Paying Attention to the History of Climate Change
One of the unfortunate consequences of the hyperbolic, circumscribed climate change discourse (It’s all hoax, No it’s not!) is that we don’t pay enough attention to the climate change that did happen in prehistory, specifically the mega-droughts that combined with other factors to cripple ancient empires.
These are complicated stories that are still being puzzled out by scientists, as I discuss in this longish piece at the Yale Forum on Climate Change & the Media. But I think these stories and the evidence of prehistoric drought are becoming clear enough for us to draw lessons from. Have a read and let me know over there what you think.
UPDATE: Via John Fleck, I see there’s an important new study on medieval megadroughts that adds to a robust body of literature.
As a paid subscriber, can I just say more like this, please? 😉
Given your interest in the intersection of climate politics and religulousness , you might find this article of interest.
Tom,
Well, I am going to give an update on my situation later this week, but regardless of what happens to Collide-a-Scape, faithful readers can still look forward to a weekly column at the other place. It was christened a while back (not by me) Kloor’s Korner (they never asked if I was a Mets or Yankees fan).
These weekly columns will be be topical, somewhat reported (meaning, I’ll interview various experts, scientists, etc) and draw on new and existing scholarship.
They will appear every Tuesday or Wed and I’ll always flag them at this site.
“we don’t pay enough attention to the climate change that did happen in prehistory, specifically the mega-droughts that combined with other factors to cripple ancient empires.”
That’s because we did not drive SUvs back then so we can’t take the blame. There is no reason to conduct a climate study on this, you won’t get the results you were paid to get.
Green Sahara, or at least Sahel, is thought to return:
http://hal.archives-ouvertes.fr/docs/00/46/35/73/PDF/Fontaine_et_al_ASL_2010.pdf
And considering your interest in “religulousness” (thanks MJ), alt-med believers, and Judith Curry, I’m surprised you haven’t discussed one of Judith’s recent posts:
http://judithcurry.com/2012/01/02/on-the-dangerous-naivete-of-uncritical-acceptance-of-scientific-consensus/
Apparently, scientists have been just as mean to climate contrarians as they have been to IDers and “Thought Field Therapy®” proponents 🙂
Fun fact: the few claims in that rant that I bothered to check turned out to be false. Semelweiss was fired for political reason, against the support of his colleagues. Sternberg did not “allow” peer-review, he bypassed it. And so on.
I’m surprised Andrew Wakefield and Peter Duesberg were not mentioned.
Toto,
Did you run away from Almira. Again.
Bad dog. Bad dog.
Climate history is one of the main reasons I am a skeptic. My experience has been that when I talk about mega droughts of multi-decade duration, believers have blank stares of surprise or…denial.
The implication of AGW is that things were great and stable pre-industry. That is a tremendous disservice to the entire discussion. And the discussion has not been controlled by skeptics.
First, I’m with hunter on this. My doubts about the AGW story were initially based on my knowledge of climate history. So, needless to say, I choked on the hokey schtick.
The more we look back at that the better.
Second, given the hysterical talk these days about ‘unprecedented’ and ‘permanent’ droughts in Texas of late, there’s no need to even delve into ancient history to know that that is ridiculous.
The link below leads to a composite video of the monthly Palmer Drought Index in the US for the past century plus. A rather amazing moving picture of climate change as expressed by drought, or lack of it, that is well worth the two or so minutes it takes to watch it.
http://www.real-science.com/droughts-happen
hunter,
Who are these people who aren’t aware that there have been severe long-lasting droughts in the past? From my experience of “warmist” blogs it’s well known amongst those who are reasonably knowlegable about the scientific arguments for AGW and it in no way contradicts the arguments for AGW being a serious threat. See http://onlinelibrary.wiley.com/doi/10.1002/wcc.81/full.
You may well have seen people claim that global temperatures have been relatively stable over the last 8k years or so, because as far as we can tell this is true and it’s a reasonable point to make, but this does not mean there have not been extreme events in particular locations. The question is whether extreme events are likely to be more common or more severe in a warmer world. AGW certainly does not imply that they did not take place in the past, if you think that then the problem is your (mis)understanding of the arguments for AGW.
You may well have seen people claim that global temperatures have been relatively stable over the last 8k years or so
Not exactly. The claim is that current temps and rate of rise are unprecedented. It’s a dubious claim.
question is whether extreme events are likely to be more common or more severe in a warmer world.
That is but one of the questions, and as far as we can tell they aren’t.
The real question is this: what is the cost/risk of AGW compared to the cost/risk of decarbonization.
aa,
No offense but you are one of those ignoring history every time you repeat some aspect of the climate catastrophe dogma of AGW.
In no way is it meaningful to claim that climate has been stable over 8k years or so. That is simply a false claim.
maybe we dont come here to read you keith
maybe we come here to fight with each other
and hope that you announce us as the winner
because we like how you write.
kdk33
Not exactly. The claim is that current temps and rate of rise are unprecedented. It’s a dubious claim.
That depends on what period of time is being referred to.
That is but one of the questions, and as far as we can tell they aren’t.
Well you might think that, I disagree. But either way the fact that there have been severe droughts in the past does not mean that there will not be worse problems in future.
The real question is this: what is the cost/risk of AGW compared to the cost/risk of decarbonization.
I agree that this is an essential question. But to answer it it is also neccessary to try to answer the question I posed.
hunter,
I’m not ignoring anything. I have no trouble with reconciling my concern for the effects of AGW with my knowledge of severe climate events which have occurred in the past. Nor do the many people who share my concerns and also have a lot more knowledge of the subject than I do.
aa,
If you and your circle of believers are up to date on weather extremes, you would be offended at the continuous hype from Hansen down to local science reporters falsely claiming this or taht weather event is unprecedented.
I think the use of the word “unprecedented”, unless a particular timeframe is mentioned (or this is clear from the context) should be avoided. If you look back far enough in the earth’s history you will no doubt find examples of any kind of extreme event which will exceed anything we are likely to see now or in the near future, even if the most dire predicted consequences of AGW come to pass.
So I’m happy to criticise where the word is used inappropriately, as long as you don’t pretend that because extreme events are not “unprecedented” we should not be concerned about them.
I already knew something about the history of climate change which is why I became a serious student of AGW after seeing Mann’s iconic hockey stick in the IPCC AR3. I knew the hockey stick was a revolutionary change in climate temperature reconstruction, and I doubted it immediately. We have Steve McIntyre to thank for his fine detective and statistical work to show that was Mann was cherry-picking and statistically incompetent. From climategate 2.0, we now know that some of his associates thought as much.
How do we get over this hysteria? So many have so much psychological investment (and $$) in saving the world from CAGW. And journalism needs a story that sells. No wonder we read all sorts of hype and bombast about climate change causing unprecedented damage in 2011. It doesn’t matter that Pielke Jr. has studied the issues and confirms no accelerating trend in hurricanes, tornados, floods, etc. We keep reading about how climate change resulted in unprecedented damages in 2011. As you’ll see in the link to Munich-Re, over have the damages were from two earth quakes unrelated to climate change. Without them, 2011 was a pretty normal year-
http://www.businessweek.com/ap/financialnews/D9S22I700.htm
#17 – I agree, almost. The climate now impacts an unprecedented number of people. Tomorrow it will be unprecedented again.
There is also unprecedented media coverage giving us an unprecedented sensitivity to every weather event imaginable, including some mud slide in Tierra del Fuego on slow days.
This creates unprecedented levels of manufactured beliefs and anxiety about things that don’t matter. And unprecedented levels of cultivated guilt about things we have no control over.
This helps support unprecedented levels of spending related to research and monitoring of the climate, or anything anybody can link to the climate – which is almost everything.
And there is unprecedented levels of fossil fuel derived CO2 in the atmosphere, which must be doing something,
But, yes, there is nothing about the recent or current climate itself that is unprecedented at all.
Oh yes… and an unprecedented number of climate related tweets.
“I think the use of the word “unprecedented”, unless a particular timeframe is mentioned (or this is clear from the context) should be avoided.”
The problem is actually that the words “climate change” and “global warming” are used without mentioning the timeframe. This is very unscientific. The linear trends are timescale-dependent. Such uses of these words is what I call linguistic/semantic hockey sticks. And it worked well. Many laypeople think there was no climate change (or global warming) before human industry.
Instead of a reasonable discussion about the history and implications of droughts for a modern global economy and society, the discussion is taking the usual turn.
It is amusing, and at the same time appalling to see the same old foolish nonsense perpetuated by global warming deniers:
*There is no problem, we have had climate change before and the planet has survived. The proponents of AGW don’t seem to know this.
*Since the climate changed before, GHG’s can’t be a problem.
*The Hockey Stick is an artifact of mistaken statistics.
All of these zombie arguments have been fully debunked,
So far, no charges of fraud against Mann, … yet.
Eric Adler
Perhaps the problem is that if you or I were to attempt to discuss the implications of enlarging Hadley cells on NH rainfall patters and key agricultural zones, the droning of the zombies would rise in volume until we were drowned out.
So people tend not to bother.
Eric, such logical fallacies don’t work anymore. The nut is cracked.
For me, just like for hunter and others above, climate history was one of the main reasons I have been a skeptic. It simply didn’t comply with my elementary education, the whole unprecedented hysteria. That was of course not the only reason.
@10
” The question is whether extreme events are likely to be more common or more severe in a warmer world.”
There is certainly a lot speculation about this in WGII. It is woefully lacking credible scientific supporting evidence though. The “extreme weather events in a warmer world” dogma also runs contrary to our own human history where clearly mankind thrived during warmer climate periods and suffered during colder periods. (see RWP, MWP, LIA, CWP) http://www.nature.com/nature/journal/v397/n6719/fig_tab/397515a0_F2.html
*There is no problem, we have had climate change before and the planet has survived. The proponents of AGW don’t seem to know this.
*Since the climate changed before, GHG’s can’t be a problem.
Surely you will oblige us with links to comments where these comments were posted on this blog? Lest we thought that you’re lying or imagining things…
Sashka @ 25
There’s being disingenuous, and there’s taking the p*ss.
You have crossed the line here.
Eric, BBD
I don’t think anyone would mine you discussing the implications of drought or speculating about Hadley cells.
As long as you don’t suggest that I should surrender my SUV because I am somehow affecting these. Then you’ll have to bring data, and that won’t go so well, and you’ll get your feelings hurt.
kdk33
Apart from the nonsense suggestion that there’s no scientific case for AGW, you are mistaken to think anyone is after your car.
Coal-fired baseload generation is what needs to go.
BBD,
Would you be ever so kind as to point to where I said: there’s no scientific case for AGW
@21 Eric says: “So far, no charges of fraud against Mann, “¦ yet.”
You are right Eric. Pasting over a clear divergence in data, using questionable tree ring studies, and inverting the Tiljander proxies, to support your hypothesis is sloppy and unethical but probably does not meet the legal definition of fraud. It does not meet the definition of science either.
ivp0
How much does it matter? Does the Mannean Hockey Stick change the atmospheric physics explored and described over decades? Does it ‘get rid’ of the radiative forcing from CO2?
Or is it now just a convenient misdirection away from the real issues?
@31
We know the earth is warming as it has been doing over the last 300 years and we know that increased atmospheric CO2 plays a role in that warming (radiative physics 101). The real questions are: 1. How much warming is due to manmade CO2? and: 2. Will a warmer planet be better/worse than it is today? We don’t know the answer to either question with any level of certainty but AR4 WGII speculated that warming would be extreme and results would be catastrophic based on the foundations of a very flawed and yet famous Mann98. This is contrary to human history which has shown that civilizations flourish during warm periods as opposed to cold climate periods.
BBD, when you develop an experiment to clearly define climate sensitivity to atmospheric CO2 let me know. Until then all future climate forecasting models are really quite speculative. Suggesting that a warmer world will result in more extreme weather events is scientifically unsupported nonsense.
Sadly, I think the climate food fight has done wound down…
Fun while it lasted.
ivp0 @30,
A dozen papers using different proxies and statistical methods have validated the conclusions of Mann 98, despite the flaws that you point to. In addition, the biggest critic, McIntyre, who falsely claimed that the use of non centered PCA was responsible for the hockey stick, and that centered PCA should have been used, actually made glaring errors in his application of centered PCA to the problem. When proper calculations using centered PCA are carried out, the results look the same as Mann’s original analysis.
ivp0 @32,
You are mischaracterizing the IPCC AR4 report. They do not rely on Mann’s original paper in their Paleoclimate section. The figure showing Paleoclimate data for the last 1300 years includes 11 different papers published up to 2006. In addition more papers have been published since then which confirm the existence of a hockey stick, with a more crooked handle, but still confirming Mann’s original conclusion.
The AR4 report does not rely on Paleoclimate data as the basis of their projection of future warming. It is the physical models that project future warming, not the Hockey Stick.
It is wrong to argue that since humans did well in past warm periods, we have nothing to worry about if it gets warm in the future. Human population was low, and migration to avoid drought and food shortages was a viable strategy. In today’s overpopulated world, where forests and agricultural land are in short supply, it clearly is not a viable strategy. Conflict and misery are going to result. One can see bad things happening as a result of drought in Africa already.
It seems idiotic to proclaim that, “Suggesting that a warmer world will result in more extreme weather events is scientifically unsupported nonsense.” This claim is made by respected scientists, and is based on sound physics. Higher temperatures enhance evaporation and will therefore remove moisture from normally dry areas and deliver more moisture to normally wet areas. Droughts and floods will therefore become worse. The effect on other kinds of extreme events, like tornadoes and hurricanes is less well understood, but that doesn’t invalidate the projection of worse droughts and floods.
Sorry E. Pure speculation on extreme weather. AR4 WGII was primarily written by politicians, not scientists.
Conflict and misery are going to result.
Oh bother. It’s not even interesting anymore.
On a brighter note, US nat gas prices are appraching $2.75. Lots of associated liquids. Positive indicators for a rejuvinated US manufacturing sector – especially petrochemicals (google Shell, cracker, Pennsylvania). Only thing standing in the way is government.
Be sure to vote.
#34,
I’ve responded to the “the errors don’t matter” nonsense over MBH98/99 and all the subsequent flawed studies many times before. The claim that McIntyre claimed short-centred PCA was solely responsible for the Hockeystick is false, as is the claim that doing it correctly restores the shape. (I know the claim you mean, but their reasoning is spurious.)
I won’t bother with that, unless you really want me to. The other topics you bring up are fresher and more interesting.
The world is less overpopulated than it used to be. Fertile land used to be scarce and was fought over, with many populations pushed to marginal areas. But with technological developments like artificial fertilizers, irrigation, and scientific plant breeding, that’s no longer true. Population is expanding because our ability to feed people is expanding. Life expectancy is extending because people are better fed, and better cared for.
And that includes Africa. Population is expanding there too, economies are growing, famine is retreating, and we already have the technology ready and waiting to do even more. Famines nowadays are caused by politics and economics, they’re caused by wars and rebellions – it is no longer the case that if the rains fail in your local area that you are doomed; the rest of the world has food for sale.
Blaming it on CO2-induced drought is just more of the weather-is-climate junk, connecting every local disaster to climate change and hence to AGW. It’s amateurish propaganda. Not all disasters are down to the weather. Not all weather is due to climate. Climates change anyway, not just because of AGW.
Higher temperatures enhance evaporation, true, but that doesn’t mean that dry areas become dryer and wet areas wetter. Did you know, for example, that the Sahara desert used to be wet, because it used to be hotter there? The heat caused stronger upward convection drawing moist air in from the Indian Ocean and an annual monsoon. When the climate cooled, the monsoons failed, and the Sahara dried up.
Climate is more complicated than that. Weather is driven primarily by temperature differences – that old heat-engine thermodynamics again – and in a warming world where the cold bits tend to warm more than the hot, temperature differences reduce. Stronger evaporation makes precipitation more difficult. You can generate similarly plausible-sounding arguments in both directions. What will happen in any given location will depend on may factors, a degree or two here or there is unlikely to make any major difference to what is already a very noisy random process, and your case is not helped by the seemingly irrepressible urge to link every single drought and flood currently going on to AGW.
Climate disasters are like crack cocaine to AGW-activists. I’ve seen them declare firmly that weather-is-not-climate, they truly believe it; swear off the weather-is-climate stories for good as damaging to their credibility and their cause; and then the moment another juicy weather disaster story comes along, start doing it again.
Why do they do it? Long may it continue, of course – there are few things more helpful to scepticism – but I don’t understand why they can’t seem to keep away from it. They know what’s going to happen, surely? Is it about keeping up the momentum?
ivp0 @32,
The earth has already done the experiments with CO2 concentration which you asked BBD to perform.
http://naturalscience.com/ns/articles/01-16/ns_jeh2.html
“Climatologists are still developing a quantitative understanding of the mechanisms by which the ocean and land release CO2 and CH4 as the Earth warms, but the paleoclimate data are already a goldmine of information. The most critical insight provided by the ice age climate swings is an empirical measure of climate sensitivity.”
NiV
The world is less overpopulated than it used to be.
You effing what? How do you justify this?
#38,
Which is rather messed up by the 100,000 year problem, yes?
Climate scientists simplistically link everything to average insolation, because they can’t think in any other terms, outside of their climate sensitivity paradigm. The problem is that average insolation varies with orbital eccentricity, precession, and obliquity, and while the latter two have the biggest effect on insolation, the ice ages appear to follow variations in eccentricity, which has the weakest effect.
You get different answers depending on how you look at it. Precession and obliquity indicate very low sensitivity, with strong forcing changes giving no result. Eccentricity indicates a high sensitivity, with a weak change in forcing giving a very dramatic result. Guess which they pick to highlight?
Clearly, it’s not just average insolation, but its distribution (spatial and temporal) that matters. And that means sensitivity is not such a simple concept.
To be clear: 2050, with some 9bn of us, and precipitation moving polewards. Agricultural impacts vs + 2 bn. It’s enough to make you think.
What 100ka problem?
ivp0 @ 35,
“Sorry E. Pure speculation on extreme weather. AR4 WGII was primarily written by politicians, not scientists.”
Your posts have a factual error in every sentence that purports to contain a fact. The 2 coordinating lead authors of AR4 WGII, the chapter on the health aspects of climate change are scientific researchers. You are making things up again.
Spatial and seasonal redistribution of RF terminates glacials and you think this is an argument for low climate sensitivity?
#41,
It makes me think about how people manage to grow food in greenhouses.
#42,
You mean to say you didn’t know? How strange.
#43,
If it quacks like a duck…
#44,
No. That wasn’t what I said.
NiV
Then average it out over geological time. The climate has cooled for ~50Ma during the Cenozoic. Why? What is your suggestion for an energetically sufficient change in forcing over that period?
NIV @37,
“The world is less overpopulated than it used to be. ”
Based on that statement, the person who seems to be on cocaine is you!
Sure there is more land in cultivation, but a lot of it requires irrigation, and fresh water in many of these areas is becoming more scarce, and that trend is expected to continue.
Your statement about the Sahara is true, however, what it illustrates, is that with climate change, the areas subject to drought and flooding change. It is true that between 10,000 and 8,000 years ago, as the last ice age receded, the Sahara desert was a kind of paradise. This situation reversed gradually over the next 3,000 years. There are a number of reconstructions of global temperature averages, going that far back, and there is no consensus on the precise evolution of temperature for that level of detail.
I haven’t read your posts explaining why McIntyre didn’t make egregious errors in his arguments regarding centered versus non centered PCA as applied to Mann’s Hockey Stick data. I haven’t run across any convincing rebuttals so far, nor have I seen a rebuttal of the graph which shows that centered and non centered PCA give the same results. I also haven’t seen convincing evidence that the dozen or so papers which show essentially the same results are fatally flawed.
It is true that global warming will warm the Arctic about twice as fast as the global average temperature. However even the equatorial and temperate oceans are getting warmer increasing the amount of moisture in the air. While this doesn’t necessarily increase the average rainfall it creates the potential for more intense rainfall events due to weather and therefore flooding when the weather systems cooperate.
http://www.nature.com/news/2011/110216/full/470316a.html
@43 Eric
haha, did you mean this peer reviewed lead author and research scientist??
http://online.wsj.com/article/SB10001424052748704107204575038742717786422.html
Doh! So much for scientific credibility. You might want to browse the WGII bibliography some time. I have and it is an eye opener.
NIV,
The reason for 100,000 year periodicity has not been figured out. There are a number of hypotheses put forward. What is clear, is that there is definitely positiive feedback making climate sensitivity, and the climate sensitivity estimates are in the neighborhood 0.7C/watt, the equivalent of 3C/doubling in CO2.
#46,
Why does it necessarily have to be a change in forcing? (I’m not saying it isn’t. I’m pointing out the assumption.)
#47,
The word “overpopulated” implies a comparison between two numbers: the population that exists, and the population that can be supported. In the most straightforward sense, it’s easy to tell the difference. If the population shrinks due to starvation or related events, then there are more people than can be supported. If the population is static, then the two numbers may be equal. If the population is increasing, then more people can be supported than currently exist, and the world is underpopulated.
There are other factors affecting population growth besides food, but in simple terms, we do know that expanding food and water supply has been a factor in the world population growth, so it is obvious that the world is now underpopulated because the number supportable has risen.
Claims that the world is overpopulated are based on a somewhat more sophisticated concept, which is the number that can be supported ‘sustainably’ – a word with a multitude of meanings but which can be taken to mean ‘indefinitely, using current methods’. This is where the disagreement occurs, because while I and a lot of economists say that ingenuity and innovation is our ‘method’, and therefore we will change and develop our methods to adapt to resource availability, there are others who regard relying on future innovation as gambling, who project assuming a frozen technology/economy and of course come up short.
The major scare campaign on overpopulation was around the 1960s-70s: it projected unstoppable famines by the 1980s, and general warfare and civilisational collapse by around 2000. There was nothing we could do to avoid it, even with crash programmes, and all we could do was soften the blow by instituting mandatory population control, sterilisation programmes, one-child policies, and so on.
When it became obvious it wasn’t happening and the doomsters were totally, totally wrong, it just quietly faded from the news and media, and everyone pretended it had never happened. But the meme that ‘the world is overpopulated’ created by that mass-media event survived. People take it for granted now as just one of those things that “everyone knows…”.
And that means that if you want to differ from the neoMalthusian creed, even nowadays a decade after the world was supposed to have ended, you have to say it with extended explanations and caveats, or people will think you’re mad. I do it to provoke ‘discussion’.
NiV
Climate scientists simplistically link everything to average insolation, because they can’t think in any other terms, outside of their climate sensitivity paradigm. [etc]
A classic NiV misrepresentation. Eccentricity synergises with obliquity to drive the ~100ka glacial terminations. Spatial/temporal redistribution of DSW is enough to trigger the self-amplifying system of feedbacks that operate to raise GAT by ~5C. These are the combined operation of seasonal albedo flip and GHG forcing (water vapour, CO2, CH4) on ice-sheet dynamics. Once initiated, the reduction in ice-albedo feedback drives the process with increasing speed until glacial conditions terminate and interglacial quasi-equilibrium is reached.
Good, clear evidence for a moderately high climate sensitivity (~3C for fast feedbacks; Hansen & Sato 2011).
Your unsubtle attempt to suggest that ‘climate sensitivity’ (in other words, the central role of GHGs) is an incomplete explanation deliberately selected by partisan researchers demonstrates your bias splendidly:
Guess which they pick to highlight?
Self-serving nonsense.
#46,
Why does it necessarily have to be a change in forcing? (I’m not saying it isn’t. I’m pointing out the assumption.)
Answer the question: what else could it be? Again, you dodge and twist and avoid. There is no assumption here: this is deduction.
#47 (continued),
Regarding McIntyre, Mann, and PCA.
PCA is a method that splits a signal into indendent components, ranked in order of importance. If you think of the data forming a cloud of points in multi-dimensional space, it often forms a roughly ellipsoidal shape. The PCA algorithm ‘rotates the coordinates’ to line them up with the centre and axes of the ellipsoid. Variation along the longest axis of the ellipse is called PC1, the second longest PC2, and so on. Each subsequent PC is a smaller correction to the main patterns of variation expressed by the earlier PCs.
The idea behind doing it is that if you throw all the tree-ring data into the algorithm, the North American dataset has so many series compared to the rest of the world that it would overwhelm the reconstruction. So you use PCA to find the most important patterns in the American data, and then use just the first few PCs to represent the whole set. That way, there are roughly the same number of series coming from each geographic area.
What Mann did was instead of centering the coordinate system on the centre of the ellipsoid, he centred it on the average for the modern data, the period for which he had an instrumental temperature record. With the ellipsoid shifted off-centre, the axis of greatest variation is not the long axis of the ellipsoid, but is distorted by the offset. This had the effect of picking out one of the lesser axes of the ellipsoid as the PC1, an axis consisting of a small number of outlier series from a dubious proxy: the famous stripbark Bristlecone pines, and another the Gaspe cedars.
These had huge spikes towards the end of the record – they were already known not to be temperature related; there was no corresponding spike in local temperatures. They had actually been collected by a sceptic (Greybill) looking for confirmation of the CO2-fertilisation hypothesis, and were deliberately selected not to be temperature proxies. Subsequently, it turns out the spikes are probably a result of the stripbarking – damage stripping the bark off one side of the tree causes it to grow asymmetrically, with a massive growth spurt as the remaining bark tries to supply the whole tree. From a temperature point of view, it’s corrupted data. This was well-known before Mann got hold of it.
(In fact, rather amusingly, if you look closely at the photo of Mann on his homepage leaning on a slice of tree trunk, you can see an example of this sort of asymmetry in the rings. You would get totally different answers depending which side of the tree you core.)
So Mann had this minor signal from a tiny number of trees promoted to PC1 being passed through to the main algorithm – which pays no attention at all to whether it is actually a temperature proxy, it simply weights any signal more heavily that has a 20th century rise like the instrumental temperatures. The corrupted data from one small corner of the US was promoted to dominate the entire reconstruction. That’s where the Hockeystick comes from.
So what happens if you use properly centred PCA? Well, the bristlecone spike is still in the data, but now it turns out to be one of the minor axes – instead of PC1 it appears in PC4. So using PC1 as the representative pattern for the whole set, a Hockeystick no longer appears. Without the spike being contributed by this tiny subset, the rest of the data looks like noise.
So Mann’s response was simply to extend the number of PCs pushed forward to the next stage. Instead of using just PC1, he said you now had to use PCs 1-5. This was supposedly justified using a rule-of-thumb called Preisendorfer Rule-N. Since the signal was in PC4, this now got pushed through, and the correlation with temperature once again grabbed it and dominated the reconstruction.
There is a lot of technical to-and-fro surrounding this, whether Preisendorfer’s justifications for the method apply and would support its use in this case, or whether Mann had used it originally; you can go see the arguments for yourself at ClimateAudit. But the bottom line is that even allowing this, the reconstruction is still not robust to the absence of bristlecones (as implicitly claimed by Mann), it still fails the cross-validation statistics (that Mann falsely claimed the original reconstruction had passed), and it’s still putting almost all the weight in the final temperature reconstruction on a small subset long-known not to be temperature proxies.
Mann’s Hockeystick is broken. The enquiries into it agreed it was broken. Independent experts agree it’s broken. There are climategate emails dating from the time where his own colleagues agreed that it was broken. But nobody will admit it in public, and it keeps on appearing in official documents, again and again, with the excuse that “the errors don’t matter” because other studies (after passing through the same flawed peer-review that passed MBH98) have ‘confirmed’ it.
That’s not how science works. And we’ll keep hitting you with it until climate science as a whole deals with it properly.
#51,
“Synergises”, eh?
Heh.
NiV
The most absurd demonstration of your self-serving nonsense concerns population, agriculture and projected NH rainfall pattern change:
BBD:
To be clear: 2050, with some 9bn of us, and precipitation moving polewards. Agricultural impacts vs + 2 bn. It’s enough to make you think.
NiV
It makes me think about how people manage to grow food in greenhouses.
That’s it. That’s your ‘response’. That and the usual wittering misdirections about Ehrlich. NiV, who cares? Who give a f-ck about Ehrlich?
It’s not the real problem.
Everything you do is misdirection and misrepresentation glazed with a superficial slick of fake reasonableness. It’s nauseating.
Nit-picking? Oh dear oh dearie me.
Try ‘modulates’ if it makes you happier. And address the comment substantively.
BBD, I already explained to you after your last little ‘episode’ that I’ve no intention of taking you seriously. As your side would say, why should I make the data available to you when your aim is to try and find something wrong with it? This is the high standard set by climate science. You should be pleased.
I’m jolly impressed that I’ve managed to get you swearing at me already, but I’d like to remind you that this is potentially a family site. It’s not my business, though, to say what anyone else is or is not allowed to say. I’ll leave that for Keith to adjudicate on. But I don’t think it’s likely to boost the persuasiveness of your case.
NiV
BBD, I already explained to you after your last little “˜episode’ that I’ve no intention of taking you seriously.
You do not have a coherent argument. And we both know it.
I’m jolly impressed that I’ve managed to get you swearing at me already, but I’d like to remind you that this is potentially a family site.
Spare me. Nothing I could say to you would be as repugnant as your endless flow of self-serving rhetoric. Now that really is nasty stuff.
Expect to be treated appropriately.
So, Eric, are you lying or hallucinating?
@ 52
Very nice exposition, NiV. Shame that they are not going to read it.
Do you remember how much variance is in the 4-th PCA?
NIV @ 52,
The number of principle components that need to be used need to be determined by some rule, not the whim of the statistician. The Preisendorfer rule is the accepted method by statisticians. It seems the McIntyre totally ignored this when he wrote his critique of Mann’s paper. Afer his error was pointed out , he claims falsely that Preisendorfers rule is not universally accepted Preisendorfer’s book on PCA is the most quoted reference on the topic of PCA.
The use of bristle cone pines and strip bark trees is not obviously as big an error as you claim.
http://www.realclimate.org/index.php/archives/2009/11/a-treeline-story/
Since Mann’s original article was published, over a dozen papers, using different analyses and different proxies, without the bristle cones have shown a hockey stick graph, with a bigger bulge in the MWP but a hockey stick nevertheless. Flawed peer review is better than no peer review at all, which is what we get from McIntyre’s blog posts. Of course if you choose to believe that all climate science is a conspiracy to produce one world government, or to rake in money for research, peer review is meaningless.
Obviously the idea that the earth is overpopulated is about sustainability, because the way the earth’s resources are currently being used to support its population is unsustainable. The people who are worried about this advocate conservation, and switching to sustainable methods of producing energy, and food. These would seem to be the technical fixes you allude to. Whether these fixes would support a population at current or future projected levels is an arguable point.
#60,
I know they’re not going to read it – at least, not with an open mind. But I wasn’t really writing it for them.
According to MM05 in GRL, the PC4 explains just under 8% of the variance in the NOAMER subset. With Mann’s short-centering, the PC1 explained 40%, of which 37% was down to the 15 bristlecone series and 3% to the other 65 (I think) series.
“The Preisendorfer rule is the accepted method by statisticians.”
No it isn’t.
There’s also the Kaiser-Guttman criterion, bootstrapped Kaiser-Guttman, Scree Plot, Broken-stick, Proportion of total variance, Sphericity test, Bartlett’s test, Lawley’s test, or the bootstrap eigenvalue-eigenvector method, just for starters. Statisticians don’t give any hard-and-fast rule, they say it depends on context. They don’t make any claims for significance – all they say is that components passing the test need to be looked at to see if there are physical justifications for including them (and which we know is not the case here for bristlecones).
McIntyre spent quite a bit of time quoting bits out of Preisendorfer’s book, and others, making the point that Preisendorfer says no such thing, (“an increasing number of researchers have used principal component analysis to study large data sets in meteorological and oceanographic settings. This method of analysis unfortunately is potentially dangerous in the sense that too much is often required of it or, worse yet, read into its results.” Overland and Preisendorfer, 1982).
They’re also quite clear that PCA is nonsense unless properly centred, and that PCA as a methodology is not valid unless the series are identical independent Gaussian distributions, which they’re not.
This is just more of Mann’s bluster and bluff.
“The use of bristle cone pines and strip bark trees is not obviously as big an error as you claim.”
In what way is this “obvious”? All your link says is that the bristlecones’ growth really did surge – which of course is exactly what I said. It in no way demonstrates that the surge is related to temperature, or that the reconstruction didn’t weight bristlecones more heavily that all the other proxies.
It also ignores the follow-up studies in the same area that failed to replicate the surge. e.g. the Ababneh thesis (which was never published), or McIntyre’s own field trip.
RealClimate have been putting up spurious defences of MBH98 since they started. You can’t just look at a post there saying “McIntyre is wrong because…” and not read the rest of the article to see if it makes sense, or actually answers the point, since usually it doesn’t.
This particular article was by Ray Bradley, the B in MBH. Bear in mind that he put his name to the original MBH98 paper without apparently checking the maths, and consider how carefully therefore one should check his arguments in defence of it.
Eric Adler
Be careful – you are getting sucked in by NiV’s misdirection game.
Let’s all bear in mind that whether or not the Mannean hockey stick was ill-founded has exactly no bearing on the atmospheric physics that underpin the greenhouse effect.
If NiV wishes to develop some kind of relevant argument, it must address this directly.
Contrarians just love waffling on about the hockey stick as if it mattered.
It distracts attention from the fact that actually, they have nothing.
#64,
You will recall, of course, that I suggested skipping the Hockeystick re-run and discussing the more interesting bits.
The relevance of the Hockeystick is not to the basic physics, but to the way the science is done. That a bad paper was written is bad enough, but scarcely unusual. That it passed peer-review in a top journal is a problem for all those who take peer-review as a stamp of authority. That it passed the IPCC review is a problem for all those who take the IPCC reports as the state of the art. That even after the flaws were discovered the authors and their clique of close colleagues tried to defend it to the death is a problem for those who believe climate science to still have any scientific integrity. And that many scientists in other fields continue to take their word for it and re-affirm the Hockeystick instead of checking for themselves tells us the problem with scientific standards is more general. And it is more general.
The Hockeystick still matters, which is why the climate scientists still drag it round with them like a dead albatross, but I agree it isn’t significant for the science of the greenhouse effect or the projection of future warming. However, there’s more to the whole climate change issue than basic GHE physics.
So what do we really know in terms of sensitivity to CO2 BBD? AR4 suggests through paleo studies 3 degrees C +/- 2C per doubling of atmospheric CO2. This is the difference between catastrophic 5 ft of ocean rise and… nothing really happened. Not a very useful number in terms of planning.
Would the world be a better/worse place with 1C warming? 3C? 5C warming? Care to speculate??
ivp0
So what do we really know in terms of sensitivity to CO2 BBD? AR4 suggests through paleo studies 3 degrees C +/- 2C per doubling of atmospheric CO2.
No, what AR4 WG1 concluded was that the most likely value for ECS was ~3C:
Since the TAR, the levels of scientific understanding and confidence in quantitative estimates of equilibrium climate sensitivity have increased substantially. Basing our assessment on a combination of several independent lines of evidence, as summarised in Box 10.2 Figures 1 and 2, including observed climate change and the strength of known feedbacks simulated in GCMs, we conclude that the global mean equilibrium warming for doubling CO2, or “˜equilibrium climate sensitivity’, is likely to lie in the range 2°C to 4.5°C, with a most likely value of about 3°C. Equilibrium climate sensitivity is very likely larger than 1.5°C.
I cannot find a single credible source that supports the idea that +3C will make the world a better place.
I suppose you can choose to ignore the error bars if you wish. Quite unscientific though. It is consistent with many IPCC author’s practice of ignoring/omitting all data that is contrary to their hypothesis… which is why there are so many critics. It is a vicious circle indeed.
I’m not ‘ignoring the error bars’. Simply pointing out that estimates converge on ~3C. This is summarised in Knutti & Hegerl (2008).
You may be missing the point here.
Not at all BBD. I think that is exactly the point. Throughout AR4 they talk about different scenarios ranging from 1-5C warming. AR4 authors suggest that Canada and Russia might see significant benefits from 1-3C warming due to longer growing seasons and they might become the bread basket to the world. I guess it depends where you live whether it would be better or worse.
I love quotes from AR4. This is one of my favorites:
“3. Projected climate change
and its impacts
There is high agreement and much evidence that with
For the next two decades a warming of about 0.2°C per de-
cade is projected for a range of SRES emissions scenarios. ”
Ummmm, not looking good so far. In fact when comparing this projection to actual observed results over the last 15 years it appears that we-don’t-know-jack about sensitivity to CO2 in a very complex system like earth.
High agreement and high confidence regarding CO2 sensitivity is looking like a big load of steer manure to anyone who is less than a complete fanboy of the IPCC process. This my friend is the point.
NIV,
Ray Bradley was quoting a recent peer reviewed paper by Salzer Hughes, et, al. which shows that the Bristlecone Pine tree ring data actually is a proxy for temperature.
http://www.pnas.org/content/early/2009/11/13/0903029106
The CO2 fertilization hypothesis was put forward by GrayBill and Idso. A review by Jacoby and D’arrigo in 1997, pointed out that this theory was contradicted by a number of other workers and the evidence was inconclusive.
The NAS committee, which investigated the Hockey Stick controversy, said that the so called short centered method used by Mann et. al. did not unduly influence the results. I don’t care how many blog posts McIntyre makes on this subject, I will take their word over his, . Their conclusion was that the original Mann paper did underestimate the uncertainty in its results. Subsequent papers showed that the MWP had more variation and higher temperatures than Mann’s original paper, but the hockey stick shape still was there.
In addition, DeepClimate showed rather definitively that McIntyre and McKittrick made some egregious errors in their critique of the methodology of Mann et. al.
http://deepclimate.org/2010/11/16/replication-and-due-diligence-wegman-style/#more-2745
“While M&M clearly identified a mistake (or, at best, a poor methodological choice), critiques of M&M pointed out two major problems with the M&M analysis. First, it turned out that M&M had left out a crucial step in their emulation of the MBH PCA methodology, namely the restandardization of proxy series prior to transformation (an issue first raised in Peter Huybers’s published comment). Second, and even more importantly, M&M had neglected to assess the overall impact of any bias engendered by Mann et al’s PCA. In particular, they failed to take into account any criterion for the number of PCs to be retained in the dimensionality reduction step, as well as the the impact of combining all of the retained PCs with the other proxies.”
All of the bickering and nitpicking is not going to change the fact that the recent temperature increases in the last half of the 20th century are unprecedented in the last millenium or even the last 2.
The Hockey Stick doesn’t really matter much. The projections of global warming were made way before there was a hockey stick or even an observed temperature increase attributable to an increase in CO2 concentration.
NIV you make so much effort in the service of such lame arguments. It is a waste.
Aerosols, dear chap.
You are a loyal soldier BBD, consistent to the end. Let us all know when you can quantify that in scientific terms that look not-so-much like wild speculation. While you are at it, let us know when you find Trenberth’s missing ocean heat. Clue: It drifted out to the blackness of space.
Have a good evening now. I am off to a social engagement.
Enjoy the evening. CS will still be ~3C in the morning.
Simply pointing out that estimates converge on ~3C.
From time to time warmists reveal too much. BBD’s is just saying that CS is 3 because his favorite scientists say so – they all agree (or are getting closer) so they must be right.
Sadly, climate doesn’t agree.
I cannot find a single credible source that supports the idea that +3C will make the world a better place.
Same as above. I’m curious though: would the world be a better place at -3C.
#71,
Good reply! I had to think about some of that for a bit…
The Salzer paper is interesting. It shows that bristlecones have been a proxy for temperature during some intervals, but not during the interval of interest. The comparison is made in figure 5, where you can see the match is poor (something like a 1 C difference) prior to 1650, there’s a reasonable match up to 1850, and then they start to diverge again, the two series having very little to do with one another after 1910. Since the dramatic 20th century rise is precisely what we’re talking about, this post-1850 divergence is surely of particular significance, is it not?
One curiosity is that the temperature in figure 5 isn’t measured with thermometers, but with trees! It’s a reconstruction based on wood density, that you can see compared to an modelled interpolation of thermometers in figure S5. The red line there is the thermometer record, doesn’t show all the inter-annual wiggles in the wooden record (which may be precipitation-related), and interestingly, doesn’t actually rise at all through the 20th century. There is no spike in temperatures, and yet there is in tree rings. Mysterious, eh?
It’s also an interesting paper in that the results shown differ significantly from the earlier ones of Greybill/Idso that Mann used. You can see these in figure S4, where the strong difference between strip-bark and whole-bark forms is obvious. Even with the modern standardisation (S4B) the divergence post-1870 can be seen. However the updated results (figure 3A) show the whole-bark trees rising too. The really odd thing about this graph is the divergence prior to 1750, which I don’t understand. Strip-bark trees start off as whole-bark, and get stripped at some later date. So the two populations ought to start off the same, and diverge later. There’s something very odd going on here – reduced sample size, possibly.
(You’ll note the whole-bark trees show comparable values to the modern ones, which if these are thermometers contradicts the unprecedentedness of modern warming, but since there’s something funny about these results I don’t propose to make anything of it.)
It’s also worth noting that these results seem to disagree with Ababneh’s, which apparently found no dramatic rise in the 20th century. That’s unclear, as Ababneh is unpublished, and no attempt to reconcile the difference is made here.
The CO2 fertilisation hypothesis has somewhat variable support, and I’m inclined to doubt it. Since the divergence between bristlecones and temperatures appears to start at 1850, CO2 doesn’t seem a likely cause, although it may be a contributor.
The NAS committee said the short-centering method biased the results. They followed this with the statement you quote, but their justification for it was not based on an assessment of the statistical impact, but on the fact that other reconstructions had come to similar conclusions. I’ve already discussed this tactic – and to criticise the use of bristlecones, and then use a list of other reconstructions that use bristlecones to support the contention that “the errors don’t matter” is disingenous. You don’t have to take McIntyre’s word for it, you just have to check whether he’s right.
The bit you quote from DeepClimate mentions two issues. The first is Peter Huybers’ comment on the covariance/correlation issue. It doesn’t actually make a significant difference, it was just the way Huybers plotted the data (the offset was selected to align the variants in the 20th century, rather than over the whole record). The second point is just the Preisendorfer issue we’ve already discussed.
All the bickering and nitpicking is about the fact that there is no solid evidence that the late 20th century is unprecedented, quite a lot of evidence (ignored by the hockeystick supporters) that it probably isn’t, and a tremendous amount of effort is being thrown into trying to defend the claim. Much of it using quite dubious reasoning.
As I said above, the significance of the hockeystick controversy is not about the projections of global warming, but about how much we should trust the whole process that has generated those projections. If they’ll lie about this, what else will they lie about?
I make so much effort because I think that if I’m going to have an opinion on a subject of importance it’s worth taking the time to understand it myself. Arguing with people like you is a way to steer the process, to force myself to clarify my reasoning, to make sure I don’t dive into my own echo chamber, looking only at evidence that supports my own thinking.
For example, I’d heard of Salzer et al., but only in the context of the Greybill restandardisation, and hadn’t considered it worth a closer look. Because you claimed it showed Mannian bristlecones actually were temperature sensitive, a startling claim if ever there was one, I now know a bit more about it. It’s another piece of evidence that the dramatic 20th century rise in bristlecone ring-widths isn’t temperature related, and that there was no dramatic temperature rise at Sheep Mountain during the 20th century. It does cast a little confusion on the strip-bark issue, but there’s clearly something odd about the data in that section. Arguing has proved educational, you see?
In the larger scheme of things, all this arguing makes no difference at all – it’s a sideshow. Political prospects for action on climate change are dead; the science discredited. It’s now purely for entertainment – time to pass the popcorn as we all watch the process of agonisingly drawn-out collapse. I guess it depends on your viewpoint, eh?
NiV,
Fascinating as ever. Where do you find the time?
These exchanges contain a commonality. The believers are more than happy to claim the such and such scientists said or such and such paper says. They provide quotes from the abstract or conclusions or from a 3rd party summary. A closer look at the data reveals that, while that quote might actually appear, it isn’t justified by the data. I’ve been down that path mutliple times, here and elsewhere…
It seems that a significant number of people believe that “science” is the body the “things that scientists say” (or write). It’s kinda sad really.
> If they’ll lie about this, what else will they lie about?
Spot the fallacy.
NIV, @ 77
The scientists who have used the Bristlecone Pines have not used the late 20th century data, where the divergence has occurred, for calibration purposes. According Salzer and other, except for this period, other proxies agree with Bristlecone Pine data. Since these trees represent a really long time period, they are a potentially valuable tool for Paleoclimatology., it is not obvious that their use should rejected. Even without them, the Paleo climate data has validated the conclusons of Mann et. al 99.
The NAS pointed out that Mann et. al 99, was a ground breaking paper, and while it may have had flaws, subsequent literature proved that its conclusions were basically valid.
So this brings us to the statement you made that reveals your real motivation and train of thought:
“If they’ll lie about this, what else will they lie about?”
This makes it clear that you believe that Mann, and the scientists who did research, that subsequently, validated his initial research, and the NAS, are dishonest.
What should we say about McIntyre who attacked Mann for using noncentered PCA, with an analysis that didn’t use any selection rule whatever, and when he is caught, argues that the Preisendorfer rule isn’t necessarily the right thing to use?
Further you claim that the issue of AGW is politcally dead, and the science has been discredited. This is true mainly in the US but not the rest of the world. The EU and Australia has put a price on carbon emissions. Even China doesn’t argue with the science, is investing in sustainable energy technology, but isn’t ready to compromise its economic growth to adopt firm targets on emissions growth. These actions may be inadequate, but show that the science is not discredited, and the issue is not politically dead.
There is an explanation for what is happening in the US. There has been a campaign, mainly based in the US, to discredit the science. It is waged by big money interests through right wing think tanks, which fund skeptical scientists, and pseudo scientists to write articles attacking the science. The result is that among the public, acceptance of AGW as a valid scientific theory aligns with political party affiliation.
Meanwhile, the overwhelming majority of climate scientists are finding more and more phenomena showing that AGW is more powerful than previously thought, and the projected temperature rise increases.
Meanwhile, the overwhelming majority of climate scientists are finding more and more phenomena showing that AGW is more powerful than previously thought
You need to quit smoking that staff.
Sashka,
There are many examples of increasing estimates and phenomena that point to increasing estimates of temperature rise.
http://web.mit.edu/newsoffice/2009/roulette-0519.html
“The most comprehensive modeling yet carried out on the likelihood of how much hotter the Earth’s climate will get in this century shows that without rapid and massive action, the problem will be about twice as severe as previously estimated six years ago – and could be even worse than that.”
http://www.tgdaily.com/sustainability-features/48721-massive-methane-release-sparks-global-warming-fears
“Vast amounts of methane are bubbling up from the East Siberian sea, raising fears of a massive hike in global warming.
Permafrost in the seabed has been previously assumed to act as an effective cap for the enormous amount of methane in the area.”
#79,
It would be a fallacy to say that because they lie about one, therefore they are lying about the other. It’s not a fallacy to ask the question. It’s not a fallacy to insist that methods and results from such people need checking.
#80,
“The scientists who have used the Bristlecone Pines have not used the late 20th century data, where the divergence has occurred, for calibration purposes.”
Yes they have. MBH98 did.
“Even without them, the Paleo climate data has validated the conclusons of Mann et. al 99.”
You misunderstand the meaning of “validated”. A conclusion is “valid” if it is a logical consequence of its premises. “Verification” is a test to see if the conclusion is true.
The distinction is important. Mann’s methods have very definitely been invalidated. Whether they have been verified is a separate question – one I would dispute – but the essential point is that the scientific method demands valid methods from true premises, the basis by which confidence in the truth of their conclusions is justified. An invalid method is not science. A failure to reject invalid methods is not scientific. The use of unscientific methods means confidence in the results is not scientifically justified. This is how science works.
Trying to make excuses is far, far worse than making the mistakes in the first place.
“This makes it clear that you believe that Mann, and the scientists who did research, that subsequently, validated his initial research, and the NAS, are dishonest.”
Yes. They are.
Haven’t people accused sceptics of being dishonest? Is that not allowed?
“What should we say about McIntyre who attacked Mann for using noncentered PCA, with an analysis that didn’t use any selection rule whatever, and when he is caught, argues that the Preisendorfer rule isn’t necessarily the right thing to use?”
“Caught” is the wrong word. He used exactly the same lack of selection rule that Mann did. While Mann had used Preisendorfer on the instrumental temperatures (justifiably), nobody knows what he used on the proxy PCs. There appears to be no rhyme nor reason to the number of PCs carried forward in each case; it certainly doesn’t fit Presendorfer’s rule. McIntyre carried forward the same number Mann carried forward, since Mann had given no reason nor justification in his methodology for doing anything else.
“This is true mainly in the US but not the rest of the world.”
It’s true in the rest of the world, too. There are a variety of ineffective gestures, with the stated aim of “taking a first step”, “showing willing”, “setting an example”, etc. but none actually directed at doing anything about climate change. The carbon taxes in the EU and Australia are instituted because they are taxes – the governments are overspending like mad, need to raise revenue, and nobody can argue with it if it’s ‘Green’, because you’ll get tarred as a fossil-fueled denier if you do.
China have stated on a regular basis that they’re not going to be restricting their emissions one iota. They’ll invest in alternative energy if they think they can make money from it.
“There has been a campaign, mainly based in the US, to discredit the science. It is waged by big money interests through right wing think tanks, which fund skeptical scientists, and pseudo scientists to write articles attacking the science.”
This is a distortion. There are right-wing think tanks who write on the subject, just as they write on many other subjects of interest to them, and just as left-wing think-tanks and foundations fund writers on topics of interest to them, including global warming. There’s relatively little money going into it, there’s rather a lot more going to the left than the right, and it’s mostly preaching to the choir.
The think-tanks generate little original or substantive content, mostly passing on the results from the scientists (funded in the usual way), and amateurs who do the bulk of the substantive work for free.
The accusation mostly comes from left-wingers who are paid by/associated with think tanks and PR agencies – it’s more likely a classic case of projection, I think.
Have you ever had a look at the list of companies who sponsor CRU? No? It would obviously be rank hypocrisy to make up conspiracy theories to explain scepticism, and not AGW activism.
“The result is that among the public, acceptance of AGW as a valid scientific theory aligns with political party affiliation.”
It may have changed recently, but it used to be that in the US right-wingers were fairly evenly split, and left-wingers firmly believers. In other words, it’s not something right-wingers as such have a defined position on. The left-wing on the other hand are solidly persuaded to take a side. What do you consider to be the default position on an issue? Was the left-wing think-tank propaganda more effective, do you think?
“Meanwhile, the overwhelming majority of climate scientists are finding…”
The overwhelming majority aren’t even looking at the question. Most scientists are looking at other questions.
kdk33 @ 75
Sadly, climate doesn’t agree.
Equilibrium and transient climate sensitivity are not the same thing. Natural variation and aerosols also need to be considered. You appear to be arguing from ignorance again.
I’m curious though: would the world be a better place at -3C.
And this is actually one of the stupidest things I think I can recall you having said. If you know nothing about a topic, silence is the best tactic.
Eric Adler
If you let NiV direct the conversation, you will be arguing about the hockey stick forever. And he will use it to pretend that all climate science is tainted, and that right-wing corporate front organisations (‘think tanks’) are fine and dandy, and that there really isn’t much fossil fuel money behind organised climate denial in the US etc.
#82,
Methane? Really?
Heh.
NiV
Revkin has modified his views somewhat:
http://theidiottracker.blogspot.com/search?updated-max=2012-01-01T05:03:00-08:00&max-results=7
And dismissing clathrates with a ‘heh’ is a remarkably silly thing for someone who believes themselves to be highly intelligent to do.
Incorrect link above. It should be:
http://theidiottracker.blogspot.com/2011/12/revkin-vs-revkin-final-battle.html
#87/88,
Revkin did indeed revise his view – he had formerly criticised the scientists for generating a media scare story; it turned out that the scientists hadn’t generated it, the media had.
As the scientists said: “We would first note that we have never stated that the reason for the currently observed methane emissions were due to recent climate change. In fact, we explained in detail the mechanism of subsea permafrost destabilization as a result of inundation with seawater thousands of years ago.”
It turns out they were questioning a modelling assumption that permafrost would melt at 0 C, when mud a couple of degrees below this was found to have melted. As far as global warmy doom goes, there’s no story.
So where did the scare story come from? Why would anyone want to make something like that up? It’s evidently not from the science – the scientists said so. So who wants to alarm people?
NIV,
Thanks for the link.
It seems I was deceived about methane as a result of imaginative journalism. It can be a contributor in the future, but probably not from Clathrates buried under the sea floor.
So BBD will the world be a better place at -3C. You didn’t answer the qeustion. You rarely do.
Let’s consider a world at +3C. Remember that warming will primarily occur at high latitudes (not the tropics), in winter (not summer) and on night time lows (not daytime highs). So the places/times when it’s hot won’t get that much hotter; places/times when it’s cold will get warmer. Expanded crop ranges, longer growing seasons, free fertilizers,,, And lower heating bills (it’s a negative feedback :-))Yet you would have us believe certain catastrophe looms, You’re being rather silly.
Yes BBD, one does have to consider natural variability. You like to wave it around to explain when the real world deviates from projection. You fail to realize that you are simply admitting the truth: we don’t know enough to predict future climate. Ordinary Joe’s, on the other hand, have it pretty much figured out.
… and among all this he said/she said climate debate the PDO index just posted it’s lowest anomaly in 50 years (-2.33C). That is a lot of missing ocean heat. We won’t be seeing any rapid rise in global temps for a while folks. I guess CAGW will just have to wait.
NiV
I am always greatly heartened to see alarmism clipped back. This is not the same as being nonchalant about CO2/CH4 feedbacks from high latitude warming. An increase in GAT of 2C – 3C by the end of this century – with polar amplification – seems more, not less, likely to increase these feedbacks.
ivp0
he said/she said
He said.
I guess CAGW will just have to wait.
The last decade has been interesting. La Nina dominant, the unusual solar cycle 24, the higher-than-expected stratospheric aerosol loading… and rather than cooling, GAT has only trended flat. Now that’s odd.
@ 82
There are many examples of increasing estimates and phenomena that point to increasing estimates of temperature rise.
You mentioned overwhelming majority last time. Do you intend to back it up wit evidence or shall we write it of as your usual bullshit?
Sashka @ 95
As for GAT, the pretty picture looks like this.
The unprecedented growth of the Artic ice cap speaks for itself 😉 and I will leave the World Glacier Monitoring Service to fill you in on the rest of the cryosphere.
Sashka
To avoid boredom:
Indicators of unusual warming come in many forms. Consider the emergence of Neolithic artefacts from the Schnidejoch ice field where they had been frozen in situ for 5ka. The ice formed in the wake of the Holocene Thermal Maximum. At no time since has it melted. What does that suggest about present conditions?
Schnidejoch is interesting. From Grosjean et al. (2007):
This […] points to an interesting feature of Schnidejoch as a palaeoclimatic archive different from timberline changes or glacier tongue fluctuations, Schnidejoch is a binary and non-continuous archive (“˜open or closed’). It operates at a precisely defined and constant threshold (Equilibrium Line Altitude (ELA) at 2750 m) and responds immediately and most sensitively to small perturbations if climatology fluctuates around that threshold value.
[…]
The critical point in the context of this paper is that leather requires permanent embedding in ice in order to stay preserved and, as it is observed today, deteriorates very quickly if exposed at the surface. In consequence, the finds at Schnidejoch suggest permanent ice cover at that site for the last 5000 years, more specifically from ca. 3000 BC until AD 2003. At first glance our conclusion differs from the conclusions drawn from exposed trees in the forefields of melting glacier tongues (Jo¨rin et al., 2006). However, the conclusions by Jo¨rin et al. (2006; see also by Hormes et al., 2006) refer to the AD 1985 level: “˜glaciers in the Grimsel [and Alpine] area were smaller than at 1985 AD during several times for the last 5000 years’; while our conclusion reads: “˜in the year of 2003 AD, the ice field at Schnidejoch has reached the smallest extent since the last 5000 years’.
——
Grosjean, M., Suter, P. J., Trachsel, M. and Wanner, H. 2007. Ice-borne prehistoric finds in the Swiss Alps reflect Holocene glacier fluctuations. J. Quaternary Sci.,Vol. 22 pp. 203″“207. ISSN 0267-8179.
http://onlinelibrary.wiley.com/doi/10.1002/jqs.1111/pdf
Sorry – duff link above. Hopefully this works:
As for GAT, the pretty picture looks like this:
http://woodfortrees.org/plot/hadcrut3vgl/offset:-0.26/mean:12/plot/gistemp/offset:-0.35/mean:12/plot/hadcrut3vgl/from:1900/mean:12/offset:-0.26/trend/plot/gistemp/from:1900/mean:12/offset:-0.35/trend/plot/hadcrut3vgl/from:1950/mean:12/offset:-0.26/trend/plot/gistemp/from:1950/mean:12/offset:-0.35/trend
And suddenly… Blammo! Nothing happens. Not exactly the predicted +.2C per decade quoted from TAR or AR4.
http://woodfortrees.org/plot/hadcrut3vgl/from:2001/to:2011/plot/hadcrut3vgl/from:2001/to:2011/trend
The primary lesson about the recent fixation of ‘climate change’ can be found in more recent examples.
Like the y2k warnings from the computer industry or Iraqi WMD story from the military-industrial complex.
They’re makin us an offer we can’t refuse… or so they thought.
The Vostok ice core data tells the whole story at a glance.
The unprecedented growth of the Artic ice cap speaks for itself
Similarly the antarctic 😉
right-wing corporate front organisations (“˜think tanks’) are fine and dandy, and that there really isn’t much fossil fuel money behind organised climate denial in the US etc.
I think now we have found the crux of the BBD matter.
Consider, briefly, fossil fuel companies – Big Oil. These are extremely technically competent organizations populated by folk who are, relative to the general population, highly educated, succesfull, informed, and scientific. Chemists, engineers, geologists, physicists – that kind of thing.
BBD would have us believe they are an organized suicide/homocide machine intent on destroying their grandchildrens future in exchange for a few extra bucks. They don’t have feelings compassion hopes and dreams for their kids. Not like ordinary people. (Nevermind that it is these very folk and their technical expertise that makes every aspect of our modern lifves possible.) It’s tin foil hat territory for sure.
It might be more revealing for BBD to explain what he would do to solve the “right wing think tank problem” and how best to deal with “organized climate denial”. Perhaps that would bring us a more intimate understanding of BBD.
“The last decade has been interesting. La Nina dominant, the unusual solar cycle 24, the higher-than-expected stratospheric aerosol loading”¦ and rather than cooling, GAT has only trended flat. Now that’s odd.”
BBD, I agree – the last decade has been interesting. All that CO2 (highest since millions of years according to IPCC/consensus), the numerous positive feedbacks (water vapor, methane, ice albedo…), Asia’s and Africa’s booming CO2 emissions and the trend was ~flat. Of course it’s only 10 years, but it will only make the next decade(s) even more interesting, much more. The weak sc23 (~12,5 years, ~8 cycles/century) didn’t lose its influence with the end of the cycle – it will affect the climate for years to come, not to mention seemingly even longer (weaker) sc24. What it means that solar cycle frequency is still lowË™(f(sc) = ~8 cycles/century) and maybe even decreasing. The plateau is about to end and cooling will take over. The cooling will be much steeper/longer than the mid 20th century cooling – the frequency lowered for shorter time (~ one 1 cycle) then and not as low as now. I also predict it will be steeper than the 1980s/90s warming so that the linear trend for 1990-2020 (30 years) will be either ~flat or negative. Now, that will be odd!
ivpo, @92,
You are showing your ignorance. The PDO index warm phase, a higher index refers to the surface temperature on the Pacific Coast of North America. It is not an index of overall North Pacific sea surface temperature. In fact a warm phase index can be associated with an overall cooler pacific surface. Check out the diagram at this link:
http://jisao.washington.edu/pdo/
@ 103
Here’s another one who knows the future. Do you have any hot stock tips?
kdk33 @ 101; 102
If you want to join the apologists for corporate vested interest, go ahead. But do not suggest in the same breath that I am the one with questionable motives or a suspect character.
And it’s Antarctic sea ice that is increasing in extent, not the Antarctic ice sheet. The West Antarctic, by contrast, is losing mass at an increasing rate – which is of course where all the sea ice is coming from. This is a tired old misrepresentation.
It might be more revealing for BBD to explain what he would do to solve the “right wing think tank problem” and how best to deal with “organized climate denial”. Perhaps that would bring us a more intimate understanding of BBD.
Anti-science codswallop should always be vigorously rebutted, especially if it is being funded and peddled by vested corporate interests. Your logic is faulty: if someone rejects the scientific position on CO2, they are hardly likely to worry about their children’s future, are they? So sabotaging US climate policy via Congress isn’t going to cause them any pain.
I’m being forced to conclude that you are thick as well as abysmally badly informed.
ivp0 @ 99:
See (94).
EdG
The Vostok ice core data tells the whole story at a glance.
Yes – it shows a sensitive climate system responding strongly to mere spatial and seasonal reorganisations of radiative forcing (Milankovitch 100ka eccentricity modulating obliquity).
What did you have in mind?
Who wants to tell me why, if there’s nothing special about the late C20th warming, the 5ka ice at Schnidejoch melted in 2003?
Those who argue that the MWP was ‘as warm or warmer’ than the present need to think about this especially carefully.
#108,
Do you mean this Schnidejoch?
@109
I’m thinking you missed this part of BBD’s cut and paste from the Grosjean article
““˜ However, the conclusions by Jo¨rin et al. (2006; see also by Hormes et al., 2006) refer to the AD 1985 level: glaciers in the Grimsel [and Alpine] area were smaller than at 1985 AD during several times for the last 5000 years’; while our conclusion reads: “˜in the year of 2003 AD, the ice field at Schnidejoch has reached the smallest extent since the last 5000 years’.”
What a difference 18 years makes!
Antarctic sea ice that is increasing in extent
Yes, indeed it is.
apologists for corporate vested interest
is that your euphamism for free marketeer. Yes, I am. Speaking of vested interersts – let’s briefly consider “green energy”.
questionable motives or a suspect character.
No, BBD, I would never question your motives, just your political persuasion, which seems to be driving your “science”. Perhaps you could enlighten us.
If someone rejects AGW catastrophism, that means we have a difference of opinion. It is you who connected it to “right wing think tanks” and “denialism”. You seem unable to argue coherently. Are you well?
BTW, would you prefer a world at -3C. You’ve yet to answer.
thick as well as abysmally badly informed.
Sadly, your list is incomplete. I am also ugly.
#110,
Why would you think I’d missed it?
I wasn’t making any point (just yet), I just wanted to make sure they were talking about the same thing. It sounds like a complicated situation – some areas stayed covered through the MWP, others were exposed during the MWP for centuries but stayed covered right up to 2003. Maybe only one particular bit was being discussed?
According to the German article: ” In the late Middle Ages, the glaciers withdrew and opened the way for few centuries, but since the Little Ice Age, those again remained blocked from the middle of the 16th to the 19th Century. Only the summer of 2003 changed that and opened the way over the Schnidejoch again.”
It is, of course, local weather in one small area of the world, not global climate – so I’m not sure what BBD’s point was. (Nothing unusual there.) But it does illustrate rather well one of the dificulties with trying to use ice extent (glaciers, etc.) as a direct proxy for temperature.
“Here’s another one who knows the future. Do you have any hot stock tip”
Stocks are too difficult. But if I had to give it a shot, I would say it will all crash sooner or later. It’s a bubble.
Climate is difficult too (especially the future), but surprisingly there seems to be one major knob – the sun. More specifically the solar cycle frequency (or length). I made a very concrete prediction (cooling in 2010s). If I’m wrong, feel free to laugh at me.
kdk33
No, BBD, I would never question your motives, just your political persuasion, which seems to be driving your “science”. Perhaps you could enlighten us.
Apolitical. You are trying and failing to create a hammer-and-sickle strawman. But I do mistrust and disdain those that place profits before people.
is that your euphamism for free marketeer.
No. For dishonest, ruthless, profiteering, self-serving vested corporate interests.
BTW, would you prefer a world at -3C. You’ve yet to answer.
What’s the point? It’s a childish attempt at misdirection. But if you are going to cling to this, then fine. The nearest thing to a sensible answer I can give you is that -3C would be disastrous for global agriculture. +3C will also be seriously problematic for global agriculture, particularly as the enlargement of the Hadley cells is already shifting rainfall polewards. This will tend to dry the great grain-producing zones in the NH.
And no, a rapid rise in GAT with polar amplification will not magically and instantly turn tundra into prime wheat cultivation land. That takes millennia.
NiV
But it does illustrate rather well one of the dificulties with trying to use ice extent (glaciers, etc.) as a direct proxy for temperature.
And it also illustrates rather well one of the difficulties with trying to claim that the MWP was as warm or warmer than the present.
Waffle on, NiV. Nobody’s fooled.
No. For dishonest, ruthless, profiteering, self-serving vested corporate interests.
Yes, yes, BBD. Please do go on. I’m finding this terribly enlightening.
You are trying and failing to create a hammer-and-sickle strawman.
Perhaps, but you are succeeding wonderfully.
So, colder would be disasterous. Warmer merely problematic. Well, at least we’re moving in the right direction. Though I must say you seem to be suffering an irrational fear of change. Perhaps we could put some bounds on problematic. For example: will it be more problematics than ridding ourselves of evil fossil fuel companies.
kdk33
Boundless stupidity.
@ 104
Sorry Eric, when the PDO index goes deeply negative, historically global temps fall. As always don’t take my word for it. Do your own homework. I am sure you will find all this inconsistent with your narrow view of climate science and completely shocking.
Boundless stupidity
Yes BBD, when all esle fails, pound the table. You’ve learned well.
You never addressed the entrenched green energy corporate interests…
You have an interesting outlook. Cooling would be terrible, warming not so much, but we should be terribly afraid of warming. You despise greedy fossil fuel corporate interest, yet have (apparently) no issue with greedy green energy interests – interests who have yet to accomplish anything, save take taxpayer money. You revile right-wing-think-tanks, but are apolitical. Apparently you have no qualms about government funded research – though private moneys are somehow tainted.
My oh my.
I’m wondering if you’ve any inkling the privately funded technological wherewithall required to extract oil from under the north sea, and how you would live without that, and how impossible it wouild be for crony government capitalsm to have accomplished it.
Well, carry on.
@112
I’m not sure what BBD’s point was. (Nothing unusual there.)
Maybe he is charging for the volume?
@ 113
If I’m wrong, feel free to laugh at me.
I have already. Too bad it’s impossible to bet on such things.
NIV @ 82
Another post void of substance..
Your quibble about the definition of “validation” is clearly a vain attempt to divert attention from the fact that over a dozen papers using different proxies and analysis methods came to the same conclusion as Mann regarding the uniqueness of the increase in temperature in the late 20th century.
McIntyre was indeed caught making errors. David Ritson showed McINtyre used 1 PC to represent tree ring data, instead of the 2 that were necessary, when he used centered PCA to show that Mann’s “short centered “PCA analysis spuriously created a hockey stick. When 2 PCA’s were used, the centered and “short centered” analysis achieved the same results.
http://www.climateaudit.info/pdf/ritson.240708.pdf
Based on this, if I thought like you, I could call McIntyre a liar. Instead I attribute this mistake to bias and incompetence. If McIntyre is going to be a critic of creative and groundbreaking science, it behooves him to be correct, especially many years after the fact.
In support of your claim that the AGW climate issue is scientifically discredited and politically dead, you point to areas where the policy response is inadequate. The fact that some action has been taken does actually demonstrate that the science is accepted, and the issue is still alive politically.
Finally, if you look at the role of right wing think tanks in attacking the science behind the theory of AGW, your answer is to create a false equivalence for the role of the left wing and environmental groups. The preponderance of the scientific peer review literature supports AGW. The role of the right wing think tanks and blogs is to amplify the small body of research produced by opponents of AGW, to create the impression that there is a significant body of scientific literature in opposition. This movement by the right began in the 1980’s and continues to this day.
The role of the right wing think tanks and blogs is to amplify the small body of research produced by opponents of AGW, to create the impression that there is a significant body of scientific literature in opposition. This movement by the right began in the 1980’s and continues to this day.
Yes, yes, those dirty republicans. Tricking the gullible into destroying the planet. Dearie me. Someone should pass a law…
kdk33 @ 119
Boundless stupidity.
I’m not ‘pounding the table’, just summarising.
Your new tack of introducing ‘entrenched green energy corporate interests’ is a further misdirection. The issue here is the FF industry and yes, far too many on the right (in US politics especially) peddling pseudo-science. For profit.
@ 123:
Yes, yes, those dirty republicans. Tricking the gullible into destroying the planet. Dearie me. Someone should pass a law”¦
The flat-earthers and boneheads and vested interests urgently need to be exposed for what they are. They are causing enormous harm by preventing the US from formulating and enacting rational climate policy. This in turn ensures Chinese and Indian intransigence. The net effect is a global stall.
If the left were doing this, I would have exactly the same reaction. As it is, I despair at the damage done to the nuclear industry by several decades of dishonest, anti-science fear-mongering by ‘environmental’ lobbyists. Nor do I believe for an instant that renewables can displace coal rapidly or significantly for baseload. That is fantasy.
Your -3C ‘question’ is another another misdirection and I’ve answered the ‘question’ (114).
I know enough about the North Sea oil industry to have nothing but respect for the engineers and geologists who made it work. Once again, misdirection.
This simplistic and obstructive debating style is tiresome. If anyone is being paid here, I suspect it is you and Sashka.
This simplistic and obstructive debating style is tiresome.
Debating? Oh, heavens no, we’re not debating. I’m watching you unravel And I find it fascinating.
vested interests
Is that your euphamism for capitalist.
I know enough about the North Sea oil industry to have nothing but respect for the engineers and geologists who made it work.
Really? So these folk for whom you have great respect – who daily demonstrate they are among the most technically competent people on earth by bringing you the low cost energy that makes your life possible – these are the same people conspiring to destroy the planet. Or do you claim they are somewhow too stupid to understand climate science. Help me out here. Are they flat-earthers or boneheads. Not like those smart people at Soylendra.
This in turn ensures Chinese and Indian intransigence
Yes, yes. If only the US would “set the example”, the developing world would happilly mire itself in poverty to assuage western guilt. Please.
rational climate policy
Good lord BBD! Whatever does this mean. I for one would absolutely support a congressional resolution insisting that climate be benign – perhaps a bit warmer though.
Your new tack of introducing “˜entrenched green energy corporate interests’ is a further misdirection.
No, just useful contrast. It’s an educational tool from days gone by to help students learn. Please compare and contrast…
@125
you may consider it ‘an educational tool’ but to the rest of us it looks like typical trolling. what subject(s) and educational level did you teach? I’m guessing earth sciences weren’t on the list…
kdk33
I’m not ‘unravelling’ and you aren’t making any valid points.
what subject(s) and educational level did you teach?
In your case it was sea level rise. Shall we review?
to the rest of us it looks like typical trolling.
Trolling is in the eye of the beholder…
I consider it therapy. I’m helping BBD understand the true origin of his “climate concern” .
Well BBD,
Sadly this therapy session is over as I’m off to participate in the capitalist free market and hopefully enlarge my carbon footprint.
Perhaps we can resume again in the near future.
I find you a recalcitrant patient, but I never give up hope.
kdk33
I consider it therapy. I’m helping BBD understand the true origin of his “climate concern” .
Really? I seem to have missed something.
#122,
Let me just say before I start that I was impressed by your response earlier on the methane question. So I’m a bit more inclined to go easy than I am with BBD. Nevertheless…
The verification/validation point is important. I’ll give you an analogy.
Dr Madd writes in to tell us that the atomic mass for carbon is 12. He tells us that he determined this by counting the letters in the word “carbon”, of which there are 12. QED. He gets his paper published in a top journal, lauded to the heavens by the world’s media, and the governments of the world turn the economy around 180 degrees on the basis.
A critic of the paper points out that in fact there are only 6 letters in the word “carbon” and the method is wrong anyway. That’s not the correct way to determine atomic mass.
Dr Madd’s response is to point out that the critic is totally wrong, that of course you have to count each letter twice as explained in textbooks on double-entry book-keeping, and anyway there are hundreds of other reports of the atomic mass of carbon giving more or less the same answer.
You are telling me that Dr Madd is therefore correct, the critic should be ashamed for having traduced his brilliance so, and an idiot amateur for having messed up his own letter-counting like that. 6 is obviously wrong. It’s fine for scientists to continue to cite Dr Madd’s paper. That this is how good science works.
I disagree. Getting the right answer for the wrong reason is not science. Defending such an approach is not scientific. And that’s even when you get the right answer, which neither Mann nor his successors did.
In support of this methods-don’t-matter scientific philosophy, and an excellent illustration in itself of the same, you’ve cited the famous “goofy” comment by Ritson in response to MM05, which McIntyre replied to by listing 7 pages worth of errors in it, leading the journal to reject it out of hand. When a second editor more friendly to the AGW trope took over it was resurrected, so McIntyre published his list of errors publicly, and it got canned again.
You really do need to look at counter-arguments carefully, you cannot just take any manuscript written by a credentialled scientist saying ‘McIntyre was wrong’ and believe that is an end to the matter. At the very least, you need to know the history of the debate and recognise junk that even radically pro-AGW editors had to chuck in the bin.
The particular point you raise, that McIntyre used 1 PC rather than the necessary 2 is doubly incorrect. McIntyre had already reported that the bristlecone signal was in PC1 in Mann’s work and in PC4 when done correctly. Thus, it’s neither true to say that 2 is necessary, nor that McIntyre missed it.
I really do appreciate the way you keep feeding me the prompts to let me talk about all this. It would be difficult to bring up these philosophical discussions and historical snippets in conversation without them. The story of how it all happened is an interesting one – or at least, I find it so – but it needs a hook to hang it off, or it looks strange and out of context. Thank you.
#124,
The intransigence of the Chinese and Indians vis-a-vis American policy and the international negotiating stalemate are over the (entirely bipartisan) Byrd-Hagel issue, not the climate sceptics. It always has been.
NIV @131,
Wahl and Amman 2007,
http://www.cgd.ucar.edu/ccr/ammann/millennium/refs/Wahl_ClimChange2007.pdf
concludes:
“Our results show that the MBH climate reconstruction method applied to the original proxy
data is not only reproducible, but also proves robust against important simplifications and
modifications. The results of this study demonstrate that the primary climatological claim
described in MM05a ““ that the method used by MBH to form PC summaries of climate
proxies from data-rich regions results in calibrations that inappropriately weight proxies with
a single-bladed hockey stick-like shape in the 20th century ““ cannot be upheld, and leaves
unchanged the overall MBH result of uniquely high Northern Hemisphere temperatures in
the late 20th century (relative to the entire 15th”“20th century period).”
> It’s not a fallacy to ask the question.
Asking a rhetorical question can be a fallacy.
It really looks like NiV asked a rhetorical question.
Not only did he asked a rhetorical question, he’s not taking responsibility for it.
Why should we believe that NiV takes any responsibility for his commitments in his exchanges, when he does not in this obvious instance?
#132,
And that one’s the famous ‘Jesus’ paper.
#133,
It wasn’t a rhetorical question.
NiV
So I’m a bit more inclined to go easy than I am with BBD. Nevertheless”¦
What a high opinion you have of yourself. I don’t recall it translating into convincing arguments though.
Nobody’s fooled.
NiV
WRT Cenozoic cooling, from Hansen & Sato (2011):
In contrast, atmospheric CO2 during the Cenozoic changed from about 1000 ppm in the early Cenozoic (Beerling and Royer, 2011) to as small as 170 ppm during recent ice ages (Luthi et al., 2008). The resulting climate forcing, which can be computed accurately for this CO2 range using formulae in Table 1 of Hansen et al. (2000), exceeds 10 W/m2. CO2 was clearly the dominant climate forcing in the Cenozoic.
#134
> It wasn’t a rhetorical question.
Who will be fooled by this proof by assertion?
Of course it’s a rhetorical question:
http://rhetoric.byu.edu/figures/r/rhetorical%20questions.htm
There are many flavors to rhetorical questions.
#137,
It wasn’t a rhetorical question.
Sceptics ask the question wanting to know the answer – it’s what motivates their scepticism, their insistence on scientific openness and careful checking. If it was rhetorical, we would be arguing for dismissing climate science out of hand without bothering to check.
You’re question asking “who will be fooled…” is a good one. BBD has said several times that nobody is fooled – presumably he has conducted a survey. You could ask him who he’s asked, and see if you can approach an answer that way.
Actually, I don’t think anyone will be fooled by what I write either.
Of course, one could also see it as a way of avoiding the issue raised. By vaguely insinuating that a rhetorical question may be fallacious you can achieve a dual purpose because rhetorical questions don’t need to be answered, and therefore no answer explaining in what way the argument is actually fallacious would be required. Neat.
I am of course used to it by now, but I do still find it a wonder that people will seriously expend this much effort defending the MBH98 Hockeystick. It’s not essential to your case, and it makes your side look ridiculous. It would do you more good in the long run to acknowledge that it was flawed, acknowledge that it got past your checks, publicly dump it without making excuses, and be especially open about the remainder of the reconstructions in order to prove that you’ve cleaned up the problem. (And, for example, dumped all the other bristlecone reconstructions.) It would deprive us of the biggest, dirtiest stick with which we can hit you, and demonstrate your absolute scientific integrity and willingness to correct mistakes.
And yet, with a few notable exceptions, the AGW-orthodox as a whole do not. It’s amazing! I do have a variety of highly cynical hypotheses as to why, but it’s not obvious to me.
NiV
I agree. The Mannean hockey stick controversy is old hat.
The missed point here is that it does not affect atmospheric physics. The other stuff doesn’t really matter much.
#138
Here is the paragraph:
> As I said above, the significance of the hockeystick controversy is not about the projections of global warming, but about how much we should trust the whole process that has generated those projections. If they’ll lie about this, what else will they lie about?
Here is the actual justification:
> Sceptics ask the question wanting to know the answer ““ it’s what motivates their scepticism, their insistence on scientific openness and careful checking. If it was rhetorical, we would be arguing for dismissing climate science out of hand without bothering to check.
Something’s askew. The actual author of this question posed in this thread becomes the voice of “skeptics”. A voice who has delved into the motivation of skeptics. A voice who has to ask this question motivates the skeptics insistence on fact checking and openness. A voice, if we’re to believe the pseudonym, that still ponders if skeptics are truthfully pondering on a law of human behavior.
Something else looks fishy. This rhetorical question showcases a superior morality that squares strangely with the opportunism seen elsewhere, for instance here:
> I really do appreciate the way you keep feeding me the prompts to let me talk about all this. It would be difficult to bring up these philosophical discussions and historical snippets in conversation without them.
Using prompts to insert one’s pet themes as an attacking weapon to force the interlocutors to defend Mann can be understood. This tactical ploy can be reinforced by following with the usual strawman:
> I am of course used to it by now, but I do still find it a wonder that people will seriously expend this much effort defending the MBH98 Hockeystick. It’s not essential to your case, and it makes your side look ridiculous.
The strawman lies behind “your”, if it refers to me, as it appears to be.
So we see three lovely tactics interwined.
First ask if we could ever trust someone who lied, as if there was a serious answer to this question, as if this answer was relevant to raising the concern, as if we were considering Humean projectible cases like if the Sun will raise tomorrow.
Second, mix purist and opportunist stances when you see fit.
Third, project the shadow of your favorite scapegoat on anyone who stands in your way. Why would they object to your never ending audit anyway if they were not defending your whipping boy? How could they ever contest tormenting based on moral superiority?
Askance about fact checking is independent from moralistic claptraps hidden behind a rhetorical question whose answer does not matter much. If skeptics were to ask for openness in science because they distrust scientists, perhaps they should own their distrust, and not simply hide it under a rhetorical question regarding the future behavior of scientists. This is quite simple to do. For instance, when underhandedly challenged:
> By vaguely insinuating that a rhetorical question may be fallacious […]
one could reiterate that there was no insinuation, but a claim. And to repeat this claim, I therefore claim that the question we are discussing seems quite rhetorical to me, and I believe I offered enough evidence why I think so.
I could offer more justifications upon request. I do appreciate when I get prompted to discuss such questions, which are at the root of our never ending audit.
May I say, I thought that was a beautiful piece of writing. Very nice. Not sure I understood it all, though.
I will try to boil it down to key points.
1. “Sceptics ask…” looks like a representation of the views of all sceptics.
2. The superior morality of insistence on fact checking and openness appears inconsistent with rhetorical opportunism.
3. The question asks “if we could ever trust someone who lied, as if there was a serious answer to this question”.
4. I am projecting the shadow of my favourite scapegoat (MBH98? climate scientists? Mann?) on anyone who argues with me.
5. Sceptics ought to own their distrust.
I’m not sure if I got all of those right, but I’ll have a go at answering them.
1. Yes, sort of. I was actually thinking of my own reasons for scepticism, primarily, and broadening it to whatever subset of sceptics it happened to apply to, which is surely more than one. I’m not making any claims to have conducted a comprehensive survey on the motivations of all sceptics, but I obviously have a fair insight into the motivations of at least one of them.
2. I hadn’t really thought of it in terms of good science being morally superior, but I suppose on looking back at it that I was indeed making such a value judgement. I’m not going to argue with that.
I’m not clear on why it is inconsistent with rhetorical opportunism, unless it is your value judgement that opportunism is morally a bad thing to do? I agree they are not the same thing: I’m a sceptic because of my position on good science; I enjoy debating hockeystick believers because it give me the opportunity to recount many examples of good and bad science. The reasons I feel I should do it and that I enjoy doing it are distinct.
3. I think you may be misreading the question slightly. The question was actually about what else they might have lied about – i.e. it was about the science, not the scientists.
I was being asked why the MBH98/99 Hockeystick was relevant to climate science, and the reason is that not being able to trust the scientists means that we can’t necessarily trust the science. It’s the damage to the science that matters. The damage to the reputations of the scientists is irrelevant to this question.
4. I’m not sure who or what you think my favourite scapegoat is. I’m not even sure I do – there are so many to choose from! But in this case I was only making those points because somebody else had chosen to try to defend the MBH98/99 Hockeystick. I suggested skipping it as old and boring, and even BBD tried to advise against it; the likely outcome is traditionally unfavourable to believers.
If you meant that I was projecting MBH98/99 Hockeystick support on AGW believers more generally, let me make clear that I project it onto anyone who does not openly repudiate this particular work, and call for the issue to be dealt with properly by the scientific method.
5. I’m guessing your complaint is that I was using the question as a way of saying “they’re liars” in a way that I could back off from; that I had phrased it as a question so if anyone challenged it I could say I was “only asking”.
It’s not true. First, as I said, my primary purpose wasn’t to make accusations, but to explain why the Hockeystick debate is relevant to the rest of climate science. And second, when asked about it, I said in #83 “Yes. They are. Haven’t people accused sceptics of being dishonest? Is that not allowed?”
So you see I’m quite open about it, and have no need to cloud it in rhetorical questions.
Does that answer any of your points?
NIV,
Do you believe Amman and Wahl 2007 is a lie? Do you have any other lies to add to your list? Do any so called “skeptics” i.e. opponents of AGW, lie? If yes who are the “skeptics” who lie? If so, why should we believe any of them?
#142,
We can go round and round in circles like this forever. Ammann and Wahl 2007 CC is one of the most famous climate science papers amongst sceptics; it’s story is extremely complicated, and I would find it hard to do it justice in a blog comment.
I shouldn’t get too hung up on the whole “lies” thing. I’m not making any “list” of lies, I wouldn’t even have made any sort of big deal over it, only I was asked.
But if you’re really desperate for a comment on Ammann and Wahl, may I direct your attention to table 1S in that paper? This was one of the particular battlegrounds in the paper’s history, and I won’t go into it all now, but basically Ammann and Wahl at first refused to include these numbers, and it was only pressure from McIntyre that got them published. They are the r-squared verification results for each stage of the Hockeystick reconstruction.
Let me explain what this means. When you do a reconstruction of some quantity from proxies, there is always a question over whether the proxies really do measure the quantity under test. To prove this scientifically, you use only part of the ‘ground truth’ data you’ve got to calibrate the proxy – to determine how much variation corresponds to how much measured quantity. By the nature of the algorithm, the result is likely to match the measured quantity in the calibration period whether there is a relationship or not. But then you compare the reconstructed values with the ground truth you held back. If it continues to line up, the ‘experimental prediction’ succeeds and there’s a good chance the proxy is a good one. If you find it matches in the calibration period (where it is forced to match by the calculation) but ceases to match the quantity it is supposed to be measuring when compared against data it hasn’t seen, then the proxy is clearly not measuring what you thought it was, and the reconstruction is probably junk.
Mann reported that it had passed this test, but for some reason did not publish the actual numbers showing it. These are those numbers.
And as you can see, the correlation between the reconstruction and the measured data during the calibration period for the critical 1400 period (top row of the table) was 0.414, a result implying that about 41% of the variance in the reconstruction could be explained by the real value. The correlation during the verification period, the test of the proxy’s validity, was 0.018, a result indicating less than 2% of the variance in the reconstruction had anything to do with temperature.
These numbers declare Michael Mann to be a liar.
The reconstruction failed the verification test. Mann must have calculated these numbers prior to publishing it, he must have known the reconstruction was statistically proven to be junk, and yet he still published it, still promoted it as the headline graph of the IPCC report, still told everyone it had passed verification, and carefully made sure not to let any unfriendly sceptics get their hands on the numbers to prove it. (When Mann emailed some related numbers to a colleague, he described it as “dirty laundry” that shouldn’t be passed on lest it fall into the wrong hands…) He knew exactly what he was doing.
And since Ammann and Wahl fought so hard to avoid having to publish those same numbers, it’s quite clear that they knew what they meant as well. And that they tried to cover it up, and write a paper saying everything was great with the Mann result and McIntyre was wrong, even while knowing that it wasn’t so.
So do you think that a reconstruction showing a less than 2% relationship with the quantity it is supposed to be measuring should continue to be defended? That the IPCC should have promoted it in the first place, although the lead author of the paleoclimate chapter certainly knew; or that it should continue to be cited in the subsequent report even after this all became public knowledge?
You ask why we should believe sceptics. My reply would be that you shouldn’t (I take my pseudonym seriously), and it’s quite clear that you don’t. That’s good!
I don’t mind that you think I am a liar, and that McIntyre and the many others who have painfully disentangled this are all liars. We need people like you thinking we’re liars to catch our errors and keep us honest.
I don’t expect your agreement. And I’d certainly like you to keep on trying to catch me out. (If we continue this, what with Keith dropping out.) But if you want a better chance of doing so, it would be to your advantage to know what ammunition sceptics already have, and avoid making it too easy for me. To that end, I’d recommend you reading Montford’s book ‘The Hockeystick Illusion’ – purely in order to debunk it, of course. It’s up to you, but you’d have known what I was going to say going in and would have been able to make a far more powerful argument if you had. It would be more interesting for me, too.
Good luck, and my respect.
I am reassured by the numerous good sceptical papers showing ECS to 2xCO2 to be <1.5c.
I’m also relieved now that the mystery forcing that caused Cenozoic cooling ~50Ma to the present has been detected and shown not to be CO2.
Nullius,
I need to take the week-end off as my first life is calling me. But rest assured that I do appreciate your reply and I will do my best to think about my response, and perhaps more importantly, edit my comment before sending it here, instead of just submitting in a rush.
Your overall contributions are commendable. You should considered by every knowledgable climate fans for the All-Stars teams. For those who know a bit of hockey, I’d imagine you in a two-way line, because you have enough versatility to score and finish your checks. As a center or a right-wing? That remains to be settled. Perhaps both.
See you on Monday,
w
NIV,
According to W & A 2007The r2 column you mention relates to ability of proxies to predict high frequency, i.e. annual behavior of temperature, rather than the average over periods of about 50 years. They provide an illustration of why this statistic is not a good measure of the value of a proxy.
This seems to me a legitimate argument, not a lie.
#146,
Hmm. If you’d taken my recommendation, you’d already know the answer to that from pages 66-70 and 156-164 of the book. Never mind.
1. R-squared is a general correlation measure that applies to both high and low frequencies equally.
2. You’re not suggesting that tree ring widths are not responding to the temperature during the year of growth, but instead to the average temperature over the neighbouring 50 years, surely? Besides anything else, that violates causality.
3. Cherrypicking statistical tests after the fact to find one that passes your preferred proxies is cheating. Throwing away the high frequency component because it doesn’t fit your conclusions is cheating. If it fails to fit the high frequencies, why would you expect it to fit the low ones? What does bad high-frequency data (if it is) do to the validity of PCA and inverse regression, the methods Mann used, which use the whole of the variance, not just the low frequency part?
4. Salzer’s results that we looked at earlier showed a stronger high-frequency correlation to local temperature than low frequency. Over longer periods, the relationship was unstable. So we would rather expect the reverse to be the case.
5. Statistical authorities recommend making a range of tests, and failure on any one of them should be considered a sign of spurious correlation. While r-squared, like all such tests, is not perfect, no authority (outside of climate science) recommends not using it. It’s the standard for a reason.
6. Their alternative metric, unlike r-squared, is not a standard one in the statistical literature. The story is too complicated to go into here, but Ammann and Wahl calculated the benchmark for it incorrectly, and via one of the most bizarre procedures I’ve ever seen. Against a correlated noise model, the Hockeystick fails significance even using their preferred metric.
7. You missed the point. Whether r-squared is a good metric or not, Mann claimed to have calculated r-squared for his reconstruction (see p158, p185 of Montford) and that it had passed. The paper includes r-squared results for one of the later steps, and his code, when he was eventually forced to release it, included code to calculate it. The claim that it had passed the test was not true, and Mann must have known before publishing it that it was not true.
Certainly, had he published a reconstruction saying it had failed r-squared, eyebrows would have been raised, and more people would probably have asked questions about what was going on a lot earlier than they did.
8. While it’s possible he could have argued that failure on r-squared was not necessarily fatal, it required a careful discussion and a demonstration to show this. Instead, Mann chose not to mention it. Ammann and Wahl tried very hard not to mention it either.
That’s what we call “withholding adverse results” and if you got caught doing it in many kinds of industrial science (drug trials, medical trials, quality tests, or anything else where big money or people’s lives ride on the outcome) you could easily face jail time for fraud or negligence. Even in pure ivory tower academic science, where it doesn’t matter, it’s considered bad form.
Only one of these really matters: the fact that Mann said that it had passed r-squared and it hadn’t. He changed his mind later, and said he hadn’t calculated it (to Congress, no less), but if that were true then the paper itself where he says he had would be untrue. We’ve got him coming and going.
May I say, I’m impressed by your tenacity. Even BBD had started trying to change the subject and say “it doesn’t matter” long before this. That’s very good. If you’re really interested in the full history of the Hockeystick, I do genuinely think you’d find Montford’s book useful to you.
NiV
May I say, I’m impressed by your tenacity. Even BBD had started trying to change the subject and say “it doesn’t matter” long before this.
That’s because it doesn’t matter. Which is why you love it so.
http://climatehistorynetwork.com/
?
Bad form, old chap.
Explain why we should look there and what we might find. Otherwise the raw link will remain unclicked.
BBD
Fair comment. I was just being lazy and I thought that that link would speak for itself.
“About
The Climate History Network grew out of discussions on H-Net Environment in 2009 with the following goals:
First, to help historians interested in climate find references and resources and network with colleagues. On these pages, you’ll find tools for teaching and research and news and updates about research on climate and history.
Second, to encourage interdisciplinary collaboration between climatologists and historians, to help reconstruct past and present climate change, and to place current climate events in long-term perspective.
If you have any questions or suggestions, please contact us.
Enjoy the site!
Best wishes from the editors and founders of the Climate History Network”
How’s that?
EdG
See # 148.
#143
First life is kept in check. I could have posted this comment yesterday, but I only had the energy for punctual comments. So I prefered to wait another day to pick a main theme.
My main theme will be Good Science.
Talking about Good Science often leads to moral superiority.
Most appeals to Feynman are moralistic. His Cargo cult essay is moralistic. The same goes for Popper. Popper warns against certainties, justifications, big words, and often finishes off with humility. These two thinkers explicitely convey moral values, even when they talk about science.
The moral higher ground limits the number of things of interest. Scoring less brownie points is a detour when one is on the path of Good Science. This might be a good tradeoff in the long run. In any case, a choice has to be made between brownie points like Mann or Jones and Good Science, if it is true that there is so much to do and so little time.
The Good Science stance does not square well with Please Do Try to Defend Mann. While the two stances are not logically incompatible, their combination hints at opportunistic self-righteousness, where Good Science is a proxy debate for political values that might have less winning chances than Good Science. Whether Mann lied or not is irrelevant to Good Science. What should matter is how to make Science Good.
As far as I’m concerned, Mann and Jones are pure brownie points, trifty futilities that waste time. Time better invested in doing things more compatible with Good Science, for exemple to build a statistical model à la Browne and Sundberg for paleos. Armwaving formal stuff is not enough for Good Science.
If what matters is “the damage made” to Good Science, one has to wonder if neverendingly raising concerns about Mann helps Good Science at all. As far as I am concerned, this is at best a personal vendetta, which can’t be excused by having made some money or having an eccentric hobby. At worse, this is scapegoating. In between, Mann serves as good whipping boy for personalization’s sake.
Projecting the MBH98/99 Hockeystick support on AGW believers more generally, and even “onto anyone who does not openly repudiate this particular work” deserves due diligence. I believe it is false on simple sociological grounds: for instance, we know that leaders do not chastize others. Nonetheless, I believe it is worse than false. It is wrong, so wrong as to undo the Good Science stance and leaves us only with self-righteous opportunism.
If Good Science really mattered, we’d raise concerns about science, and never speak about scientists. I believe this ain’t gonna happen soon. I’d gladly stand corrected on that hypothesis.
Another interesting to test is this: rehearsing the Mann story will not always be “unfavorable to believers.” After a while, people can recognize scapegoating, and when this happens the moral higher ground of Good Science is lost. For instance, reading our good Bishop’s rendition of this incident reveals that Good Science as a mere rhetorical trick.
So not only one needs to be able to frame minds with the whipping boys, but one needs to make sure no one will pick up the “toxic assets”, so that they could be used at one’s convenience. To that effect, more tricks can be used. For instance, once upon a time, some tried to sell that nobody wanted to condemn Jones’ askance to delete emails. A lukewarm misrepresentation, to say the least.
***
I believe the question I claim to be rhetorical pertains to this overall narrative. The question raises concerns that are tough to audit, inasmuch as it can only raise concerns, concerns which should be shared by every friends of Good Science. These concerns starts with a single case base. The question produces the induction step it needs to raise concerns. Concerns that are trivial to raise: who can afford to be against Good Science?
My claim is that it’s a rhetorical device whose answer can’t have an empirical basis. The usual answer is that no, we can’t know if they don’t lie about anything else. How the hell are we supposed to decide anything about that question?
Under that interpretation, this is a rhetorical question. How can we trust these scientists? We just can’t. The rhetorical question hides this insinuation: “We should not trust them”. It also presumes that trust matters. Interestingly, Popper advised against trusting scientists and scientific theories in general: it was not rational to trust any of both.
Another way to see it’s a rhetorical question is that, logically speaking, our trust in some scientists should not impact on the science. Science is not a matter of trust anyway. And so we fall back to what se said earlier: these questions are irrelevant to the scientific endeavour. Unless, of course, we’re talking about the science of public relations.
Trying to argue that this ain’t a rhetorical question is unwinnable. I will disclose here that I spare my arguments in the hope that this won’t be conceded. More arguments can always be forthcoming to make that point clearer and clearer. If that’s not a rhetorical question, there are arguably no such things as rhetorical questions.
***
To recapitulate, that audit starts with some concerns. Then emerge questions about trust, spiced with some stories abour dead trees. And then more concerns. More questions about trust. A bit of Good Science. Perhaps some other dead trees, for good measures.
The audit never ends.
NIV,
In response to your echo of the criticisms of Montford, McIntre and others with the same point of view, I offer this criticism of their work:
http://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/
This sentence:
> Scoring brownie points is less a detour when one is on the path of Good Science.
should be read:
> Scoring brownie points is a detour when one is on the path of Good Science.