Bishop Hill Explaining Otto
Mar 9, 2014 Climate: sensitivity The Otto et al paper, along with all the other observational estimates of low climate sensitivity, has been a bit of a bore for upholders of the climate consensus, distracting them from the daily grind of generating ever more more outlandish estimates of future warming and ever-more scary tales of the impacts.
Riding to the rescue is Drew Shindell of NASA GISS, who has analysed the models and found that he can explain the discrepancy with the observations:
Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10–15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (<1.3 °C) is very unlikely.
Reader Comments (54)
The ongoing problem with Lewis And Crok, Otto et all and other ECS estimates based on recent records is that they are based on surface temperatures rather than the energy content of the system.
The temporary slowing of the surface temperature rise has led them to underestimate the long term rate of change and hence underestimate the ECS.
Might I suggest you go and read the Lewis Crok report, which provides an introduction to climate sensitivity assessment?
It's just that everything you have written in that comment is wrong. From the report:
Entropic Man. "The ongoing problem with Lewis And Crok, Otto et all and other ECS estimates based on recent records is that they are based on surface temperatures rather than the energy content of the system. "
And, what problem would that be? My hunch is that Entropic man not knoweth what he speakith.
EM: you are not in the staff room, now, talking to heads buried in various newspapers; nor are you in the classroom, talking to heads filled with dry sponges, thirsting for every drop of knowledge that may be poured into them, yet still unable to assimilate, analyse and assess. You are with the big boys, now, and many (myself included) can spot crap whenever it is spouted, though not all (such as myself) can summon the information (or can be bothered summoning; your choice) to shoot you down.
Perhaps I should do what so many others appear to be doing, and just ignore your copious, erroneous output.
What benefit is there from analysing the output of models that demonstrate skill levels approximating zero ? I equate this with analysing cow patties to determine the sensitivity of the climate to runaway heating caused by CO2 concentrations in the atmosphere ... except that the cow patty methodology is more skillful. ;)
Did you see this report on the sun's variability over the last 1,000 years?
http://www.eurekalert.org/pub_releases/2014-03/cu-sei030714.php
In short the author, set to find 'its worse than we thought ' and with enough computing power and by ignoring reality , the found their 'proof '
So we are up to how many excuses for the pause now?
EM, you are such a loyal apologist. I actually respect your loyalty.
Entropic Man."The ongoing problem with Lewis And Crok, Otto et all and other ECS estimates based on recent records is that they are based on surface temperatures rather than the energy content of the system."
Because that is what climate sensitivity is about. It is feedbacks caused by mainly evaporation of extra water. If temperature is not rising at the surface then there will be no extra temperature driven evaporation. It is such feedbacks that make the models rise but it's not happening in the real world.
"This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks."
This is the first of three problems with the low sensitivity estimates.
Lewis 2013 and Otto use HadCrut4, which underestimates total warming by leaving out the Arctic completely. GISS, BEST, NCDC and Cowtan and Way all take Arctic warming into account and all show both higher warming totals, and less slowdown. These would all have given higher sensitivity.
The 21st century data is from a predominately negative PDO, giving low Pacific sea surface temperatures. Again, this leads to an underestimate of the long term rate of change.
The Lewis method is very sensitive to the data used. Adding six years to the data post 1995 dropped the calculated sensitivity by a third. This suggests that the confidence limits are large.
Overall the whole low sensitivity case depends on shaky data and shaky technique. It is not reliable.
I read this and said to myself "Hmm. Historical aerosols..."
The climate modeller's favourite fudge factor.
If the climate were highly sensitive to CO2 forcing, wouldn't it be, uh, hotter now?
Schindell's paper is fundamentally illogical. He builds on the recent nonsense finding that models with higher sensitivity did a better job recently (that is, missed the pause by less). They still missed. And the reason was (since one cannot go back and simple erase the CMIP5 archive) that they overstated aerosols. So higher sensitivities ran cooler. Now, how is this so relative to hind casts? Because they would also have run hot in hind cast without overstated aerosols.
Lower sensitivities did not need as much overstatement, but would not run a it hotter.
There is an old adage that applies. Two wrongs do. OT make a right. Even in the aw kynworld of climate science.
"GISS, BEST, NCDC and Cowtan and Way all take Arctic warming into account and all show both higher warming totals, and less slowdown. These would all have given higher sensitivity."
Would you care to tell us where the thermometer measuring the temperatures in the Arctic for GISS, BEST and NCDC are located?
Colwtan and Way has only been published a couple of months, only in clisci Where there is desperation at the lamentable forecasting skills would a paper from a couple of novices working out of an activist web site be accepted without replication by others.
If I may summarize:
"The models are wrong in a very bad way and we don't know why and can't make correct unless we back off on CO2 forcing. We can't actually say that, you see, so we've written this little missive above as filler until we find the cajones to actually share the truth with the world. Please read it, rate it, tell your friends, subscribe to this channel, and be the first to Like this post."
I can see another Nobel Peace Prize in the offing....
EM is the stupid version of Nick Stokes. Like an alter ego.
Mark
In the extract The Bishop included there is the following sentence.
Now one has to assume that these are negative feedbacks not previously taken into account by the models. So the next versions should include yet another now known unknown unknown for the previous release.
The modellers will have to do a lot of recalibrating.
BBC News - Why has global warming stalled?
http://www.bbc.co.uk/news/science-environment-23409404
Doug Elliot
Mr Shukman writes, "no one is really sure why the rate of warming has stumbled." Stumbled? Doesn't he know we're not out of the woods yet?
Re; Rud Istvan
> Schindell's paper is fundamentally illogical. He builds on the recent nonsense finding that models with higher sensitivity did a better job recently (that is, missed the pause by less).
The models he claims are better are those that picked up other features of the climate. For example, there have been a couple of papers recently (cant remember offhand), about models that better modelled precipitation and others that better modelled clouds. These models had higher sensitivity (and missed the pause by more) but because they were better at that particular feature he claims sensitivity is high. The fact that the features are clouds and precipitation and that those good at clouds fail with precipitation (and vice-versa) doesn't concern him. The overriding feature the model that must be preserved is that it has high sensitivity.
Any model with high sensitivity has to be investigated to find out why it is correct and any with low sensitivity* has be investigated to find out why it is wrong. It's a fundamental axiom of climate research.
* Are there models with low sensitivity?
Doug Elliot
Thanks for that link, I only visit BBC Science/Environment once or twice a week these days. I was struck by this from Shukman
Now that is an interesting thing for a BBC man to say.
EM is Robert Billings!
Mailman
Any particular reason for bringing up the David Shukman posting from last year again?
EM is the stupid version of Nick Stokes. Like an alter ego.
Mark
Mar 10, 2014 at 4:19 AM | Unregistered CommenterMark T
I don't know which one that insults the worse. :)
Mailman
And who is Bob Billings ?
Logic fail here:
"In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities."
That is the wrong assumption that leads directly to the wrong conclusion. No recent studies have concluded that anything about any of the models are realistic. They tweak one parameter and it gets better in one place and worse in another but the net effect is that they are still grossly inadequate both temporally and spatially. But only using the averaged anomaly allowed them to get even that close. Frankly it is cheating! Using an anomaly obscures the fact that real temperatures are not hindcastable at all anywhere and using the average obscures the fact that they cannot get major climate zones spatially correct.
By happy coincidence there has always been at least one model projection (Russian I believe) that provided the lower bound of the IPCC output sensitivity at 1.1K - based on a low input CO2 sensitivity - and it tracks reality better than the rest. Honest scientists/engineers can easily then conclude that the climate has a low CO2 sensitivity simply by rejecting obviously crap models.
Shindell once wrote a good paper on how well you can predict the past if you use solar proxies. I guess that wasn't giving him the career path he felt he deserved.
BS is an interesting substance. It is not lying. To lie you have to know what the truth is. BS is more along the lines of saying what you'd like to be true - and presenting it as the truth - but without actually knowing or checking whether it is actually true.
BS of the highest quality is produced by those who think they know the truth but in fact they don't know that they don't know.
And if one used the southern hemisphere's data only (which has just one-third of the aerosol and ozone forcing according to the paper), one would get an even lower ECS.
"It's just that everything you have written in that comment is wrong."
You've done it now, EM - you've upset the headmaster.
Mark T, mailman, jamesp
Keep the insults coming. They tell me
1) You are thinking about what I say and you dont like it.
2) You cant refute it.
And if one used the southern hemisphere's data only (which has just one-third of the aerosol and ozone forcing according to the paper), one would get an even lower ECS.
Mar 10, 2014 at 12:45 PM | Bill Illis
Precicely Shindell's point. He is saying that the Otto and Lewis have been using data which is unbalanced in that it underweighs the higher latitude Northern Hemisphere temperature changes and gives too much weight to the Equatorial and Southern Hemisphere changes. Hence the low sensitivity estimates.
The Southern Hemisphere is mostly ocean, with a higher heat capacity per square kilometre. It also has the massive heat sink of the Antarctic ice sheet. You would expect a slower rate of temperature change and therefore lowr TCR and ECS estimates using Southern Hemisphere data only.
EM
It wasn't intended as an insult, merely an observation. And I think the Bishop has refuted it.
EM
You do realise you are arguing like a cleric?
All of your arguments and in fact your 30 indicators on another post all stem from the assumption that AGW is real. Or more precisely that it is the only explanation for temperature increase in the last 150 years.
The problem is that this is not how you make a scientific argument. To make the AGW argument you need to have characterised the AGW effect in very detailed ways which hasn't been done. Then you could rightly claim such things as climate sensitivity and maybe then we could apply this to the Earths climate.
Otherwise the default is: we don't know.
I'm trying to think why a science teacher wouldn't understand this basic concept.
EM,
You are right! I should apologise to Robert Billings for the completely unfair comparison with yourself. It was uncalled for!
Btw, Robert Billings was one of the central characters in a booki read several decades ago at high school called "The Wave". The character was the class loser who only came to prominence when a new movement was started in a school that eventually lead to the death/murder of another student. The Wave gave Robert something to belong to, which incidentally he was "unelected" as the leader because the teacher got the class to turn around while lived up and Mr Billings was on the end of the line sand became the leader.
Basically everything you seein the religion of Mann Made Global Warming (tm) is the sort of The Wave! Unelected, unaccountable, violent organisations full of losers.
Hmm...perhaps the comparison IS warranted?
Mailman
Ps. This is all from memory so don't quote me about the plot, characters or anything else to do about the book!
EM says:
Unfortunately that claim is based on a tautology, but this is a common way for EM to try and present an argument that actually relies on circular reasoning. The models predict greater warming in the arctic, but because there is very little areal coverage by thermometers this is simply surmise, not fact. Geronimo makes the same point by asking EM to produce the thermometers confirming this prediction. In the same way we are still waiting for the thermometers in the deep ocean too. Isn't it funny how this AGW hypothesis appears to constantly depend on extreme effects in just the places where we don't happen to have any data?
Rud Istvan also makes the important point that the models actually run even hotter, because they have overstated aerosols in CMIP5. We should also note that the idea that models are best with high sensitivity assumes the cooling forcing from aerosols is correct. Of course, the aerosol history is also an unknown and subject to revision. So the models are a clever balance of two competing and unknown forcings. You could make them fit anything you like, really.
Oh - except they don't correctly fit the natural temperature rise up to the 1940's, neither in timing (overshoot) nor magnitude (undershoot). Just another example of relying on unverified models that cannot make simple historical predictions.
As for GISS and the warming trend - when someone satisfactorily explains to me why the trend in the adjustments is (a) larger than the putative warming trend for the 20th Century and (b) the physical explanation why the temperature adjustment should be a systematic accelerating trend with time then maybe I will actually believe that modern temperatures are actually significantly warmer than the 1930's decade. I would also like a clear physics explanation justifying why global mean temperatures are based on calculating (Tmin+Tmax)/2 instead of being calculated on Tmax only
http://stevengoddard.files.wordpress.com/2014/01/ts-ushcn_anom25_diffs_urb-raw_pg.gif
Finally, would love to see a model run matched to the GISS historical temperature without adjustments.
Micky H Corbett
I don't believe in fairies or imaginary alternative explanations.
Feel free to believe in them yourself, but I'll stick with cAGW until you can provide evidence for something that explains my list better.
Thinking scientist
For average temperature data above 80N go to
http://ocean.dmi.dk/arctic/meant80n.uk.php
For raw Arctic buoy data go here.
http://iabp.apl.washington.edu
You'll need to work your way in via the data page. They are big and rather unwieldly files.
For the ocean the water is its own thermometer. Subtracting the other inputs to sea level rise, the residual rise is due to thermal expansion. The energy input and resulting average temperature rise can be calculated from the volume increase.
BUT what do the actual, Real Life (tm), temperature recordings say?
Mailman
What are you on, EM? You reinforce the point made by Thinking Scientist. The location maps at the University of Washington site show the tiny number of buoys giving temperature readings from the Arctic basin.
EM
You're doing it again. To make a scientific case you need a mechanism or an effect that has been demonstrated to work with careful experiment. Until such time all you have is a theory which does not mean its correct.
Fairies controlling the Earth's climate is actually not that far removed from CO2 being the controller. There is little real evidence for both. However as has always been my point, with a little effort CO2 effects could be tested and characterised and we would have clarity on the subject.
But please believe all you want without evidence. There is a delicious irony to it.
Oh and btw your list only demonstates a warmer world and more CO2 in the atmosphere. Some of your statements are actually wrong e.g sea ice indicators. I'll get round to answering each one on the discussion board.
They do not show that heating is due to CO2. You have provided a circumstantial argument.
I don't think you realise this.
Over on CA, Nic Lewis is providing a response to Shindell. He identifies serious problems with four of the 6 models chosen by Shindell (including that wonderful Canadian model that consistently produces the highest estimate of GW).
*sigh* Once more, EM, let me re-iterate: you DO NOT have to have an alternative explanation for the original explanation to be wrong!
The evidence against cAGW (whatever you might mean by that) is quite convincing, especially as it has been collected primarily to prove its existence, and has quite catastrophically (pun intended) failed.
Lance Wallace has beaten me to the news of Nic Lewis' response at Climate Audit.
But at least I can provide a link.
From the arctic page linked to by Entropic Man:
So Entropic Man tries to rebut a point about the lack of actual temperature measurements by linking to a page that describes arctic temperatures obtained from the "average of the 00z and 12z analysis for all model grid points inside that area.". So no measurements, just models.
We then get treated to comment about "reanalysis". Ie analysing model output as though it were real data.
Its just models all the way down. Show me the DATA.
Entropic Man you are starting to look and behave like prize idiot. I rest my case.
Its a shame, you used to make good points and even concede points in the past by admitting when you were wrong, as did others when you made a good point. I respected you for that. Now you look like a PR consultant version of BBD.
"For the ocean the water is its own thermometer."
Haha. Is this some kind of Zen koan or just pure nonsense?
Pilot: "What is our altitude?"
Co-Pilot: "For the sky, the air is its own altimeter"
Right...
Thinkingscientist
Churchill called it the Black Dog. Good days and bad days. Goodnight
EM,
The ocean is a terrible thermometer. It will absorb vast quantities of heat before it expands. It is moved by solar and lunar tides, currents, storms, trade winds and breezes. It is an even worse thermometer, if possible, than tree rings.