How To Be A Global Warming Sceptic

[CapelDodger]

None of those three graphs go back further than 1600, though. Not really far enough to prove that the present warming is unprecedented in human history.

We could consider just recorded history and ask whether warming of the current rate and magnitude would have left a mark. I think any such event in the last two thousand years would certainly show up, but it doesn't. Climate variation there has been, and quite rapidly in regional terms, but nothing global on this scale. There's a big global signal at 535-537; that seems to have been volcanic in origin so it works as proof-of-principle.

The Little Ice Age and Medieval Warm Period only emerged as historical concepts within the last century, and from Europe. The LIA came first, and suffers from the problem that 17thCE European society was in prety constant turmoil with a strong apocalyptic flavour. The disruptions and destruction of warfare had a far greater impact than climate, and every bad harvest was promoted as proof of the god's wrath on backsliders.

In comparison, the Medieval Period saw progress from post-Roman anarchy, via feudalism, to the establishment of great nation-states that ultimately conquered the world between them. Which was a Good Thing . A Golden Age indeed, so of course the weather was lovely.

Those are the popular images that GWSceptics brought to the table, and they've been desperately data-mining support for them ever since. It ain't there. European history is robust to the exclusion of climate as a forcing . Just as the hockey-stick is robust to the exclusion of brittle-cone pines.

 

[CapelDodger]

If you do not understand what the hockey stick concept implies, that is quite interesting. It is certainly explained on wikipedia. Do your homework.

I'm asking what the hockey-stick means to you. It's obviously important to you because you keep falling back on McIntyre's exorcism of it as a comfort-blanket. The hockey-stick has not gone away if it's just about the shape of a climate-reconstruction graph (Alric presented one with the blade-end circled for your convenience). Yet you seem to think it has, which implies that it's a more abstract concept in your way of thinking.

 

[a_unique_person]

We have heard of James "Lysenko" Hansen, or Michael Mann or Gavin Schmidt or any number of hoaxers if carbon dioxide were not conveniently rising and the same time as a short part of the 20th Century?

You make a very weak point about Steve McIntyre and the statistical climatologists. McIntyre was the first person to actually reproduce Mann's result from first principles. As far as I am aware, none of the statistical climatologists mentioned have laid a glove on McIntyre's work or on Wegman's response. Neither did the NAS Panel.

Is this the best you can do?

It is standard scientific procedure to produce papers to supersede or refute other papers without resorting to calling the previous paper's authors liars and frauds. I don't recall anyone calling Newton a liar or fraud, even though science has moved on a long way past his pioneering work.

 

[Bananaman]

My personal opinion is that nobody really has a clue whether the ups and downs we see in temperature have anything to do with human CO2 emissions or not.

It's impossible to prove one way or the other.

Bananaman

 

[Bananaman]

My personal opinion is that nobody really has a clue whether the ups and downs we see in temperature have anything to do with human CO2 emissions or not.

It's impossible to prove one way or the other.

Bananaman

 

[Bananaman]

My personal opinion is that nobody really has a clue whether the ups and downs we see in temperature have anything to do with human CO2 emissions or not.

It's impossible to prove one way or the other.

Bananaman

 

[Alric]

Except that C02 and other human produced gases ARE greenhouse gases. Its not a question if they do. Its a question of how much.

 

[Bananaman]

Can some kindly mod delete my repeat posts, I had trouble submitting and kept hammering the 'submit reply' button with the above result.

Bananaman

 

[varwoche]

My personal opinion is that nobody really has a clue whether the ups and downs we see in temperature have anything to do with human CO2 emissions or not.

I suggest you acquaint yourself with the facts.

 

[Bananaman]

All good stuff, Varwoche, but then for instance you get this:

http://www.digitaljournal.com/article/162241/17_200_Scientists_Dispute_Global_Warming

...which, you can either take with a pinch of salt, or not, as the case may be.

Bananaman.

 

[Alric]

Only published peer-reviewed articles for data please.

 

[varwoche]

All good stuff, Varwoche, but then for instance you get this:

http://www.digitaljournal.com/article/162241/17_200_Scientists_Dispute_Global_Warming

...which, you can either take with a pinch of salt, or not, as the case may be.

My link leads to information concerning peer-reviewed studies conducted by experts at organizations such as Scripps, NASA, Woods Hole, NOAA, Hadley, Livermore, Cal Tech, Rutherford Appleton, British Antarctic Survey, US Natl Snow and Ice Data Center, Potsdam, NCAR, Planck Institute, NAS, DOE, etc., all of which arrive at the same basic conclusion.

Your link leads to an anonymous blog that babbles about a goofy, discredited list of unnamed scientists.

A pinch of salt? At the very least.

 

[mhaze]

"A telephone survey of 1,093 Americans", well stop the presses.
Do what now? The 'Murrican public has abundant confidence in scientists? I've heard that a fair chunk of it is Creationist. A journalistic leap too far, I fear.

After after you are through poking fun at the American Creationist hordes, remember that Americans find your problems with Muslim immigrant hordes equally curious.

As for your other question as to what a hockey stick means, it is most enlightening that Warmers might think that they could pick anything that resembles a hockey stick and say that hockey sticks of global warming still exist. Pixel42 does understand the matter; my impression is that Alric does not. It is well defined in Mann 1998; I'll pull that up a bit later and provide the usual Skeptic Schools Warmer In Basics of Science routine. I provided a link to Wikipedia.

Suffice to say that no, "Hockey Stick" does not mean any old graph that looks like a hockey stick, it is a statistical analysis of an extended period of climate which indicates that for that extended period, natural variation was not outside the bounds of statistical noise (the shaft) and then from a recent period, such as 1900 onwards, AGW is the dominant factor or the only factor affecting temperature causing a historically unprecedented temperature rise.

So in my opinion, we should not be re defining a concept such as "Hockey stick" to suit the purposes of the moment. It is a fundamental and basic question: Is current temperature unprecedented in the last millenia, and thus must it most likely be due to man's effects?

Not only Mann by Hansen asked this exact question, and tried to answer it.

 

[varwoche]

Mann's original graph showed a fairly flat temperature for the last couple of thousand years, followed by a kick upwards in the last century or so. That's the "hockey stick" shape.

The nitpicking over the stick prompts me to pay homage to a favorite TV character -- the hyper-literal Hymie the Robot from Get Smart.

 

[Alric]

Suffice to say that no, "Hockey Stick" does not mean any old graph that looks like a hockey stick, it is a statistical analysis of an extended period of climate which indicates that for that extended period, natural variation was not outside the bounds of statistical noise (the shaft) and then from a recent period, such as 1900 onwards, AGW is the dominant factor or the only factor affecting temperature causing a historically unprecedented temperature rise.

You have a reference for that definition? No blogs or newspaper clippings please.

As far as I know "hockey stick" is just a colloquial and not a technical term.

 

[mhaze]

You have a reference for that definition? No blogs or newspaper clippings please.

As far as I know "hockey stick" is just a colloquial and not a technical term.

Come back after doing your homework.

May I suggest reading Mann et al 1998?

 

[Pixel42]

After after you are through poking fun at the American Creationist hordes, remember that Americans find your problems with Muslim immigrant hordes equally curious.

What problem with Muslim immigrant hordes?

As for your other question as to what a hockey stick means, it is most enlightening that Warmers might think that they could pick anything that resembles a hockey stick and say that hockey sticks of global warming still exist. Pixel42 does understand the matter;

And I say that hockey sticks of global warming exist.

Suffice to say that no, "Hockey Stick" does not mean any old graph that looks like a hockey stick, it is a statistical analysis of an extended period of climate which indicates that for that extended period, natural variation was not outside the bounds of statistical noise (the shaft) and then from a recent period, such as 1900 onwards, AGW is the dominant factor or the only factor affecting temperature causing a historically unprecedented temperature rise.

Agreed.

So in my opinion, we should not be re defining a concept such as "Hockey stick" to suit the purposes of the moment. It is a fundamental and basic question: Is current temperature unprecedented in the last millenia, and thus must it most likely be due to man's effects?

Not only Mann by Hansen asked this exact question, and tried to answer it.

And the consensus is that the answer is "Yes". The graph Alric keeps posting showing temperature variations for many different NH regions over the last two thousand years reveals why. Different regions have approached the current temperature at different times, but there was no previous point in the last two thousand years when all regions approached a peak simultaneously as they are doing now.

 

[mhaze]

And I say that hockey sticks of global warming exist.

CCSP Workshop Nov05
McIntyre/McKitrick 2003
MM05 (GRL)
MM05(EE)
NAS Panel
Reply to Huybers
Reply to von Storch

From Andrew's List.

What is the ‘Hockey Stick’ Debate About? (PDF) (Ross McKitrick, Ph.D. Environmental Economist)

The Broken Stick (Financial Post, Canada)
The decay of the hockey stick (Climate Feedback)
The `Hockey Stick': A New Low in Climate Science (John L. Daly, B.Sc. Economics)
Lessons & Limits of Climate History: Was the 20th Century Climate Unusual? (PDF) (Sallie Baliunas, Ph.D. Astrophysics and Willie Soon, Ph.D. Astrophysics)
In Climate Debate, The 'Hockey Stick' Leads to a Face-Off (The Wall Street Journal)
The IPCC, the "Hockey Stick" Curve, and the Illusion of Experience (PDF) (Ross McKitrick, Ph.D. Environmental Economist, Stephen McIntyre, B.Sc. Mathematics)
NAS report "Surface Temperature Reconstructions for the last 200 Years" (National Academy of Sciences)

QUOTE (National Academy of Sciences)With respect to methods, the committee is showing reservations concerning the methodology of Mann et al.. The committee notes explicitly on pages 91 and 111 that the method has no validation (CE) skill significantly different from zero. In the past, however, it has always been claimed that the method has a significant nonzero validation skill. Methods without a validation skill are usually considered useless.

[...] Thus, the public perception that the hockeystick as truthfully describing the temperature history was definitely false.

We find it disappointing that the method of Mann et al. was not sufficiently described in the original publication, and thus not peer-reviewed prior to publication, and that no serious efforts were made to allow independent researchers to check the performance of the methods and of the data used.
​

 

[Alric]

Could you find some published peer reviewed work?

By the way. Your last reference is not from the NAS but some guy. Regardless of the hockey stick straw man the NAS recognizes there is man-made climate change along with all G8 academies of sciences:

http://royalsociety.org/document.asp?latest=1&id=3222

http://royalsociety.org/displaypagedoc.asp?id=20742

In the end the NAS did affirm the "hockey stick" graph.

http://www.nature.com/nature/journal/v441/n7097/full/4411032a.html

And had this to say:

"The academy essentially upholds Mann's findings, although the panel concluded that systematic uncertainties in climate records from before 1600 were not communicated as clearly as they could have been. The NAS also confirmed some problems with the statistics. But the mistakes had a relatively minor impact on the overall finding, says Peter Bloomfield, a statistician at North Carolina State University in Raleigh, who was involved in the latest report. This study was the first of its kind, and they had to make choices at various stages about how the data were processed, he says, adding that he would not be embarrassed to have been involved in the work."

I call it a straw man because since Mann's result many others studies have been performed confirming Mann's initial observations. Not a single one contradicting it. The graph I constantly show with the hockey stick at the end contain Mann's and others results.

 

[Pixel42]

Yes, I've seen all that. It's a minority view, and those who hold it are entitled to it. I just find the majority view - that the recent global increase in temperature is indeed unprecedented in the last couple of millenia - more convincing. There are multiple lines of evidence which support it, whilst the minority view seems to require much cherry picking.