantic, the statement has an infinite number of possible meanings.
e.g. it could mean -0.05 ± 0.001 degrees per century at 95% confidence
or
e.g. it could mean -0.05 ± 100.00 degrees per century at 95% confidence
because it only says
-0.05 ± X degrees per century at 95% confidence and X is unstated.
So, the data you present cannot be known to be different from one another because their confidence limits are not stated: they are meaningless numbers obtained from cherry picked samples.
Richard

John Finn
November 1, 2013 5:57 am

dbstealey says:
November 1, 2013 at 4:41 am
John Finn obviously believes, like Michael Mann, that the climate never changed prior to the industrial revolution. No MWP, no LIA, just a flat, unchanging hockey stick shaft.

Can you point to anything I’ve written which shows that I even suggest that climate is unchanging. Even the early CET record shows fluctuations – but these are cyclical and the net effect is a ZERO trend.
However, that aside, you again misrepresent my initial points. The author of the above article made a specific claim, based on the 353 year CET trend, that it would be 800 years before the 2 degree threshold would be breached. I say this is nonsense and I’ve given my reasons, i.e. the trend between 1700 and 1900 is broadly flat while the trend since 1900 is around 0.8 degrees per century. Thus far, no-one has managed to show that my figures are wrong.
Let me be clear what I’m actually saying so there is no confusion:
Nick Catto has made a claim which is invalid basing it as he did on the 353 year CET trend.

November 1, 2013 6:01 am

John Finn says:
“I cannot see how I can possibly be accused of cherry picking. The author of the article cites a trend extending back to 1659. I have split the last 300 years into one period of 201 years (1700-1900) and another period of 113 years.”
Well if you had started from 1659 like the Author, then you would see the trend, but hey, if CET went back a further 9yrs then the trend would be less as it would include the hot years of 1651-54:
http://booty.org.uk/booty.weather/climate/1650_1699.htm
I do agree though that there is no long term recovery from the “LIA” through CET as such, the recovery from Maunder is the steepest rise on the series, but after that, as you say there are at least two centuries where it is largely flat. Here’s my cherry pick, 1730-1930:
http://snag.gy/2q2kT.jpg
The whole notion of a gradual recovery from LIA through CET would have to imply an influence of sea surface temperatures on CET, is that a reality, or is CET dominated by the NAO irrespective of local SST’s? I would suspect the latter.
It is natural that the 20th century should be warmer, while on average two or three solar cycles are weaker every ten cycles, the intervals wander, the last downturn ended in the first few years of the 1900’s, and the next weak cycle is this one, so the 1900’s missed out on such a period.
Warming on CET from 1906-1986 has hardly been dramatic: http://snag.gy/B2rkz.jpg
The curious bit is from 1989: http://snag.gy/fMryT.jpg (CET 1659-2012)
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.timeseries.gif
The solar wind was unusually strong around the maxima of solar cycles 22&23:
http://snag.gy/nf9SK.jpg

richardscourtney
November 1, 2013 6:13 am

John Finn:
In your post at November 1, 2013 at 5:57 am you say

Even the early CET record shows fluctuations – but these are cyclical and the net effect is a ZERO trend.

and

Nick Catto has made a claim which is invalid basing it as he did on the 353 year CET trend.

OK. So which are you claiming
“the net effect is a ZERO trend” in the early record (which is untrue, see the above graph)
OR
there is a “353 year CET trend”?
Or are you demonstrating Orwellian doublethink?
Richard

John Finn
November 1, 2013 6:32 am

richardscourtney
Your two questions can be answered “yes” but both of them are MEANINGLESS.

I asked you if you disagreed with the figures and you replied “Yes” but you haven’t shown what is wrong with the figures. We can assume, therefore, that the trends have been calculated correctly.

Firstly, as I said, you are comparing different lengths of time. Your two periods are samples of the data from the complete CET data set. The samples are of different amounts of the data so they are not similar samples. Hence, you are comparing ‘chalk and cheese’.

OK – let’s use time periods of equal length.
1700-1800 -0.25 degrees per century
1800-1900 0.03 degrees per century
1900-2000 0.65 degrees per century

And just for good measure
1912-2012 0.83 degrees per century
Now then, Richard, I challenge you or anyone else to find any pre-1900 100 year trend which is even half the 1900-2000 or 1912-2012 trends.

Secondly, choosing samples which fit what you want to say is a form of cheating called ‘cherry picking’: it provides misleading results. And, as I and others have told you, it is what you have done.

I think we’ve now addressed these concerns above.

Indeed your cherry picking is extreme. Why did you not compare ‘1900 to present’ with ‘1690 to 1803’? Could it be that such comparison would show the opposite of what you are claiming?

I am slightly reluctant to use pre-1700 CET data, but if you insist we can compare 1690 -1803 to 1900-2012 as you suggest.
1690-1803 -0.3 degrees per century
1900-2012 0.81 degrees per century

Clearly, Richard, the comparison doesn’t show the opposite of what I was claiming.
Again I invite anyone to check my calculations.

John Finn
November 1, 2013 6:51 am

richardscourtney says:
OK. So which are you claiming
“the net effect is a ZERO trend” in the early record (which is untrue, see the above graph)
OR
there is a “353 year CET trend”?

Richard
It’s becoming increasingly apparent that you lack a basic grasp of Statistics. My 2 statement s are not mutually exclusive.
For the first 250 years or so, the CET record has a trend which is close to ZERO.
For the whole of the 353 years the CET record exhibits a positive trend which is due almost entirely to the warming over the past 50 years.

which is untrue, see the above graph

The graph is deliberately misleading. I’ve already explained this. See this graph of exactly the same data.
http://www.metoffice.gov.uk/hadobs/hadcet/

NeilC
November 1, 2013 7:24 am

Can I just point out;
a). I explained this record is recognised as the longest instrumental record in the world
b). We have no other instrumental data going that far back in time – it the best we have
c). Yes there are problems with early age thermometer accuracy – the UKMO adjust for this
d). Yes there are problems with swapping site locations during the record – the UKMO ajdust for this too (I disagree they should have changed reporting site)
e). Yes there are problems with increased UHI since the industrial revolution – the UKMO adjust for this too (IMO far too small an adjustment)
f). Cherry picking is when you pick particular start/end dates or particular periods within a record
I did not cherry pick, the data I used was the start date of the record to the end of the last full year (end date) of the record. I made no attempt to size the graph, just a simple xls linear graph.
Lastly, my claim was and still is, based on the trend of this whole record 1659-2012 it would take 800 years to get to the 2 Deg C point, that some say is catastrophically dangerous.

NeilC
November 1, 2013 7:44 am

If you want to cherry pick data: the last 20 year (1993-2012) the trend has been downward. Yes that’s right the UK has been COOLING for 20 YEARS, on that trend it is impossible to reach 2 Deg C. But we won’t cherry pick will we?

John Finn
November 1, 2013 7:54 am

Neil
You simply cannot justify this claim. I’m going to play Devil’s advocate here. Let’s suppose I propose that increased atmospheric CO2 due to fossil fuel burning is responsible for global warming.
Clearly the warming effect is going to be most apparent in the mid to late 20th century. (CO2 forcing is currently about 3 times what it was in 1958).
To test my hypothesis/theory/belief I would like to know how much warming/cooling occurred up to about 1950 and compare that with the warming after 1950.
The CET record actually supports me.
The CET trend is essentially flat for the first 250 years of the record (even if we include the rather unreliable 1600s). It is only in the 20th century that a sustained positive trend is evident.
In fact, the strongest signal occurs in the late 20th century – exactly is it should if my hypothesis is correct. We have seen an increase of over 0.8 deg since 1950. AND if my hypothesis is corrrect then we should see a similar increase over the coming 50 years.
Whatever – if you have a flat period for 200 years followed by steady warming for 100 years you cannot assume that the 300 year trend is applicable for future warming.
I’m not accusing you of cherry picking the data. However, I do believe your graph is misleading.

richardscourtney
November 1, 2013 7:59 am

John Finn:
In your post at November 1, 2013 at 6:51 am you say

It’s becoming increasingly apparent that you lack a basic grasp of Statistics.

Now that’s funny. It’s really, really funny!
I am accused of lacking “a basic grasp of Statistics” by an ignorant twit with reading comprehension difficulties who does not understand dissimilar samples are not comparable, does not know what cherry picking is, and does not know why a statistical datum has no meaning unless its error estimate is stated!
Funny? One could not make this stuff up.
John Finn, your error is stated by NeilC who says at November 1, 2013 at 7:44 am

If you want to cherry pick data: the last 20 year (1993-2012) the trend has been downward. Yes that’s right the UK has been COOLING for 20 YEARS, on that trend it is impossible to reach 2 Deg C. But we won’t cherry pick will we?

But I suspect you are such a mentally deficient dolt that you will fail to understand that, too.
Richard

richardscourtney
November 1, 2013 8:01 am

Crikey!

John Finn
November 1, 2013 8:03 am

NeilC says:
November 1, 2013 at 7:44 am
If you want to cherry pick data: the last 20 year (1993-2012) the trend has been downward. Yes that’s right the UK has been COOLING for 20 YEARS, on that trend it is impossible to reach 2 Deg C. But we won’t cherry pick will we?

You’re clearly having trouble with this. We’ve seen lots and lots of fluctuations in the CET record – many of which have lasted 20 years and more. We know this. It’s apparent in the Hadley graph. However these fluctuations tend to be cyclical. and over time have very little influence over the long term trend.
There is a lot of difference between a 20 year trend and 100 or 200 year trend.
In any case, I’m not arguing one way or the other. Even though the data supports CO2 warming I’m not going to draw any conclusions about the temperature increase over the next 50, 100, … or 800 years.
It’s you who is making a claim which simply doesn’t stack up . The warming trend since 1950 has been stronger than any other 50-odd year period, EXACTLY what we would expect if CO2 was the cause.

richardscourtney
November 1, 2013 8:04 am

Friends:
Sorry, “Crikey!” went while I was typing.
I had written that I suspected John Finn is “such a mentally deficient dolt that” he would fail to understand the post from NeilC, and he proved my suspicion was right while I was typing it!
Hence, the “Crikey!”
Richard

John Finn
November 1, 2013 8:12 am

richardscourtney says:
November 1, 2013 at 7:59 am

Richard
I’ve given you trends for equal time periods. I’ve even used 1690-1803 a period selected by yourself. None of the trends support your argument. In fact increasing it’s apparent that the CET record apart from cyclical fluctuations has been, by and large, invariant between the late 1600s and 1950.
Now run along , Richard, and learn how to perform Least Squares linear regression then you might be able to offer some to this discussion.
Incidentally you could ask NeilC if he disagrees with my calculations. The best he can come up with is that we’ve has a -0.02 degrees per decade cooling since 1993 – consistent with .many imilar fluctuations in the past. This further highlights the fact that I’m not cheery picking since the end point of my period is in a ‘trough’.

richardscourtney
November 1, 2013 8:40 am

John Finn:
I will try to make this easy for you because you are clearly way, way out of your depth here.
At November 1, 2013 at 8:12 am you say

Richard
I’ve given you trends for equal time periods.

No, YOU HAVE NOT.
YOU HAVE NOT GIVEN ME ANY TRENDS; none, zilch, nada.
You have given me meaningless numbers.
The numbers would be valid trends if they had their attached confidence limits, but they don’t. Without those confidence limits it cannot be known if they differ from each other. I explained this for you in my above post at November 1, 2013 at 5:43 am.
John, I will say this two more times because iteration may get get it through your thick skull.
YOU HAVE NOT GIVEN ME ANY TRENDS; none, zilch, nada.
You have given me meaningless numbers.
YOU HAVE NOT GIVEN ME ANY TRENDS; none, zilch, nada.
You have given me meaningless numbers.
Have you got that now?
If so, then provide the confidence limits so you will then have provided some trends.
After that we can discuss what – if anything – those trends suggest.
Richard

Mr Green Genes
November 1, 2013 9:21 am

@richardscourtney
Richard, please, chill a bit.
I’m afraid that you tend to come over as an arrogant overbearing bully whenever you come across a post (or poster) with which you happen to disagree. I, like many others I suspect, come here to learn things. I’m sure I could learn things from you but, frankly, your attitude makes that difficult as I am increasingly finding myself thinking “Oh dear, Richard’s gone off on another hectoring rant, quick, scroll down”.
There is no excuse for describing another poster as a “a mentally deficient dolt”, however vehemently you may disagree with him (or indeed, however incorrect he may be) so please stop it. You are doing youself a disservice with your attitude.

richardscourtney
November 1, 2013 9:38 am

Mr Green Genes:
When a person spouts ignorant twaddle then ignores what I politely take the trouble to reply to him and writes saying to me

It’s time to put up or shut up, Richard.

and

It’s becoming increasingly apparent that you lack a basic grasp of Statistics.

and

Now run along , Richard, and learn how to perform Least Squares linear regression then you might be able to offer some to this discussion.

etc.
then you expect me to reply with respect?
No chance.
Richard

PeterB in Indianapolis
November 1, 2013 9:43 am

@ John Finn,
So the temperature change from 7.2 C in about 1700 to 10.2C in about 1740 (3 degrees C in 40 years, or 0.75C per decade, wasn’t actually any warming???
In fact, we currently appear to be at about 10.8C on that same CET record, so the warming from 1740 to 2010 is 10.2C to 10.8 C for a total of 0.6C.
0.6C/27 decades = 0.0222 degrees C/decade since 1740, so I don’t think we have much to worry about.

November 1, 2013 9:47 am

John Finn says:
“Can you point to anything I’ve written which shows that I even suggest that climate is unchanging.”
Yes, of course I can. You were questioning any temp change as the planet emerged from the LIA. Then you go into Hockey Stick mode: T shot up recently.
If I am misunderstanding you, then just answer this: in your opinion, was there a LIA in which global T declined by ≈1º – 2ºC?

PeterB in Indianapolis
November 1, 2013 9:51 am

“The warming trend since 1950 has been stronger than any other 50-odd year period, EXACTLY what we would expect if CO2 was the cause.”
Ummm, no, I just demonstrated that for the 40-year period of 1700 to 1740, there were 3 degrees of warming, while you could only demonstrate that from 1950-2010 there were 1.7 degrees of warming PER CENTURY, or only about 1 degree of ACTUAL WARMING during that 60 year period of 1950-2010.
It seems to me that 3 degrees of warming in 40 years (1700-1740) is FAR MORE SIGNIFICANT than 1 degree of warming in 60 years (1950-2010), so just how, pray tell, was CO2 so significant from 1700 to 1740???? I thought it was level at about 250ppm back then, no????

John Finn
November 1, 2013 10:08 am

dbstealey says:
November 1, 2013 at 9:47 am
John Finn says:
“Can you point to anything I’ve written which shows that I even suggest that climate is unchanging.”
Yes, of course I can. You were questioning any temp change as the planet emerged from the LIA. Then you go into Hockey Stick mode: T shot up recently.

No I wasn’t. I was questioning the temperature change in the CET record. I have calculated the trend between 1700 and 1900 and it is as near to zero as makes no difference. In other words there is no evidence for warming or cooling in the Central England region over that 200 year period. That’s what the data tells us. I’m sorry you if it doesn’t agree with your preconceptions.

John Finn
November 1, 2013 10:35 am

PeterB in Indianapolis says:
November 1, 2013 at 9:51 am
“The warming trend since 1950 has been stronger than any other 50-odd year period, EXACTLY what we would expect if CO2 was the cause.”
Ummm, no, I just demonstrated that for the 40-year period of 1700 to 1740, there were 3 degrees of warming, while you could only demonstrate that from 1950-2010 there were 1.7 degrees of warming PER CENTURY, or only about 1 degree of ACTUAL WARMING during that 60 year period of 1950-2010

I suppose I should thank you, Peter B, for giving us a perfect example of “cherry picking”. You have selected an individual local low reading and compared It with an individual selected high value.
Tell you what, Peter, I’ve got an even better cherry pick than that. Check this out
2006 10.62
2010 8.83

That’s a 2 degree decline in 4 years – or 50 degrees per century. That’ll make the last ice age seem like a picnic by comparison, but hang on a minute, Peter, look what happened in 2011
2011 10.7
A 1.9 degree increase in just one year. What do you think might be going on, Peter?
I take it you don’t understand the concept of Least Squares linear regression. Basically this method of calculating linear trends ensures that anomalous dips or spikes don’t unduly influence the calculated trend. You also need to gain some understanding of data ‘noise’.

November 1, 2013 10:47 am

John Finn says:
“1950-2012 1.7 degree per century. All the warming has taken place in the last few decades.”
1903-2012 is less than 1°C and about 75% of that was from 1988 onwards.

richardscourtney
November 1, 2013 10:48 am

Mr Green Genes:
I have deliberately kept out of the discussion for a while because PeterB in Indianapolis attempted to start a polite and informative discussion with John Finn as I had, and I did not want to interrupt it.
Please read the response John Finn provided to PeterB in Indianapolis at November 1, 2013 at 10:35 am. It is similar to all the replies I obtained from John Finn. And please suggest what you think would be an appropriate response of PeterB in Indianapolis in reaction to that offensive, insulting and blustering reply which John Finn provided to cover his ignorance and stupidity.
Richard

Doug Proctor
November 1, 2013 11:39 am

The warmists’ position is that only the 1850 to present time period is relevant, and only from 1975 onward :”shows” signs of CO2 warming. As much as it might show that today’s trends are not much different from yesterday’s, the long term records are not pertinent to the CAGW debate. In fact, what your CET record shows is a step-function at 1983 or so. Step-functions may or may not be related to CO2 suddenly “breaking through” regional dullness.
Sorry, but argument based on historical trends/data holds no grounds with the understanding the IPCC/Al Gore has. If you want to discount the IPCC, you have to start with 1850, with a particular focus on post-1975, and really grind on the observations and the match between observations and models/predictions.

Mr Green Genes
November 1, 2013 3:15 pm

richardscourtney says:
November 1, 2013 at 9:38 am
Richard
Insofar as I failed to mention that he should also cease the name-calling and denigration of another’s point of view, you have a good point.
So, to modify my original post, EVERYONE should behave with decorum. That way, those of us who know little but hope to learn do not have either to wade through name calling etc. or to skip past any post from someone with “a history”.
That is all.

richardscourtney
November 1, 2013 3:34 pm

Mr Green Genes:
I read your November 1, 2013 at 3:15 pm.
I notice that you did not answer my serious request that you suggest what you think would be an appropriate response of PeterB in Indianapolis in reaction to that offensive, insulting and blustering reply which John Finn provided to cover his ignorance and stupidity.
There are two options; i.e.
(a) leave the untrue point of an aggressive blaggard stand (as PeterB seems to have chosen in this case) which encourages others to provide falsehoods in similar manner
or
(b) fight fire with fire (which – as you note – I have a history of doing) to discourage others using the same tactic.
I always treat people with the respect they accord to me. Your reframing of your point is spurious.
Richard

November 1, 2013 4:03 pm

Personally, I completely agree with Mr Green Genes at November 1, 2013 at 3:15 pm.
And I disagree with my father’s response.
Two wrongs do not make a right.
Fighting fire with fire wins battles but scorches the Earth, a Pyrrhic Victory.
Once upon a time RichardSCourtney debated a Greenpeace spokesman called Jeremy Leggett. Leggett legged it before the public questions began – clearly a victory!
But Greenpeace have refused all further debates and Leggett does too. The War went badly for those who want debate to winnow out the truth.
In this case being too vigorous in duelling-online leads to people scrolling past the rudeness.
If you have a point then make it.
Then repeat it.
And politely repeat it.
In this precise case the point is:
Picking points in the CET and drawing straight lines between them is meaningless. The lines need error boundaries, a justification for the error boundaries and a justification for being straight.
But no-one will have.got that from the debate. It was too fierce.

milodonharlani
November 1, 2013 4:25 pm

Doug Proctor says:
November 1, 2013 at 11:39 am
The CACA time period remains fungible, intentionally. You can’t pin them down. Since CO2 levels allegedly started accelerating after WWII, the relevant period ought at least to start in 1945, but that doesn’t work because from about then to c. 1977 was a cooling time frame. If you go back to the end of the LIA in the mid-19th century, then they have to explain the apparent warmings comparable in amount & rate during the early 20th & late 19th centuries, without benefit of steadily increasing CO2.
Instead of confronting these problems honestly, CACA advocates simply cook the data books to lower actual surface station T readings during older decades & raise it as much as satellite observations will allow in recent decades.
This is not just post- but para-normal “science”.

November 1, 2013 6:06 pm

John Finn says:
“In other words there is no evidence for warming or cooling in the Central England region over that 200 year period. That’s what the data tells us. I’m sorry you if it doesn’t agree with your preconceptions.”
My preconceptions?? That, coming from Mr Junior Hokey Stick!
Your preconceptions assume that there is no evidence for warming or cooling over that 200 same year period. Having your preconceptions, you ignore the fact that there is agricultural and other real world evidence that deconstructs your beliefs.
That is the problem with the alarmist crowd: they cherry-pick only the evidence that supports their alarming scare story. Scientific skeptics, OTOH, take all the evidence into consideration, not just one thermometer record — and all the evidence together deconstructs Mann’s hockey stick, which was based on one single tree, YAD061.
There was natural global warming [MWP] and global cooling [LIA] before the ramp-up in CO2. But the alarmist crowd just cannot admit to the evidence that contradicts their belief.

Mr Green Genes
November 1, 2013 10:03 pm

richardscourtney says:
November 1, 2013 at 3:34 pm
I notice that you did not answer my serious request that you suggest what you think would be an appropriate response of PeterB in Indianapolis in reaction to that offensive, insulting and blustering reply which John Finn provided to cover his ignorance and stupidity.

==============================================================
Apologies, I missed that. I have no excuse other than that I’m on holiday.
You could always ask him politely to stop it.
I try (but do not always succeed) to remember 2 small dictums (dicta???):-
1. Never wrestle with a pig – you both get dirty and the pig enjoys it.
2. Don’t argue with an idiot – (s)he will inevitably bring you down to his/her level.

John Finn
November 2, 2013 6:06 am

Mr Green Genes says:
November 1, 2013 at 10:03 pm
richardscourtney says:
November 1, 2013 at 3:34 pm
I notice that you did not answer my serious request that you suggest what you think would be an appropriate response of PeterB in Indianapolis in reaction to that offensive, insulting and blustering reply which John Finn provided to cover his ignorance and stupidity.
==============================================================
Apologies, I missed that. I have no excuse other than that I’m on holiday.

Dear Mr Green
I’m sure you won’t bother going to the trouble but if you scan back through the posts you’ll find that it is Richard Courtney who began the insults – as per usual. Richard is well known for it. He has, over time, somehow managed to become accepted (by some) as an authority on the subject of climate. He is no such thing, He has no training or expertise in Maths, Physics, Chemistry or any associated discipline. That shouldn’t matter and I have no problem with Richard offering an opinion. I do, though, object to constantly being referred to as “stupid” and “thick” by someone who is nowhere near as qualified as myself (I hate saying this but it’s true).
Throughout this thread I have maintained that Neil Catto is wrong to conclude that the 2 deg threshold will be reached in 800 years based on the 353 year CET trend. I have given my reasons and provided the data to back them up. Basically there was very little net warming in the first 250 or so years of the CET record. The vast majority of the warming has occurred since 1950.
I have invited readers (including Neil himself) to check my numbers and if they are shown to be in error then I will accept that I am wrong. Thus far, no-one has managed to do this.

John Finn
November 2, 2013 6:56 am

M Courtney says:
November 1, 2013 at 4:03 pm
In this case being too vigorous in duelling-online leads to people scrolling past the rudeness.
If you have a point then make it.
Then repeat it.
And politely repeat it.
In this precise case the point is:
Picking points in the CET and drawing straight lines between them is meaningless. The lines need error boundaries, a justification for the error boundaries and a justification for being straight.

Mr. Courtney
Your father’s request for error boundaries came relatively late on in the discussion, His first complaint was that I was cherry picking the time periods. (i.e. a period of 200 years in a 353 year record was apparently “cherry picking”). Despite disagreeing with him on the “cherry picking” accusation I, nevertheless, calculated the trend for a 113 year period suggested by him. Have you got that.
Richard Courtney asked why I didn’t calculate the 1690-1803 trend and compare that with the recent 112 year (1900-2012) trend
So I did – and I found the following trends.
1690-1803 -0.30 degrees per century
1900-2012 +0.82 degrees per century

Now, apparently, Richard thinks the numbers are meaningless because there are no error bars. First thing to point out is that the numbers are NOT meaningless. For example, we know that the central value for the 1690-1803 trend is negative and error bars will only show one of 2 things:
(i) There is a statistically significant cooling trend between 1690 and 1803.
(ii) There is NO statistically significant trend between 1690 and 1803.
For the purposes of this discussion that would have pretty much settled the debate because it would have shown there was no warming in Richard’s preferred 113 year trend.
However, just to satisfy everyone on this issue, I will present the trends with 95% confidence Intervals.
1690-1803 -0.30 (+/- 0.4) degrees per century
1900-2012 +0.82 (+/- 0.29) degrees per century

i.e. No significant 1690-1803 trend; Significant 1900-2012 warming trend.
I do, though, find it a bit strange that your father made no such demands on the author of this article. How come he was happy to accept the 353 year trend AND the 800 year prediction based on the trend without any error boundaries being specified?

John Finn
November 2, 2013 7:16 am

dbstealey says:
November 1, 2013
Your preconceptions assume that there is no evidence for warming or cooling over that 200 same year period. Having your preconceptions, you ignore the fact that there is agricultural and other real world evidence that deconstructs your beliefs.

You still don’t get it. I don’t have any preconceptions. I am simply interpreting the data in a single dataset. The CET record shows NO significant trend between 1700 and 1900 (and probably longer) – but does show a significant warming trend since 1900.
That’s what I’ve found.
That’s what the data says.
That’s all I am going on … nothing else.
I am only commenting on the CET record because that is the data referenced in the above article.
Is that clear enough?
Now it is possible that I have made an error in my calculations, so I invite anyone who feels competent enough to get hold of the CET data and check my workings. If I am found to be wrong I will admit to the fact.
Finally, take a look at this Realclimate blog post from December 2004
http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/comment-page-1/
and take particular notice of comments 4, 5 and 6.
If you’re able to follow the argument you might notice that I picked up on the “hide the decline” trick about 5 years before Climategate. So much for me being a Hockey Stick supporter.

November 2, 2013 8:13 am

Go back 200 years before the MET numbers (which were starting at the Little Iceage Through) and tell me what the trend is up until today?
Negative?
Oddgeir

November 2, 2013 8:19 am

Question everyone should ask is
How much did our ocean’s CO2 solubility change for which temperature increase?
Very nice to learn that the 2 degree target is set as a result of reverse understanding of what does NOT constitute a problem…
How much CO2 was released from our oceans due to said 2 degrees?
Oddgeir

November 2, 2013 5:57 pm

John Finn says:
November 1, 2013 at 8:03 am
” The warming trend since 1950 has been stronger than any other 50-odd year period, EXACTLY what we would expect if CO2 was the cause.”
Here’s 1950 to 1987: http://snag.gy/r8Usk.jpg
It all happened with a sharp step up from 1988 onwards: http://snag.gy/fMryT.jpg

John Finn
November 3, 2013 3:56 am

Ulric Lyons says:
November 2, 2013 at 5:57 pm
Here’s 1950 to 1987: http://snag.gy/r8Usk.jpg
It all happened with a sharp step up from 1988 onwards: http://snag.gy/fMryT.jpg

Probably because there was a cooling phase of the CET cycle in the 1950-80 period. I’ve already acknowledged there are clear cycles evident in the CET record. However, the net effect of these in the past was ZERO.
But you are correct – most of the warming has occurred since 1980. Even more reason to reject the 353 year trend as a predictor of future warming. Note I wouldn’t use the post-1980 trend either – but I’m not the one making claims about 800 years to reach 2 degrees C

November 3, 2013 4:06 am

John Finn,
Here is a chart by your alarmist pal Phil Jones that deconstructs your contention that the warming is mostly recent.
It isn’t. The planet has been warming — naturally — since the LIA. And it has nothing to do with “carbon”.

Girma
November 3, 2013 5:52 am

Neil Catto
Can you do a similar estimate for HadCRUT4 and then post it?

November 4, 2013 6:04 am

John Finn says:
“Probably because there was a cooling phase of the CET cycle in the 1950-80 period. I’ve already acknowledged there are clear cycles evident in the CET record. However, the net effect of these in the past was ZERO. ”
I agree that from the very early 1700’s to 1950 CET is almost flat, but to argue that there was natural cooling from 1950 to 1987 that mitigated CO2 warming, one would have to acknowledge a far larger forcing value for natural variation that for CO2 to allow for the rapid step up from 1988 onwards.
“But you are correct – most of the warming has occurred since 1980.”
From 1988 onwards actually, from when the NAO went strongly positive, I already showed that 1950 to 1987 is flat.

John Finn
November 4, 2013 6:45 am

dbstealey says:
November 3, 2013 at 4:06 am
John Finn,
Here is a chart by your alarmist pal Phil Jones that deconstructs your contention that the warming is mostly recent.

You really do appear to have trouble understanding the issue. The ABOVE post by Neil Catto uses a 353 year trend from the CET record to predict the time taken to breach the 2 degree warming threshold.
You have posted a graph of global temperatures which extends back to 1860 – so it’s completely irrelevant to the conclusion of the author.
However, even if it were relevant, there are a number of reasons that the graph is misleading and should not be used graph.
1. As I’m sure Richard Courtney would point out – the graph shows the trends for non-equal periods of time, i.e.
1860-1880 20 years
1910-1940 30 years
1975-2009 34 years
So as RC would tell you this is “cherry picking”
2. We are well aware of cyclical nature of global temperatures (probably governed by the PDO) and this can be seen in the graph. However, cycles tend to return to have a net ZERO effect. This is seen in the first 2 cycles. Note that the 1860 trough is at roughly the same level as the 1910 trough. However the 1970s trough is not that much different to the 1910 peak.
The cycles exist but there is also an underlying warming trend which accelerated over the 20th century – probably due to an increase in Greenhouse gases.

John Finn
November 4, 2013 7:08 am

dbstealey says:
November 3, 2013 at 4:06 am

I note you’ve still failed to respond to the Realclimate and WUWT which show that I was challenging Michael Mann about the “hide the decline” trick long before “climategate”
The WUWT link is given in the last comment of this post
http://wattsupwiththat.com/2013/10/31/blind-faith-in-climate-models/

November 4, 2013 7:53 am

John Finn says:
“However, cycles tend to return to have a net ZERO effect.”
So if the step up since 1988 is not CO2 forced, that would imply that have cooling ahead then.

November 4, 2013 7:55 am

November 4, 2013 at 7:53 am
sorry typo: that would imply that we have cooling ahead then.

John Finn
November 4, 2013 9:58 am

Ulric Lyons says:
November 4, 2013 at 7:53 am
John Finn says:
“However, cycles tend to return to have a net ZERO effect.”
So if the step up since 1988 is not CO2 forced, that would imply that have cooling ahead then.
It really comes down to Climate Sensitivity.
If CO2 has a sensitivity as high as most of the models suggest then there should be NO cooling. In fact there should still be some weak-ish warming.
If sensitivity is around the value that many “lukewarmers” think it is, i.e. 1-1.5 degrees per 2xCO2 then a flattish or slight cooling trend might be expected. In fact pretty much what we’re seeing at the moment.
But, as you say, if warming is not CO2 forced there could be a noticeable cooling ahead.
Of course this assumes each cycle behaves much the same.

John Finn
November 5, 2013 4:13 am

Ulric Lyons says:
November 4, 2013 at 6:04 am
I agree that from the very early 1700′s to 1950 CET is almost flat,

Thanks for that.

but to argue that there was natural cooling from 1950 to 1987 that mitigated CO2 warming

Ulric
The main point of my argument is that Neil Catto (the author of the blog post) is wrong to use the 353 year trend to predict further warming. That’s it really. I made no comment about what caused the warming other than to suggest the CET record provided more support for a CO2 influence than it did for a natural recovery from the LIA.
It was others who changed the point of discussion.
Thanks again for your input.

November 6, 2013 7:55 am

John Finn says:
“I made no comment about what caused the warming other than to suggest the CET record provided more support for a CO2 influence than it did for a natural recovery from the LIA.”
If warming from CO2 had been cancelled out by negative NAO conditions and hence CET temperatures from 1950 to 1987, and then had augmented the positive NAO conditions and CET temperatures from 1988 onwards, then we should get some idea of the relative level of forcing by how negative the NAO (and the AO) has returned to since 2009. 😉