There is a continuing debate about global warming and about climate change, despite the cries that ‘the science is settled’. It is, in my view, a most sloppy debate, mostly because of the argumentative style of many of those who involve themselves in it. My own rule is to look at the arguments and see if they are backed up by good evidence. I was taught so as an undergraduate, and it has been the basis of my scholarly work. But there are other styles, most of them fallacious in whole or in part. Indeed, there are scores of them (you can see a long list here). My advice is to recognise them, and never consciously to use them, in discussions about global warming or indeed about anything else. Here are a few. They’re easy to recognise.
Attacking the person and not the argument (ad hominem)
There’s been a lot of that on this website. Why would anyone go to WUWT, or read anything by Jo Nova? To which the counter is Why would anyone go to SkepticalScience? I’ve said myself that I regard SkepticalScience as mostly worthless and hypocritical, and I’ve explained why. But I have certainly gone there to read their arguments. In fact, if you are going to take part in a debate you have to know what the other side thinks, and why it thinks the way it does. Not to go there, and not to read their stuff, is intellectually empty.
Moving the goalposts
There’s been a good deal of this one, too. If you successfully address some point, you are told you must also address some further point. This can go on for some time. It is an argument by distraction. I think the underlying trouble with so many of these false argumentative forms is that the user is trying to win. It is better to take part in order to discover what you yourself think, and why you think that way. You will not convince most people, anyway, whatever you say, but you will be a lot more confident about your own position.
Incidentally, you can sometimes see the goalposts lowered rather than shifted. I take Vitamin C, have done for years and years, and rarely have colds. But if were to catch a cold I might be tempted to say (I hope I wouldn’t do this!) that my cold would have been a lot worse had I not taken Vitamin C. You can see variants of this one frequently.
Changing the subject
Another familiar ploy in the Comments section could also be called the arrival of a red herring, or just misdirection. You say something substantial, and your opponent picks you up on a spelling issue, and by the time you have dealt with that the issue has gone. You use a particular verb, and your opponent asks you to define the meaning of that verb, or asks whether or not you are aware that Marx/Hitler/Mao also used the verb in that way. Avoid those people!
Using numbers without context
You will come across people telling you that five trillion tons of ice have melted, or that 70 per cent of the Great Barrier reef is dead, or the we’ve passed 400 parts per million of carbon dioxide — as though these numbers have significance in themselves. They don’t, of course. What is the context? How much ice is there, anyway? How well have we sampled the Reef? In what sense is coral dead?And so on. The context usually puts the large number in proper perspective.
The Fallacy Of The Crucial Experiment
This one is widespread. You will say something, and your opponent says, ‘Oh, Bloggs debunked that ages ago!’ It is sometimes called ‘the smoking gun’ or ‘the canary in the coal mine’. The media frequently report scientific papers in this fashion, if only because to do so makes a better story. I remember being told by an elder and better, when I was enthusing to everyone about my first paper published in a leading journal, that the test would be if anyone remembered it ten years later. In fact, only one of about a hundred papers I have written was ever given much recognition later on, but at least that one had lots, and was reprinted in two different collections.
Argument From Authority
I’ve dealt with that one in two essays in this set. The supposed fact that 97 per cent of climate scientists think whatever they think, or that leading academies support them, means nothing. Science is not based on authority, but on questioning and testing theories with experiments or observations. A variant is for your opponent to point to your apparent lack of authority — ‘What would you know about it?’
Argument By Repetition (Argument Ad Nauseam)
If people say something often enough, other people will begin to believe it. ‘The science is settled’ is just such a slogan. It isn’t true, and doesn’t stand up to more than a few seconds’ scrutiny, but it has been widely accepted, nonetheless.
Statement Of Conversion:
The speaker tells you that he used to believe in AGW, but he doesn’t now or, conversely, that he used to discount AGW, but not any longer, not since — and then you are likely to get one or other of the bad arguments listed here. The only good basis for such a statement is a straightforward and fact-filled account of the basis of one’s current view with no appeals to authority. Familiar versions of this one are ‘I used to think that too, when I was your age…” People of my generation need to resist that one!
Burden Of Proof
A familiar version of this one is the claim that whatever has not yet been proved false must be true (or vice versa). Essentially the arguer claims that he should win by default if his opponent can’t make a strong enough case. I call this one the Steven Mosher ploy, because Steven says (correctly) that until sceptics come up with rival theory to explain global warming the orthodoxy will continue to win. That doesn’t mean that the orthodoxy is right, for it is easy to point out all sorts of problems with the AGW scare. But in this case the burden of proof is reversed, and placed on the sceptics. It oughtn’t to be there, because the one with the theory is the one who needs to show that it must be right. Maybe some day sceptics will have a rival theory. I wouldn’t hold my breath.
An underlying problem here is the supposed need to know. Some things are not known properly, and in my view AGW is one of them. CO2 is cited as a necessary cause of warming, because the models can only reproduce warming if CO2 increases are factored in. But that implies that we know everything there is to know, which is plainly not the case.
There seem to be an insistent need, also, to be sure, to be confident, so that governments can make the right decisions. In my view the right decision is to do nothing, and deal with other more important problems. We will know more in due course. But I am not part of the orthodoxy.
Here an apparently sensible proposition slides into something much more objectionable, and the best example I know is the so-called precautionary principle. The Wikipedia summarises it like this: if an action or policy has a suspected risk of causing harm to the public, or to the environment, in the absence of scientific consensus (that the action or policy is not harmful), the burden of proof that it is not harmful falls on those taking an action that may or may not be a risk. Sounds reasonable? The problem is that the same caveat ought to be applied to the absence of action, or the proposed cure. Shouldn’t we look hard at the consequences of a carbon tax, which on the face of it will make no difference of any discernible kind to temperature, but will cost everybody more?
There are many more poor argumentative styles, but these I think are the important ones. I hope setting them out like this helps, and that readers recognise when they are about to employ one — and resist!
Join the discussion 68 Comments
Don I agree with your points above and hope I haven’t been guilty of employing too many of the bad arguments you’ve mentioned.
But I think the best argument against their CAGW ( not some AGW) is the point that there is nothing unprecedented or unusual about our climate or weather since 1950. Human population is booming and the world is greening and life expectancy continues to increase. The calorie intake in developing countries has increased substantially, but unfortunately there is certainly an obesity problem in wealthier countries.
It looks like there may be some shifting of goal posts by the alarmists because Antarctica is cooling and more ice is being measured. They seem to want us to forget about global warming now and start to concentrate on the world’s regions instead. Here’s a good post from Jo Nova.
Thanks Don – I am now better armed to deal with these underhand practices. Two Comments:
Shifting goal posts. Years ago, we were suffering from constant shifting of goal posts and a work colleague, an AFL fan, believed it was a deliberate ploy by bosses to ensure that when we missed goals, behinds were kicked.
More seriously, I believe sceptics do have an alternative theory for climate variation – it is mostly, if not all, caused by natural factors. Solar variability is the main suspect, but the factors are not all known, although their combined effect is well recorded in the geological record that generally rules out significant CO2 influence at current levels and tells of much greater past changes when no human influence was possible..
‘Natural factors’ is not a theory. A theory would be able to specify the natural factors and their inter-relationships, offer a plausible causal nexus, and survive observation and testing. We don’t have one yet. I agree that the AGW orthodoxy theory is weak, but it is a theory, or hypothesis, if you like.
Don, didn’t Henrik Svensmark link a natural factor (incoming cosmic radiation) into a theory by proposing that such radiation induces cloud formation which, in turn causes cooling because clouds block incoming solar energy?
Really useful thanks, and changing the subject, the vitamin C tip – I’m off to buy some.
Margaret, I was not offering you advice! That Vitamin C is good for you in these domains is widely believed, and Linus Pauling tried very hard to find the causal link, without success. It seems to work for me, because I used to get an annual fluey cold. I do have a ‘flu shot, too, but that is more recent.
Of course you weren’t – ‘thanks for the tip’ didn’t infer that. Chewable vitamin C tablets were a favourite while I had kids at home (probably bad for the teeth as they were as addictive as lollies).
Your ‘goalpost lowering’ example simply jogged a thought that I don’t take vitamin c anymore but it’s worth a try for common colds as the flu shot is specific.
I love oranges so maybe I should just buy more of those.
Roy Spencer has posted the May temp anomaly and there is a drop of 0.16 C from April’s 0.71 C to May’s 0.55 C. Werner Brozek has calculated that drop compared to the post 1998 el nino temp drop and found that UAH V 6 data would probably deliver a temp rise under 0.5 C by 2100. This of course is the temp measured in the troposphere were global warming is supposed to be higher than at the surface. That’s according to the IPCC.
Wasn’t it a great autumn though Neville?
I’m just terrified that we’ll have autumn weather like that as the norm! We desperately need a carbon tax to ensure it isn’t so. A carbon tax will fix it.
(Perhaps ignoring reality is one of those styles of argument the warmists use the most. eg- a carbon tax will have no effect on the weather even if CO2 is a greenhouse gas – best ignore that. No matter how much solar/wind energy generation capacity is installed, it can’t produce any energy on a cold foggy morning – best ignore that. Corals grow in warm tropical sea – don’t address that… )
A good inventory of the polemical bad habits, Don.
The ‘Argument From Authority” can be delicious. A fellow poet told me of his occasional mischief in a tutorial when, say someone had given a paper on Yeats, Kevin would chip in, “But you’ve read Nutthall on Yeats?” “Uh?” says the person with the paper. “You’ve NOT read Nutthall on Yeats?!!” “Well, No, I…” “Oh well! In that case we can’t possibly proceed. Nutthall has dealt with all the stuff in your paper and his conclusions are compelling.” Silence around the tutor’s room from both tutor and tutored because it seems no-one has read Nutthall on Yeats…unsurprising since Nutthall does not exist. Only someone with a fearsome reputation for erudition, bumptious self-confidence, and mischieviousness can pull this off, but my mate Kevin had all these qualities.
I was involved in a similar hoax as an undergraduate. We had a fellow student who always seemed to have the read the article or book or whatever, and a friend and I decided to trick him by proposing a person who had written about X and the other would say that he ad read this too. We would then wait for the clever bugger to say me too. Alas, he didn’t, but the lecturer was fascinated, and wanted to find out much more. Eventually we had to confess, and were ticked off, with some humour, fortunately.
Enjoyable as well as informative. Perhaps the ‘post hoc ergo propter hoc’ fallacy may be involved in CAGW. From 1750 Britain and others perpetrated the industrial revolution. Now some 250 years after that CO2 has reached 400ppm. Therefore the industrial revolution caused the rise in CO2 and the nations responsible must pay.
I certainly recall hearing Roz Kelly, Member for Canberra, making the argument that Britain owed us compensation for ringbarking because Britain had instigated settlement.
The 97% consensus is very effective in making sceptics feel inadequate. Obama uses it to good effect with his slick authority but it is so obviously wrong and now they are extending it to litigious activity to shut us up.
The never-ending errors in medical science that regularly change direction 180 degrees are a great example of the foolishness of consensus.
Reading the “consensus” of the writers and commenters at “The Conversation” in virtually every aspect of science is possibly an even better display of the ignorance of “experts”.
You may be interested in the following (from WUWT): A landmark California bill gaining steam would make it illegal to engage in climate-change dissent, clearing the way for lawsuits against fossil-fuel companies, think-tanks and others that have “deceived or misled the public on the risks of climate change.”
The bill seems to have been shelved, according to WUWT a day after telling us about it.
Following the plethora of bed-wetting articles on the looming death of the GBR from coral bleaching I just had to send a couple of those JCU experts this:
The expression bed-wedding introduces emotive dimensions and a false or misleading analogy: which of Don’s categories above – if any – could apply to this usage dear reader?
I had hoped that expression was short-lived and until drongoed spangles (playing with a Shaun Micallef type persona) brought it up again I was relieved. It’s hard to categorise but it’s definitely a slide in language at least and offensive to anyone who may have been or is the parent of, or is, a bed-wetter!
Therefore it is ad hominem and ad feminim.
Bed-wetting was often excused because of a perceived nervous disposition on the part of the bed-wetter when it was often laziness or a careless attitude.
When university professors refuse to give balanced accounts of their studies and predict doom, gloom and disaster in order to extract huge taxpayer funding as a result of their bias, they show their contrived nervousness to be worse than any bed-wetting child.
I think a bit of honest ad hom beats thievery and deception anytime.
And as Bryan says above, these robbing, deceiving “bed-wetters” are now trying to put the whistle blowers in gaol for calling them out..
“when it was often laziness or a careless attitude.”
That’s very hard line drongled spango!
Were you not able to work out what the real cause was?
You have the best name of all commenters but … you do make some odd remarks!
“but … you do make some odd remarks!”
So, Margaret, you’ve obviously never heard people boast about wetting the bed [and worse] as children?
That’s interesting, Margaret. I must admit that the ones that told me were boys who had since grown out of it and possibly boasted about it out of an honest bravado.
But to get back to your original criticism: me calling something a “bedwetting article” whilst talking to a third person is only remotely ad hom.
Particularly when I list access to their well known and tiresomely repeated, biased [have I ad hommed again?] arguments awa supplying my own.
“You have the best name of all commenters but … you do make some odd remarks!”
So does the spangled drongo bird, most unusual calls indeed.
Is it a tinkling sound?
The call is like a harsh chatter, that breaks into some metallic clanging. Reminds me of someone dropping a piece of metal onto a concrete floor.
Very evocative dlb – I believe I’ve heard that call recently from a pair of the species.
You’re cherry picking again, dlb.
With a tin ear.
And Margaret is ad homming and femming spangled drongos
I like ‘ad feminim’!
A physiotherapist says on her blog –
“. But I take exception to Scott Morrison or any other politician using bedwetting as an insult. Bedwetting is problematic for many children and their families and even for quite a few adults, both men and women, and should not be used flippantly for political point scoring. It’s such a putdown and these kids, teenagers and adults who are burdened with this condition suffer enough without being reminded of it over and over again as an insult by a politician (the repetition on every news report for days on end is nauseating).”
Exactly – please don’t reintroduce violent or demeaning metaphors that the Scott Morrison’s of this world just copy from America.
It’s a plural, Margaret. You don’t need apostrophes at all, and I speak as the National President of the Australian Society for the Extirpation of Inverted Commas…
Thanks for the tip ?
I did need to correct the auto spell though.
For ? read smiley face.
Agree with Don – the sooner we have brown shirted men armed with Apostrophe Pistol’s bursting into our home’s at 0100 hours, the better. And have them cart away recidivist users’ of them to re-education camp’s’.
So, Margaret, you’re certain a physiotherapist knows the mental make-up of all our bed-wetting kids [and adults?], eh?
I personally think “bed-wetter” is a perfect description of a public funded scientist who is so unscientific as only give their own biased view of any climate event and claim that it is catastrophic when it is likely natural and beneficial.
How would you describe it?
Anthony Albanese was considered funny and clever a few years ago when he referred to the “convoy of no confidence” as the “convoy of incontinence”. “Turn about is fair play” as the more britishly inclined amongst us may sometimes say.
(Personally, I find the best turn-about was the “convoy of inconsequence”, which was all the diselected Labor members and the numerous staffers leaving Canberra after the 2013 election.)
Margaret might be happier if I referred to those bed-wetters as incontinents.
It might seem less ad fem.
Antarctica is always high on the alarmist’s agenda, so here is an interesting contrast over 100 years.
The ship of fools was trapped by ice in 2013, but Mawson landed in the same area in Commonwealth bay surrounded by clear water in 1912. Here’s the proof you can see with your own eyes. This area is choked by ice today.
Don didn’t mention cherry picking, but this is the technique you or should I say Andrew Bolt used in criticising the Turney Antarctic expedition. If you look at the graph Bolt provided you can see there is considerable year to year variability. Had Turney gone in 2011 or this year he may well have found less ice, as Antarctic sea ice in these years was below the recent 37 year average. And how do we know that when Mawson went it was just a lucky year? Except for this one year, Bolt provides no evidence that the early 20th century had less sea ice on average than at present.
Even if evidence shows that the Antarctic does have more ice on average than 100 years ago this is totally ignoring the crash in Arctic summer sea ice over the last 40 years.
Dr. Duncan Steel, a highly respected and much published astrophysicist, wrote an essay on his blog (duncansteel.com) postulating that the different response of the Northern and Southern hemispheres was due to precession of the earth’s axis. Although supported by detailed mathematics that I didn’t understand, this was torn apart on skeptical science by people who probably didn’t understand it either, mainly because Dr Steel was not a climate scientist, and his opinion had not been subjected to peer review (even though he had invited comments from peers). A classic example of appeal to authority.
The fog of corruption, mysticism, religion, and just play bullshit, about climate ‘science’ means it can probably be dismissed as another ‘we’re all gonna die’ scare, like the hole in the ozone layer, which apparently is still there, although none of the awful effects have materalised. If ‘climate alarm’ is real, I seriously doubt that humans can do anything about it (Australians certainly can’t), and although virtue may be its own reward, it has no effect on global temperature.
Unfortunately I could not find any reference to climate on Dr Steel’s website. As the earth’s precession period is 26000 years, I find it unlikely to cause any noticeable climate changes over 100 years.
He has obviously removed it from his site, but you can find it here: http://www.duncansteel.com/wp-content/uploads/2014/09/EOaCCC.pdf
Thanks Bryan, I’m slowly going through it. It’s not too technical but does require some thought to see if his theory does have merit.
Dlb I think you are clutching at straws. The difference between Mawson’s 1912 ice free Comm bay and the ship of fools 2013 experience is like chalk and cheese. Sure some years may have less ice than others but overall you’ll find that there is much more ice on and around Antarctica today than earlier periods.
The UAH V 6 satellite data shows that Antarctica has been cooling slightly since Dec 1978. And the Arctic and Antarctic seesaw effect is well known, where one pole loses ice while the other gains more ice then vice versa. There are many peer reviewed studies that show this paradox.
There are also many PR studies that show Greenland gaining ice using satellite measurements. The Glacier Girl P 38 bomber was found 260 feet under the ice in Greenland after about 50 years. It had landed there and abandoned in the early 1940s and recovered in the 1990s. See youtube video describing the recovery.
In the past I’ve linked to PR studies that show the earlier 20th century Greenland warming was much faster than the more recent warming after the mid 1990s. And Prof Phil Jones was a member of one of those studies. So where is the impact of extra co2 emissions after 1950?
Neville, I’m not necessarily saying you are wrong, but what you are indulging in is cherry picking and hand waving, much like what we see on the other side of the debate.
“overall you’ll find that there is much more ice on and around Antarctica today than earlier periods”
What earlier periods are these? do you have any evidence pre satellite of this?
“And the Arctic and Antarctic seesaw effect is well known, where one pole loses ice while the other gains more ice then vice versa”
Is it well known? I couldn’t find any research on this, and I shall indulge in a cherry pick myself. Amundsen first sailed the NW passage in the early 20th century so there must have been less ice in the Arctic then and by your theory more in the Antarctic when Mawson was there at a similar time.
“The Glacier Girl P 38 bomber was found 260 feet under the ice in Greenland after about 50 years.”
Obviously much snow had fallen in the 50 years since it landed, but more snow does necessarily mean the Arctic is cooling. A warmer arctic ocean could well produce more snow.
Dlb, and bear in mind the voyages of Frobisher, Davis et al in ships the could travel “nary an inch to windward” which effectively meant that half of the ice-free ocean was denied them yet they explored far into the Arctic waters in the 16th C.
I’m one of the few foolish people left who still have a cruising sailing boat without an engine and even though my boat goes very well to windward you would not get me exploring those waters today.
You can read about Glacier Girl here:
You’re not just a pretty face, Don.
dlb, it is kind of funny, watching you try to be the voice of reason with Neville & Spang. Best of luck.
David, I get tired of the clichéd arguments on both sides of the debate. If climate sceptics want to be taken seriously they need to smarten up their act, otherwise it’s just game playing. Unfortunately or perhaps fortunately sceptics don’t have “the appeal to authority” to fall back on.
dlb, no one has the appeal to authority to fall back on simply because there is none.
But there is such a thing as rational scepticism and when we see “experts” such as those GBR scientists being roasted by their boss for their bed-wetting interpretations of reality it is not hard to work out just who is game-playing.
“I must admit that the ones that told me were boys who had since grown out of it and possibly boasted about it out of an honest bravado.”
Spang you are sharing too much personal information. I suggest that you stick to climate change.
David, these aren’t things you seek but you do occasionally find. Sounds like you may have, too.
And bed-wetting is very pertinent to “climate change”.
Antarctica and Greenland combined hold about 99% of the Planet’s ice mass. Here is the Royal Society’s graph showing expected SLR for the next 300 years. The graphs show all of the models used by the IPCC. You’ll note that Antarctica ( 89% of ice mass) is NEGATIVE for SLR until 2300 and Greenland ( 10% of ice) is positive for SLR until 2300. So where is the problem of dangerous SLR?
Yes, Neville, and to prove exactly that point I invite everyone interested to witness the highest astronomical tide of the year this Sunday night on the east coast and [providing it isn’t accompanied by a falling barometer and a storm surge which may be the case with the current weather pattern] compare it with data for the same event going back 40, 50, 60, 70 years.
Not only is there NO dangerous SLR, NO accelerating SLR but there is NO SLR whatsoever in that period.
The big tide last night on the east coast was exaggerated considerably by the atmo pressure being considerably lower than normal [up to ~ 18 Hpa below] plus strong winds.
Tides were up by around 15 cm. But as you are all no doubt aware, sea levels rise by 1 cm for every 1 Hpa fall in pressure.
“Activist scientists and lobby groups have distorted surveys, maps and data to misrepresent the extent and impact of coral bleaching on the Great Barrier Reef”
Russell Reichelt is far too kind to these “experts” who tell lies for a living:
The concerned and convinced consensual “scientists” break every rule in the book when it comes to arguing their case. Jo Nova explains very well, today, just how close they get to ruling the planet with their propaganda:
What I have been on about is Don’s 4th paragraph of using numbers without context. Another well known instance of this is to use models [which is all of them] that can’t quantify the influence of water vapour, a GHG far in excess of that demon GHG CO2.
It’s called argumentum ad ignorantium.
Here is the 2009 Box et al study from Greenland covering the temp record from 1840 to 2007. The 1920s warming has a much higher trend than the recent warming. Co2 levels were much higher in the recent warming than the 1920s, but the trend was lower. Here is the study summary from Co2 Science and the link.
We’ll probably learn a lot more about Greenland temps when the AMO starts to change to the cool phase. Who knows when but probably post 2020.
Near-Surface Greenland Air Temperatures: 1840-2007 Reference
Box, J.E., Yang, L., Bromwich, D.H. and Bai, L.-S. 2009. Greenland ice sheet surface air temperature variability: 1840-2007. Journal of Climate 22: 4029-4049.
What was done
“Using a set of 12 coastal and 40 inland ice surface air temperature records in combination with climate model output,” the authors say they reconstructed “long-term (1840-2007) monthly, seasonal, and annual spatial patterns of temperature variability over a continuous grid covering Greenland and the inland ice sheet,” after which they say they compared “the 1919-32 and 1994-2007 warming episodes” and made “a comparison of Greenland ice sheet surface air temperature temporal variability with that of the Northern Hemisphere average.”
What was learned
The near-surface air temperature history that Box et al. derived for Greenland is reproduced in the figure below, along with the corresponding history of Northern Hemispheric near-surface air temperature.
Figure 1. Low-pass-filtered Greenland and Northern Hemispheric near-surface air temperature anomalies with respect to the 1951-1980 base period vs. time. Adapted from Box et al. (2009).
Based on the results depicted in the figure above, the four researchers determined that “the annual whole ice sheet 1919-32 warming trend is 33% greater in magnitude than the 1994-2007 warming,” and that “in contrast to the 1920s warming, the 1994-2007 warming has not surpassed the Northern Hemisphere anomaly.” Indeed, they note that “an additional 1.0°-1.5°C of annual mean warming would be needed for Greenland to be in phase with the Northern Hemisphere pattern.”
What it means
In spite of all the fuss climate alarmists make about Greenland being on the verge of crossing a tipping point and beginning to experience dramatic ice loss, the results of Box et al. demonstrate there is nothing unusual, unnatural or unprecedented about the nature of its 1994-2007 warming episode. In fact, it is much less impressive than the 1919-1932 warming; and it becomes even more “less impressive” when it is realized that the atmosphere’s CO2 concentration only rose by about 5 ppm during the earlier period of stronger warming but by fully 25 ppm (five times more) during the later period of weaker warming.
Reviewed 5 May 2010
Copyright © 2016.
This Axford et al study from Greenland shows extremes of temp over the Holocene. During the earlier Holocene temps were 2 to 3 C higher than today and during the LIA temps were the lowest for the entire Holocene at this site. So the temps today along with much higher Co2 levels are not unusual or unprecedented at all.
Here is the link and the study summary from Co2 Science.
“Holocene Temperatures at the Western Greenland Ice Sheet Margin Reference
Axford, Y., Losee, S., Briner, J.P., Francis, D.R., Langdon, P.G. and Walker, I.R. 2013. Holocene temperature history at the western Greenland Ice Sheet margin reconstructed from lake sediments. Quaternary Science Reviews 59: 87-100.
The authors write that “predicting the response of the Greenland Ice Sheet to future climate change presents a major challenge to climate science,” but they say that “paleoclimate data from Greenland can provide empirical constraints on past cryospheric responses to climate change, complementing insights from contemporary observations and from modeling.”
What was done
As they describe it, Axford et al. “present Holocene climate reconstructions from five lakes along the western Greenland Ice Sheet margin, near Jakobshavn Isbrae and Disko Bugt,” where “insect (chironomid) remains from North Lake are used to generate quantitative estimates of summer temperatures,” and where “changes in sediment composition at the five study lakes are interpreted as evidence for ice sheet fluctuations, changes in lake productivity, and regional climate changes throughout the Holocene.”
What was learned
The six scientists report that “temperature reconstructions from subfossil insect (chironomid) assemblages suggest that summer temperatures were warmer than present by at least 7.1 ka (thousands of years before present), and that the warmest millennia of the Holocene occurred in the study area between 6 and 4 ka.” They also note, in this regard, that “previous studies in the Jakobshavn region have found that the local Greenland Ice Sheet margin was most retracted behind its present position between 6 and 5 ka,” and they say that they used chironomids to estimate that “local summer temperatures were 2-3°C warmer than present during that time of minimum ice sheet extent [italics added],” while indicating that the Little Ice Age “culminated at North Lake with 19th century summer temperatures that were colder than any other period in the record since deglaciation [italics added].”
What it means
Against this backdrop of data-based information, it should be clear to everyone that there is nothing unusual, unnatural or unprecedented about current temperatures along the western Greenland Ice Sheet margin – or anywhere else on the planet, for that matter – for temperatures there currently fall well within the extreme bounds experienced over the course of the Holocene. And it should also be realized that starting from the coldest point of the entire Holocene (the depths of the Little Ice Age), one could well expect that once started, warming (for whatever reason) could well be anticipated to be substantial.”
Reviewed 17 July 2013
Because of the fraudulent COP 21 BS in Paris we have more and more corruption in developing countries. Countless billions $ of OECD countries funds are wasted in bottomless pits of useless schemes that syphon off money but do nothing to fight climate change.
While stupid OECD countries pay developing countries to “fight climate change” these same countries can build numerous new coal fired power stations to ensure their Co2 emissions will boom for decades into the future. As Dr Hansen said what BS and fraud and zero change to temp or Co2 levels. These people are barking mad.