UKH

It seems like there's large numbers of people on here who remember climbing late 70s to late 80s, during a period of relative glacial stability or even advance in the alps. Older guidebooks date from the same period. This is contrasted to conditions since 1990 which are obviously much worse, making some routes impassible etc. 

What I'm interested in is if anyone here remembers, or remembers hearing, what it was like during the rapid period of retreat in the 50s and 60s - I don't see any mention in classic books from that period of conditions in the alps worsening, or walk-ins becoming difficult. Surely if a glacier is in retreat, the bottom of it is necessarily "rotten", with muck on the ablation zone, increased crevasse and serac risks, and similar. Can't post photos so I've included a link (if it comes up properly) showing glacier blanc retreat history. There is a reference that the current footpath is being used next to the glacier (indeed, is threatened by it) in the 80s so perhaps people just avoided lower glaciers? And this is now impossible due to the ablation zone starting so high up?

Past and Forecast Fluctuations of Glacier Blanc (French Alps) | Annals of Glaciology | Cambridge Core

From 1955 -1965 there's a 200m retreat of GB, comparable to the losses seen in the 90s. 

Buhl's account of his ascent of the Eigerwand in late July 1952 records the absence of the First Icefield.

I made the point that glaciers ebb and flow on another thread and was met with quite some disbelief - I watch this thread with interest!

Really? It seems pretty obvious that glacial budget and flow regimes would fluctuate. You weren't trying to use that as evidence against climate change were you?  

No, I'm absolutely not a denier (although I confess to being an aficionado of the Copenhagen consensus).

I got flamed becuase I dared to say AGW was accelerating glacial retreat in the alps. My correspondents wanted to blame the whole thing on AGW. 

1. Personal accounts in english will be thin on the ground as there's only going to be a few english 'native' people to see this over the time period you mention, and not many will be writing books? What about french, german language accounts?

2. If not, pictures tell a 1000 words.  I didn't see many in the reference you quote, but you should be able to google up a few which will give you something.

Re. Copenhagen consensus - ha ha, ironic to base inaction on climate change on cost benefit analysis, should really state cost benefit analysis for the US as the people most likely to get the 'siht end of the stick' don't really have an economic presence commensurate to the number affected (poor people don't matter)

Is there anything left of the icefields on the Eigerwand these days? I suppose it's very dangerous in summer now. 

What's that?

Seen pictures of it completely clear in summer. Read on a thread here its climbed in March now for this reason

Re written accounts - its the exact period of etoiles et tempets and there is no mention of poor glacier quality (that I can remember) in that book. I don't read German so can't comment on that side. I've seen pictures I was really wondering if anyone remembered what conditions were like for climbers, rather than the actual retreat itself.

Presumably there were similar permafrost issues lower down causing loose rocks and so on? I wonder also if the latest bout of melting is qualitatively different, more driven by heatwaves in summer rather than a decline in winter snow cover (which killed off low altitude ski resorts in the same period, I think). Maybe that's what makes summer glacier quality particularly affected.

You've TLA'd me what is AGW?

Anthropogenic Global Warming?

I can't throw any light on this from personal experience -- I didn't start Alpine climbing until 1964 -- but on the basis of a quick search of the glaciological literature I'm not convinced that glaciers in the Alps generally were retreating rapidly in the decade before that. That might explain why you haven't found much discussion of retreat in the climbing literature from that period.

See for example the Figure whose thumbnail is on the front page of this open-access paper:

ttps://tc.copernicus.org/articles/12/759/2018/

or Figure 3 in this one:

https://www-cambridge-org.ezphost.dur.ac.uk/core/journals/annals-of-glaciol...

So maybe the Ecrins Glacier Blanc was a bit of an outlier? My understanding is that glaciers in the same region don't necessarily all behave in exactly the same way. We tend just to think cooling --> advance and warming --> retreat, but these occur through the interaction of mass balance and ice dynamics and the details are quite complicated. Shorter glaciers tend to respond more rapidly to climate fluctuations than do long ones. The topography of the valley matters; for example, in a period of negative mass balance the tip of a glacier on a low gradient or reverse slope will downwaste with little or no snout retreat, whereas one on a steeper gradient will retreat. 

There was a mini advance in the 1920s (which left terminal moraines which are still visible) so quite possibly there was a modest retreat in the following decades, but perhaps to the status quo ante, and so not so obvious?

Thanks for sending those. Links won’t load on my phone so I’ll take your word for it - and your point about local / topography conditions. I did find it bizarre that Cham glaciers seem to be able to flow down below the tree line when it’s only 60 miles north of the ecrins give or take. 
 

I’d love to get some old archived guidebooks with topos. Probably a few knocking around in the back of various refuges

Was the splitting of the glacier blanc / noir into two systems already complete by then? Must have been around 1900?

I think so based on information from the Ecrins hut facebook page.

Re the Chamonix glaciers reaching much lower than the Ecrins ones then that is largely a function of much higher precipitation around Chamonix plus maybe being slightly colder due to being a bit further North, although the main driver will be increased precipitation as Chamonix sits on the NW corner of the Alps and picks up all the fronts from the Atlantic.

RIF knows more about glaciers than me but worth noting that the glaciers in the Ecrins are further south & don't have the same climate as those around Mt Blanc.

There are aerial photos from 1950 - 1965 available on the IGN website (https://www.geoportail.gouv.fr/carte ) although it doesn't seem to give a date for the images around Chamonix. I guess there are other sources of aerial photos if you search.

As well as what LakesWinter said about the difference in climate, the Mont Blanc massif has higher summits, so its glaciers tend to have bigger accumulation zones. That allows them to extend to a lower elevation before total melting equals total accumulation (which is what determines snout position in steady state). Think of the Bossons, Miage, and Mer de Glace. 

Thanks, makes sense. Possibly also greater distance from sea meaning colder winters? isn’t this part of why Austria has lower snow lines (or used to)

Thanks for the link

Makes sense

Go read an IPCC report. Current alpine retreat is almost entirely due to AGW and is way out of the fluctuations we would expect without warming.

Yours sincerely, ianstevens PhD, Glaciology

Hi Ian, spoken like a true believer!

To make such sweeping statements you will need to explain why:

(a) the onset of glacial retreat and sea level rise predate any plausible AGW influence by at least 80 years (commencing around 1830 - 1850) and therefore directly contradicts the temps and model result in Fig 1 in the IPCC AR6 SPM which only shows a warming onset from 1910. 

(b) why glacial retreat in the latter half of the C19th and early C20th is at a rate similar to the late C20th century.  Even the IPCC only claims significant AGW post-1950s.

(c) how it can be solely AGW, if the rate of retreat late C20th vs early C20th shows a ratio of 1.4x (as does sea level rise and temperature rise) but AGW CMIP6 forcings require a ratio of about 3.4x based on forcings used to drive the models and the model responses.  That's > 2x error in rates.

Whilst it is possible there may be some modest impact of AGW on glacial retreat there are direct physical observations that contradict the notion it is all AGW (or even significantly) AGW or that recent (late C20th/C21st) retreat is unprecedented compared to earlier post-LIA in the last 170 years or so.  Also recall that the Alps were likely ice free and/or with a much higher treeline during the Roman Warm period.  It is also self evident from even a cursory inspection of climate model outputs that they run too hot by a factor of at least 2.0 - 2.5x.  This is very evident in latest AR6/CMIP6 results which almost seem worse than the previous CMIP5 models.

I notice at Aberystwyth Uni you are listed as having an MSc (2014) from the Geography Department but have not yet finished your PhD in glacial surface microbial processes - they probably should update your details now if you have completed your PhD?

References: Jevrejeva 2014; Leclercq & Oerlemans 2011; Leclercq et al 2014; Nussbaumer & Zumbuhl 2011

Where can I read more about the Roman warm period in the alps? Is that based on written historical sources or is there a more reliable way of reconstructing the roman climate? The only source I've found on this claims Aletsch glacier was at 1980s -esque levels in 200, and 2000-ish around 0, both a fair bit longer than now

That’s an impressive amount of detail for a forum post (though the ad hominem bit is more typical of the genre).

But I’m not sure what your point is. Are you saying there’s no need to take any action?

Joerin has published a bit in this area:

https://www.researchgate.net/publication/201169725_Multicentury_glacier_flu...

The above paper gives some good references.  There is also work by Dr. Christian Schlüchter on dated wood under glaciers - google is your friend.   "In fact the Alps were nearly glacier-free again about 2,000 years ago. Schlüchter points out that “the forest line was much higher than it is today; there were hardly any glaciers. Nowhere in the detailed travel accounts from Roman times are glaciers mentioned.""

I am working from home currently so not accessing my office study library shelf.  There is some popular written material in The Chilling Stars by Calder & Svensmark concerning discovery of Roman and Bronze age artefacts now revealed by modern retreat on alpine passes.

Well thanks for your comment, although characterising my phrase "spoken like a true believer!" as an ad hom. is perhaps a little strong.  Should have put a smiley on it!

I have a lot of detail because (a) I get a bit sick of the UKC "glaciers are retreating 'cos climate change" line and think people need a bit more historical perspective/science and (b) because I have analysed and modeled the raw data myself I have some knowledge on the topic and have the references and results to hand.

Regarding your comment on action, what action do you think will stop glaciers retreating?

I see. And apart from glacial retreat, would you say human action can do anything about global heating at all?

UKC is pretty bobo and doesn't seem to admit non bobo-approved opinions, go on the (wisely locked for new members) "politics" forum if you doubt that lol

I know pretty much nothing about glaciers, but I would say I like them and wish they were heading in the other direction. A few major volcanos just before summer, a few years in a row, is my policy priority

What does “bobo” mean?

French term meaning bohemian bourgeoisie. I suppose roughly similar to champagne socialist

Why would they? The Romans had a very different view of the natural world to modern people. Quite likely, they wouldn't 'see' a glacier as something to be remarked upon since it was just there and had no bearing on anything of importance to them. Julius Caesar mentions the sea between Britain and Gaul because it bigged up his invasion by being able to cross it. People had been crossing Alpine passes for millennia so why would he bother describing details of what he could see there? When Tacitus describes the campaigns of Agricola he doesn't mention trees (or lots of things) - does that mean Britain was completely treeless?

Except there is direct evidence from archeological finds of Roman and Bronze age artefacts that have clearly been droped or lost on alpine passes.

Alpine passes that have only become free of snow/ice in summer during the latter stages of the C20th/earlyC21st century.

So Romans were almost certainly alpine passes that were clear but, until recently, were permanently under snow cover.

Thanks. If that makes me bohemian, I’m flattered! I guess those French hedonists were always asking questions about climate change claims.

The evidence is that the Roman Warm Period, at most, resulted in temperatures somewhat less than we currently have, and only regionally, not globally.

https://climatefeedback.org/claimreview/the-earth-was-not-warmer-in-medieva...

'The Romans' were around for quite some time. Constantine (who was in Britain and crossed the Alps) was much further removed historically from Julius Caesar (same credentials) than we are from Napoleon. Plenty of time for glacial advance and retreat. I've personally seen glaciers advance and retreat in New Zealand over several visits spread over just twenty years.

I'm not doubting this, but can you cite some sources?

Are you saying that the presence of Roman artefacts on Alpine passes is evidence that the pass was free of snow? Your wording is unclear.

The is also Otzi (pre-roman) who melted out of a glacier a little while ago, showing that the current glacial retreat is greater than since at least 3000BC in the Austrian alps.

no i would imagine the main reason is due to the much much bigger catchment area, and much more of that catchment within the accumulation zone. i dont think that chamonix gets meaningfully more precipitation than the Ecrins, the ecrins are still on the 'atlantic' side of the divide. 

LOL! You refer me to a "factchecker"!  The High Priests of Climate have spoken.  Or not.

Marcott 2013 gives a good paleo reconstruction of the last 11kyr and clearly shows the Roman Warm Period as comparable or warmer than today.  The linked image below is also a good demonstration of whats wrong with climate models: the climate model for the Holocene (Liu 2014) was run using orbital and GHG and gives a temperature prediction the complete opposite of the Marcott reconstruction.

Not interested in the linked blog, it just happened to show the graph I was looking for to make my point:

http://tofspot.blogspot.com/2017/06/a-glance-at-holocene.html

Sorry, mistyped.  The sentence should have better read:

"So Romans were almost certainly using alpine passes that were clear at the time but since, and until recently, were permanently under snow cover

You said "but I would say I like them"

Me too.  Awesome, if dangerous, natural features

"and wish they were heading in the other direction."

Me too.  Not much we can do about it I suspect.

"A few major volcanos just before summer, a few years in a row, is my policy priority"

A few volcanos might help, but there may be other factors such as oceans in play.  Sea level rise, glacier retreat and temperature data sets all suggest a fairly linear rate of warming since possibly as early as 1830 - 1850, but on which is superimposed a fairly noticeable quasi-periodicity with a cycle length of the order of 60 - 70 years.  Is pretty distinctive.  We are in the warming upswing of one of those cycles now (not too dissimilar to the upswing 1910 - 1945).

https://woodfortrees.org/plot/hadcrut4gl/plot/hadcrut4gl/from:1910/to:1945/...

The trend in the latter half of the C20th century has a warming rate about 1.4x the early C20th warming cycle.  Climate models say that ratio should be about 3.5x

Hi Flash, 

detailed posts. Do you have a professional background in this area?

Professional geophysicist with specialist expertise in forward and inverse modelling.  Also expert in geostatistics and stochastic processes.  37 years of experience to date.  Was a Visiting Lecturer in Geostatistics at Imperial College 1998 - 2014 (just a few days a year teaching MSc and PhD students).  I am a Fellow of the Royal Astronomical Society and MI Soil Sci.

In fairness I thought the working assumption was that Otzl was dressed for extreme cold and was likely crossing the glacier when he was murdered? (RIP)

Fair point also I’m not sure I buy the whole Ecrins are southern alps, Ecrins-Vanouise-Mont Blanc is pretty much a continuous block and not that big a north / south difference. Slightly irrelevant but area also culturally seems more Savoyard / northern than southern. The ‘sunny and dry’ ecrins smells like a tourist board plot (300 days of sunshine???) 

Hang on - so if I’m reading that graph right between the real ice age (10kish BC) and the little ice age the majority of the time temperatures were as warm if not significantly warmer than today?

what possible explanation could there be for the little ice age then?

Interesting. 
 

coming back to the original issue though - if the glaciers were stable or growing, even if much smaller, alpine routes involving crossings should be much less dangerous. Do you expect them to find a new equilibrium or will that be after completely melting?
 

Thanks.

Impossible to argue with the fact that you are better qualified to comment on this than other contributors to the thread. But, for someone who doesn’t have a background in geophysics but who does have a fair understanding of how to interpret evidence in another field, how have you reached your conclusions that the IPCC consensus is wrong? I’ll be honest and admit I get skeptical when people claim to have seen something that the great majority of other equally or more qualified people in their field haven’t. Is it that they are unaware of the data you reference? If not, and they are aware of it, what would they say to account for it?
 

and what is your conclusion- that we are witnessing a natural warming phase + superimposed AGW; or that the main factor is natural warming? And if the latter, are net zero plans are therefore pointless in your opinion? 

http://www.earthworks-reservoir.com/ashley%20francis%20profile.htm

Well quite. And only melted out a few years ago, rather than during the apparently ice free Roman period.

Is it? Clearly well read but I don't see how expertise in borehole modelling and geophysics gives specialist insight into climataology.

Heres the paper

https://www.science.org/doi/10.1126/science.1228026

With commentary from the authors here

https://www.realclimate.org/index.php/archives/2013/03/response-by-marcott-...

Where they are at pains to point out there data cannot be compared to high resolution (i.e. less than 100 year) records, so I think your claim is at best unfounded.

Is the difference in model results and measured temperatures not simply due to the fact that the two are essentially measuring differnt things rather than the models being wrong, as explained in this blog from climate brief https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected...

solar cycles. google 'Milankovic theory'.

if it wasnt for anthroprogenically produced greenhouse gas emissions then we would still be in a cooling phase, but we went and disrupted the natural order of things...

edit: i meant orbital cycles, but solar cycles play a part too

"the majority of the time temperatures were as warm if not significantly warmer than today?"

Correct, almost the entire Holocene was warmer than today.  We are in a colder period.  That is not particularly contentious and is well known amongst geoscientists.

Little Ice Age explanation - no-one knows really, nor why it ended.  Lots of speculation.  To my mind, if you cannot explain (a) the LIA and (b) why we started warming around 1850 (or even slightly earlier), way before anthropogenic greenhouse house gases became significant then you don't really understand the processes - the knowledge is very incomplete.

And by explanation I don't mean arm waving.

"Do you expect them to find a new equilibrium or will that be after completely melting?"

No idea, but it does seem to me that AGW effects are likely smaller than currently modelled by a factor of 2.0 - 2.5x.  That to me, together with the timing of the onset of warming post-LIA being much earlier than IPCC GHG warming, suggests another process is the driver.  There may be AGW on top, but if so it is much smaller than claimed.  A modest warming is likely to be benign.  The idea that the LIA was an optimum temperature for humans seems pretty bizarre to me.  We we born out of warmer climes and civilisations appear to be more successful during warmer than colder periods - for pretty obvious reasons, I think.

My views on the climate science are aligned with Steve Koonin.  He has authored a very good book called "Unsettled" on the problems of climate models, data and the IPCC.  Having read the original APS transcript from the on-the-record forum he chaired back in 2013 I think he has done more than anyone to shine a light on the problems with climate models.  The transcript is linked below.  Its long and somewhat technical but its interesting because its the closest we have to an honest debate between 3 warm and 3 sceptic climate scientists, all with impeccable atmospheric sciecne credentials.  Its honest because its on the record and there are 6 other high quality physicists in the room with them.

https://www.aps.org/policy/statements/upload/climate-seminar-transcript.pdf

Your first point is pretty sound and fair: "I’ll be honest and admit I get skeptical when people claim to have seen something that the great majority of other equally or more qualified people in their field haven’t"

Fully understand that.  I am not the only one holding my views.  The best known and public one is Steve Koonin who has written the book "Unsettled" pointing out the fundamental issues with climate models which he says are demonstrably unfit for purpose.

Regarding IPCC and scientists believing the models are correct and we are heading for "climate breakdown" or whatever the latest hyperbole is, there is a tendency to play the man and not the ball.  Steve Koonin is a good example.  I read Koonin (and others, such as Dr John Christy) and the results agree with my own (modest) independent work.  They also agree with work on empirical estimates of climate sensitivity, which also tend to support a much lower (2x lower or more) GHG response.  The model output can be shown to be problematic quite trivially - if I can find a way to link to some plots I'll post something to show my point.

In response to your second question: "and what is your conclusion- that we are witnessing a natural warming phase + superimposed AGW; or that the main factor is natural warming? And if the latter, are net zero plans are therefore pointless in your opinion? 

The long term cooling across the Holocene is mostly Milankovitch response as far as I can see.  The short term variations are really not explained.  GHG's clearly don't work as a climate model predicts the wrong way in the graph I posted.

Explaining short term variations by CO2 encounter a further problem - why would the CO2 vary?  In the modern age the explanation is given as anthropogenic, but that doesn't work for previous short term warmings that could only be natural.

It may just be chaotic internal variation, it may be some unknown solar coupling (I thought Svensmark may have got it, but it seems the effect is too small).  Volcanoes certainly cool, but other than Milankovitch (long time scales) the IPCC has no mechanism for natural warming.  That seems implausible to me.

Net zero is pointless.  And doubly so if only the UK and a few countries did it.  It will likely cause huge economic hardship and a drop in standard of living whilst having no impact on climate.

John Christy ran the climate models forward to show the effect of eliminating the entire USA emissions from 2012.  That's not just reducing them, that's completely removing the USA to zero in 2012.  The predicted modeled temperature difference in 2050 would be 0.08 degC, unmeasurable by any known technology.  The UK emissions are nearly 14x smaller than USA, so if our emissions went to zero in 2012 the temperature impact would be 0.006 degC in 2050.  That's less than the natural atmospheric lapse rate difference between ground level and 1 m elevation.

So even if the climate model predictions are correct, to me the only rational policy is adaptation.  Humans have been successful at that for millennia.  On that general topic I would recommend Michael Shellenberger's book "Apocalpyse Never".

You said "Is it? Clearly well read but I don't see how expertise in borehole modelling and geophysics gives specialist insight into climataology."

Well I last worked in borehole seismic back in 1991, since then I have developed expertise in Geostatistics (from 1993).  I have worked on and developed complex 3D forward and inverse solvers including algorithms with full stochastic capability with spatial correlated constraints.  So I am not a numpty with this stuff.

Forward and inverse modelling is the core of geophysics.  Climate models are just complex 3D forward models.  They require domain specifications, conditioning and input drivers.  All of this is common across geophysical modelling, there is nothing inherently special about climate models - they are more complex than many models, but they suffer from the same limitations.  The main issue with climate models is that for some important factors there is no know specifiable physics, just parameters.  Clouds would be a good example.

You don't need to know exactly how a geophysical black box works in order to test the validity of the output or its sensitivity to input either.  Model testing is simply a matter of comparing output to observations - its hardly rocket science.  And definitely in my area of competency.

Steve Koonin's book "Unsettled" goes into the issues very clearly.  They are not difficult to understand.

"Heres the paper" Thanks.  I already have a copy.  I read it when it came out in 2013.

Yes, the resolution is 100 years.  The Roman period is a lot longer than 100 years.  The main issue with Marcott is the claim to compare to modern temps by simply pasting them on without accounting for the difference in temporal resolution.  That's a very common trick in climate science.

Geostatistics has a lot to say about how to deal with different resolution and I have spent a lot of time working in this technical area.  Its critical to stochastic seismic inversion, upscaling, reservoir modelling and many other areas.  I have developed a tool for 3D upscaling using spatially correlated constraints, so I know something about the topic.

As you go back in time and when using paleo measurements, you lose resolution.  The effect is to smooth things out.  Smoothing means you cannot see the extremes or short time scale events and the variance is reduced.  To compare modern measurements you would need to downgrade them by averaging.  So the modern period would plot as just 1 or 2 modest temperature points on Marcott's graph. On the basis of the same resolution, the Roman Warm Period is warmer and of longer duration than the current warming.

I think it was the IPCC that stated our climate is a: “coupled, non-linear, chaotic system”,  for which  “the long-term prediction of future climate states is not possible.”

The initial state is unknown therefore future states are unknown, it represents a non-equilibrated system.

DC

Climate models don't measure anything.  They use input forcings to try and predict output temperatures.  We can then compare the output predictions and see how well the model did.

However we have to be aware of many factors.  Some simple ones are:

(a) The models need input changes to convert to output modeled temperatures.  The inputs may be wrong.

(b) The internal workings of the model may be wrong.  In climate models, some is physics (eg spectral lines of the atmosphere) but for a lot of key elements such as clouds the physics is poorly understood or unknown. These are then introduced as parameters - a knob you can turn to make the model fit

(c) All geophysical problems suffer from non-uniqueness.  This means the link between observation an cause could be modeled in different ways and still get the same answer.  This is particularly a problem for climate models because key elements have poorly understood physics (see (b)).  For a fully specified physics problem non-uniqueness is really only an issue for inverse problems (deducing the input from the observations) but climate models have incomplete physics. 

(d) Error propagation is a significant problem in climate models.  They are inherently unstable and small errors or differences can rapidly lead to the oceans boiling or snowball earth.  So the models are "tuned" to make them fit the observations.  Tuning makes your result look like what you wanted (easy to fool a lay audience), but of course creates circular reasoning - the model proves nothing, only that you can make it fit.  The mathematician von Neumann was famous for talking about overfitting curves to data "with four parameters I can fit an elephant, and with five I can make him wiggle his trunk"

A final point about climate models and physics.  If climate models were really "just physics" as often claimed why do we need so many of them?  If it were just physics then all climate models would give the same output from the same inputs and we would would only need one model, not 40+.

Thank you for replying in such detail to mo_more_scotch_eggs’s questions. But you’ve missed one (though they were too polite to put it this way): how could it happen that thousands of scientists, around the world and from multiple relevant disciplines, would be so wrong over so many years, while an oil industry consultant knows better than them all?

You said "if it wasnt for anthroprogenically produced greenhouse gas emissions then we would still be in a cooling phase, but we went and disrupted the natural order of things...

edit: i meant orbital cycles, but solar cycles play a part too"

Milankovitch is long time scale - 26,000 - 100,000 years or so.

The idea that we would be in a cooling phase if it weren't for man interrupting nature with GHG emissions is essentially the IPCC story.  Warming only starts in 1910 (and is actually too fast to agree with their own models anyway!) and then gets worse.

This ignores the glacial retreat from around 1830, which is backed up by sea level rise data.

The IPCC has only three natural influences of any significance in its models:

1. Solar - assumed trivial in IPCC modellings

2. Milankovitch - trivial on the timescales post LIA

3. Volcanoes - only cooling

So the IPCC has no short term mechanism for warming and only volcanoes for short term cooling.  What caused the Little Ice Age? Why do ice cores record short term warming and cooling?  The IPCC mechanisms seem incomplete to me.

And who would want to be heading into further cooling?  Do you think the LIA was a good temperature to live with in Europe during those years?  I don't.

FOOTNOTE: I think I got to most people's posts and tried to answer them.  There is just me and a lot of everyone else, so its time consuming.  I have to do some (geophysical) work now and will not be able to answer much further today.  If I can find a simple way to link to some images I will.

Except if you read the commentary, they are at pains to point out they are not doing that.  However, you do seem be by claiming Marcott shows current temperatures (ie. those measured over a period much less than 100 years) are no higher than Roman Warm Period ones.

I don't doubt your expertise in geophysics but you can't use that to claim particular insight into climatology, or climatological modelling.  They are vastly different fields both in terms of the physics involved and the appropriate modelling methods.  Saying they both involve inverse problems, and forward predictions is irrelevant.  That's true of, for example, fire dynamics, blast behaviour and evolutionary biology too, and I assume you aren't claiming expertise in all such fields are you? 

With respect that is a false assumption. There are almost 1000 global scientists on the Clintel list who question the narrative. There are many scientists globally who are sceptical, usually for very good reasons, yet they are not paid for their opinions like the alarmist side.

It is a given that most scientists are paid to follow the narrative - e.g. check out the eye-watering money going to some UK academics to study carbon capture, mostly money from NERC. A technology that is uneconomic and can't make a blind bit of difference to the numbers.

Check out £800 million annual subsidy to Drax Power plc (>£2+million a day), yet they produce more CO2 and particulates than a clean coal station (and also ravage American forests, transport the material long distances etc etc). Total corrupt hypocrisy.

DC

Well if you don't like Marcott, its not the only line of evidence.

Try the GISP2 ice core:

https://www.climate4you.com/images/GISP2%20TemperatureSince10700%20BP%20wit...

The Minoan, Roman and Medieval periods all have a clear warm signature.  And check out the CO2 curve at the bottom of the figure - steady increase from 7000 yrs BP to today, whilst temps are bouncing up and down significantly on a gentle cooling trend.  Marcott is more pronounced for the cooling trend, but the basic principle is clear.

I made an exception and replied to your post, last one for most of today as I have work to do.

You seem well informed and I appreciate you taking the time to reply to questions and challenges. Are you sure this statement is correct and what did you base it on?

I don't have access to the full text of Marcott et al 2013, but in the abstract they say:

'Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history.' 

There is also an additional comment, presumably an update:

'Temperatures have risen steadily since then, leaving us now with a global temperature higher than those during 90% of the entire Holocene.'

https://www.science.org/doi/10.1126/science.1228026

Sorry, I wasnt very clear (I should also confess I am a professional geologist with some experience of modeling, allthough not in climate science, well at least not forward looking). What I meant was it seems that the carbon brief blog clearly explains the discrepancy between IPCC models and observations. The discrepancy looks to be a simple case of comparing to different datasets rather anything to do with difficenes in the model.  I thought this was worth pointing out as you seem to be suggesting AGW wasnt as serious as currently thought as the science behind it was wrong which I don't think is the case. 

That’s a lot of people you’re dismissing in one go!

> Check out £800 million annual subsidy to Drax 

I’m afraid I don’t get the relevance of this.

You seem to have ignored the remainder of my comment:

"You don't need to know exactly how a geophysical black box works in order to test the validity of the output or its sensitivity to input either.  Model testing is simply a matter of comparing output to observations - its hardly rocket science.  And definitely in my area of competency."

Climate science includes all of the main earth and geosciences as well as geophysical forward and inverse modelling.  All of that is in my general competency as much as any High Priest of climate science.  Earth scientists are trained in geological and physical earth processes as well as interpretation of geological and geophysical data.  That would include ice core data, geochemistry and many other topics.  I am not necessarily specialised in those areas but I have to interact and deal with people who are every day in my multi-disciplinary work over the last 37 years.

The physics of fire dynamics and blast behaviour is most definitely outside of my competency.  I know very little about Evolutionary Biology but I would be surprised if it includes any earth physics.

Sorry, what was the point you were trying to make with this statement? Firstly, that graph you refer to does not go up to the present day. Secondly, the CO2 increase is small - from 260ppm to 280ppm over 7000 years. For context, latest CO2 is at around 410ppm.

I just think its wrong.  You do need to know what is going on inside any computer or mathematical model to judge it's output.  Saying the task is simply comparing output and observations is wrong - there are many ways to get superficially plausible output which are plain wrong physically. I have extensive experience of modelling in one area too, but wouldn't begin to claim expertise in another on the basis of this.

Thanks, had never even heard of this. Reading now

I think the (possibly arm waving) explanation I'd heard was that somehow the end of the medieval warm period was because of the black death and related asian / european population decline / growth of tree cover. The 300 - 400 year lag doesn't really make sense though in that context.

Another problem with that graph is that it shows the temperature at the summit of the Greenland ice sheet, which I doubt is a suitable proxy for global temperatures. 

"Ashley has worked in or on behalf of service companies, consultancies and oil companies in North and South America, Europe, Africa, Middle East, Far East and Australia."

Just saying.

This is broadly irrelevant though, unless you are claiming that the technical details are so arcane and complicated they can't be explained to outsiders. If the papers cited come from credible publications (and so aren't fake) anyone is free to interpret them and be criticised for the interpretation not where they work

I think most people in fields that involve any kind of modeling (financial, scientific w/e) are familiar with the concept of it being safer to be wrong together. Definitely this was true in the run up to '08.

I don't have a horse in this one as I genuinely know very little about it (and originally asked the question in relation to climbing safety), but the poster you're replying to has responded thoroughly and with evidenced claims, so I think its lowering it a bit to say "but everyone thinks your wrong! you haven't answered this!" 

It's commonly called "follow the money".

DC

Yes. In the debate about whether it’s possible to limit global heating, or whether the oil and gas industry (among others) can simply carry on, which side do you think has the most money?

Thanks for your comments.

Regarding Marcott, the uptick on which those claims were made in the published have now been conceded as not statistically robust.  The paper had a lot of controversy at the time which I followed closely.  RealClimate is the warmist side of the argument, ClimateAudit is another more rigourous technical side (Steve McIntyre, who I regard as trustworthy and holding the feet to the fire of people making unsupportable claims).  just one example page - search for Marcott on ClimateAudit will give you a long history of detailed examination.

https://climateaudit.org/2013/03/31/the-marcott-filibuster/

As SteveM points out Marcott concedes:

"20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions."

Which is probably why the egregious uptick did not appear in Marcott's thesis (from whence the work came) but magically appeared in the published paper.  Of course, based on the above comment by Marcott the paper should have been seriously revised and an errata issued.  Seldom is in climate science and the resulting nonsense is left in the record.

Fair enough.  But don't take my word for it (not that you would - some random bloke on UKC blog!).

I would strongly recommend reading Steve Koonin's book Unsettled.  He was Under Secretary for Science in the Obama administration.  I think he has nailed the problems with current climate models and climate science pretty well.

The point about the CO2 is it does very little except increase slightly for 7000 years, as you note.

Meanwhile temperature is spiking up and down quite rapidly over hundreds of years.  So it ain't CO2 doing it.  What is?  If you cannot explain the past you are unlikely to predict the future.

You said: "I just think its wrong."

Fair enough.  Opinions vary.  I would recommend reading Steve Koonin's book Unsettled for another opinion.

First, thanks for your OP, which raised an interesting question. It was perhaps surprising  that within four or five posts controversy had set in; current glacial retreat hardly looks debatable.

It’s relevant to me. I’m not a scientist, but I have every respect for science and I understand how it works. The rigorous process of challenge built in means that an agreement that endures carries a lot of weight. I recognise that everyone is subject to institutional biases: but many or most academic scientists are less tied to particular outcomes than those working in industry. I mean no disrespect here ; I have close family members on both sides of that divide and they are people of integrity.

So I’m not equipped to assess each scientific claim on it’s own merits. I have to make judgments about credibility. That includes allowing for the fact that everyone sees things from their own personal perspective. 

Yes- I used to study major industrial accidents and groupthink is a useful concept. But I don’t think it applies plausibly to the variety and duration of work on global heating. The scientists I know might object to being lumped in with sub-prime lenders!

I’m sorry if it came over that way. It’s definitely not everyone who disagrees with flash 635. But there’s another useful concept here: “blinding with science”, in this case in service of the claim that we needn’t change anything, just because the glaciers are disappearing in front of our eyes.

You said "Another problem with that graph is that it shows the temperature at the summit of the Greenland ice sheet, which I doubt is a suitable proxy for global temperatures."

Why not? If you made that statement about Antarctic ice cores I might be more inclined to somewhat agree with you, but for Greenland the atmosphere is likely pretty well mixed.  It may not be so well mixed for Antarctica.

And the ice cores are fairly direct measures of temperature through oxygen isotope ratios.

If you don't accept that data, then there is no data other than even more tenuous proxies.  Geoscientists generally agree on the value of preserved ice core data using oxygen isotope ratios as an indicator of global temperatures.  Its one of the strong pieces of evidence as to how we know about the ice age cycles.

Wrong, that you have particular insight into climatology due to expertise in geophysics.

A point I doubt is addressed in this book.

More to the general discussion, I don't really see the case you are making.  We have established Marcott makes no particular claims about this century's temperatures but reconstructs historic temperatures and shows them to fluctuate somewhat, sometimes regionally, sometimes globally.  Your claims that a) current temperatures are lower than during the Roman Period and b) nothing special therefore isn't supported by Marcott because he doesn't compare the current with historic.  Further, although Marcott doesn't estimate recent temperatures, that hardly matters because we have copious actual measurements of all types, all of which show very rapid and significant warming over the last 50 years, much more rapid than we have evidence for historically.

Your language about "alarmists" and such like and confidence that you are right while the overwhelming evidence we have of climate change is wrong, makes me think you aren't being objective at all.

You said: ""Ashley has worked in or on behalf of service companies, consultancies and oil companies in North and South America, Europe, Africa, Middle East, Far East and Australia."

Just saying."

No, you are not just saying.  You are trying to play the man and not the ball with a sly ad hominen.  I have worked as a professional geophysicist in oil & gas, engineering, hard rock mining and nuclear repository host rock applications.  I am also currently discussing geophysical applications for wind turbine foundation design and geotechnics.

You want to argue against what I say, please go ahead.  If you want to make sly ad homs. then you will be ignored from now on by me.  If you can't raise your game to address what is actually said then don't bother posting.  Your post typifies everything that is wrong with debate in modern society and especially concerning climate science and other environmental issues.

You might like to go and read Michael Shellenberger's book Apocalypse Never and inwardly reflect.

The uptick in temperatures during the 20th century is from direct measurements. Global temperatures are - on average - 1.2deg greater than pre-industrial levels. From Marcott it appears that peak holocene temperatures were about 0.7deg higher than the low in 18thC/19thC.

How do you justified your assertion that temperatures during most of the holocene were warmer than they are today? 

I think you would find Koonin's book does address many of those points, and certainly one's I raised.  

Regarding your point: "copious actual measurements of all types, all of which show very rapid and significant warming over the last 50 years, much more rapid than we have evidence for historically."

The warming has been going on a lot longer than 50 years. But the IPCC only attributes warming post-1950s to be largely or wholly anthropogenic.  My fundamental point is that warming has been going on at almost the same rate since as early as 1830-1850.

Not even early C20th warming can be properly explained by anthropogenic GHG's.  I will try and post a demonstration of my point with a couple of linked images.

I think at this point we can call bullshit.  This is wilful misrepresentation  The GISP2 record finished in 1850!!, which I assume flash635 knows.  Trying to pass it off as evidence that current temperatures are not increasing isn't a mistake, it's dishonesty. 

This article is interesting.  It appears that current temperatures are higher than anytime in the last 2000 years in Greenland, but not higher, yet, than around 5000 years ago.  The temperature changes aren't stopping, however...

https://www.cabonbrief.org/factcheck-what-greenland-ice-cores-say-about-pas...

thanks. You didn’t answer my question though. The data you cite is not secret. Why do the IPCC come to a different view to you?

Here’s the thing: I may not be a climate scientist, but I do make a living by interpreting scientific evidence and translating that into real world decision making. Core to this is evaluating the strength and reliability of evidence, and where individual pieces of evidence fit in an overall body. When I see people from outside a specialist field claim their knowledge extrapolates seamlessly into it, and that they have then made visionary insights which overturn the settled consensus, and dismiss the position of the overwhelming majority of experts actually working in the field as “hyperbole”, then that sets multiple alarm bells ringing for me. 
 

You are making the same fundamental mistake as everyone does.  You cannot directly compare modern direct temperature measures to paleo-proxies.  People do it all the time and its fundamentally misleading.

Marcott has nominal resolution of 100 - 300 years.  So modern temps would plot as pretty much a single point at the resolution of Marcott.  The variance of modern temps is much higher than can ever be seen in proxies, which are inherently smoother.  This is also why you cannot compare rates of change from paleo-proxies like Marcott to modern measurements.

Change of scale of measurement is very fundamental and critical to making those kinds of comparisons.  You can convert modern measures to the resolution/scale of proxies (ie filter/average them to reduce resolution) but you can't do it the other way round.

Thanks- you put that better than I did.

I am not going to give a detailed reply as I have answered this point elsewhere on the thread.  From your post its clear you don't really understand the issue of comparing modern direct measurements to paleo data and proxies.  They are not directly comparable and your trivial assumption is not correct.

And none of that changes the issue of climate models running at least 2x too hot.

You keep saying this but I don't think its true! unless I am fundamentally misunderstanding somthing.

From carbonbrief:

Global surface air temperatures in CMIP5 models have warmed about 16% faster than observations since 1970. About 40% of this difference is due to air temperatures over the ocean warming faster than sea surface temperatures in the models; blended model fields only show warming 9% faster than observations.

Recent nature paper:https://www.nature.com/articles/nature22315.

Contrary to popular opinion, the IPCC does not actually undertake any scientific research.  They collate and present with the intent to persuade.  This is because they are essentially a politicised organisation.  Lead authors are carefully selected not for their neutrality but for the views.

If climate science doesn't involve very significant areas earth science and geophysics, what is it? (I appreciate it also includes the atmosphere and meterology but for paleo data its pretty much all earth science, geology and geophysics.

Koonin has a whole chapter on why the IPCC and its findings are rather dysfunctional.  Michael Shellenberger also covers environmental hyperbole quite well in his book Apocalypse Never.

You see, every time you post something like this, my inclination is to take what you say with ever greater helpings of salt. 

And I am reminded more and more about Climate Inactivitism

https://www.theguardian.com/environment/2021/nov/11/inactivists-tangling-up...

I mean if academia is state funded (including by the US government) than certainly academia (as an extension of the state)? The US government's annual expenditure is three times global oil and gas revenues. In a conflict between the interests of the two there's no chance oil producers would win. They might be able to delay that conflict enough to find time to adapt but I don't get how you can square the idea of all powerful 'industries' with, just as one example, the banning of diesel cars.

In a completely oil dependent economy like Saudi perhaps different but globally that's an indefensible position. The US spends on just school age education ($760 billion) around 7 times total annual oil and gas revenues in the US (110ish). Even compared to individual tech companies that's a tiny industry (Apple well over 200 annually)

So in short, absolutely the policy preferences of the state are more important and have much vaster resources than oil firms

You yesterday 18.54:

"Marcott 2013 gives a good paleo reconstruction of the last 11kyr and clearly shows the Roman Warm Period as comparable or warmer than today."

No that's fair enough and you're obviously right about the direction of the glaciers.

Personally I can't see any solution to environmental degradation (even ignoring the climate side, just deforestation etc) without a reasonably big population decline. Seems the elephant in the room on most policy discussions 

I think you fundamentally misunderstand how academia is funded, and also the relationship between academia and the state. 

The concept that reaseachers (who are a disparate and argumentative bunch at the best of times) have more money and influence then even moderately big industries, let alone oil ang gas is hilarious. 

But I suppose as someone who receives government money to work on deccarbonisation I would say that (cue evil laughter as I slide back into my secret gold plated lab)

The GISP2 reconstruction falls some way short of what is generally considered suitable. 

It uses a single location, does not take account of altitude, and uses questionable assumptions regarding the relationship between the oxygen isotope data and the temperature. If you wish to make a point, you would be better advised to use less questionable data. 

Even if you consider the GISP2 data to be acceptable, it remains the case that the graph to which you linked tells us nothing about temperature anomalies over the period during which the CO2 concentration has increased from 280ppm to the current level of 416ppm. 

You said to rsc: "Personally I can't see any solution to environmental degradation (even ignoring the climate side, just deforestation etc) without a reasonably big population decline. Seems the elephant in the room on most policy discussions"

Read Shellenberger's book Apocalypse Never.  Its the perfect antidote to those thoughts and does not require big population decline.

No it hasn't.

As you know I could provide a long list of links, but then I know you'll start prattling on about something else, we'll go round in circles..... and you'd have achieved your aim, which is make the righteous dismissal of your bullshit look like a genuine scientific discussion.

I think you are proof that when someone has expended so much energy getting so far down a rabbit hole, reversal is very hard to contemplate.

Interesting reply because in stating that 'almost the entire Holocene was warmer than today.' you are making the exact same mistake that you claim that I am making: 'You cannot directly compare modern direct temperature measures to paleo-proxies.'

So where is the justification that 'almost the entire Holocene was warmer than today.'?

Yup. 
 

https://en.m.wikipedia.org/wiki/Gish_gallop

he lost me at “I did my own analyses, and the IPCC are *wrong*”…

Hi Mike,

Last time you argued these points, as I recall, you managed to convince yourself that a Met Office model output was in fact the real observed temps.  As I said at the time, it was a bit of a gift to me.

I gave the references up post pointing out that glacial retreat and sea level rise start as far back as 1830 - 1850.  Look them up, not going to repeat it here.

Average temperature anomaly in the modern period (1850 - present) relative to the baseline of 1850 (which is what is used in AR6 SPM Fig 1) is +0.25.  Compare that to Marcott - which is baselined to the same 1850 level as close as we can get - and almost the entire Holocene is warmer than today.  According to Marcott we might be slightly above Medieval, definitely not above Roman or almost everything prior back to 11 kyr.

I don't think I have. You are claiming that the provost of Harvard has less power and influence than a Texan (or Nigerian) oil exec? 

My point was that it doesn't all boil down to money. Jeff Bezos could decide he wanted to fund a expedition to bomb Mongolia; if he tried he would be immediately arrested and lose his position, anyone who went along with it would be in deep trouble. Money isn't the same thing as influence or power. Most people intuitively know this, and top positions in academia give a level of influence that someone wealthy but low status (say a drug dealer) could never have.

I'm not claiming you live a lavish lifestyle or being critical of your profession, I have good friends in similar positions, but absolutely academia is linked to state power, very explicitly. An academic working on research which goes against the ideology of the state of his university will very soon be out of a job (this has happened countless times). Climate is I suppose an outlier in that usually physical sciences are less influenced by this

Hmmm sounds a bit Pinkery. I would just appreciate less people crowding up the hills!

Perhaps you can point me to where I said: "I did my own analyses, and the IPCC are *wrong*"

As for gish gallop, well call me stupid for trying to respond to genuine and diverse questions from contributors as best I can.  there are quite a lot of people directing their questions and debating points to me.

Hey ho.  Damned if you do, damned if you don't.

I think we would all prefer a little less crowding, but it is good that there are lots of people who want to share the great outdoors.

No one is calling you stupid.  Initially people responded positively to your  claims and looked at the evidence you presented.  However it has become apparent you have variously

a) Cherry-picked data

b) Mis-represented data

c) Claimed expertise you clearly don't have

d) Dismissed the overwhelming and broad consensus of those with relevant expertise.

e) Thrown in lots of vague assertion between links to scientific papers

f) Objected to people comparing data in ways you did early in the thread

Taking this together I think a lot of use have reached conclusions...

As I said to you earlier, opinions vary.  You can reach whatever conclusion you like.

Of your list, I would say (a), (b), (c), (e) and (f) are not true.

(d) I would say I disagree with some of the consensus, but to use the word dismiss is exaggeration.  Oh, and lets not forget that consensus is politics, not science.

And on that point and just for the record I'll repeat here what I wrote up thread when asked about the influence of AGW.  I said:

It does seem to me that AGW effects are likely smaller than currently modeled by a factor of 2.0 - 2.5x.  That to me, together with the timing of the onset of warming post-LIA being much earlier than IPCC GHG warming, suggests another process is the driver.  There may be AGW on top, but if so it is much smaller than claimed.  A modest warming is likely to be benign.

and I then added:

My views on the climate science are aligned with Steve Koonin.  

And on that final line I would point out that yes my views are in the minority but in science that does not mean I am wrong (or right).  Right or wrong is determined by evidence and argument, not by consensus.  If my views align with Koonin's (and others) I feel pretty comfortable that I am in good company.  Time will tell.

Thanks to all those who engaged.  If I get time I'll still try and link to the graphs I mentioned. I think I have found a way I can do that.

IPCC have said that 'Human-induced warming reached approximately 1°C (likely between 0.8°C and 1.2°C) above pre-industrial levels in 2017' (https://www.ipcc.ch/sr15/chapter/chapter-1/). That estimate is mostly from direct measurement.

Yes, but to labour the point:  You cannot compare direct measurements to paleo because they are at much higher resolution than paleo.  The paleo of Marcott would not "see" the variation of the modern period because it is averaging with a resolution of 100 - 30o years. Modern temps are only over about 170 yrs, so at the resolution of Marcott they would plot as 1 data point - the mean.

The mean anomaly of modern measurements is about +0.25.  So that is the comparison to make to a paleo reconstruction like Marcott. 

The tendency to compare a modern measurement directly to paleo measures without correcting for the resolution is what (wrongly) leads to the multiple claims that warming now is either at an unprecedented level or the rates now are faster than before.  And that point is absolutely in my competence - its a foundation of geostatistics where it is called the support correction.  Feel free to google that.

Given that the measurements from 1850 to date are direct observations, and show an anomaly of a little over 1°C (as shown in your quoted ARM SPM Fig 1), what is the point of making a comparison with Marcott's paleo reconstruction? 

I said I would post some graphs.  The first is linked below.  On the left is panel from the latest IPCC report AR6 Summary for Policymakers (SPM).  The black curve is the temperature data (HadCRUT4) and the light borwn the CMIP6 model prediction.  Note how the brown line runs below the black line from about 1960 - 1990 (which used to be the baseline period in AR5).

https://postimg.cc/yJ4srvhP

On the right is the same data plotted by me but aligned to HadCRUT4 so the 1979 - 2019 data is aligned at 1979 (when the satellite data starts).  The alignment is by linear regression of the data 1979-2019 and then shifting the baseline to match the intercept in the year 1979 for all the datasets.  Its pretty standard.  I have overlaid the UAH satellite data in green, also aligned the same way.  Note:

(a) Aligned to 1979 the satellite data plots lower than HadCRUT4

(b) The fit of the model (brown) going backwards is pretty poor

(c) The model is clearly above HadCRUT4 going forward to 2019.  It shouldn't be because real temps include El Nino's (natural warm spikes) but models do not.

So that's the introductory plot.

I think some in our present government wish this was true!

I didn't really want to get involved in this thread but I feel compelled to write something in case people come across this and think that flash sounds like he's right.

I'm not going to argue with specific points here, partly because I don't have the time or motivation, partly because I don't want to imply I understand more than I do, but mostly because I don't need to. There is universal academic consensus.

What's my expertise? None really. I'm an applied mathematician, I study chaotic dynamical systems and fluid turbulence, and in the past I've studied some specific cases of this related to oceanography.

But I have met a lot of oceanographers, climatologists and general geophysicists in the process and heard lots of seminars from them. These people are not paid shills in some climate conspiracy, in fact a reasonable number are partly funded by fossil fuel companies. When I was in Cambridge I regularly used to go to seminars at the BP Institute, where climate change was openly discussed as a man made problem that needs to be solved (but also seminars on how to make fracking more efficient 🤦).

Climate models are incredibly complex and unreliable, and people (including me in a very small way) work on understanding different bits of the whole system to make them as accurate as possible. And they're still crap and disagree, with huge uncertainty. But all the reputable models from different academic groups predict that unless we dramatically reduce greenhouse gas emissions quickly, things are going to go from already bad to a heck of a lot worse.

And yes, they will still get worse even if we cut all emissions now. And yes, glaciers have been retreating at various rates for a couple of centuries. But one thing is clear: the rate of warming in the last 40 years is completely unprecedented, man made, and a big problem.

Second plot is the rate of warming for the HadCRUT4 temps and the CMIP6 model from AR6 Fig 1.  The data is downloaded directly form the offical Fig 1 data link.  The moving slope is calculated in a trailing 30 yr window (30 yrs is the usually accepted length for "climate" rather than weather).  Moving slopes are also independent of baselining and of course the rate of warming is a key output because the rate of warming predicted by the model determines expected future temperatures.

https://postimg.cc/94dC3ZJj

The real temps are in red.  Note the real rate of warming is above 0.01 for the entire period 1930 -1950 (remembering this is the slope over the preceding 30 yrs that is shown).  The model (blue line) gets the timing wrong (20 yrs too early) and only gets above 0.005 ie only half of real observations.

Then looking at the post-1950s warming, the temperature rates are above about 0.015 and are not showing rapidly increasing warming. But the model just keeps on getting faster and faster over that most recent period.  The ratio of the model warming post-1950s to the early C20th is at least 2x greater than is observed.  That, to me, is a serious red flag.  And if the rates are out by a factor of 2x in the early C20th, why would you have confidence in predictions to the end of the C21st?

This graph is slightly older as it uses AR5 CMIP5 models, not AR6, but its makes the point.  I have AR6 again on the next and final slide.

On this graph I have overlaid the temperature reconstruction from glacier data published by Leclercq and Oerlemans (2011).  That's the green line.  I have overlaid the sea level curve of Jevrejeva (2014) in blue (for water!).  That is shifted by cross-correlation peak and scaled by linear regression to the temps to make the comparison easy.  Black is the previous AR5 climate model, Red the HadCRUT4 temps.  All aligned using a 1961-1990 baseline.

https://postimg.cc/yDsGjyPM

I think the onset of warming and sealevel rise back as far as 1830-1850 is pretty clear.  Certainly the onset of glacial retreat in the early-mid C19th is pretty unequivocal.  IPCC GHG forcings are negligible until at least 1910 and only really significant post-1950s, so its not GHG's.

Final plot is a recent one.  The glacier curve is my own using the 18 long record glaciers from the Leclercq 2014 database.  These are the only glacier retreat data with good coverage back to at least 1800 (or earlier for 7 of them).  The current AR6 temps and model are overlaid, as is UAH satellite data.  Everything is aligned by intercept in 1979, like my earlier slide.  The model only really fits 1960-2000, outside of that its a bust.

https://postimg.cc/hXbc6VCR

I just cant reconcile you're claim of the model being 2x out with the analysis I linked to earlier from carbon brief who state the models are actually a pretty good fit. What am I missing?

Which UAH data are you using? You be aware that the UAH TLT data is open to criticism, so I'm slightly surprised you're using this as a meaningful comparator.

Having said that, UAH v5.6 dataset gives a trend of 0.158C per decade since 1980, and UAH v6.0 gives a trend of 0.136C per decade since 1980, both of which give an anomaly over that period considerably in excess of the 0.25C you cited earlier. Since it this period, and the future, which is of most relevance, it seems to me that it is more meaningful to consider this more recent period than the longer term dating back to 1850. 

I do hope you're not trying to prove a point with one piece of data. 

Thanks for your contribution.  I think you have encapsulated Koonin's point about climate models in a nutshell.  He says they are demonstrably unfit for purpose (ie informing public policy).  You confirm they are crap, disagree, have huge uncertainty (and I would add there are 40+ of them, all with different answers)  and yet seem to believe they still are fit for purpose.  That seems strange to me.

You are clearly someone who would understand the following points.

Averaging the output of a series of wrong models, in terms of forward modelling, simply returns your input forcings as all the other noise cancels out.  This is actually what is happening in climate modelling.  This can be seen if you subtract the mean model from the individual models: the residuals for each model are uncorrelated random noise.  The variance is also at least 4x too large for CMIP6 models (but that allows everything to appear to be in the "error bar" when they are combined).  And finally, the mean model output can be almost completely reconstructed (r=0.96) from the input forcings.  That means they are no more than linear transforms.

John Christy has also pointed out the warming rate of the tropospheric tropical region (the so-called "fingerprint" of AGW in the models) is warming 2.5x faster than in the real world satellite data observations.  That's a bust.

You would find a lot of interest in Koonin's book Unsettled.

They are comparing rates of warming for one period, not between two periods.  The models are tuned to post-1950s so of course they look ok.

But if you look at the early C20th they under-predict hugely, whilst tending to over-predict in the late C20th (and definitely in the C21st).

IPCC GHG forcings are 3x larger in the later 20th century than the early C20th century, that's why the models predict very different warming rates for the two periods.  But the difference (ratio) of those warming rates in the observations is at least 2x smaller.  So the models fit post-1950s (because they are tuned to do so) but cannot fit the early C20th century without getting the rates wrong by 2x?  Why? Something missing from the assumptions?

Comparing two (or more) periods is how the data based estimates of GHG sensitivity are calculated.  And they all tend to come in it at about 2x lower or more cooler than climate models. 

UAH6.  I think the comparison to HadCRUT4 (as used by your very own IPCC in AR6 Fig1) shows it is pretty close.  I include it for completeness but its not relevant to my points.

You cannot calculate the anomaly from 40 years of satellite data and then compare it to a 100-300 yr resolution plot such as Marcott.  The closest you can get is to take the entire HadCRUT4 of 170 yrs and treat it as a single point, and then only because HadCRUT4 does at least get back to 1850.

Nope, just demonstrating my original point that in the published literature glacial retreat starts around 1830-1850, which is much too early to be related to anthropogenic GHGs, which is where this thread started.  And sea level data agrees with that too.

Along the way I have noted some other issues, like rates of warming.

When we have decadal changes of the scale we are currently seeing, reducing 170 years to a single point makes no sense whatsoever.

You only think they are of the "scale you are seeing" because your comparison to paleo events is through a very strong averaging filter.  Of course they look huge and extraordinary, but when you think that paleo like Marcott is seen through a 100-300 yr averaging filter, what you would see now would be very unexciting if seen through the same averaging filter.  You have to compare on a like-for-like basis.  Variance and rates of change are completely different (and much more dramatic) at annual resolution (modern data) than they are at 100-300 yr resolution.

Its quite funny, no matter what I post its automatically down voted by 2 or 3 people instantly.  LOL!

Perhaps this one will get the same treatment.

Not posting again this evening, any questions directed at me I'll try and answer tomorrow (except any lazy ad homs!).

Your solution to the problem of comparing climate change - which is happening on the timescale of decades - to paleo reconstruction - with a resolution of 100-300 yrs - is to average over 170 years. Yes you can do, but it is meaningless and will tell you nothing about the recent climate change and how it compares historically. You appear to be using it downplay the magnitude of recent climate change.

It is appropriate to compare recent measurements with the paleo reconstruction by saying, say, that global temperatures today are higher than the vast majority of the Holocene. What you couldn't say is that global temperatures today are higher than at any other time in the Holocene. 

Only you are obsessing with Marcott. They are myriad ways of comparing current  and historic temperatures  and they all point to the current temperatures being as high or higher than historic ones. We are measuring pretty much annual records. We have detailed knowledge of the mechanisms of the greenhouse effect. We have higly accurate models that are predicting exactly.the changes we are seeing, increasingly at regional level as well as globale

That you think that you have spotted something every scientist with any relevant expertise has missed is laughable. Particularly when you claims are so ludicrously simple. Were models so crudely flawed as you make out, f*cking everyone would notice.

I’d suggest that’s because there are several people on here that find your absolute certainty that you’ve found the killer evidence that the consensus on AGW is wrong, and that you’ve had the vision to see what all the others couldn’t, to be absurdly self aggrandising; and your loaded language when describing the IPCC implies you have an axe to grind that is likely to be distorting your interpretation of any evidence that doesn’t fit with your pre existing views. 

Anyway, if your findings are really as robust and important as you claim, and overturn the established consensus on AGW, then surely this should be your target publication, not UKC..?

https://www.science.org/

I'm not equipped to discuss the science with you but here's what has leaped out at me from reading this thread:

There's an evangelical quality about your repeated reference to Koonin and his book.

Interesting comment.  I originally prepared a lot of my material for a Geol. Soc debate in February 2020.  I pulled together all my work at the start of this year in preparation for a Geological Society conference on Climate Change in May 2021, where I formally presented it as a poster (using AR5/CMIP5 data, not the latest AR6 results which I have just updated).

Checking my emails just now, I only bought Koonin's book on Amazon on 12 October 2021.  So if you think its some kink of Damascene Conversion it's not.

So an alternative interpretation is that Koonin's book represents an independent overview, easily accessible in the public domain, from a former Under Secretary of Science in the Obama administration and therefore it makes sense to suggest to people not to take my word for it (unlikely! ) but read something else.

Who knows, they might even find it interesting.  As Feynman used to say there is still "the pleasure of finding things out".

… another physicist turning to the lunatic fringes…. A classic cherry picking contrarian…

My understanding is that he was hired to round out the unit so it wasn’t all people in agreement; that isn’t healthy.  Problem is to find a counter viewpoint this late in the day it looks like they had to scrape the barell.

If you put so much stance on his Capital Lettered Role In Government, how do you discount the views of his boss and others in said unit?

Beep beep beep (the sound of a cherry picker at work) 

Reducing 170 years of observational data to a single data point is meaningless in the context of current conditions. As you have said yourself, it is very hard to compare paleo data with instrumental data, and yet you seem to think it can be done by applying a simple mean value, and the only reason you need to do this is because of the constraints imposed by the limitations of the paleo reconstructions. You don't throw away perfectly good data just to make a comparison with another set of data acquired under completely different circumstances. 

Also, he is a theoretical physicist, not a climatologist so, while clearly capable won't have particular expertise in the areas he criticises.  There do seem to be certain groups, physicists and geologists notably, who are attracted to wacky contrarian (to be polite) theories.  Similar characters 15 years ago were pushing how the WTC towers were blown up, or whatever, despite no expertise in structural mechanics or engineering.

You said "It is appropriate to compare recent measurements with the paleo reconstruction by saying, say, that global temperatures today are higher than the vast majority of the Holocene."

Both paleo and measured temperatures used for climate work are measured on relative scales with arbitrary baselines.  Neither are absolute temperatures.  If they don't have overlap periods then there is no direct way to compare them without making a lot of assumptions.

Modern measures on an annual (or even monthly) basis have way more variance and dynamic range than paleo measures, which typically have low resolution of the order of 100 - 300 years.   Low resolution estimates change much more slowly because...the resolution is lower.  Comparing modern temps to paleo can led to the false conclusion that current changes are really exciting and dynamic when in fact its just a change of resolution.

There are some high resolution cores from the Greenland Ice sheet that show that during Dansgaard Oeschger events (Bond events in the Holocene) the temperature in Greenland rapidly increases by 5 - 8 degC in just 30-40 years.  Imagine how that would be reported if one were happening now?  And yet they are natural events and are known to have occurred many times back to the last glacial.

Natural variability in temperature is likely a lot greater than people realise, humans have only formerly recorded it for just about 150 years, and the early part of that record pre-1900 back to 1850 is very sparse.

Well if character assassination and ad hom. makes you feel better you go right ahead and get it off your chest.  Makes no difference to the actual science.

I have no idea what your relationship to the book actually is I just noticed that you mentioned it a lot and seem to place a lot of importance on it.

I wouldn't want to suggest you are a conspiracy theorist but there's a definite parallel with CT methodology where people who disagree are directed to fringe publications often by scientists outwith the field in question.

One my my personal favourites from when a physicist goes off the wall...  Influenza.... From Space!

https://en.wikipedia.org/wiki/Diseases_from_Space

There's a whole group of them, some still at it.  It's almost beyond belief that some real heavyweights have fallen down to writing a letter to the Lancet claiming that original SARS came from space.

Edit: Here's the letter to The Lancet.  It's the best example I've seen yet as to how the letter's section is at times more akin to the a comedy magazine than to actually science...

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(03)13440-X/...

A book from the other side of the fence...

https://en.wikipedia.org/wiki/Merchants_of_Doubt

You said "Also, he is a theoretical physicist, not a climatologist "

Not sure what a climatologist is, but by your standards Feynman should not have been allowed to investigate the Space Shuttle Challenger disaster because he was a theoretical physicist and not a rocket scientist.  And Feynman was in a minority of one, its where the phrase "Minority Report" originates from.  I still re-read his Appendix F from time to time, it is a masterpiece.

So the rest of your comment is passe ad hom. about wacky contrarian and conspiracy theories.  Surprised you didn't mention the "moon landings are fake" one while you were at it.  I particularly like that one.  Personally I don't subscribe to grand conspiracy theories and prefer Hanlon's Razor and groupthink to explain why science sometimes goes off course or gets bogged down.

In the meantime, none of your comment impacts on whether he is right or wrong.  Play the ball, not the man.

I am sure you are.

An interesting case but Feynman's role was much more about listening to those who actually understood what happened and communicating it, than investigating and determining what happened first hand.

Says the man going on about "alarmists", "hyperbole" etc above?

There is some overlap where temperatures reach a minimum in about the 18thC/19thC. This, I presume, was what you used to make you assertion.

Yes, that is obvious - you can't examine short term variability below the resolution of the data. But that is not what you did. You said 'almost the entire Holocene was warmer than today.' If there is no overlap then your statement is invalid. If there is overlap, even accepting uncertainty, your statement can be shown to be flat-out wrong.

"Michael Shellenberger also covers environmental hyperbole"

"Regarding IPCC and scientists believing the models are correct and we are heading for "climate breakdown" or whatever the latest hyperbole is, there is a tendency to play the man and not the ball"

Neither of those statements where I used the word "hyperbole" is ad hom.  The first self-evidently isn't, the second the word hyperbole refers to the phrase "climate breakdown".  If you don't think that phrase (and similar in the MSM) is hyperbole, well.

As for the word "alarmists", a search on the page reveals that the only person who used that word is....you.  I didn't.

PS Just checked the singular "alarmist": Dave Cumberland used the word "alarmist".  Again, I didn't.

The early-mid industrial revolution was coal fueled. Burning coal produced a lot of dark particulates which settled reducing reflectivity, absorbing more energy than pristine snow causing surface melting which moves heat and lubricating water down into the glacier. Perhaps not AGW directly but the human activity associated with greenhouse gas emission could still account for the slightly earlier than might be expected glacial retreat (if it really is slightly earlier than expected, not my field).

jk

Sorry, it was "warmist".

Yes, that's been proposed although it doesn't seem to appear as a serious alternative in the glacial literature that I have read.  Currently in the published work by Leclercq & Oerlemans 2011 with the temperature reconstruction from glacial retreat, which I reproduced on a graph up thread, they say its temperature controlled.  They also specifically note its not thought to be due to precipitation change either as that would require a "great drying" event as they put it, for which there is no evidence.

Hi Rob, I seem to remember remarking that whereas when I first started climbing in Cham (1962-3) we used to get the full blast of the depressions coming through they shifted so that we seemed to be more on the edge of them in later years. Surely one marker that could be readily researched  is the Bossons glacier which was the école de glace. I need to look at my diary to find more precise dates for when that stopped but I remember taking Vanessa Winchester who was working on lichens (and working with Mme Gubler) as markers to teach her how to climb overhanging ice there in the mid 1980s . That would coincide  roughly when, following a climb on the Grepon, with my first reference in my diary that the climate seems to be changing. A number of people who have looked at my photo gallery have remarked on pictures that illustrate the rapid changes in Cham  that have accelerated.

Sorry this is a bit anecdotal, but I would need to dig into my diary which I have just re-edited and talk to one or two people who would certainly be able to flesh out these remarks if they are of any use.

Yes, ‘warmist’. I noticed that.

Also ‘MSM’. He’s got some interesting bedfellows in using that term. 

wonder what other denialist buzzwords we’ll get to tick off?

Thanks for your reply.  The sentence I used was:

"RealClimate is the warmist side of the argument"

which to my mind is not pejorative or ad hom.  Describing the side of the scientific argument which thinks warming is very strong from GHGs as "warmist", in contrast to the "sceptic" side of the argument.  I used similar language in the following sentence:

"Its long and somewhat technical but its interesting because its the closest we have to an honest debate between 3 warm and 3 sceptic climate scientists, all with impeccable atmospheric science credentials."

Note I describe both sides in that debate as having "impeccable atmospheric science credentials".  Warm and sceptic serves to identify the two viewpoints, its hardly ad hom.  I try very hard not to insert ad homs.  It should really be about science and open debate.

I would also add that there is tendency to dismiss people by using words like "contrarian" and the last few posts a few people are implying conspiracy theorists.  What I find often happens is a credentialed physicist like Koonin is dismissed without any evidence like wintertree did with the statement "… another physicist turning to the lunatic fringes…. A classic cherry picking contrarian…".  What is laughable is that wintertree then offers Naomi Oreskes book "Merchants of Doubt" as the view from the other side.  I realise you didn't say those things, but I think they are germane to the ad hom point.

So Koonin is a credentialed physicist writing a book on science (as he sees it).  But wintertree dismisses with an ad hom.

Oreskes is a historian who writes a book not on science but on her central theme which is that sceptical science views are the result of a grand conspiracy and collusion by the fossil fuel industry.  And wintertree thinks that represents balance?

Oreskes is actually a conspiracy theorist and written a book on her ideas, Koonin is clearly a physicist and written a book on science (and policy). If it weren't for the fact that it destroys any chance for rational, grown up debate it would almost be funny. 

It's not my field of work or of particular interest but it's an idea I've come across dozens of times over the years (usually in the context of volcanic ash or airliner particulate emissions), particularly of late in relation to the accelerating mass loss from Greenland's ice cap through melting and indirectly through sub-glacial melt water destabilising the glaciers by lubricating the boundary between rock and ice. I've never seen it presented as contentious, just an incompletely understood part of the story of how glaciers change.

The idea that human industrial activity as early as the mid 1800's could have destabilised alpine glaciers doesn't seem unlikely to me. It'd be interesting to compare the early industrial revolution movement of alpine glaciers to those of more remote regions or even those locally which were protected from 19thC industrial emissions by the prevailing weather. Scandinavia presumably would fit the bill. I doubt the historical record is as good as for the European alps but where a glacier is in continuous retreat the trees colonising the morain presumably provide a pretty reliable and high resolution record.

Sorry, you've lost me.

jk

The green line on the following graph is the temperature reconstruction published by Leclercq & Oerlemans 2011.  Its the most up to data one I have seen:

https://postimg.cc/yDsGjyPM

Mainly actually I wanted to see what you'd have to say on the matter....

You call it an ad-hom, I call it a condensed summary of the view of many credible scientists with evidence at their backs.

I didn't claim balance, I claimed it was the "other side of the fence".  I didn't imply that a balance is found between opinions on either side of the fence.  I'm not a fan of pretending balance lies between equally valid opinions, mostly because I don't believe in equally valid opinions.

Play the ball, not the man?  Resorting to Ad Homs?  Such irony.

I'm not laughing.

Detailed glacial retreat data for Mer de Glace and Bossons were published by Nussbaumer & Zumbuhl 2011.  The key figure I have uploaded in the link below:

https://postimg.cc/MnLxcD4S

The Bossons is somewhat different to the other 3 on the plot, perhaps because its north facing?  It reached a local minima around 1950 and then advanced quite strongly until the early 1980s before retreating again up to the end of the plotted data which is about 2005.  The retreat leading to the minima around 1950 was pretty steep too.

I was on the Bossons 1981/1982 and recall the remains of what I was told was an aircraft crash in (I think) the 1950s coming to the surface and out of the glacier.

People would take you a lot more seriously if you said "Koonin, ex BP Chief Scientist" whenever you mentioned him.

"> Oreskes is actually a conspiracy theorist

Play the ball, not the man?  Resorting to Ad Homs?  Such irony."

Are you trying to assert that someone who has actually written a book in which the main theme is a conspiracy theory is not a conspiracy theorist?

What I said about Oreskes' Merchants of Doubt was not ad. hom, it was factually accurate.  Your comments on Koonin were unattributed character assassination by people who don't agree with him.

According to the authors, 'The temperature record obtained from glacier fluctuations confirms the pronounced warming of the twentieth century, giving a global cumulative warming of 0.94±0.31K over the period 1830–2000 and a cumulative warming of 0.84±0.35K over the period 1600–2000.'

You are calling it a "conspiracy theory".

I would call it a rational, evidenced deconstruction of the influence of large international mega corporations in favour of short term profitability over long term sustainability.

It's not factually accurate; your'e choosing not to engage with any of the evidence from the the two authors (you keep returning to one) and instead seek to dismiss them with a label that is clearly pejorative and based on your pre-conceived opinions and not their rational, evidenced case.

You're such a fan of engaging with the material and not writing people off based on who they are - on what factual, evidenced grounds do you dispute their book.

It's not a character assignation, it's a classification.  One based in evidence.  Contrarian.

I'm sensing there's no point in continuing because you're attacking me for the exact same methodology which which you're disagreeing with Merchants of Doubt.

The wheels on the bus go round and round, round and round, round and round...

https://xkcd.com/1732/

Hi Harry,

Yes I know, I have read the paper.  My point still stands - glacier retreat commenced as far back as 1830.  Its not some sudden-caused-by-man late C20th century phenomenon.  Its much earlier.

The plot you re-linked too clearly shows there is an inconsistency.

The IPCC forcings used for climate modeling do not allow for any warming prior to 1910 and even post 1910 the modeled AGW is on average about 3x smaller than attributed post-1950s. 

Rates of warming from the results in the latest AR6 show that:

https://postimg.cc/94dC3ZJj

Model is blue, temps are red.  Data downloaded from Fig 1 AR6 SPM

Following this debate with interest. I have no special insight or knowledge and no expertise or training which would allow me to make a serious weighing of the opposing views. What I do know is that the issue is incredibly complex and the data hugely varied and unfortunately historically incomplete. 

When something is hugely complicated and by necessity, draws on the expertise of those pre-eminent in a multitude of fields, it would seem sensible to adhere to the consensus view. You obviously disagree. Could you explain why?

Your position seems doubly obtuse when you look at the potential outcomes of which side gains the upper hand in matters of Global policy. If those currently winning the debate are wrong, we'll have wasted a lot of time and money.

If the few currently advocating your position manage to cloud the issue sufficiently to tone down the response (as seems to be happening in many countries), we'll have killed millions, eradicated many species and habitats and, at the least done irreparable damage to our planet. 

The correct position to adopt seems a no brainer to me. You got kids? What do they think about your theories?

Flash, what are you hoping to achieve with this. As I’ve said already, I think the likelihood of a hobby scientist (disclosure: that’s effectively my status too) having discovered the smoking gun that overturns 30 years of multidisciplinary and global effort on climate science rounds down to zero. But, I have no doubt you are sincere in the position you are taking, and that you genuinely believe the data you are advancing is very important.
 

So, why are you posting about it extensively on here? I know you’ve presented a poster on it at the Geological Society, but with all due respect, that’s a pretty low-level audience for such important findings. In the normal run of events, scientists submit their findings to peer reviewed journals, the reach of the journal picked being greater for more compelling and important findings. You claim to have data that demands we reconsider the global policy approach to climate change. Surely the more appropriate  venue for scrutiny of this is an internationally important journal such as  Science, not the forums of a climbing website?

Actually I have not offered an opinion on the validity of Oreskes' book because I haven't read it.  However, I do know (because I have read a synopsis) that its central thesis is a conspiracy theory.  You have interpreted that as an ad. hom.  Just because she wrote it doesn't make it true (and neither does it for Koonin).  I read the popular Erich von Daniken books as a teenager but I didn't think the theory they promoted is true, although I am sure Daniken would assert they are.

You clearly think Oreskes' arguments have merit.  Good for you.  I presume therefore that you have read it yourself and are not taking a second hand opinion on it, as I suspect you are on Koonin's book.

I recommend stuff I have actually read.  I have actually read Koonin and I have actually read Shellenberger.  I have also read An Inconvenient Truth, although I wouldn't recommend it.  But then I would say that wouldn't I?

I don't really know what point you're trying to make with that graph. As far as I can see, there's a considerable increase in the modelled and actual warming rate since  1970 or so. I find that rather worrying. 

Thanks for your comment.  I don't want to repeat stuff continually that I have already said and will probably be criticised for doing so as well!

My motivation is based on people not realising that glacial retreat starts much earlier than most people think and therefore it cannot be caused solely by anthropogenic effects although it is often characterised as such.

With regard to your last point:

"The correct position to adopt seems a no brainer to me."

Fair enough.  I think that adaptation makes far more sense both politically and economically.  The impact of your preferred route is about to be tested in anger with the push to "Net Zero".  I think it is likely that the impact of policy will actually be much worse, especially for low income families, than any impact of climate change it is supposed to prevent.  Time will tell.

Understanding the tangled web of corporate interests and policy influence isn't a "conspiracy theory".  It does't have to be conspirational.  Some would call it recent history.  

It's certainly a book I've recommended to others on here before...

Yes, I'm quite happy to take second hand opinion on Koonin's book when it domes from a large number of highly credible scientists.  I think I've been clear on that.   It's not "groupthink", it's "science".

Even if burning fossil fuels had no detrimental impacts to the environment, the resources are limited and shrinking, whilst demand is ever growing.  

It's clear that economically we have to move beyond fossil fuels, and given that they're neither very cheap nor very equitably distributed around the world, there are plenty of reasons other than the environment to make net zero a lofty and economically fruitful goal.

The actual warming rate in the temperature data is marigally higher post-1990 than the peak at 1945, not 3x higher as GHG models predict.  The early C20th warming cannot be significantly attributed to GHGs because the IPCC forcings are too low - which is evidenced by the low warming rate shown by the model curve in blue.

So my point is there a significant discrepancy.  If you can't get the warming rate accurate 80+ years in the past to within a factor of 2x with supposedly known forcings, how can you expect to predict reliably 80 years forward into the unknown C21st?

Have you actually read Oreskes' book Merchants of Doubt?

It's clear that economically we have to move beyond fossil fuels, and given that they're neither very cheap nor very equitably distributed around the world, there are plenty of reasons other than the environment to make net zero a lofty and economically fruitful goal.

That's a pretty good argument, except.... the 3rd world is crying out for reliable power.

The dilemma (for me) is whether we deny them that (through not funding fossil fuel power generation - E.g. the EU's sustainable finance directive, disincentivizing funding for such schemes) or allow the 3rd world to develop quickly in the hope that this ultimately puts less pressure on the environment.

Interesting. That’s almost word for word the Climate Inactivism line. From the recent Guardian article: 

In the months that followed, however, disquiet over the net zero transition began ramping up in sections of the UK press – initially in outlets such as Spiked Online and GB News, but eventually creeping into the pages of major newspapers such as the Daily Telegraph and the Sun, too. In August, the Spectator magazine printed an image of banknotes tumbling into a void on its cover, with the headline “The cost of net zero”; by September, right-leaning media commentators were homing in on the government’s aim of gradually phasing out gas boilers as part of the decarbonisation plan, and replacing them with air- or ground-source heat pumps instead. The far greater economic costs of inaction on climate crisis were rarely mentioned in these reports, but again and again, efforts to reduce our collective carbon emissions were framed as an elitist power-grab. “People want a cleaner, greener planet,” wrote Andrew Neil for the Daily Mail in October. “But they will not tolerate a green strategy that involves posh folk telling plain folk what they must do. Especially when the posh folk are doing very nicely out of greenery and the plain folk are picking up the tab.”
 

https://www.theguardian.com/environment/2021/nov/11/inactivists-tangling-up...
 

a line being pushed heavily this year by NetZeroWatch, formerly called The Global Warming Policy Forum, and set up by Nigel Lawson, the Lord of Climate Change Denial. 

https://www.desmog.com/net-zero-watch/

Headquartered at 55 Tufton Street, the nexus point for a range of libertarian, pro Brexit, AGW skeptic groups:

https://www.desmog.com/55-tufton-street/

I think Flash is correct; this is going to become a, sorry I couldn’t resist, flashpoint. Watch out for the same tactics that poisoned the well of the Brexit debate being applied to undermine efforts to reduce emissions, with an increasing populist narrative being deployed. 
 

not suggesting for a minute you are a shill for NZW, Flash; but it’s clear this issue has got backers who will take contrary voices and give them a platform, so maybe the call will come… 

I'll say it again. Clumate models aren't designed to predict glacier retreat. They are. Validated by a host of historical measured atmospheric data that collectively show that the models categorically can predict the past. Any model that fails this test is not approved and is not used in ipcc or indeed any other publication. 

I suspect you know this and you are deliberately picking a measure that is not representative of the global climate(as is often stated here) because it by definition cannot validate the model and won't be predictable by climate models, simply to create doubt in the science. You do that because you are a f*cking arse. 

No, but I have read Oreskes and Conway's book, Merchants of Doubt.  Quite regularly put me in mind of Grogan from "Edge of Darkness" and it's interesting how Koonin falls in to a certain pattern of physicists covered in the book.

It's not the first time I've asked why you omit one of the author's names.  It's curious.  

I think solar offers far more potential for much of the developing world, both (terrestrial and beyond...).  The economics of solar are changing constantly in one direction to the point it's reaching parity with fossils, and it comes without so many of the harms, and with a much more decentralised nature that could be to the advantage of developing economies.

I recognise your point though that pushing development ahead could net reduce environment harm, but that needs a much more holistic solution than just the energy side.

Difficult questions.

You said "Clumate models aren't designed to predict glacier retreat"

Never said they were, but they are predicting temperatures which strongly affect glacial advance/retreat.  And scientists have inverted glacial retreat data in order to estimate temperature.  That is clearly directly comparable to temps output by climate models.

Regarding direct physical observations that relate to temperature over the last few hundred years there are in fact three that are relatively unambiguous (although with their own uncertainties): temperature, glacial retreat and sea level rise.  Two out of three of those go back to at least the early C19th and also happen to contradict the third (temperature) in the part pre-1900 or so.

Regarding the rest of your comment, ascribing motive to my actions probably says more about your thought processes than it does about me.  And your final sentence suggests you are incapable of constructing a compelling argument and so resort to profanity and name-calling.

youtube.com/watch?v=_GwbhKN-jUE&

I wasn't aware of the phrase "climate inactivism" until I read it here.  I am aware of GWPF and NetZeroWatch.

I do have concerns when those arguing from one side of a problem characterise those with an opposing view as arguing in bad faith.  In my view the Guardian has a tendency to do that and one or two posters here have done that with me.

The reason it concerns me is that when one side implies their opponents are arguing in bad faith it shows to me they are so entrenched in their position that they are not going to listen to any alternative views regardless of merit.  It is the metaphorical equivalent of sticking your fingers in your ears and chanting "lalala I can't hear you".  The belief in the righteousness of their argument then overwhelms any opposing views as not being worth listening too.  In my view that is a very dangerous place to be in a modern society and reflects a complete lack of tolerance in debate.  It leads to very bad decision making and, in extremis, to authoritarianism.

Also worth pointing out that some of the current research being done in Quaternary cave sediments in the Mendips confirms massive and sudden swings in flora and fauna due to very rapid climate changes - tundra to savannah and vice versa. This was documented to the CGS in September 2017 in a fantastic talk in Penrith. The speaker took no position on future prediction - she was just describing what happened over the past 26,000 years, quite frightening really if it happened again or we went into another cold period very suddenly.

DC

I think you're confusing the following:

• Listening to an alternative view and reaching their own conclusions on its veracity (or otherwise) by holding the alternative view up to the consensus scientific position 
• Not listening.

Ah, I see what happened, I misread temperature controlled as 'controlled for temperature' which makes no sense, as opposed to 'driven by temperature'. I presume your contention is they're somehow wrong?

jk

That looks suspiciously like cherry-picking the date of 1945 as being the year of maximum divergence. Alternatively, if you picked 1960, or 2002, or 1896, you would have exact convergence. Picking single data points as a means of comparison is rarely meaningful. The fact that there is that significant divergence does show that the models are not without fault. The fact that the general shapes of the model and the instrument data are so close over much of the period suggests they are not without some merit.   

I did.  I'll moderate that to arguing with such blind conviction it is indistinguishable from bad faith.  As an example, using ice-core data that stopped in 1850 to suggest that current temperatures aren't hotter than historic ones.

You can see that there are two periods of cooling ending approximately 1900 and 1970 and two periods of warming with peaks centred around 1945 and 2000 can't you?

The argument I put forward works whether you make it on peak warming or on the average warming over, say, 20 years.  So no its not cherry picking.

You comment makes no sense to me.  Leclercq and Oerlemans inverted glacial retreat data in order to estimate temperature.

No, I don't think Leclercq & Oerlemans are wrong.  If they are right their result contradicts the IPCC warming onset in 1910 by showing glacial retreat due to temperature rise commenced over 80 years too early to fit the IPCC forcing model.

The only significant point of divergence is over the period 1930 to 1960. For the rest of the time, the graphs show good agreement. It's not meaningful to make extrapolations for the period beyond 2010, since the shape of data may well change in years to come. 

It's also the case that your graph the 2020 warming rate is about 0.02C, or about 0.2C/decade. If this continues, we'll have a increase of 0.6C by 2050, and 1.6C by the end of the century. We have already had a little over 1C of warming since 1850, so the Paris target of 1.5 C is already baked in and will be well and truly breached by the end of the century. I don't find any comfort in that. 

"It's not meaningful to make extrapolations for the period beyond 2010, since the shape of data may well change in years to come."

Er...no.  Its a trailing 30 yr slope.  So its valid to 2019 (which is the end of the data used in AR6 SPM Fig 1 from whence this comes.  and models are currently showing significantly more warming than is observed.  Temperatures have actually almost plateaued , the last little uptick more due to the most recent El Nino (natural) than anything - something models cannot simulate currently.

True, true. That’s why I found your use of terms like “warmist” troubling- like “evolutionist” in a discussion about creationism, it carries a particular set of baggage and marks the person using it out as coming from a particular entrenched position.Your use of it, and emotive terms such as “hyperbole”, and insinuating the IPCC are primarily a political rather than scientific exercise, signal that shortcomings you accuse others of are your own shortcomings too. You’ll disagree, of course;    but when you then go on to rehearse the talking points pushed by climate denial lobby groups, it’s hardly a surprise some people will question your motives.

and you haven’t addressed the point I’ve made several times- when am I going to read the article setting out your findings and interpretations in a high impact factor peer reviewed journal? 

The graph does not suggest a plateauing of temperatures. For that to be the case, the warming rate would be zero, which has not been seen since 1980. 

At this point, I think I'll leave you to it. I have other things to to do. 

Exactly.  Why is he posting about it extensively on here?

I worked for many years with 'elite' members of the scientific research community (e.g. people with multiple significant patents to their names, acknowledged world authorities, etc), in a number of disciplines.  And when I entered that world my naive ideal that all these very clever people would be dedicated exclusively to the pursuit of knowledge was very quickly undermined when I came to see just how important ego was to them.  That is, you must be the one in the room who knows more than anyone else, you must be the top dog who wins the argument.  That's your claim to fame, your status symbol, your wealth, your power.   

And if you're not given that recognition by your peers, it all becomes very, very disappointing. So instead go for the easy win.  And go on a grand tour of random internet forums, where it's so much easier to find the ignorant plebs to impress.  All of a sudden you can become an intellectual big fish in a very tiny pond.  No matter that it's the equivalent of shouting into a dust bin on an empty street.

Just saying.

Yes I can see that. I'd misread something you wrote about it, now I see how I misread it and what you actually meant.

Ah, which explains the need to dismiss possible alternative early industrial revolution human influences on glacial retreat as not significant. They may not be significant of course, it's equally possible we're looking in the Alps at relatively localised 'weather' and the slim possibility remains that you've seen further and clearer than your brainwashed peers. The history of extreme flooding for example across Europe exhibits several superimposed cycles, some decades, some centuries long, I see no reason to suspect glaciation should be different.

To a greater or lesser degree I think most of us are eventually going to find ourselves in your shoes, looking back on a life lived being told we unwittingly did immeasurable harm by those who've inherited our mess. Denial of that by whatever means necessary will be the easy way out for many, myself included probably.

Incidentally, the choice is not between climate change mitigation and adaptation, with even just the harm done to date both will be the work of the 21st century.

jk

Possibly worth also pointing out that as interesting as it may be in a local context the dynamics of glacier movement for small isolated glaciers can tell you very little about global temperature change. The same can be said for plants in mendip caves. Isolated local events cannot be used as a global proxies. 

Hasn’t this been thoroughly debunked by Zeke Hausfather and his team at Berkeley. Others no doubt as well. 

The wheels on the bus...

As said on another thread, drawing an arbitrary starting point in the late 20th century might suit the point you are trying to get across but the date of 1830 segues much more with the seismic change the Industrial Revolution brought about.

I'm not a climate scientist, but paleoenvironmental science is a small part of my academic and professional background and I can spot when the data : result sequence is the wrong way round.

The many papers you are referencing are meaningless to me and likely most people on here, partly as I likely wouldn't understand enough of what is being discussed to critically appraise them, but more that I'd have to do a lot of background research, (aka fact-checking) to ascertain that the papers were worth reading and not from a suspect source. You have been called out on this on another thread and failed to give a convincing response, so you will understand my and others' scepticism.

True, but Leclercq and Oerleman's reconstruction of temperatures by inverting glacial retreat data uses the entire global database of glacier data.  That's data documented from 471 glaciers, so its not just restricted to European Alpine and it does include all the really big ones as well as a lot of small ones.  The same general comment is true of sea level data.

The real issue is that the database does become more geographically restricted as you go back in time.  Such is the general problem of reconstructions of past climate.  The same is true of temperature data, with coverage pre-1900 being very restricted.

You said "The graph does not suggest a plateauing of temperatures. "

You are correct, I should have said the graph suggests the rate of warming has currently plateaued.

You said "when am I going to read the article setting out your findings and interpretations in a high impact factor peer reviewed journal? "

When I finish writing it up and get round to publishing it.  But it takes 18 months - 2 years.

You do accept that "The IPCC does not conduct its own research."?

No one claims it does.  Much like, for example, SAGE doesn't conduct it's own research.  That doesn't make them political organisations.

I've lost the plot a bit - this is comparing "HadCRUT4 Slope 30yr" with "CMIP6 Slope 30yr"?

By what methodology do you determine that the HadCRUT curve has plateaued?  

The data as plotted has no y-axis uncertainties or CIs, so the probabilistic tests I would normally use to assign a hard probability to the possibilities of "plateaued" or "growing with X rate" aren't applicable.

Still, we could get some idea as to which of "plateaued" or "growing" is a better fit to the data, for example by doing 0th and 1st order fits, and looking at the scale and temporal correlation of the residuals, for example with a Durbrin-Watson statistic.  

Do you know what I expect such an analysis would show?  

That it's more accurate to describe the last 30 years of the HadCRUT4 slope as growing, meaning that the actually temperature is growing faster than linearly.  I think the DW test would be interesting.

You might find some helpful advice on UKC in the mean time to refine the way you look at data and translate claims about graphs into scientifically testable theories.  

You said "drawing an arbitrary starting point in the late 20th century"

Its the IPCC that makes the claim that post-1950s warming is mostly/almost exclusively anthropogenic.  Its not my arbitrary starting point. 

And its also evidenced in the model forcings.  There are no warming forcings input to climate models prior to 1910 and the forcings 1910 -1945 (or thereabouts) are >3x smaller than the forcings 1975-2010 (or thereabouts).

You said: "You might find some helpful advice on UKC in the mean time to refine the way you look at data and translate claims about graphs into scientifically testable theories. "

That's very kind and sound advice.

Ok fair enough, keep us posted. And if nothing else you’re getting prep for the points that peer reviewers are likely to raise…