About angech

harry@asoliduniverse.com

BEAUTY

Let me assure you I usually mean what I say and know what I do.” the bright girl said, not knowing the meaning of what she said when she did. [NNT]

Beauty is sometimes described as being in the eye of the beholder and also as only being skin deep. Hence it has no actual link or need for truth. It would be nice for a theory to be pleasing, to be beautiful but there is no valid reason for this to be so. Our concepts of beauty are both personal and cultural and may rely on conciseness and symmetry and evenness [flawless] but most of us know there is more beauty in a handmade, flawed piece of pottery done by someone we love than in a Venus de Milo or Winged Victory of Samothrace, though admittedly they are beautiful to me.
So science and scientific theory do not have to be beautiful, they just have to work, concise or complex, no need to care, just to appreciate.

On the theory of the discs in general, appropriating it to theory suggesting that turbulence could act to promote, rather than inhibit, this planet formation process.
If appropriate for discs in other contexts it does not imply that it must work in all disc settings or subsets but it is still of interest as to why when a lot of the basic physics is very similar.
Gets back to the gravity interactions of that mass of stellar dust thrown together in that cluster. Larger or smaller sizes presumably of different density and thermal activity materials [stars and planets] might behave differently in accumulating mass.

wicked

angech says:

Your comment is awaiting moderation.

“how to frame anthropogenically-driven climate change.
In particular, should it be framed as a wicked problem? A number of people involved in the discussion had a problem with this framing. One very simple reason was that if you consider the standard definition of a wicked problem it is a problem that is difficult or impossible to solve because of incomplete, contradictory, and changing requirements that are often difficult to recognize.”
“”Those defending the wicked framing suggested that it applied only to the socio-political aspects of the problem, not to our scientific understanding (which is pretty clear).”

Joshua “wicked problems” are very, very complicated problems. The definition used here. Another meaning of wicked is evil not that that seems to be important here.

ATTP you start of addressing one wicked problem, anthropogenically-driven climate change and then move to another, how to solve it.
The wickedness of the first, scientific certainty is totally different to the psycho social problems found in trying to develop strategies to combat it, “Wicked problems are not well bounded, are framed differently by various groups and individuals, harbor large scientific to existential uncertainties and have unclear solutions and pathways to those solutions”

Either on their own is a wicked problem [very,very complicated]. Not to mention the first as a problem for the second. DM “some that argue the science is insufficiently well understood as a method of avoiding addressing the socio-political issues”.
So they could be addressed seperately to reduce one level of confusion.

Roger Jones said with possibly a touch too much confidence
“Wicked problems are solvable, but need to be addressed with a set of methods and techniques that you otherwise might not use.”
Sometimes a simple method works eg cutting the Gordian knot.
Sometimes someone comes up with a new approach, Gallileo, Einstein etc.
Other than brute force at the cutting edge or genius and luck at the other, wicked problems are that precisely because they are unsolvable or result in unsatisfactory solutions.

Call them complex if it bothers you, but Willard would say that substituting one word for another might make you sleep better but does not take away the angst as the meaning might be hidden but resides. Resident Complexity I think was the movie series.

ecs again

angech says:
Your comment is awaiting moderation.
December 9, 2017 at 3:10 am

From Paul’s site
“Given your results, what do they imply for the climate sensitivity of the system at the moment. Given that the widely used figure in models is around 3C and you have found them under-
predicting, I assume the ECS from your work would be in the 3.5-4C range?
Yes our constrained central estimate of ECS is 3.7.”

The ECS he uses [I thought we just had a big discussion where you guys said you cannot work out ECS?? practically like this but….] is on average 3.7 instead of the Climate models 3.0.
Plug this into the graphs and you get a 27% higher rate of increase.

Fine.
Not able to afford the paid look so what is studiously not mentioned here is what the “recent” in Earth’s recent observational energy budget refers to.
Please do not tell me that they picked the 3 most recent El Nino years and then worked out an energy budget and ECS on those 3 atypically hot years.
Or just the last 5 years.
Please tell me it refers to the budget worked out from 2000 at least.
ATTP?
Paul?

…and Then There’s Physics says: November 29, 2017 at 4:13 pm
“We can estimate the actual change in radiative forcing and then relate that to the equivalent change in atmospheric CO2, to then produce an estimate of the TCR/ECS. This is essentially what Nic Lewis’s work does”

Presumably not only Lewis but Brown is working out ECS.
A higher ECS, as in this case, gives a greater temperature rise for a doubling of CO2.
The only difference being one uses a long term study of temps and the other a short term study of temps to determine the ECS.
I imagine this study could be done for a number of recent observational ranges.
If one was to choose the 5 years from 2007 to 2012 for comparison the ECS may well have been below 2.0.
Presuming the paper was done on the last 5 years of observation which is a very uneducated guess on my part.
Do we know which time frame the recent observations were done in?

Polar Bears decimated

Internet Blogs, Polar Bears, and Climate-Change Denial
Jeffrey A. Harvey Daphne van den Berg Jacintha Ellers Remko Kampen Thomas W. Crowther Peter Roessingh Bart Verheggen Rascha J. M. Nuijten Eric Post Stephan Lewandowsky Ian Stirling Meena Balgopal Steven C. Amstrup Michael E. Mann.

A star studded line up to attack one person, or should I say woman?
Yes. Why not, it is late 2017 after all. I guess they did the paper before Harvey.
They need to attach her.
Ragnaar says:
“I Googled this: population polar bears Crockford gets hits 2, 3 and 4.”

For what it is worth I totally agree with Joshua and Steven on this in their first comments.

The paper is a statement of the obvious. If AGW, ice all melts and polar bears die. Logic impeccable for warmists.
However, If AGW is denied, if ice melt is denied, then polar bears live. Logic impeccable for denialists.

Hence the problem, how many polar bear specialists are there? Like one does not get up real close and friendly like gorillas in the mist. How many reports on numbers are there and how reliable?
Ragnaar again
“There’s is a lack of data. I looked at a few maps, and there are large unknown areas.”

Then there is this
“A boatload of tourists in the far eastern Russian Arctic thought they were seeing clumps of ice on the shore, before the jaw-dropping realisation that some 200 polar bears were roaming on the mountain slope.”.
Perhaps it was fake news. Perhaps 1 litter of 200 babies was born in this area last year.
All I can think of is that if one extrapolates out 200 bears in 1 square kilometer then the number of Polar bears in the Arctic has been sadly and badly underestimated by everyone , including Dr S Crockford.

angech says:

Your comment is awaiting moderation.

It is good to see Jeff Harvey put up his perspective on his paper.
A few comments for consideration
The article was never about the science.
It was about the *direction the planet is going in and how to save it.
Consequently the aim of the paper

“My final point. Our paper was about scientific transparency and integrity ”
“one of the major aims of the paper was to advise general readers not to take at face value what they read on blogs.”
was lost in the execution which resulted in
“Instead they accuse us of ad hominem smears of Susan Crockford and leave it at that. They can dish it out but can’t take it.”

“[I] and the other authors had the courage to show that blogs which habitually dismiss climate change-related threats to polar bears do not refer to the primary literature but to a blogger that disagrees with the primary literature, and not through scientific journals but through her blog.”

Instead of dismissing a scientist as a mere blogger the intent of the article would have been best achieved by providing the data on Polar Bear numbers, distribution and time changes, real and known firstly extrapolated secondly and then addressing the scientist bloggers extrapolations and conclusions and scientifically, with transparency and clarity, proving her wrong.
Simple.
Can the paper be redone with this aim?

Who raised it first? Polar Bear numbers.
Who then linked it to global warming??
Polar Bear numbers had been in decline because of hunting and human encroachment for ages.
Eli says “The ice is shrinking at times of the year when the bears need it and more.”

May I be so bold as to ask for the quote or source?

Yet Bart’s introduction points out the obvious .
“The polar bear species has survived the previous interglacial ~125,000 years ago. even though during the previous interglacial summers were probably not completely ice-free, as is expected to happen later this century as a consequence of continuing warming.
Besides shrinking sea ice there are currently also other factors that negatively affect polar bears, such as human settlements, industrial activities, hunting, bio-accumulation of toxins, and smaller seal populations.”
[disclaimer yes I have only taken parts of the quote that I like as usual].
At WUWT this comment
“The skeptics of AGW will point to the fact the polar bear population is up to approx 26,000 vs the 10k when hunting was stopped.”
cannot be true?

Eli, I acknowledge that if the ice all went all year round the Polar Bears would be forced to evolve or perish.
How far do you go in insisting a little loss of mid summer ice would imperil them totally in the next 1000 years?

 

Using a sledgehammer to crack a nut in a a china shop and then finding the nut was in another building and perhaps was not a nut at all.

“We have clearly hit the target dead-on judging by the bitter response of the climate change skeptics and deniers. They are inadvertantly helping to spread the message.”

As opposed to advertently helping, I guess.

Look Arctic Ice is down on all measures since satellites were “formally”” used to measure it.
The time span is short to know anything about long term trends.
If one shows CO2 increase, and then the CO2 increase shows the warming it is predicted to, then the ice will melt over the long term.
The long term result of this in thousands of years is that Polar Bears may or may not be endangered [they may or may not adapt].
Speculation on linking the two separate calamities if they eventuate is fraught with difficulty and should never have been poster childed in the first place.

“How blogs convey and distort scientific information about polar bears and Arctic sea ice”
Starts with this lovely line
“Internet blogs have strongly contributed to this consensus gap by fomenting misunderstandings of AGW causes and consequences. Polar bears (Ursus maritimus) have become a “poster species” for AGW, making them a target of those denying AGW evidence. Here, focusing on Arctic sea ice and polar bears, we show that blogs that deny or downplay AGW disregard the overwhelming scientific evidence of Arctic sea-ice loss and polar bear vulnerability.”

Problem ?
All the blogs try to promote scientific information, some for and some against AGW. This is the money comment.

“overwhelming scientific evidence of Arctic sea-ice loss and polar bear vulnerability.”

So Bart,
what is your estimate, from the experts, of
1.The number of Polar bears in the Arctic now.
2. The number of Polar bears back when satellite records showed the decrease in Arctic ice from AGW starting.
3. How much the ice extent in feeding time has diminished
4 How the decline in Polar bear numbers over this time matches.

I would expect a paper attacking concepts of Polar bear numbers now and in the future would set these facts out in large clear scientific numbers and hence shoot Crockford down. .

. much of the public remains unconvinced of the human influence on climate, This chasm between public opinion and scientific agreement on AGW is now commonly referred to as the consensus gap
climate-change denial involves a growing labyrinthine network of Internet blogs
Watts Up With That (WUWT), which consistently denies AGW and/or threats linked to it, is described as “perhaps the most visited climate website in the world,
Many denier blogs exist described as “foot soldiers of AGW denial”
Despite the growing evidence in support of AGW, these blogs continue to aggressively deny the causes and/or the projected effects of AGW and to personally attack scientists who publish peer-reviewed research in the field with the aim of fomenting doubt to maintain the consensus gap.
science-based and science-denier blogs may draw on similar examples, they frame their claims differently. For example, scientific blogs provide context and associated evidence, whereas denier blogs often remove context or misinterpret examples
The same frame can be presented in both negative and positive ways,
A growing body of scientific research reports the wide array of negative effects of AGW on biodiversity
, when alleging sea ice recovered after 2012, Crockford downplayed the contribution of sea-ice loss to polar-bear population declines in the Beaufort Sea.
Yet habitat loss is not always immediately followed by abundance declines of species dependent on that habitat. (Kuussaari et al. 2009)
As in other ecosystems, when critical thresholds in habitat availability are passed, tipping points occur, and species dependent on that habitat suddenly experience sharp declines (Dai et al. 2012)

“1. Once again the climate science community beclowns itself

angech says:
Your comment is awaiting moderation.
December 2, 2017 at 7:18 am

“1. Once again the climate science community beclowns itself by critiquing an article on non-scientific grounds”.
I did not understand, is he complaining about the article or the article reviewers views?
ATTP
“I simply think that in many cases science communication is aimed more at providing information, than at influencing opinion. Critiquing the former, for not achieving the latter,”
So the problem is critiquing the science- rather than thanking the guys for putting the vital information out there.
A selection of the gist of the article
“”Ice Apocalypse ”
(A Rolling Stone feature earlier this year dubbed Thwaites “The Doomsday Glacier.”)
Next to a meteor strike, rapid sea-level rise from collapsing ice cliffs is one of the quickest ways our world can remake itself. This is about as fast as climate change gets.
Antarctica is a giant landmass — about half the size of Africa — and the ice that covers it averages more than a mile thick.
Around 3 million years ago, when global temperatures were about as warm as they’re expected to be later this century, oceans were dozens of feet higher than today.Previous models suggested that it would take hundreds or thousands of years for sea-level rise of that magnitude to occur
Pollard and DeConto are the first to admit that their model is still crude, but its results have pushed the entire scientific community into emergency mode.
the full 11 feet of ice locked in West Antarctica might be freed up, their study showed.
All this could play out in a mere 20 to 50 years — much too quickly for humanity to adapt.
“It could happen faster or slower, I don’t think we really know yet,”
– ATTP said
“scientists (well, climate scientists, at least) [seem*] incapable of communicating with a public audience and regard them as being in denial when it comes to cognitive science and narrative theory.”
Not these scientists, they have communicated the threat extremely well.
Pity about the science

data

“”To claim that observations can tell us something about ECS, we first have to see whether it is a meaningful test by using the best info to hand – model output ”

Or in other words ignore data. Who needs data anyway.
It is useless without models.
Now as someone once said all models are wrong.
But we can discuss a lot of physics in the models and the answers are always right.

Further proof,
“Observations therefore are not likely to usefully constrain ECS in any Bayesian assessment”
We do not need observations or data to construct highly reliable models, especially when we know what the data will be in the future without looking at it.
“Whereas by 2095, the correlation between total warming and ECS is 0.77. Correlation over the period 2006 to 2095 is 0.81. The best way to estimate climate sensitivity is to be there, not here and now.”
In fact model data gets better and better in correlation with the models as it gets further away from actually being observed.

 

angech says:

Your comment is awaiting moderation.

“Roughly speaking, this result seems broadly consistent with the IPCC range of 1.5-4.5K (although that might be a 17-83%, rather than a 5-95%, range),”
Eyeballing the graphs roughly there appears to be little correlation with the Lewis best estimate way below the IPCC estimate.
BBD prefers 3.0 Lewis would be lucky to be 2.0.

“What would be nice would be to maybe include more physics so as to exclude regions of parameter space that we regard virtually impossible (for example, ECS values below 1K).”
If the physics is right why do we have to include “more” physics? Surely impossible results will be excluded by the physics we have, if it is right in the first place, not more of it.

no pause

Mal Adapted says:
November 21, 2017 at 11:44 pm

angech:

All the hand waving afterwards and altering of the data sets afterwards do not change the premise, at the time, on the data that was available and used, that there was a pause.

Except there was no pause, if by ‘pause’ you mean a short-term interval when the slope of the long-term statistical trend in GMST fell to zero. There was an interval between 1998 and 2012 when observed GMST appeared to the eye to rise more slowly than projections for that interval produced by an ensemble of coupled GCMs, although still within modeled lower confidence bounds. Change point analysis, more rigorous than eyeball methods, found no statistically significant change in the trend of the previous three decades. From the latter article, by Rahmstorf, Foster and Cahill earlier this year in ERL:

[T]he data are fully consistent with a steady global warming trend since the 1970s, superimposed with random, stationary, short-term variability. All recent variations in short-term trends are well within what was to be expected, based on the observed warming trend and the observed variability from the 1970s up to the year 2000. We discuss some pitfalls of statistical analysis of global temperatures which have led to incorrect claims of an unexpected or significant warming slowdown.

Although the alleged ‘pause’ was not statistically significant and was conclusively terminated in 2014, it attracted attention from climate scientists seeking to resolve ‘internal’, short-term variability to forcings. Rather than casting doubt on the AGW consensus, the short-term slowdown in observed warming led to refinement of models as well as datasets. Climate science advanced pretty much as one expects, and the consensus case for AGW grew still stronger. AGW-deniers hoping to weaken it, OTOH, found their ‘pause’ rhetoric had backfired ;^D!
angech says:
Your comment is awaiting moderation.
November 22, 2017 at 2:45 am

“The problem becomes worse, in that a lot of people here dispute that there was a pause at all”
Mal Adapted says: re
“All the hand waving afterwards and altering of the data sets afterwards do not change the premise, at the time, on the data that was available and used, that there was a pause.”

“Except there was no pause, if by ‘pause’ you mean a short-term interval when the slope of the long-term statistical trend in GMST fell to zero”

Note I did say premise, not fact.
And thank you for one definition of what a pause might be.
It is difficult to discuss what one believes does not exist.
Particularly when giving proof that it did not exist because you [*Xiangdong Zhang] have found extra missing data that proves it did not exist.
angech says:
Your comment is awaiting moderation.
November 22, 2017 at 3:12 am

Mal Adapted
“Except there was no pause, if by ‘pause’ you mean a short-term interval when the slope of the long-term statistical trend in GMST fell to zero”

I would be happy with a definition of a pause, in general, to be a zero slope trend for any graph with a time base over any reasonable fraction of the presented graph.
This is not a standard definition but since we are discussing unicorns this is the sort of definition I would prefer.
At Lucia’s 2 years ago she and others argued that a steady slope with no acceleration could be taken in some circles to mean a pause. I get the idea of a non changing rate being paused but in the real world I would insist on a zero slope, that is there was a rate which has now altered to a zero slope.
As for short term there is no short term in my definition if showing a single pause as the requirement is for it to be visible on the graph shown.

Commenting specifically on “[T]he data are fully consistent with a steady global warming trend since the 1970s, superimposed with random, stationary, short-term variability”
We have a graph of 47 years, the authors dispute the existence of a pause while admitting several occurred by my definition [random, stationary, short-term variability]. Karsten himself acknowledges a pause was seen and named by some people ” the inappropriately named “hiatus”. John Hart references “average global temperatures from 1998-2012 ” which would be a significant 14 years out of 47, hardly short term in the context of a 47 YO graph.

Since a lot of people here dispute that there was a pause at all.
Not to mention all authors referenced above
With good arguments.
Too short a time frame.
The graph actually went up 0.05C in the misquoted study.
Cherry picking a time after El Nino.
Definition of a pause is completely wrong.
etc.
There is no need to throw in studies showing there was a pause but….

Anthropogenic Climate Change as an entity.

 

  • angech says:

    Your comment is awaiting moderation.

    John Hartz
    “I believe that the Womens March on Washington will go down in history as the pivotal event for shifiting the momentum.”
    Really?
    “I was wondering where Liv Tyler has her hands to cause the expressions on the face of Trump and the Emir.”
    “Hmm err, so Trump is married to a mannequin I mean seriously, have you ever seen her move? I haven’t.”
    Really pivotal?
    Cue the Princess Bride Spaniard.
    Mind you the first comment was funny in my non PC correct world.

  • angech says:

    Your comment is awaiting moderation.

    DM
    ” For someone that doesn’t accept the existence of anthropogenic climate change, there is no “impact of the accompanying production pathway” in this respect, so how are they going to accept any ownership of a problem they do not believe to exist?
    “Making people own their position can be very difficult. Sometimes the best you can do is expose the evasion.”

    There is a subtle difference between knowing and believing.
    Found this out studying Italian Conditional verbs last week.

    I guess some of the people that do not accept the existence of anthropogenic climate change know they do not have enough proof. Show them enough proof.

    Others are believers, They do not need proof and you will never convince them.
    They are still people and we all need to get on with people so the best thing is to be nice to them [especially your elders] and not harangue them and embarrass them in public as others have done. Some are mothers, sisters, wives, girlfriends or family, some are bosses.
    No need to argue with them. just ignore them.

    Some are difficult contrarians on blogs. Fight them with all you have got. Expose my evasion.

    For the record.
    The world has a lot of problems and potential problems and if your justified fears on Climate change come true there may well be severe “problems” as you put it.
    If I waved a magic wand and fixed it today forever the rest of the problems would still exist.
    Some of the problems would still be the same, deforestation and species rundown from anthropogenic, non climate change reasons.
    Some of the problems are much more urgent and pressing than climate change and can be fixed for a fraction of the cost. Overpopulation and famine for a start.
    Which one should I give allegiance to, and at what detriment to all the others?

    None of the problems for a single person last more than a thinking lifetime.
    Duties and obligations seem to be an undercurrent. Yet why are we lumbered with duties and obligations, culturally burdened, when we did not ask to be born?
    Do you blame your forebears for not considering the consequences of invading the new world or starting the Industrial Revolution? Did they consider their descendants?

  • angech says:

    Your comment is awaiting moderation.

    “I’m sorry, but as far as I can see, you have not answered the question”
    Anthropogenic Climate Change as an entity.
    Willard might have a list of levels.
    Absolute denial. Some deluded people. Not CO2 , not happening
    Relative Denial Some deluded people. Not CO2.
    Specific denial Some deluded people Not CO2, something else
    but then we have another group of people also called denialists who absolutely agree that there is AGW but just do not believe that it has to be bad or severe.
    Judith Curry and R Pielke spring to mind as do nearly all Climate etc followers and most WUWT bloggers.

    A definition of Anthropogenic Climate Change would be that harmful warming due to human activity [ specifically increased CO2] that produces 110% of all the warming that has occurred to date since humans first built fires and will cause anything between a 2.0 and 6.0C temperature rise by 2100 if fossil fuel use increases at the current rate.
    Harmful warming being sea level rise of several meters, Increased severe flooding, droughts and weather disturbances etc.
    Special mention that this effect will be irreversible and last for 100’s of years.

    For some strange and unaccountable reason a lot of people just do not buy this product despite testimonials from 97% of dentists.

 

scourge of despair

The term scourge of drugs was mentioned yesterday.

The image that came into my mind was not that of a drug addict but that of a person suffering from despair. What else would drive  most people to use and continue to use drugs that have such a terrible effect on their lives.

Some people obviously use drugs out of curiosity initially. What sort of effect does it have?

ATTP, This is a discussion of clouds

ATTP,
This is a discussion of clouds precisely because they are a very important part of the climate puzzle.
“Clearing Clouds of Uncertainty by Mark Zelinka, David Randall, Mark Webb and Steven Klein. Their commentary is really a summary of our recent understanding and – as illustrated by the figure on the right – they conclude that the evidence is converging on the cloud feedback likely being positive.”
From FAR 1990 positive but cloud feedback represented the largest source of uncertainty in climate sensitivity among atmospheric models.
To SAR Second Assessment Report; 1995), more climate models were predicting the mass of cloud liquid and ice, and generally finding negative cloud opacity feedbacks, albeit of widely differing strengths. The report concluded that it was not possible at that time to judge the sign of the net cloud feedback.
TAR 2001 …the sign of [the cloud] feedback remains unknown.
AR4 2007 it is not yet possible to assess which of the model estimates of cloud feedback is the most reliable
AR5 “The sign of the net radiative feedback due to all cloud types is…likely positive”
BUT Cloud opacity feedback “is highly uncertain”

You say,
“I don’t really see why I should be expected to post comments that are certain, but wrong.”
I repeated a fact, “Averaged globally and annually, clouds cause cooling ” from the article overview. I said in view of this,
“any increase in cloud cover should have a stronger negative than a positive effect.”
The current point of view says this is likely wrong but admit to high uncertainty still in areas like cloud opacity. There is a threefold variation in the global sensitivity parameter FAR 1990 due to
differences in cloud feedback.
This is a most important discussion which is not yet settled and needs open discussion.

 

 

  • angech says:

    Your comment is awaiting moderation.

    Izen
    The article overview states
    “Averaged globally and annually, clouds cause 18W/m2 of cooling relative to a hypothetical
    cloud-free Earth. This is the net result of a 46 W/m2 cooling from reflecting sunlight back to space (an albedo effect) partly offset by a 28 W/m2 heating due to reduced terrestrial radiation emitted to space (a greenhouse effect). The net planetary cooling provided by clouds is roughly five times as large as the planetary heating from a doubling of CO2.”
    So even though the albedo effect usually works only half the time [there is a minuscule effect for moonlight etc] it produces much more cooling in that 12 hour period than a whole 24 hours of
    cloud GH positive effect.

    “Why would the albedo negative effect be larger than the cloud GH positive effect if they increase”

    Because it is positive with more clouds. As stated above in a cloud free earth it would be 18W/M energy warmer. So if there is no effect with no cloud and 18 W/m2 cooler with current cloud it stands to reason that with more cloud from global warming there should be an increase in the cooling effect.

    The authors state,
    “The overall cloud feedback is actually the aggregate effect of several individual cloud feedbacks, commonly separated into three components: cloud amount, cloud altitude,and cloud opacity feedbacks” “Nearly all current climate models simulate an overall positive cloud feedback ”

    Despite Victor’s assertion he is referring to a decreasing amount of ice and here we are referring to an increasing amount of water vapor. Which up to this point in the climate causes cooling of a known degree. The models simulate and argue for positive feedbacks from clouds from this point on without acknowledgment of how the clouds caused cooling in the first place.
    It appears to be models all the way down with “weak further support from observations”

  • paulski0 says:

    angech,

    ATTP ” they conclude that the evidence is converging on the cloud feedback likely being positive.”
    This comment must therefore be directed at the increase in clouds, not their current status as the article demonstrates an original strong negative feedback (18W/m2).

    Positive feedback in this case refers to enhancement of warming rate due to changes in cloud behaviour in response to temperature increase.

    The -18W/m2 figure refers to the net present day radiative effect of clouds, relative to a hypothetical Earth without clouds (all else remaining the same). I guess you could argue that clouds wouldn’t exist at 0K temperature, so the “warming” to present day 288K temperature has resulted in a -18W/m2 negative feedback, but the temperature at which clouds can form is so far below 288K that it makes no sense to extrapolate a continuing increase in cloud amounts with temperature.

    It’s actually fairly easy to dispel any “intuitive” idea that cloud amounts must increase with temperature at present day levels by looking at seasonal cycles. Certainly in the Northern Hemisphere mid-latitudes, Summers are considerably less cloudy than Winters.

    Putting into numbers AR5 concluded with a best estimate of 0.6W/m2/K for net cloud feedback. That means a 1K warming from now would result in a change from -18W/m2 to -17.4W/m2 cloud radiative effect. Don’t know if it’s been done, but might be interesting to produce a diagram giving some idea of how Earth’s net cloud radiative effect, total cloud fraction, low cloud fraction varies with temperature from 0K up to 300K.

  • Magma says:

    That’s a nice commentary/short review in Nature Climate Change, open-access and well worth reading.

    I have the strong impression that much of the contrarian opinion on cloud feedback originates from the fact that when one is outdoors on a sunny day and a cloud passes in front of the sun, ground level insolation and perceived temperature quickly drop. Coupling this to the undeniable facts that it still gets cold in mid-latitude winters and major coastal cities are still above sea level, it is but series of short logical steps to the “all scientists are liars and climate change is a hoax to bring about one world government” held by many of these rather dim individuals.

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  • Eric Michel says:

    Just a quick note of thanks. Not nearly well versed enough to comment on the material, but enjoy reading and learning bits and pieces.

    Eric

    On Sat, Oct 7, 2017 at 3:02 PM, …and Then There’s Physics wrote:

    > …and Then There’s Physics posted: “A few years ago I posted a video by > Andrew Dessler that was discussing whether or not Equilibrium Climate > Sensitivity could be less than 3oC. The bottom line was that the best > estimate for ECS is about 3oC. Given that we’re quite confident about water > v” >

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  • angech,
    I don’t like having to justify moderation decisions, but I will illustrate this just this once. You said

    SInce the first effect is primary ie albedo and since this effect is negative any increase in cloud cover should have a stronger negative than a positive effect.

    Well, this is wrong, as others have indicated. Yet, you said it as if you understood this well enough to make a strong claim. I don’t really see why I should be expected to post comments that are certain, but wrong.

    Your comment is awaiting moderation.

    Overview of #cloudfeedbacks in the 5 IPCC reports & beyond [link].
    An interesting blog on this over at ATTP. “A bit more about clouds”
    This is a discussion of clouds precisely because they are a very important part of the climate puzzle.
    “Clearing Clouds of Uncertainty by Mark Zelinka, David Randall, Mark Webb and Steven Klein. Their commentary is really a summary of our recent understanding and – as illustrated by the figure on the right – they conclude that the evidence is converging on the cloud feedback likely being positive.”
    From FAR 1990 positive but cloud feedback represented the largest source of uncertainty in climate sensitivity among atmospheric models.
    To SAR Second Assessment Report; 1995), more climate models were predicting the mass of cloud liquid and ice, and generally finding negative cloud opacity feedbacks, albeit of widely differing strengths. The report concluded that it was not possible at that time to judge the sign of the net cloud feedback.
    TAR 2001 …the sign of [the cloud] feedback remains unknown.
    AR4 2007 it is not yet possible to assess which of the model estimates of cloud feedback is the most reliable
    AR5 “The sign of the net radiative feedback due to all cloud types is…likely positive”
    BUT Cloud opacity feedback “is highly uncertain”

    The article overview states
    “Averaged globally and annually, clouds cause 18W/m2 of cooling relative to a hypothetical cloud-free Earth. This is the net result of a 46 W/m2 cooling from reflecting sunlight back to space (an albedo effect) partly offset by a 28 W/m2 heating due to reduced terrestrial radiation emitted to space (a greenhouse effect). The net planetary cooling provided by clouds is roughly five times as large as the planetary heating from a doubling of CO2.”
    The albedo effect works only half the time [there is a minuscule effect for moonlight etc] yet it produces much more cooling in that 12 hour period than a whole 24 hours of cloud GH positive effect.

    “The overall cloud feedback is actually the aggregate effect of several individual cloud feedbacks, commonly separated into three components: cloud amount, cloud altitude,and cloud opacity feedbacks” “Nearly all current climate models simulate an overall positive cloud feedback ”

    Too much information. The link I had from Victor Venema has gone down but the article could have said Cloud Albedo negative effect had x5 the effect of GHG doubling. That observational was very weak and most of the proof came from climate model simulations which duh incorporate positive cloud feedbacks in the first place.

    To the amateur eye if going from no clouds to what we have causes 18 W/m2 cooling any further cloud increase should cause more cooling.
    Miraculously this article has found a new physical fact on model evidence. That clouds cool the earth as it goes to a surface temp of 14 degrees and then at that precise point start to warm the atmosphere up.
    Not on the basics of testable physics.
    I do not see a kettle of water cooling down as you get past a certain point in heating it up.
    But on the basis of models, observationally wrong and incorporating the very features the claim to be looking for.
    Science, shame.