I dispute your last paragraph @ 11:22. The recovery from the depths of the Little Ice Age, the coldest time of the Holocene, has not exceeded the Holocene Optimum. Even if it were true, we're just putting off glaciation.
=============

Kim

The Little Ice Age bottomed out around 1850 at a global average temperature of 13.8C. We are now around 14.8C.

The consensus estimate that the Holocene Optimum was 14..4 +/- 0.2C, based on Marcott et al 2013.

What Holocene Optimum temperature are you using and where did you get it?

Please, you can't even prove that present temperatures exceed the height of the Medieval Warm Period, and that was surely lower than the Holocene Optimum.

Marcott, eh? Heh.
=============

'like an elevator, whoosh, to the top'. If we can identify Marcott as the source of your misunderstanding, then we've made progress.
=========================

Kim You still haven't given me numbers.

Kim

Mediaeval Warm Period was about 13.9C.

We passed that 35 years ago.

Nor have you proven we've exceeded the temps of the Holocene Optimum.

Look, you are arguing at cross purposes. You've conceded that interglacials have a maximum temperature at approximately midpoint, and then gradually decline. If in fact we've exceeded that, then we are putting of the onset of glaciation, if only by a few decades or centuries.
==============

I suspect you are still fooled by Marcott. The fatal flaw, the hubristic fraud, of his study is to smooth into meaninglessness the shaft of the Hockey Stick, thus concealing the natural variability of the past. Phil Clarke also refuses to admit this point, though I suspect he understands it.

The slope of recovery from the coldest of the Little Ice Age, the coldest depths of the Holocene, remains unchanged from then until now. You had better hope that that recovery if predominantly natural, for if we are doing the heavy lifting of warming, we're going to run out of fuel before long. The higher the sensitivity, the colder we would now be without AnthroCO2.
===================

I particularly like javier's little joke that the next time we'll have to be scared of global warming is 70,000 years in the future. Have you read his post? What do you think of it?
====================

Kim

Mediaeval Warm Period was about 13.9C.

We passed that 35 years ago.

Oct 26, 2016 at 6:33 PM | Entropic man

Line 1 kim is correct as supplied

Line 2 is a flying guess

Line 3 is wrong, due to Line 2

Line 4 is date, time and name as supplied.

That is 50% accuracy in 4 Lines, only because 2 Lines used supplied information.

Or 100% Inaccuracy in Climate Science terms.

EM

Thank you for the compliments. I am enjoying our discussion. Could I take you up on your final 3 paragraphs in your response to me (sorry it's a late response to yours, I've been busy today)?:

"Another point that you persistently have trouble with is that these urban and industrial areas make up a small proportion of the planet.

Although they show up as warm in the urban station data, their extra heat, once dispersed across the system, makes very little difference to the overall temperature. As far as climate is concerned, the overall temperature is more important.

Imagine SandyS in his laboratory. Switching on his soldering iron makes little difference to the temperature of the building."

I absolutely get your second and third paragraphs as set out above. The logic is impeccable, I understand it, and I agree with it. However, it's the first of those 3 paragraphs that I take issue with. I have no trouble with the fact that "urban and industrial areas make up a small proportion of the planet." The issue, for me, is the fact that they represent such a large part of the temperature datasets. Therefore, there is a real danger that they massively distort those datasets.

If UHI-affected temperature records are higher than non-affected records, they are going to contaminate the datasets, and give a false impression of warming. That is why I 100% agree with what you say here:

"That leaves those measuring current and historical global temperatures with a dilemma.

Do they ignore UHI and therefore overread the global average?

Do they correct for UHI, which actually produces lower global averages, and get complaints from sceptics that they are adjusting the figures?"

It's the nub of the issue, or as you say, a moot point. How can it be dealt with in a way which will satisfy sceptics? Ignore the issue, and we'll (quite rightly) cry foul. Make adjustments, and we'll question the adjustments. Are they right? Too big? Too small? Just generally inappropriate? I get all that, and I appreciate the dilemma, and the attempts made to deal with it. By and large, I don't question the motives, integrity, or honesty of the people making the adjustments.

And yet....when I read things like the Berkeley Earth paper (Influence of Urban Heating on the Global Temperature
Land Average using Rural Sites Identified from MODIS Classifications) I can't avoid a nagging feeling that having identified the problem, they set out to answer it in such a way as to shut up the sceptics, and simply make the problem go away.

I just can't get past this statement in the paper: "The estimated warming trend for the very-rural group is larger
than that based on all records, in the opposite direction expected from urban heating." It is a denial of the UHI effect. It is utterly inconsistent with your helpful calculation for me showing that UHI probably accounts for 7.8% of global warming (a calculation made by extrapolating from the paper's own figures). Something isn't right.

Petersen (1984) says something similar:

"Once biases caused by differences in elevation, latitude, time of observation, instrumentation, and nonstandard siting were adjusted out of the data, contrary to generally accepted wisdom, no statistically significant impact of urbanization over the contiguous United States could be found in the existing in situ temperature observation network."

Those words could, I suppose, be read in 2 ways:

1. Once we have adjusted the records, there is no UHI - the apparent UHI is in fact due to other factors; or
2. There is UHI, but we have accounted for it, and having done so, it does not have a statistically significant impact on the datasets.

Perhaps it is the pedantic lawyer in me, but I wish he had used clearer and less ambiguous language.

Mark Hodgson

I can't avoid a nagging feeling that having identified the problem, they set out to answer it in such a way as to shut up the sceptics, and simply make the problem go away.

You don't know the mindset of typical scientists very well.

They don't earn much by the standards of other professions. Most of the academics whose names you hear in the climate debate would earn much less than you do. A typical research scientist earns £29,000.

What matters to them is two things, curiosity and reputation.

You are familiar with the problem of perjury in court. It is rare for several reasons. From the viewpoint of the witness, there is a severe penalty if caught, which makes it not worth the risk. From the viewpoint of the barrister perjury is easily spotted when the perjury disagrees with the other evidence. It also casts doubt on the rest of the barrister 's case.

False practice in science is similar to perjury, though when caught your reputation is trashed and you become unemployable rather than going to jail. You will be caught. If you publish false data it rapidly becomes obvious because the false data will not match with data produced by other researchers.

Science is cumulative, like building a wall. Papers are the bricks and better understanding comes from building new research on previous research. If a paper is based on false evidence, then everything built on it will also be false and will become wasted effort when the fraud comes out. There is also the problem that any previous work by the same author becomes suspect and everything based on that has to be rechecked.

The big reason why other scientists hate false data. It is like pissing in the well. It contaminates genuine data and makes it harder to work what is actually valid science.

One way or another an accusation of falsifying research is the worst thing of which you can accuse a scientist. It is why I and others react so strongly when sceptics suggest it.

Imagine how you would be affected if I publicly accused you, as a solicitor, of perjury, suborning to perjury or other illegal practice. If true it would lead to you being disbarred. Even unproven, it would ruin your business.

Fortunately, the type of sceptic who makes such accusations is not usually a credible witness. ( Now watch the reaction from golf charlie and her ilk! :-) )

"The estimated warming trend for the very-rural group is larger
than that based on all records, in the opposite direction expected from urban heating."

That is a different way of saying that the mean UHI is negative; remember that -0.1 +/- 0.24C. The statement concisely describes in scientist-speak what they observed. I would bet 50p that over coffee they are saying the same thing as us. This is probably wrong based on other evidence, and has occurred because the uncertainty in the UHI is bigger than the mean.

Peterson's statement is typical of scientist-speak. In a paper one sometimes writes using extremely precise language. It gives a precise meaning but is difficult to understand. I am sure you can give examples of similarly precise but obscure paragraphs in legislation.

In Peterson (1984) your second interpretation is probably the correct one.

2. There is UHI, but we have accounted for it, and having done so, it does not have a statistically significant impact on the datasets.

EM, Mark

"I can't avoid a nagging feeling that having identified the problem, they set out to answer it in such a way as to shut up the sceptics, and simply make the problem go away.
You don't know the mindset of typical scientists very well"

Keep your scepticism Mark, EM is talking black and whites. I remind you of the reaction of the CRU mafia when others wished access to their data. Or the defence of made-up Chinese data.

Scientists, even those with reputations to preserve, are fully capable of hiding data that doesn't fit to present a prima facie case.

EM, how many times has Gergis been caught? What has Climate Science done? Nothing.

What was Peter Gleike guilty of? What has Climate Science done to the Ethics expert? Nothing

How long a list do you want typed of Climate Science rewarding dishonesty?

EM

A little earlier on this thread I said that I think we shall have to agree to differ, and I think that remains the case.

Much, it seems to me, depends on one's preconceptions. You believe in the science. I doubt both the science and the policy prescriptions that stem from it. You can say this with a straight face:

"False practice in science is similar to perjury, though when caught your reputation is trashed and you become unemployable rather than going to jail. You will be caught. If you publish false data it rapidly becomes obvious because the false data will not match with data produced by other researchers."

While most of the regulars on this site would probably consider such a statement to be untrue, even risible.

I think we've both made a strong case for our respective positions, but it remains the case that we aren't going to convince each other, so I think I'll duck out of this thread for now - not admitting defeat, but just because I think you and I have taken it as far as we can (I have anyway).

Mark Hodgson

While most of the regulars on this site would probably consider such a statement to be untrue, even risible.

I will refrain from discussing the quality of judgement displayed by most of the regulars on this site.

Thanks for a pleasant conversation. Another time, perhaps.

EM. On occasion you can be a proper little snot-rag. Consider this one of them. Be careful not to fall from your recently constructed high pedestal of logic and mathematical expertise.

“Why, sometimes I've believed as many as six impossible things before breakfast.” 
― Lewis Carroll, Alice in Wonderland

How climate science got wrotten

EM. On occasion you can be a proper little snot-rag. Consider this one of them. Be careful not to fall from your recently constructed high pedestal of logic and mathematical expertise.

Oct 29, 2016 at 2:51 PM | ACK

ACK, you are very polite. Entropic Man has reduced himself to Phil Clarke's level of petulance, having run out of science, and been found out. Again.

ACK

I begin to see why you were marginalised at UAE. I can imagine you sitting alone in the corner of the common room because of your odd views and your unpleasant personality.

There is also an element of hypocrisy here. The man who admits abusing his academic position, giving climate change lectures to students biased towards his minority opinions, is in no position to criticise the probity of other scientists.

Golf Charlie

I realise that you are ill, so I have made allowance for your odd behaviour. There are limits. Please return to politeness before I am tempted to become impolite.

Radical Rodent, kim

My source is, of course, Marcott et al 2013. Go to Figure 1a. Draw a line up to the curve from 1000BP on the x axis and across to the y axis. The mean temperature measure is -0.1C. Since the baseline is the 1961--1990 average of 14.0C the actual mean temperature is 13.9C. Uncertainty is +/- 0.2C.

I realise that denial of Marcott et al is a necessary part of your belief system, so don't bother to comment.

Radical Rodent

You did notice that American Thinker is a right wing propoganda site?

EM, you are marginallising yourself, by championing what is the minority position.

What evidence do you rely on to assume you represent the majority? Scientists? Electorate? Taxpayers?

Climate Science has failed at Science.It create a faked "Consensus" instead.

Science has never been about Populism, popular culture, the will of the people etc. But seeing as how Climate Science has fallen back on emotional blackmail, and trying to marginalise people (see your post above) you have failed at that aswell.

Stick to science, and working out which bits of Climate Science are worth saving.

Radical rodent, Kim

Just read an interesting item on an analysis of Mediterranean temperatures.

This passage struck me particularly. It provides additional evidence that modern temperatures are exceeding those of the Holocene Optimum.

The researchers analysed tens of thousands of pollen samples across the Mediterranean region, building up a record of the climate going back 10,000 years – a period known as the Holocene.
Comparing past with present, the new study show that average Mediterranean temperature in the first decade of the 21st century has already exceeded the warmest century of the entire Holocene.