Global Warming Debate: Refuting Common Arguments

[Andre]

Which sounds absolutely logical. No problem with that all.

The problem however is if you try to coerce the world to change habits with something that is not true. Eventually, sooner or later, may it be next week or in fifty years, the truth will have its boots on.

Try to convince the world then, to change habits: "but this time it is really really true, cross my heart"; "Right that's what you say all the time".

The need to change things should be based on facts and that damage to science will be very very hard to repair.

Therefore, the sooner the straying is corrected, the better. However anybody who attempts to do so is automatically a folk devil (the deniers) as has been demonstrated in this thread once more.

 

[Skyhunter]

Andre,

You are projecting. You https://www.physicsforums.com/showpost.php?p=2383401&postcount=15" that is easily debunked.

Instead of defending your position you accuse others of being dishonest.

Not very scientific.

 

[Andre]

Well, one could not wish for better demonstration of what I'm trying to say.

Note the density of strawmans.

 

[Skyhunter]

So why don't you defend your argument instead of attacking others?

 

[z0rn dawg]

Could you provide a citation to the page where this is stated?

Page 188, Figure 3.1.

I get your point. You don't like Al Gore or his politics. That has absolutely no bearing on his film. And BTW he was not sued by 30,000 scientists. He was threatened with a lawsuit by deniers, but that was more a publicity stunt on their part that never amounted to actual court action. He was not found guilty of fraud in the UK. His film is still being shown to students in the UK with caveats, so that students don't confuse advocacy with science.

I'm pretty sure they sued, whether it amounted to anything I'm not sure of. It may have been a publicity stunt, but so was "An Inconvenient Truth." I was mistaken: Gore was not found guilty of fraud. The judge just found nine significant errors, proving Gore's "documentary" is not a documentary. The only thing that bothers me about the guy is that he lied to get his point across. If he had so many scientists working with him on it, how could they make nine significant mistakes? Seems too high to be mistakes.

Then I suggest you broaden your list of literary selections.

So some scientists don't believe that CO₂ is causing global warming? There's no way you can just not listen to what they have to say. They're part of the scientific community. I've looked at both sides, and there does not seem to be a consensus. The media talks about man-made global warming due to CO₂, but many scientists don't agree. I've read parts of the IPCC's 2001 and 2007 reports (I'm citing the 2001 report because that's what I have on hand). I'm pretty sure that's one valid, respected source that blames human activity.

 

[Count Iblis]

There's no way you can just not listen to what they have to say

If they don't publish what they say in peer reviewed journals, then what they say has no more value than what my grandmother has to say about this issue.

 

[Skyhunter]

Thanks for the citation Zorn.

I would point out however that the same figure shows the cycle in balance before the human contribution. It is not the size of the carbon cycle but the differential between emission and sequestration that is creating the problem.

Nothing wrong with being skeptical. But the errors in the documentary were not significant, besides, the film was meant to educate people to the broader public problem, not to answer open scientific questions. I don't remember all the errors found, I assume one was that you could see the clean air act in the ice cores, and another was an incomplete explanation of the correlation between carbon dioxide and temperature, leaving the insinuation that temperature would follow carbon dioxide levels, when the truth is that the temperature rise would be about 1/3 the carbon dioxide rise. Generally the film does a good job of education and was therefore approved for use in public schools with caveats.

 

[Bored Wombat]

When the first hokey stick graph was debunked, I began to take an interest in global warming.

I'm not sure that this is the scientific view.

Probably the most respected scientific journal in the world is Nature. (Certainly the most respected would be Science, Nature or Cell)

Their take on the National Academies review of the Hockey stick is that http://www.nature.com/nature/journal/v441/n7097/full/4411032a.html". Which is approximately the reading that scientists gave the report.

It was critical of how the data was used, and there were statistical methodological errors, but these made no material difference.

Probably your view that it was "debunked" has its origins in the counterscientific blogs and opinion pieces that proliferate on the internet, rather than an unbiased scientific source.

I read different arguments surrounding many of the graphs and models used to predict temperatures. When I saw them I was shocked by how inaccurate they were and their inability to even predict temperature as of now.

Again, it seems like you are not reading scientific sources.

Current climate models hindcast global mean surface temperature within the 90% confidence interval much more than 90% of the time, so the question is actually the opposite. Why are they so accurate? (See:http://www.agu.org/pubs/crossref/2008/2008GL034932.shtml" - Geophys. Res. Lett., 35, L18704, doi:10.1029/2008GL034932)

I was also amazed at the overwhelming number of scientists signatures confirming global warming that had no connection to climate studies what so ever.

The closer a scientist's field is to currently publishing on climate change, the more likely they are to agree with the human influence on climate. (see: http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf"[/URL], Eos Trans. AGU, VOLUME 90 NUMBER 3 20 JANUARY 2009)

[quote="jordanfan20, post: 2382847"]As the years seemed to go by Al Gores movie appeared so incorrect I began to wander why so many people took it literally, and like other things I realized that many people only believed it because they thought all people believed it except the crazy skeptics.

I do not deny global warming or man made global warming I merely believe that global warming is not going to cause enormous catastrophe.[/QUOTE]

The current drop in biodiversity is attributable in part to climate change. And that is about 30% in the last 35 years. That should concern most people.

Analysis of species ranges has been pretty grim. (see: [PLAIN]http://www.gbltrends.com/doc/nature02121.pdf"[/URL], Nature (2004))

Note also that adaptation is very expensive. Bhutan was the first nation to receive UN funds for the underdeveloped nations to deal with climate change. The $3.5 million was supplemented further by other international donors, but has been insufficient to drop the level of the new glacial lakes to avoid floods ... and they are only working on one of over two thousand glacial lakes in the small country. (see:[URL]http://www.nature.com/news/2009/091021/full/4611042a.html"[/URL], nature news.)

I am aware of desert ecological communities, and sub antarctic communities that don't exist any more because of climate change, and I think any ecologist could tell a similar story of whatever system they study. Corals are also under severe stress in many parts of the world, with large areas of bleaching (meaning the symbiote is dead). This will lower the entire productivity of the oceans. As will acidification.

The change from snow to rain in the Himalayas puts about a quarter of the worlds population under fresh water stress for most of the year. (And floods their homes and croplands for the rest of the year)

I think the science shows a lot of expensive consequences, but you have to read about them from scientific sources, because there is a lot of fossil fuel-funded nay-saying on the net. If a site is dedicated to global warming denial, it is pretty safe to not read it.

[URL]http://www.nature.com/climate/index.html"[/URL] is a good way to keep up with the science, without it becoming overly technical, and it is important to read a science based site on this subject occasionally, because the signal to noise ratio in the popular press and the blogs and forum sites is very low on this subject.

 

[DrClapeyron]

http://www.youtube.com/watch?v=eScDfYzMEEw&feature=related

People shouldn't be afraid of the future, especially young people such as myself. We should view the potential catastrophic consequence as a very stimulating problem to solve. Why back down and shoot ourselves in the foot?

 

[mheslep]

I'm not sure that this is the scientific view.

Probably the most respected scientific journal in the world is Nature. ...

I think you mean prestigious, not respected, and for its peer review process of submitted papers, and not because of its news articles like the one linked here:

Their take on the National Academies review of the Hockey stick is that http://www.nature.com/nature/journal/v441/n7097/full/4411032a.html". Which is approximately the reading that scientists gave the report.

Probably your view that it was "debunked" has its origins in the counterscientific blogs and opinion pieces that proliferate on the internet, rather than an unbiased scientific source.

How ever one characterizes the Mann et al 1200 year temperature reconstruction, there is the observable point that it appeared http://www.grida.no/climate/ipcc_tar/wg1/005.htm"[/URL]to the paleo section and merged in with several other reconstructions that show the medieval period as warm.

[QUOTE=Bored Wombat]I am aware of desert ecological communities, and sub antarctic communities that don't exist any more because of climate change,[/QUOTE]Could you cite one please (obviously one in the last 30 years to be associate w/ AWG)?

[QUOTE=Bored Wombat]The change from snow to rain in the Himalayas puts about a quarter of the worlds population under fresh water stress for most of the year. (And floods their homes and croplands for the rest of the year)[/QUOTE]Source?

[QUOTE=Bored Wombat]I think the science shows a lot of expensive consequences, but you have to read about them from scientific sources, because there is a lot of fossil fuel-funded nay-saying on the net. If a site is dedicated to global warming denial, it is pretty safe to not read it.[/QUOTE]Science can show consequences, I don't know that estimating costs is also science, certainly not by climate scientists.

 

[Bored Wombat]

I think you mean prestigious, not respected, and for its peer review process of submitted papers, and not because of its news articles like the one linked here:

Nature News is still respected on the strength of the scientific basis of the organisation.

And given that most people aren't going to read the national academies report, its a good source of the scientific opinion on it.

Other news sources said the same of course:
http://news.bbc.co.uk/2/hi/5109188.stm" .

And the scientific blogosphere had the same analysis. The point is that the national academies report supported the hockey stick graph, and a scientist that read it could tell you that, even the reporters for Nature.

How ever one characterizes the Mann et al 1200 year temperature reconstruction, there is the observable point that it appeared http://www.grida.no/climate/ipcc_tar/wg1/005.htm" to the paleo section and merged in with several other reconstructions that show the medieval period as warm.

The finding of Mann et al, that the little ice age and the medieval warm period where not at the same time over the northern hemisphere is interesting, valid, and still holds now. This is why whole hemisphere reconstructions show it much more weakly than the 1990 IPPC graph from one site in central England. (still used in the denialist literature such as "swindle".)

The national academies said that it was over used, considering at the time it had not yet been reproduced.

Your argument that it "vanished from the summary", therefore it must be considered wrong doesn't follow. The IPCC reports are about the science that has been learned since the last report. The hockey stick was well reported in the 2001 IPCC report. There is no reason to put it in such a prominent place in the 2007 IPCC report.

It is true that it doesn't appear in the summary for policy makers. You are exaggerating your case when you call this the summary. It does appear in the technical summary.

Could you cite one please (obviously one in the last 30 years to be associate w/ AWG)?

I know that from conversations with ecologists, I don't know where or if they have been published. The rainy season in outback east australia has changed time of year. The ecological communities that blossom in the vastly different temperatures are different. (And not the interesting and unique ones). Freshwater communities devastated by the same effect. The rivers are out of water at the wrong time of year.

The damage to the subantarctic is from interviews with those studying it. I'll look one up if you like, but I'll submit this first, as I might not get a chance.

Source?

Common knowledge.

But the first google hit I got was this:
"Dr Claudia Sadoff of The World Bank, said in her
opening address: “The countries in the Himalayan subregion
account for 40% of the world’s population. The
rivers in the region are extreme in terms of population
density, sedimentation and variability. Each river is in
effect many rivers in one; each is an ecosystem in itself. Hence, issues related to
the Himalayan rivers are complicated. These are difficult rivers to understand,
manage and talk about. They are shared rivers, which increases complications.
There has been a lot of talk recently about how these rivers are under threat.
Glaciers are disappearing, rivers are running dry; rivers are overdrawn and
polluted. These rivers are extremely variable in terms of floods and droughts.
They are even more threatened due to climate change. The World Bank has
identified climate change hot-spots. One is over the Himalayas." - http://www.strategicforesight.com/Kathmandu Report.pdf

Will it do? I'm sure I could find something by the IPCC or a NGO about the consequences of climate change in the region if you want.

Science can show consequences, I don't know that estimating costs is also science, certainly not by climate scientists.

I wasn't really meaning financial costs.
But economics is a science of sorts. And an important one for deciding on climate change policy.

 

[mheslep]

Your argument that it "vanished from the summary", therefore it must be considered wrong doesn't follow.

I did not say that.

It is true that it doesn't appear in the summary for policy makers. You are exaggerating your case when you call this the summary. It does appear in the technical summary.

Summary, as in Summary for Policy Makers.

I know that from conversations with ecologists, ...

That's fine, but not appropriate for this forum.
https://www.physicsforums.com/showthread.php?t=280637

 

[Bored Wombat]

I did not say that.

I doubt that I misinterpreted you. If you think that the paraphrase has lost your meaning, could you point out how?

Summary, as in Summary for Policy Makers.

I can see that that's why you must mean, because of the way that it appeared in the Technical Summary. But you should still be specific when claiming something "vanished" from somewhere, and using that to imply that it has lost favour.

That's fine, but not appropriate for this forum.

It's pretty common knowledge, and not at all controversial that ecosystems are being impacted by climate change, and neither that for ecosystems with smaller geographic ranges, (being the unique in especially interesting ones) that impact is more often extinction or increased risk of extinction.

Since its not controversial, its not inappropriate.

 

[heldervelez]

Google for 'Joanne nova' her handbook is very helpfull.
Her 16 pages "The skeptics handbook" can help you.
quoting from her site "Volunteers have translated it into German, French, Norwegian, Finnish, Swedish, Turkish, Portuguese and Danish. (Versions in Dutch, Spanish, and possibly Italian are on the way). "

The translation to pt-br has been done by university teachears that are brasilian climatologists.
Joanne is not a scientist but, as myself and a lot of us, are tracking the inconvenient facts behind all that noise that pervades the media.
And her site has links to helpful sources.

 

[mheslep]

...I can see that that's why you must mean, because of the way that it appeared in the Technical Summary. But you should still be specific when claiming something "vanished" from somewhere, and using that to imply that it has lost favour...

I referred to the exact title in the first part of the sentence; in the same sentence I referenced it again. Sorry for the confusion.

How ever one characterizes the Mann et al 1200 year temperature reconstruction, there is the observable point that it appeared right up front in the 2001 IPCC Summary for Policy Makers almost as an icon, with no medieval warming period, and then in the 2007 third IPCC report after the investigation it vanished from the Summary, was moved to the paleo section and merged in with several other reconstructions that show the medieval period as warm.

And yes I'd say it is fair to say that some of the key ideas reflected in the MBH 98 hockey stick, namely that there was little or no medieval warming period, has indeed lost favour; that this is reflected by its removal from the Summary for Policy Makers and its subsequent embedding in the graph in the Paleo section with several other competing studies that show a substantial medieval warming, comparable with today's warming.

 

[mheslep]

On this other point, I'm referring to this specific claim:

Iam aware of desert ecological communities, and sub antarctic communities that don't exist any more because of climate change

Could you cite one please (obviously one in the last 30 years to be associate w/ AWG)?

I know that from conversations with ecologists, I don't know where or if they have been published.

That's fine, but not appropriate for this forum.
https://www.physicsforums.com/showthread.php?t=280637

It's pretty common knowledge, and not at all controversial that ecosystems are being impacted by climate change, and neither that for ecosystems with smaller geographic ranges, (being the unique in especially interesting ones) that impact is more often extinction or increased risk of extinction...

Perhaps I misunderstood. By 'ecological communities' that 'dont exist anymore' do you mean a species extinction? I took that to mean human communities. This another good reason for cites - in addition to the data, they avoid ambiguity.

 

[Xnn]

The Medieval warm period was only warm in comparison to the 17th century cold.

See Box 6.4 on page 468 to 469 in the following link.

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf

The evidence currently available indicates that NH mean temperatures during medieval times (950–1100) were indeed warm in a 2-kyr context and even warmer in relation to the less sparse but still limited evidence of widespread average cool conditions in the 17th century (Osborn and Briff a, 2006). However, the evidence is not sufficient to support a conclusion that hemispheric mean temperatures were as warm, or the extent of warm regions as expansive, as those in the 20th century as a whole, during any period in medieval times (Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briff a, 2006).

So, the 20th century (1900 to 1999) was warmer than the MWP.

Also, notice the following conclusions:

Centennial-resolution palaeoclimatic records provide
evidence for regional and transient pre-industrial warm
periods over the last 10 kyr, but it is unlikely that any
of these commonly cited periods were globally synchronous.
Similarly, although individual decadal-resolution
interglacial palaeoclimatic records support the existence
of regional quasi-periodic climate variability, it is unlikely
that any of these regional signals were coherent at the
global scale, or are capable of explaining the majority of
global warming of the last 100 years.

• The TAR pointed to the ‘exceptional warmth of the late
20th century, relative to the past 1,000 years’. Subsequent
evidence has strengthened this conclusion. It is very likely
that average Northern Hemisphere temperatures during
the second half of the 20th century were higher than for
any other 50-year period in the last 500 years. It is also
likely that this 50-year period was the warmest Northern
Hemisphere period in the last 1.3 kyr, and that this
warmth was more widespread than during any other 50-
year period in the last 1.3 kyr. These conclusions are most
robust for summer in extratropical land areas, and for
more recent periods because of poor early data coverage.

 

[mheslep]

The Medieval warm period was only warm in comparison to the 17th century cold.

See Box 6.4 on page 468 to 469 in the following link.

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf

[my bold] Yes I've been all through it. I think you misread? Your first sentence directly contradicts the box:

The evidence currently available indicates that NH mean temperatures during medieval times (950–1100) were indeed warm in a 2-kyr context and even warmer in relation to the less sparse but still limited evidence of widespread average cool conditions in the 17th century (Osborn and Briff a, 2006).

One can not draw that conclusion from MBH 98, hence its disfavour.

 

[Xnn]

good point mheslep; "only warm" is overstating.

However, the MWP was not as warm as the 19th century, which some people would tend to consider as a baseline.

 

[Bored Wombat]

Google for 'Joanne nova' her handbook is very helpfull.

It looks like a reproduction of some debunked counterscientific fossil fuel pressure group propaganda.

In what was is it "very helpful"?

Off the top of my head, a brief response to her "only four points that matter" are:

1) The greenhouse signature is missing.

No it's not. The greenhouse signature, the cooling of the stratosphere and the exaggerated warming at the poles is unambiguous, measured and real.

The "hot spot" that you are mistaking for a greenhouse signature has nothing to do with the greenhouse effect. It occurs under any warming that causes the air to hold more water vapour, and is caused by the release of the latent heat of vaporisation of that water when it condenses as rising air cools.

2) The strongest evidence was the ice cores, but newer more detailed data turned the theory inside out.

No the strongest evidence is the physics of optics, by which we understand the greenhouse effect, and therefore know that increasing the concentration of greenhouse gasses will make it warmer.

A 600 or 800 year lag in temperature change over 5000 or 6000 years is an 80% co-incidence. The fact that greenhouse feedback drives the switch from a glaciation to interglacial, set of by milankovich cycles, is perfectly in line with all previous theory. The 10 or 12 K temperature change over that time was only ever about 2 or 3 K due to the 50% increase in CO2 that occurs over that time.

The current best estimates for the effect of doubling CO2 is about 3 or 4 K.

3) Temperatures are not rising.

No they're not.

"In a blind test, the AP gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented. The experts found no true temperature declines over time." http://news.yahoo.com/s/ap/20091026/ap_on_bi_ge/us_sci_global_cooling"

4) Carbon dioxide is doing almost all the warming it can do.

No. The current best estimates for the effect of doubling CO2 is about 3 or 4 K.

And that's the top four points.

So I'm at a loss as to what help we've got from them, especially on a physics board, where people probably have some basic scientific understanding.

 

[Bored Wombat]

I referred to the exact title in the first part of the sentence; in the same sentence I referenced it again. Sorry for the confusion.

Well, I'm big enough to accept the apology, but I still suspect that you were trying to overstate your case. If you use an abbreviation for a term you should use it when you first use the term. But in this case it would look better for full disclosure if you explicitly mentioned that it did appear in the technical summary. Or at least that the term "summary" wasn't a good description for the summary for policy makers, especially to an audience interested in physics, who would be more familiar with the other summary.

And yes I'd say it is fair to say that some of the key ideas reflected in the MBH 98 hockey stick, namely that there was little or no medieval warming period, has indeed lost favour;

Well other northern hemisphere reconstuctions can have a slight bump around 1000 AD, but certainly not all of them.

The consensus is that it is certainly not as pronounced as might have been suspected from early, one site based studies. And the suspicion is that this would be further ameliorated if the southern hemisphere were included.

But the National Academies review found nothing wrong with Mann et al's treatment of the data at that time. It was the very recent end that they found that the statistical mistreatment resulted in Mann et al. under-reporting the expected error.

In what way do you mean "fallen out of favour"? Probably we can agree that any medieval warm period was likely at least half a degree cooler than temperatures this decade if we are talking about global mean surface temperature?

that this is reflected by its removal from the Summary for Policy Makers and its subsequent embedding in the graph in the Paleo section with several other competing studies that show a substantial medieval warming, comparable with today's warming.

Disagree. It's removal from the report was because it wasn't new, and had been covered in the 2001 report.

It speaks volumes for the respect that it is still held in that it nevertheless occurred twice in a report that is supposed to be about the findings since the previous report.

 

[Bored Wombat]

Perhaps I misunderstood. By 'ecological communities' that 'dont exist anymore' do you mean a species extinction? I took that to mean human communities. This another good reason for cites - in addition to the data, they avoid ambiguity.

Population extinction of many species, sometimes including total extinction.

No, I wasn't talking about human communities. I don't even know what a sub antarctic human community might mean. And we're talking about global warming, not Godzilla.

I will endeavour to cite more, but I have spoken in the last few years to ecologists looking at Australian freshwater communities, Australian desert communities, European amphibians, and Australian wetlands affected by dry land salinity, and only the last one did not speak with grief of the destruction of their studied area.

And the devastation of various sub-Antarctic communities by invasion by temperate species is now, I am told, well represented in the scientific literature. The concern seems to be now that Antarctic communities may soon fall by the same mechanism.

 

[Bored Wombat]

[my bold] Yes I've been all through it. I think you misread? Your first sentence directly contradicts the box:
One can not draw that conclusion from MBH 98, hence its disfavour.

Please cite a source for this claimed "disfavour".

 

[Andre]

One can not draw that conclusion from MBH 98

Please cite a source for this claimed "disfavour".

The http://republicans.energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf

Overall, our committee believes that Mann’s assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year of the millennium cannot be supported by his analysis.

 

[Andre]

Population extinction of many species, sometimes including total extinction.

No, I wasn't talking about human communities. I don't even know what a sub antarctic human community might mean. And we're talking about global warming, not Godzilla.

I will endeavour to cite more, but I have spoken in the last few years to ecologists looking at Australian freshwater communities, Australian desert communities, European amphibians, and Australian wetlands affected by dry land salinity, and only the last one did not speak with grief of the destruction of their studied area.

And the devastation of various sub-Antarctic communities by invasion by temperate species is now, I am told, well represented in the scientific literature. The concern seems to be now that Antarctic communities may soon fall by the same mechanism.

Where is the peer reviewed source?

 

[Bored Wombat]

The http://republicans.energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf

The Wegman report raised some issues, and was certainly harsher than the more transparent and peer reviewed National Academies report.

It doesn't really stand for scientific opinion though. Do you have a peer reviewed source?

 

[Andre]

The Wegman report raised some issues, but and was certainly harsher than the more transparent and peer reviewed National Academies report.

What is your peer review resource to make that assessment?

 

[Bored Wombat]

Where is the peer reviewed source?

"The future problem these animals face is via displacement by alien species from lower latitudes. Such invasions are now well documented from sub-Antarctic sites." - http://www.frontiersinzoology.com/content/2/1/9" , Peck, Frontiers in Zoology 2005, 2:9 doi:10.1186/1742-9994-2-9

Perhaps for example: "Warming is likely to remove
physiological barriers on lithodid crabs that currently place a
limit on the invasion of shallow waters of the high Antarctic;
a scenario that is especially likely for waters oV the Antarctic
Peninsula" - http://epic.awi.de/Publications/Tha2008c.pdf"
Thatje et al, Polar Biol (2008) 31:1143–1148 DOI 10.1007/s00300-008-0457-5

(http://www.independent.co.uk/enviro...life-threatened-by-crab-invasion-782989.html", as the popular press put it)

http://www.telegraph.co.uk/science/science-news/3325543/Antarctic-seabed-ecosystems-invasion-threat.html" is another popular press write up, this time about a presentation at the AAAS conference in 2008:
"Unique Antarctic seabed ecosystems are under threat from invasions of species taking advantage of global warming, scientists have warned.

Predatory giant crabs, sharks and other fish are poised to make a return to the rapidly warming shallow waters around the South Pole for the first time in tens of millions of years.

Their come-back will disrupt the make-up of ancient communities of unusual animals such as sea spiders, brightly-coloured brittle stars, thin-shelled muscles and giant relatives of the woodlouse called isopods."

But, again, this is hardly controversial. The fact that species range changes is contributing to the 30% biodiversity drop over the past few decades is well marked in ecology.

 

[Bored Wombat]

What is your peer review resource to make that assessment?

It's not controversial that the National Academies Report's peer review process was transparent and the Wegman reports wasn't.

I have provided the news at nature's article that Mann et al. was vindicated. That is also what was reported in the popular press, and it was also the response of scientists. It is you who are making the controversial claims that needs peer reviewed support.

 

[mheslep]

Well, I'm big enough to accept the apology, but I still suspect that you were trying to overstate your case.

Im little interested in what you suspect about me.

If you use an abbreviation for a term you should use it when you first use the term. But in this case it would look better for full disclosure if you explicitly mentioned that it did appear in the technical summary. Or at least that the term "summary" wasn't a good description for the summary for policy makers, especially to an audience interested in physics, who would be more familiar with the other summary. Well other northern hemisphere reconstuctions can have a slight bump around 1000 AD, but certainly not all of them.

[...]

The consensus is that it is certainly not as pronounced as might have been suspected from early, one site based studies. And the suspicion is that this would be further ameliorated if the southern hemisphere were included.

But the National Academies review found nothing wrong with Mann et al's treatment of the data at that time. It was the very recent end that they found that the statistical mistreatment resulted in Mann et al. under-reporting the expected error.

In what way do you mean "fallen out of favour"? Probably we can agree that any medieval warm period was likely at least half a degree cooler than temperatures this decade if we are talking about global mean surface temperature?
Disagree. It's removal from the report was because it wasn't new, and had been covered in the 2001 report.

It speaks volumes for the respect that it is still held in that it nevertheless occurred twice in a report that is supposed to be about the findings since the previous report.

By disfavour I only refer to MBH 98/Mann99, not any broader topic in AGW, or paleo reconstruction. Perhaps I should say instead that it has been updated in 2007 w/ reconstructions considered more accurate? Anyway I see Vanesch has spoken more clearly here on the subject.
https://www.physicsforums.com/showpost.php?p=1926328&postcount=11

 

[mheslep]

The http://republicans.energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf

Thanks Andre, though I think the National Academies report itself, when read in detail also does a good job of pointing out limitations.
Edit: In particular, I mean what the Academy has to say about:

...the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium.

from

• Mann, M.E and Bradley, R.S. (1999), Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations, in Geophysical Research Letters, Vol. 26, No. 6, p.759

...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.

from

• Surface Temperature Reconstructions for the Last 2,000 Years, Report in Brief, The National Academies, June 22, 2006

http://dels.nas.edu/dels/rpt_briefs/Surface_Temps_final.pdf

 

[Andre]

It's not controversial that the National Academies Report's peer review process was transparent and the Wegman reports wasn't.

I have provided the news at nature's article that Mann et al. was vindicated. That is also what was reported in the popular press, and it was also the response of scientists. It is you who are making the controversial claims that needs peer reviewed support.

Really amazing, anyway, apparently the transcripts to the senate hearings of Oliver North seem to have disappeared; however his exact answer in testimony was recorded on numerous places, -when asked if he disputed the methodology conclusions of Wegman's report- he said:

No, we don’t. We don’t disagree with their criticism

 

[Monique]

The http://republicans.energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf

This is a link to policy makers, but not to the real science. We all know political parties are colored, that's why there's an objection to the source.

 

[Andre]

It would be nice if examples can be given in the Wegman report to demonstrate that the sciencific conclusion is not supported by rigid unbiased reproduceable science especially when the NAS committee agreed with that conclusion as I showed in my previous post.

 

[Andre]

Anyway, let's do a quick recap. So here was the hockeystick in the Third Asssesment report of the IPCC of Mann Bradley and Hughes form 1999 (MBH99) which showed a flat temperature from 1000 Bc up intil about 1850 AD with suddenly rising temperatures. McIntyre and McKitrick demonstrated that MBH had used improper statistic methodologies.

So it was asked to the NAS and to http://www.galaxy.gmu.edu/stats/faculty/wegman.html to verify the critisism of McIntyre and McKitrick. Wegman confirmed that. The NAS with Oliver North in the chair had a more subtle approach. They had misgivings about the procedures of MBH but it would not matter because they stated that other research came to similar conclusions.

So in this thread it is now assumed that Wegman wrote something politcal (which seems to be threated here as biased/spin/fraud) while it also is assumed that the NAS endorsed MBH99. They did not. Because in the hearings of the Committee on Energy and Commerce of the House of Representatives, these were some of the statements of members of the NAS:

CHAIRMAN BARTON. I understand that. It looks like my time
is expired, so I want to ask one more question. Dr. North, do you
dispute the conclusions or the methodology of Dr. Wegman's report?
DR. NORTH. No, we don't. We don't disagree with their
criticism. In fact, pretty much the same thing is said in our
report. But again, just because the claims are made, doesn't
mean they are false.
CHAIRMAN BARTON. I understand that you can have the right
conclusion and that it not be--
DR. NORTH. It happens all the time in science.
CHAIRMAN BARTON. Yes, and not be substantiated by what you
purport to be the facts but have we established--we know that
Dr. Wegman has said that Dr. Mann's methodology is incorrect. Do
you agree with that? I mean, it doesn't mean Dr. Mann's
conclusions are wrong, but we can stipulate now that we have--and if
you want to ask your statistician expert from North Carolina that
Dr. Mann's methodology cannot be documented and cannot be verified
by independent review.
DR. NORTH. Do you mind if he speaks?
CHAIRMAN BARTON. Yes, if he would like to come to the
microphone.
MR. BLOOMFIELD. Thank you. Yes, Peter Bloomfield. Our
committee reviewed the methodology used by Dr. Mann and his coworkers
and we felt that some of the choices they made were inappropriate.
We had much the same misgivings about his work that was documented
at much greater length by Dr. Wegman.

Now what to say about the discussion/allegations in this thread? like:

It's not controversial that the National Academies Report's peer review process was transparent and the Wegman reports wasn't.

I have provided the news at nature's article that Mann et al. was vindicated. That is also what was reported in the popular press, and it was also the response of scientists. It is you who are making the controversial claims that needs peer reviewed support.

I leave the conclusions to the readers.

 

[mheslep]

This is a link to policy makers, but not to the real science. We all know political parties are colored, that's why there's an objection to the source.

Edit:
The Wegman report in this link happens to be hosted on a policy maker's website.
Wegman is a scientific report, non-peer reviewed unless one counts the publicly documented statements on Wegman by the authors of the National Academies North report. On the other hand, the Nature News report post https://www.physicsforums.com/showpost.php?p=2419819&postcount=58" up thread on the subject is not peer reviewed material either.

 

[Xnn]

Of course science marches on and these past reports and reconstructions did not have the following available:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

https://www.physicsforums.com/attachment.php?attachmentid=21606&stc=1&d=1257469597

From the above perspective, it appears that the MWP (950 to 1100) was only minor warming period superimposed on a 1900 year cooling trend that was distinctly interrupted around 1900.

 

[Xnn]

Notice, that now we can say the following authority:

Arctic temperatures in the 1990s reached their warmest level of any decade in at least 2,000 years, new research indicates.

and it has nothing to do with tree rings or Michael Mann.

 

[Bored Wombat]

Im little interested in what you suspect about me.

You miss the point if you think I was discussing our personal relationship.

MBH 99 appeared in what most people here would consider the summary of the IPCC 2007 WG1 report.

By using the term "Summary" to refer to the SPM, you misrepresent the respect in which MBH is held.

By disfavour I only refer to MBH 98/Mann99, not any broader topic in AGW, or paleo reconstruction. Perhaps I should say instead that it has been updated in 2007 w/ reconstructions considered more accurate? Anyway I see Vanesch has spoken more clearly here on the subject.
https://www.physicsforums.com/showpost.php?p=1926328&postcount=11

I certainly agree that there is more data out there now, and that that increased the confidence that we have in these reconstructions. And that the more modern ones have had a many more datasets included in the analysis, and this also increases confidence in the results.

But MBH 1999 is not an outlier amongst reconstructions, and certainly the current view is nearer the MBH view than the pre-MBH view. So I don't think that it has fallen into any "disfavour".

 

[Bored Wombat]

...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.

from

* Surface Temperature Reconstructions for the Last 2,000 Years, Report in Brief, The National Academies, June 22, 2006

Less confidence than the confidence that we have that the "Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium."

That's a fairly complete vindication of MBH, which has the average for the 20th century to be within the error bars on the temperature reconstruction for most of the time prior to about 1600.
http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg"

So, despite the phrase "even less confidence" this is exactly in line with the findings of the MBH 99 paper, for someone who has understood the error analysis in MBH 99.

 

[Bored Wombat]

It would be nice if examples can be given in the Wegman report to demonstrate that the sciencific conclusion is not supported by rigid unbiased reproduceable science especially when the NAS committee agreed with that conclusion as I showed in my previous post.

No the NA report found the same methodological flaws.

They, however, found that the conclusions were largely sound. Partly because the flaws did not affect the shape of the reconstruction, but only lead to an understating of the errors. And partly because those conclusions were supported by later work.

 

[Bored Wombat]

Edit:
The Wegman report in this link happens to be hosted on a policy maker's website.
Wegman is a scientific report, non-peer reviewed unless one counts the publicly documented statements on Wegman by the authors of the National Academies North report. On the other hand, the Nature News report post https://www.physicsforums.com/showpost.php?p=2419819&postcount=58" up thread on the subject is not peer reviewed material either.

The news at nature is not controversial.

It noted that the NA report found that there were methodological errors, but that these were not material, and it criticised the way the report was used.

But the claims from outside the scientific field were that the whole shape of the hockey stick was due to incorrect methodology, and this was shown not to be the case.

The Wegman report didn't focus so much on the fact that the methodological problems didn't make any material difference, and spent several pages looking at who in the field has published papers with each other ... Which I think is difficult to justify in the absence of any analysis as to what difference this makes to scientific publishing nor the peer review process.

Claiming that Mann et al is in a state of "disfavour" is controversial, because its findings have been nearly completely vindicated. So you need to provide a peer reviewed source to back that up. The Wegman report doesn't establish that "disfavour", certainly not amongst the scientific community. (About whom I assume we are talking about. Certainly there is disfavour from the aforementioned Jo Nova dot com, and other semi-professional science deniers.)

Does the IPCC 2007 report, which reproduces Mann et al 1999 twice, mention anything about its results being questionable?

 

[Bored Wombat]

Of course science marches on and these past reports and reconstructions did not have the following available:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

https://www.physicsforums.com/attachment.php?attachmentid=21606&stc=1&d=1257469597

From the above perspective, it appears that the MWP (950 to 1100) was only minor warming period superimposed on a 1900 year cooling trend that was distinctly interrupted around 1900.

Yes. Global warming is exaggerated at the poles, because CO2 overlaps with H2O, and there's not much atmospheric H2O concentration at the poles.

This gives more evidence that the warming is a greenhouse warming, but it is a little unfair to compare it with temperature reconstructions for the whole hemisphere, because it is stronger than the warming for the whole hemisphere.

 

[Xnn]

Yes. Global warming is exaggerated at the poles, because CO2 overlaps with H2O, and there's not much atmospheric H2O concentration at the poles.

This gives more evidence that the warming is a greenhouse warming, but it is a little unfair to compare it with temperature reconstructions for the whole hemisphere, because it is stronger than the warming for the whole hemisphere.

I agree. However, the reconstructions and analysis that have been done in the past did not have this new source of information available. It's not dependant on tree rings or Michael Mann. So, if a reconstruction of NH temperature history were to be constructed today, it should include this new data, which shows the MWP in an entirely different perspective.

For example, the period 950 to 1100 was not the warmest period prior to 1900 within the Arctic and we can say that the 1990's appear to be the warmest decade for the Arctic over the last 2000.

 

[mheslep]

The news at nature is not controversial.

Yes, it can be as it's news, but that matters not. It is not an peered reviewed source.

It noted that the NA report found that there were methodological errors, but that these were not material, and it criticised the way the report was used.

The mistakes were as I detailed https://www.physicsforums.com/showpost.php?p=2426834&postcount=81", which state that Mann deserves little "confidence" beyond 400 years (their word, not mine). I'd appreciate it if we stick to direct quotes from the sources (Mann and NA), and not other summaries.

But the claims from outside the scientific field were that the whole shape of the hockey stick was due to incorrect methodology, and this was shown not to be the case.

Not interested in claims from non scientific sources for discussion here, hopefully we can dispense with reference to those as well.

Claiming that Mann et al is in a state of "disfavour" is controversial,

Disfavour was a poor word choice on my part, as it smacks of a reliance on some community somewhere. I corrected it above.

because its findings have been nearly completely vindicated.

There's no room for 'completely' in that sentence regarding Mann 99, given the actual source material presented in this thread.

...So you need to provide a peer reviewed source to back that up. The Wegman report doesn't establish that "disfavour", certainly not amongst the scientific community.

As has been discussed in this forum, it's not useful to try and speak for the sentiment of the scientific community. Argument based on the sources is the way to go.

 

[mheslep]

But MBH 1999 is not an outlier amongst reconstructions, and certainly the current view is nearer the MBH view than the pre-MBH view. So I don't think that it has fallen into any "disfavour".

We mean here Mann et al 1999, the millennial reconstruction covering the MWP and featured in the Summary For Policy Makers 2001, not MBH 98's 400 year reconstruction. And yes I think Mann et al 1999 deserves little "confidence" further back than 400 years as the NA report states, and yes I think there's a significant difference between what Mann et al shows around 1000AD, basically showing no MWP to my eye, and what is said in the IPCC 2007

mean temperatures during medieval times (950–1100) were indeed warm in a 2-kyr context

Based on this, other reconstructions shown in IPCC 2007, and my glance at http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg" , I qualitatively call Mann 1999 wrong about the MWP.

 

[mheslep]

Of course science marches on and these past reports and reconstructions did not have the following available:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

https://www.physicsforums.com/attachment.php?attachmentid=21606&stc=1&d=1257469597

From the above perspective, it appears that the MWP (950 to 1100) was only minor warming period superimposed on a 1900 year cooling trend that was distinctly interrupted around 1900.

The actual paper and abstract:

• Kaufman, D.S. et al, 2009. Recent Warming Reverses Long-Term Arctic Cooling, Science 4 September 2009, Vol. 325. no. 5945, pp. 1236 - 1239. DOI: 10.1126/science.1173983

Abstract:

The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000.

http://www.sciencemag.org/cgi/content/abstract/325/5945/1236

I wonder what type of proxies are available at those latitudes. Reading to come.

 

[Bored Wombat]

I agree. However, the reconstructions and analysis that have been done in the past did not have this new source of information available. It's not dependant on tree rings or Michael Mann. So, if a reconstruction of NH temperature history were to be constructed today, it should include this new data, which shows the MWP in an entirely different perspective.

For example, the period 950 to 1100 was not the warmest period prior to 1900 within the Arctic and we can say that the 1990's appear to be the warmest decade for the Arctic over the last 2000.

Good point.

 

[Bored Wombat]

Yes, it can be as it's news, but that matters not. It is not an peered reviewed source.

I’m not saying that news can’t be controversial; I’m saying that in this particular case isn’t controversial.

The NA report was a vindication of Mann et al. The only people saying otherwise are not only not peer reviewed, they’re on website’s whose editorial position is explicitly counterscientific.

The mistakes were as I detailed https://www.physicsforums.com/showpost.php?p=2426834&postcount=81", which state that Mann deserves little "confidence" beyond 400 years (their word, not mine). I'd appreciate it if we stick to direct quotes from the sources (Mann and NA), and not other summaries.

They do not state that Mann deserves little confidence.

They state that less confidence can be placed in the statement that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” than the statement that “the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium.”

The previous paragraph talks more specifically about Mann et al: “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 the additional large-scale surface temperature reconstructions and documentation of the spatial coherence of recent warming described above (Cook et al. 2004, Moberg et al. 2005b, Rutherford et al. 2005, D’Arrigo et al. 2006, Osborn and Briffa 2006, Wahl and Ammann in press) and also the pronounced changes in a variety of local proxy indicators described in previous chapters (e.g., Thompson et al. in press).”

As I have pointed out already, the error bars in Mann et al 1999 also show that there is not strong confidence in the conclusion that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium”. So again the NA report, is in full agreement with Mann et al on that point.

This is why those secondary sources are all explaining that the NA report backed the hockey stick graph. Now they are not peer reviewed, but neither is your own opinion that they said “that Mann deserves little "confidence" beyond 400 years”. You're misreading the report to get that, you're taking the paragraph about "confidence" isolated, out of context, and claiming it refers to Mann et al (1999) in general. In this case respected secondary sources such as news at nature can be useful, because they make it clear that your analysis is an outlier.

 

[Bored Wombat]

http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg" , I qualitatively call Mann 1999 wrong about the MWP.

It agrees within the error with other reconstructions.

So it's right.