How To Be A Global Warming Sceptic

[Alric]

Clearly you stand by your opinion, but as for evidence, naught.

What about this?

http://www.globalwarmingart.com/wiki/Image:1000_Year_Temperature_Comparison_png

 

[TrueSceptic]

Sourcewatch as reference, now? Throw in some Bigcityliberal and a bit of Mediamatters, sprinked with BBC and Fenton communications.

Of course. They support what they say. What do you dispute?

Of course, you use Anthony Watts and similar as sources. No problem with that?

 

[mhaze]

What about this?

http://www.globalwarmingart.com/ima...ng/450px-1000_Year_Temperature_Comparison.png

http://www.globalwarmingart.com/wiki/Image:1000_Year_Temperature_Comparison_png

Your graph , erroneous in repeated demonstrations, provides gullible warmers with needed solace in the face of an onslaught of newer science. But in spite of these functions it provides to a few radicals, it does not support the hypothesis of Pixel42....

I stand by my statement: the opinion of the majority of climatologists is that the current warming is unprecedented in the last couple of millenia.

 

[Pixel42]

Clearly you stand by your opinion, but as for evidence, naught.

I think we're in danger of forgetting here that the statement in question is that the majority of climatologists are of the opinion that the current warming is unprecedented in the last couple of millenia. I said I found the evidence and arguments in support of that majority opinion convincing; it was the word "majority" that you questioned.

Let's turn it round. If my statement is false, as you allege, then the majority of climatologists are actually of the opinion that there has been at least one period in the last couple of millenia when the average global temperature was higher than it is now. Do you seriously believe that is the case?

 

[Alric]

I stand by my statement: the opinion of the majority of climatologists is that the current warming is unprecedented in the last couple of millenia.

And you would be wrong. Where are all those climatologists getting published?

 

[hammegk]

What I find more puzzling is the apparent -- or is it real? -- controversy with regards to what the historical climate record depicts vis-a-vis today.

A quick google showed a couple of colleges one British, one S.African with post-doc AGW studies.

Does anyone have an idea on how many PhD level climatologists exist?

 

[mhaze]

I think we're in danger of forgetting here that the statement in question is that the majority of climatologists are of the opinion that the current warming is unprecedented in the last couple of millenia. I said I found the evidence and arguments in support of that majority opinion convincing; it was the word "majority" that you questioned.

Let's turn it round. If my statement is false, as you allege, then the majority of climatologists are actually of the opinion that there has been at least one period in the last couple of millenia when the average global temperature was higher than it is now. Do you seriously believe that is the case?

Ok, turn it around, reverse, converse, obverse, whatever.

Many scientists would simply and accurately say we don't know.

You seem to have ignored that.

Does anyone at all agree with your statement?

I said I found the evidence and arguments in support of that majority opinion convincing that the majority of climatologists are of the opinion that the current warming is unprecedented in the last couple of millenia

 

[Pixel42]

Many scientists would simply and accurately say we don't know.

I would hope they would all say that. Doesn't stop them forming an opinion, based on the best available evidence.

Does anyone at all agree with your statement?

Well let's ask the contributors to this thread, shall we? Is there anyone here who agrees that the majority of climatologists are of the opinion that the current warming is unprecedented in the last couple of millenia?

ETA: http://www.ncdc.noaa.gov/paleo/pubs/mann2003b/mann2003b.html

 

[Alric]

I agree. And so do these academies which in turn represent hundreds of scientists:

Scientific consensus

A question which frequently arises in conveying the scientific opinion to a broader audience is to what extent that opinion rises to the level of a consensus. Several scientific organizations have explicitly used the term "consensus" in their statements:

American Association for the Advancement of Science: "The conclusions in this statement reflect the scientific consensus represented by, for example, the Intergovernmental Panel on Climate Change, and the Joint National Academies' statement."[22]

US National Academy of Science: "In the judgment of most climate scientists, Earth’s warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere. ... On climate change, [the National Academies’ reports] have assessed consensus findings on the science..."[42]

Joint Science Academies' statement, 2005: "We recognise the international scientific consensus of the Intergovernmental Panel on Climate Change (IPCC)."[43]
Joint Science Academies' statement, 2001: "The work of the Intergovernmental Panel on Climate Change (IPCC) represents the consensus of the international scientific community on climate change science. We recognise IPCC as the world’s most reliable source of information on climate change and its causes, and we endorse its method of achieving this consensus."[44]

American Meteorological Society: "The nature of science is such that there is rarely total agreement among scientists. Individual scientific statements and papers—the validity of some of which has yet to be assessed adequately—can be exploited in the policy debate and can leave the impression that the scientific community is sharply divided on issues where there is, in reality, a strong scientific consensus. ...IPCC assessment reports are prepared at approximately five-year intervals by a large international group of experts who represent the broad range of expertise and perspectives relevant to the issues. The reports strive to reflect a consensus evaluation of the results of the full body of peer-reviewed research. ... They provide an analysis of what is known and not known, the degree of consensus, and some indication of the degree of confidence that can be placed on the various statements and conclusions."[45]

More telling:

Statements by dissenting organizations

With the July 2007 release of the revised statement by the American Association of Petroleum Geologists, no remaining scientific body of national or international standing is known to reject the basic findings of human influence on recent climate.[40]

All references at:

http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change

 

[cloudshipsrule]

Things are lookin' up!

http://wattsupwiththat.wordpress.co...es-say-globally-cooler-in-the-past-12-months/

 

[mhaze]

I agree. And so do these academies which in turn represent hundreds of scientists:

No, these organizations do not agree with the statement in question.

But Pixel42 now has a consensus of two! (and in that consensus, the majority opinion .....)

 

[mhaze]

Things are lookin' up!

http://wattsupwiththat.wordpress.co...es-say-globally-cooler-in-the-past-12-months/

Cool!

 

[Pixel42]

No, these organizations do not agree with the statement in question

AFAIK these organisations have never expressed either agreement or disagreement with the statement in question. They have however expressed agreement with the IPCC, and hence by implication have endorsed the findings of papers like the one I linked to in my last post, which form the basis for the IPCC consensus.

Take a look at the graph of reconstructed global temperature over the last 2000 years in that paper. What would be a simple way to describe it, would you say? Perhaps a simile from the world of sport would be appropriate?

 

[Round Robin]

Well let's ask the contributors to this thread, shall we? Is there anyone here who agrees that the majority of climatologists are of the opinion that the current warming is unprecedented in the last couple of millenia?

Well, here's what the NRC arm of the NAS had to say on the subject. (source)

The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward.

Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium.

(my emphasis)

This indicates support for the basic conclusions of Mann et al. Where the NAS begins to express more uncertainty is in comparing small time scales--1 to 10 years. That's a fair cop, I think; the NAS continues:

The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming. Even less confidence can be placed in the original conclusions by Mann et al. (1999) that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods and because not all of the available proxies record temperature information on such short timescales.

(note that "lower our confidence" <> "we disagree") This qualification of uncertainties of short time scales is balanced with a reminder in the next paragraph:

Surface temperature reconstructions for periods prior to the industrial era are only one of multiple lines of evidence supporting the conclusion that climatic warming is occurring in response to human activities, and they are not the primary evidence.

This reads to me as general agreement with the basic point, but with a caveat that some comparisons of very short time periods (e.g. 90's being the warmest decade) carry too great an uncertainty to be declarative. They then seemed to remind the reader (in the last quoted paragraph) not to "take their eye off the ball" by putting too much concern in the validation or discrediting of a single line of evidence.

 

[a_unique_person]

Cool!

Cherry picking at it's finest. You will find many similar dips on the temperature chart. Each time it gets warmer again.

 

[CapelDodger]

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

I can't help thinking you'd fail the Turing Test. My gentle mockery was directed towards the journalist - "A journalistic leap too far, I fear".

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.

It's my understanding that an entirely different scientists is credited with the term "hockey stick" as descriptive of the MBH98 reconstruction. I'm suprised to hear that it was actually defined in MBH98.

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.

Well that's clear as mud. But clearly it does mean that for you "hockey stick" no longer refers to a shape but has taken on a more abstract meaning. Which was my original surmise.

So in my opinion, we should not be re defining a concept such as "Hockey stick" to suit the purposes of the moment.

Indeed, but by abstracting the term you've done precisely that. Since so many other reconstructions than MBH98 show the shape, and it's only MBH98 that McIntyre claims to have demolished, it can't (for your purposes) mean the shape any more.

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?

If a global climate excursion similar to what's occurred in the last fifty years had happened in the last two thousand years it would have left its mark in recorded history. No such mark has been observed. The marks of regional excursions can be oberved that were most likely less severe than what's going on globally now. Short-term global excursions due to vulcanism have also left their mark. But nothing like this, which is making a mark in the modern world. Imagine what it would do in a world where 95% of the population worked in agriculture.

Something we do know is particular to this current period is the inclusion of a mature industrial society built and powered by fossil-fuel. Something else is the global sophistication of our observational techniques - we can, for instance, directly measure solar output rather than rely on sunspot numbers as a proxy. We know that CO2-load has increased significantly since the 19thCE (by over a third, and counting) and that scientists predicted this would have an impact on climate long before the event. Global warming has occurred, and no alternative forcing has been observed.

Is this a coincidence? Some invisible influence just happens to kick in during the window that coincides with AGW predictions and our inability to observe it? I don't think so. As Harry Hill would say, what are the chances of that happening?

And that's not even to get into why the scientific predictions of AGW were also concidentally wrong, and there's about to be a revolution in radiative physics when the fact finally gets across to the hidebound scientific community. (Irony)

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

Well they are scientists, and that's what they do, ask questions and try to find ways of answering them.

 

[CapelDodger]

This reads to me as general agreement with the basic point, but with a caveat that some comparisons of very short time periods (e.g. 90's being the warmest decade) carry too great an uncertainty to be declarative. They then seemed to remind the reader (in the last quoted paragraph) not to "take their eye off the ball" by putting too much concern in the validation or discrediting of a single line of evidence.

A good summation, IMO.

In a more general sense, it's the many caveats of science that give the lie to GWSceptic claims of scientific "alarmism". Drawing a conclusion about a particular decade in a 600-year reconstruction is, in principle, a bit dodgy, the sort of thing that makes your professor wince. In principle there could have been a decade back in the LIA - let's call it the Golden Decade - that came and went leaving no evidence because of its short time-scale.

It doesn't (or shouldn't) mean the professor rejects your work entirely. If it's good and interesting work it just needs some caveats added.

Of more immediate interest is that this century has been warmer than the 90's. Of even more immediate interest is what happened to Arctic ice last summer, and what will happen to it in the next couple of summers. Interesting not just in scientific terms but in geopolitical terms.

 

[CapelDodger]

I would hope they would all say that. Doesn't stop them forming an opinion, based on the best available evidence.


Well let's ask the contributors to this thread, shall we? Is there anyone here who agrees that the majority of climatologists are of the opinion that the current warming is unprecedented in the last couple of millenia?

ETA: http://www.ncdc.noaa.gov/paleo/pubs/mann2003b/mann2003b.html

I agree.

 

[CapelDodger]

McIntyres old web page has a link to his presentation at the NAS. He takes it so seriously, they listen, they say thanks, you're correct to an extent, but it doesn't really change anything. End of Story.

You would think. With McIntyre, though, it's in one ear, out the other. Instead we have the great "hockey stick" controversy that's like whirlwind around the blogosphere, but a storm in a teacup for the NAS.

Worse than that, when you poke through the "hockey stick" shell you find it's the bristlecone pine controversy and concerns only the early 15thCE. Which in the old days (remember them? Before MBH98? When Diamond was TitanPoint? 'Course you do! ) was deep in the Little Ice Age, one of the original death-knells of AGW (a theory in crisis).

Poor old mhaze has been left flapping in the wind again, a Diamond drive-by not being worth a bucket of warm spit in practical terms. Perhaps one day mhaze willl realise that his fellow zealots regard him as nothing more than a useful place-holder while they retire to camp to lick their wounds and concoct a new plan of attack.

 

[TrueSceptic]

The point about the canonical Mann Hockey Stick is that it overweights a single proxy, the Graybill Bristlecone Pines of Western Colorado. Without that one proxy, the Hockey Stick shape disappears.

This is a very strong unambiguous claim. I'd like to pursue this in terms of HTBAGWS. Can anyone supply evidence, for or against, this claim? I think it would be instructive re the OP.