Wednesday, October 28, 2009

Briffa, Mark II: McIntyre Used Biased Sample

I think Steve has backed away from most of his accusations re the Yamal tree-ring chronology here, or had them convincingly refuted. Nevertheless, Briffa and several co-authors have decided to make a more thorough response to his various blog posts on the matter. From their abstract:

McIntyre's use of the data from a single, more spatially restricted site, to represent recent tree growth over the wider region, and his exclusion of the data from the other available sites, likely represents a biased reconstruction of tree growth. McIntyre's sensitivity analysis has little implication, either for the interpretation of the Yamal chronology or for other proxy studies that make use of it.

From their conclusion:

So what can we conclude on the basis of this and McIntyre's sensitivity tests? Does either version of the Yamal chronology as presented in Briffa (2000) and Briffa et al. (2008) present a misleading indication of the likely history of tree-growth changes near the tree line in the Yamal region over the last two millennia, or can McIntyre's 'sensitivity analysis' be taken as evidence that tree growth has not increased in this region in the second half of the 20th century as is clearly implied by the 'extreme' version of the Yamal chronology he produced? On the basis of the evidence we report here, the answer is very likely 'NO' on both counts."

McIntyre states "If the non-robustness observed here prove out .. this will have an important impact on many multiproxy studies ...". We have shown here that the "KHAD only" example constructed by McIntyre itself represents a biased chronology, contradicted by the evidence of other chronologies constructed using additional and more representative site data. The evidence does not support a conclusion that our previous work was in any way seriously flawed. The last 8 years of our chronology ARE based on data from a decreasing number of sites and trees and this smaller available sample does emphasise the faster growing trees, so this section of the chronology should be used cautiously. The reworked chronology, based on all of the currently available data is similar to our previously published versions of the Yamal chronology demonstrating that our earlier work presents a defensible and reasonable indication of tree growth changes during the 20th century, and in the context of long-term changes reconstructed over the last two millennia in the vicinity of the larch treeline in southern Yamal.

All that is really left now is for McIntyre, and Pielke Jr., to apologize.

32 comments:

John Cross said...

Very interesting post. I see that Briffa is going to write it up as a journal submission as well as provide a version on his site. The least remarked thing about this kerfuffle is how publishing has changed.

A very minor point - your link after "From their conclusions" does not work.

Thanks for keeping on top of this.

Best,
John

bigcitylib said...

Works now.

Unfortunate though that Briffa et al would have to waste extra time over this. It really just covers old ground again and is driven more by the accusations Mc kicked up than anything useful in his analysis.

Mark Francis said...

..and this won't shut up a single denialist. But, hey, we gave up on those liars a long time ago.

Rob Harvie said...

I was listening to Rex Murphy this morning, and what struck me, we his sharing of my feelings that there is a certain, uh, "religious" element to the climate debate which seems pretty unhealthy.. starting with the assertion of a POLITICIAN, Al Gore, that "scientific debate is closed".

Imagine that assertion. What ever side of the debate you are one, that has to frighten true scientists.

I think this is part of the problem of the ACC crowd.. the over-stating of their position, which leads to a knee-jerk by those who have questions.

How about simply, "most scientists have accepted the fundamental theory of man-made climate change?"

I'm pretty much bored by the whole argument between Briffa and his detractors.. because, it really establishes nothing of susbtance on either side of the debate anyway.

Let's get beyond the argument, and accept that there is at least "potential" merit to climate change. No one can seriously argue against that, IMHO.

And let's then talk about:

a) a reasoned discussion regarding the range of possible outcomes, good and bad, and a legitimate discussion of the range of responses - which isn't simply hinged on some dim-witted attempt at income redistribution a la Kyoto;

b) some immediate effort, even if it's modest, to change our reliance upon oil and coal as the be-all-and-end-all - not simply for reasons of climate change, but also for reasons of other pollutants hazardous to our welfare, and for reasons of global security;

c) reduced "debate", and increased "discussion" generally to find commonality between the camps, as opposed to an insistent concentration on the differences..

ie) "denialists", "liars".

Why not use the terms that you really, deep down, waht to use MF.. "blasphemers" and "heretics".

bigcitylib said...

Rob,

The scientific debate is closed. HIV causes AIDS. Does that one frighten you? How about: the scientific debate is closed: Earth orbits the Sun and not vice versa. I know of very few scientists who are frightened of that one.

Ti-Guy said...

I'm pretty much bored by the whole argument between Briffa and his detractors.. because, it really establishes nothing of susbtance on either side of the debate anyway.

You're bored, therefore the discussion has to be about what you decide it will be.

That's pretty bossy, Rob.

Rob Harvie said...

Really BCL? You see the climate change issue as a scientific equivalency to the earth orbits the sun?

Go ahead, read the materials again - Climate theory is based upon models. It's based upon analysis of historical carbon data. It's not based upon scientific certainty, even by the most argent scientic advocates. It is a "theory" supported by evidence.

But so what? My point is, as a conservative, I approach my own constituency and say, "how about at least conceding it's POSSIBLE that man-made climate change is occurring. Would you believe it is responsibile to do NOTHING?

On the other hand, if we make it a debate between "camps" and it's an "us" v. "them" proposition, you limit discussion of commonality and possible movemement forward, even if it is incremental, and you just have a battle of egos.

That's what I mean by tedious. I think people like Suzuki would be better of not attacking the "heretics" and try to engage them and say, "what if you're wrong?" And say, maybe a little progress is a good start.

Right now it's this stupid all or nothing - and in this economic climate, it's closer to nothing. If you engage both sides, while the lowest common denominator may not appease the "True Believers", you know, the yellers and screamers who disrupt parliament to no good purpose - it will result in real change as opposed to continued argument.

Ti-Guy said...

Go ahead, read the materials again...

What are some of the materials you've read, Rob, beside blog posts?

FrankD said...

They would like you to think the debate is over Rob because what they are planning for in Copenhagen will leave Kyoto in the dust.

Lord Monckton has this take on Copenhagen. A thinly veiled attack on democracy and national sovereignty by the UN supported by the socialist EU, third world countries, wrapped up with a massive wealth transfer scheme. Well duh! Didn't he read Kyoto. Nothing new here. Except Copenhagen, he believes, might have some teeth to it.

I think his concerns are a bit overblown. For one, notwithstanding The Obamessiah the US Senate will never ratify rendering the thing DOA. The Brits mired in recession, an MP "expenses row" and never ending succession of new 'green taxes' have about had it with 'New World Order' Gordon Brown and Nu Labour. Some of the UN types are conceding their wont be a new treaty from Copenhagen. The developed world is starting to wake up to the scam that is AGW. The worm has turned and the warmers are now the deniers.

Here is Lord Monckton on the Copenhagen scam. Enjoy.

bigcitylib said...

"Climate theory is based upon models. It's based upon analysis of historical carbon data. It's not based upon scientific certainty..."

It is based on the work done by Fourier on heat transfer almost 200years ago.

Holly Stick said...

Rob doesn't read, he just listens to that old blowhard Murphy. Then he complains that Gore is not a scientist.

FrankD prefers his old blowhards to be British.

John Cross said...

Rob: the idea of AGW does not depend on climate models. It depends on radiation physics and if you wish to dispute AGW on the basis that a lot of people seem (i.e. adding CO2 won't cause a warming) then you need to rewrite a great deal of quantum physics. So yes, I would say that - in the broad sense at least - it is as firmly established as the earth orbiting the sun.

Are there details that we are unsure of - absolutely! Some of them are fairly significant (e.g. exactly how much water feedback will we get, what is the accuracy of the CO2 prediction, etc). And that is where the real discussion should be.

But we still have a number of people who repeat the mantra:

1) We are not causing all the rise in CO2

2) If we are causing the rise it won't harm us.

3) If it will harm us it will be more expensive to do something.

And so on.

If people presented rational arguments, they would be treated as rational.

Regards,
John

John Cross said...

Frank D: and for your enjoyment, here is my review of an interview that Lord Monckton gave when he was in Canada.

Regards,
John

lenny said...

Right Rob, the people on the side who point to the scientific literature and the vast majority of scientists are "religious".
The right-wing christians and assorted other nuts and vested-interests who'll believe anything and anyone who tells them AGW is a "hoax" (as Yamal once again demonstrates) are "skeptics".


"And let's then talk about:

a) a reasoned discussion regarding the range of possible outcomes, good and bad, and a legitimate discussion ..."

Are you joking, or are you really that ignorant?
Why don't spend some time educating yourself instead of wasting it lecturing on topics you don't have the first-fucking-clue about?

Rob Harvie said...

Ok. You all win. You are smart, and I am stupid.

Now go have fun watching the Maldives disappear as you're patting yourselves on the back that you didn't need to enter into a discussion with those "inferior" to you.

How's that "greenshift" program going by the way?

lenny said...

Frank,
Here's my favourite Monckton story.

Just one of the lunatics that credulous idiots like you and Rob think rational people should have "reasoned discussions" with.

lenny said...

Shorter Rob:

A real consensus can only happen when we find the middle ground between what the science says, and what I believe.

FrankD said...

Rob, most warmers couldn't stand a real debate. You can't debate a religion, it's a belief. So they just dismiss any and all dissenting views as kooks, oil lobbyists etc. If you like, here is the full 90 minute St. Paul, Mn presentation by Lord Monckton. Watch the Lord eviscerate Al Gore, the IPCC and its cherry picked, data manipulated, pseudo science.

Monckton has repeatedly offered to debate Al Gore anytime anywhere. But Gore is nothing more than a script reading front man for the warming religion and is heavily conflicted with his personal investments in carbon trading schemes. Don't look for that debate anytime soon.

Ti-Guy said...

Shut up, FrankDenier.

It's funny...on another blog, Rob is screaming about how the health care system is headed for disaster and yet is dismissing the science used to predict future events with respect to the climate.

In what grade did you drop math, Rob?

Ti-Guy said...

Here's my favourite Monckton story.

I just don't get it. Don't the deniers ever wonder that if their champions lie so blithely about simple matters of fact like this, that there's absolutely nothing stopping them from lying about small details that are nearly impossible to verify?

I suspect they do, but, as usual, just don't care.

lenny said...

Shorter Frank:

Sure, Monckton has a history of lying, has no scientific training whatsoever and can't get any of his claims published in the literature, but I believe him because I'm a "skeptic".

Rob Harvie said...

You are such a bunch of ignorant bigots, it's laughable that you deride others for being "narrow minded".

Are the "converted" truly that ignorant? I understand TG's limitations (yes, health care in Canada is perfect, there are no waiting lists and everyone who wants a family doctor in Toronto has one).. but is it really better to stick to your own understanding that to make REASONABLE effort to communicate with those who happen to not agree with you?

My earlier post was not completely in jest. If we believe the worst of the predictions on climate change, as you people are busy patting yourselves on the back - the Maldives could disappear. Literally.

Because, apparently, there is only one way to respond to the climate change issue and that is to assure complete and total acceptance of your point of view. And if the price in that insistence is that nothing constructive gets done - well, you would prefer that to modest and certain progress.

This is Stephane Dion in a microcosm. He was convinced of his "rightness" on this point, and put it to the electorate - and got thrashed.

Now the Liberals cry in their beer, about how "stupid" everyone was who supported Harper, but, the reality is that it's Harper in power and not Dion.

Think about THAT.

And think about THIS - if you, and those like you who refuse to make any effort to reach out to the great unwashed masses, get your asses kicked again, and Harper ends up with a majority.. well, you can again feel very smug that you were right.

It's like you have a Conservative who is trying to get other conservatives to soften their position on the climate issue - and rather than, apparently, show weakness, you attack and diminish the effort.

I'm sure the citizens of the Maldives will be raising a plaque(or perhaps submerging a plaque) in honor of the great brain trusts who were "right", but, in the end, got nothing done because they didn't have the simplest clue how to engage those who didn't agree with them.

Ti-Guy said...

yes, health care in Canada is perfect, there are no waiting lists and everyone who wants a family doctor in Toronto has one)

Nice strawman, counsellor.

I refuse to take seriously people who are minimally informed or entirely ignorant of the subject about which they have, nonetheless (and mystifyingly) strong opinions.

Why would anyone?

Ti-Guy said...

Sure, Monckton has a history of lying, has no scientific training whatsoever and can't get any of his claims published in the literature, but I believe him because I'm a "skeptic".

Up is down with these people.

Ironically, they provide me with a weird kind of heuristic that enables me to make a lot of decisions quickly: whatever they recommend, do the opposite. It's marvellous how well that's worked since 9/11.

John Cross said...

FrankD: I pointed out specific errors in what he presented and detailed why they were in error. Can you find anything wrong with my analysis?

However for the record, I am willing to debate Lord Monckton anytime.

Regards,
John

Holly Stick said...

Rob "..It's like you have a Conservative who is trying to get other conservatives to soften their position on the climate issue - and rather than, apparently, show weakness, you attack and diminish the effort..."

So get your ass over to the Conservative blogs and try to educate them. If you make an honest effort they will probably burn you at the stake, but that's rightwing conservatives for you.

Ti-Guy said...

So get your ass over to the Conservative blogs and try to educate them...

That'll never happen. He's scared to death of them. You should see how his fellow Albertans tore a strip off of him when he criticised the Wild Rose thing-a-ma-whatsit.

lenny said...

Shorter Rob Harvie:

It'll be your fault if the sea swallows the Maldives because you were mean to me!
Also, if we want to get anything done we have to find the "middle ground" between science and anti-science.

Rob Harvie said...

Read todays post.

Tories 40
Liberals 26
NDP 15

..at some point, only a sociopath refuses to ask, "maybe it's me".

Ti-Guy said...

..at some point, only a sociopath refuses to ask, "maybe it's me".

Sure Rob. Insisting that someone else be reasonably informed about something when they have strong opinions about it is the hallmark of a sociopath.

Tell me: What do you believe that 40% of decided voters translates to in terms of actual voters? Probably not much more than the 22% of the eligible electorate who voted Conservative in the last election. Given that a margin of Canadians have various personality disorders and given...beyond a shadow of a doubt...that most right wingers are lunatics, it really isn't "just me." Not by a long shot.

lenny said...

Longer Rob Harvie:

40% of voters in a poll support the Conservatives and 41% support the Liberals or NDP, thus disproving AGW.
And this is but the latest triumph of Pollscience which has also proven that Saddam was responsible for 9/11, falsified the Theory of Evolution, and proven that Celine Dion and Garth Brooks are two of the greatest musicians of all time.

Ti-Guy said...

Rob's not reading anymore. We were too mean to him, thus providing more evidence that AGW is a hoax.