Claim: climate feedback is low due to clouds "impeding global warming"

From DOE/LAWRENCE LIVERMORE NATIONAL LABORATORY

Clouds are impeding global warming… for now

Lawrence Livermore National Laboratory researchers have identified a mechanism that causes low clouds – and their influence on Earth’s energy balance – to respond differently to global warming depending on their spatial pattern.

The results imply that studies relying solely on recent observed trends are likely to underestimate how much Earth will warm due to increased carbon dioxide. The research appears in the Oct. 31 edition of the journal, Nature Geosciences.

The research focused on clouds, which influence Earth’s climate by reflecting incoming solar radiation and reducing outgoing thermal radiation. As the Earth’s surface warms, the net radiative effect of clouds also changes, contributing a feedback to the climate system. If these cloud changes enhance the radiative cooling of the Earth, they act as a negative, dampening feedback on warming. Otherwise, they act as a positive, amplifying feedback on warming. The amount of global warming due to increased carbon dioxide is critically dependent on the sign and magnitude of the cloud feedback, making it an area of intense research.

The researchers showed that the strength of the cloud feedback simulated by a climate model exhibits large fluctuations depending on the time period. Despite having a positive cloud feedback in response to long-term projected global warming, the model exhibits a strong negative cloud feedback over the last 30 years. At the heart of this difference are low-level clouds in the tropics, which strongly cool the planet by reflecting solar radiation to space.

“With a combination of climate model simulations and satellite observations, we found that the trend of low-level cloud cover over the last three decades differs substantially from that under long-term global warming” said Chen Zhou, lead author of the paper.

“The key difference is the spatial pattern of global warming”, said Mark Zelinka, LLNL climate scientists and co-author of the study. “Not every degree of global warming is created equal, in terms of its effect on low clouds.”

In response to increased carbon dioxide, climate models predict a nearly uniform warming of the planet that favors reductions in highly reflective low clouds and a positive feedback. In contrast, over the last 30 years, tropical surface temperatures have increased in regions where air ascends and decreased where air descends. “This particular pattern of warming is nearly optimal for enhancing low cloud coverage because it increases low-level atmospheric stability that keeps the lower atmosphere moist and cloudy”, said Stephen Klein, the third co-author.

“Most satellite data starts around 1980, so linear trends over the last three decades are often used to make inferences about long-term global warming and to estimate climate sensitivity,” said LLNL’s Chen Zhou, lead author of the study. “Our results indicate that cloud feedback and climate sensitivity calculated from recently observed trends may be underestimated, since the warming pattern during this period is so unique.”

Global temperature has gradually increased over the instrumental record due to increased greenhouse gas concentrations. But superimposed on this warming are large temperature fluctuations due to natural internal variability of the climate system, as well as influences from volcanic eruptions, aerosol pollution and solar variability. Whereas warming due to CO2 tends to be relatively spatially uniform, surface temperature trends due to internal climate variability and aerosol pollution are highly non-uniform, with trends on one side of an ocean basin often opposing those on the other. Trends computed over short time periods are often strongly influenced by factors other than CO2 and can be highly misleading indicators of what to expect under CO2-forced global warming.

The team emphasized that clouds are particularly sensitive to subtle differences in surface warming patterns, and researchers must carefully account for such pattern effects when making inferences about cloud feedback and climate sensitivity from observations over short time periods.

###

The work was funded by the Regional and Global Climate Modeling Program of the Office of Science at the U. S. Department of Energy (DOE) under the project “Identifying Robust Cloud Feedbacks in Observations and Models.”

The paper: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2828.html

Impact of decadal cloud variations on the Earth’s energy budget

Chen ZhouMark D. Zelinka & Stephen A. Klein

Feedbacks of clouds on climate change strongly influence the magnitude of global warming1, 2, 3. Cloud feedbacks, in turn, depend on the spatial patterns of surface warming4, 5, 6, 7, 8, 9, which vary on decadal timescales. Therefore, the magnitude of the decadal cloud feedback could deviate from the long-term cloud feedback4. Here we present climate model simulations to show that the global mean cloud feedback in response to decadal temperature fluctuations varies dramatically due to time variations in the spatial pattern of sea surface temperature. We find that cloud anomalies associated with these patterns significantly modify the Earth’s energy budget. Specifically, the decadal cloud feedback between the 1980s and 2000s is substantially more negative than the long-term cloud feedback. This is a result of cooling in tropical regions where air descends, relative to warming in tropical ascent regions, which strengthens low-level atmospheric stability. Under these conditions, low-level cloud cover and its reflection of solar radiation increase, despite an increase in global mean surface temperature. These results suggest that sea surface temperature pattern-induced low cloud anomalies could have contributed to the period of reduced warming between 1998 and 2013, and offer a physical explanation of why climate sensitivities estimated from recently observed trends are probably biased low4.

Figure 1. a, Shown are the 30-year net feedback estimates from AMIPFF simulations, plotted at the midpoint of each 30-year period. Thin black lines are calculated from individual runs, and thick black lines are calculated from ensemble mean value…
Figure 1. Evolution of decadal net and cloud feedbacks from CAM5.3 simulations. a, Shown are the 30-year net feedback estimates from AMIPFF simulations, plotted at the midpoint of each 30-year period. Thin black lines are calculated from individual runs, and thick black lines are calculated from ensemble mean value.

 

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PaulH
October 31, 2016 6:38 pm

Not a very surprising excuse, as the climate simulations are useless at modelling clouds.

george e. smith
Reply to  PaulH
October 31, 2016 7:18 pm

Not again.
More warming more evap, more clouds, less sunlight less warming less evap, more precip less clouds more sun, more warming.
Better throw your super computer in the trashcan.
G

george e. smith
Reply to  george e. smith
October 31, 2016 7:26 pm

DOE LLNL needs to get back to their task of capturing the energy of the sun in their giant whack a mole machine that squishes glass pellets one at a time to turn DT into hot neutrons or something.
g

rogerthesurf
Reply to  george e. smith
November 1, 2016 1:14 am

climate feedback is low due to clouds “impeding global warming”
Im surprised they admit that there is less global warming, most others are telling us how its hear and biting us already and watch out for the floods.
Of course clouds affect climate – what a lot of plonkers.
Roger
http://www.thedemiseofchristchurch.com

Greg
Reply to  george e. smith
November 1, 2016 1:16 am

Yes this seems to confirm stronger neg. f/b in tropics in a period when GHG forcing was increasing. This is broadly in agreement with Willis’ suggestions about tropical feedbacks.

. Specifically, the decadal cloud feedback between the 1980s and 2000s is substantially more negative than the long-term cloud feedback. This is a result of cooling in tropical regions where air descends, relative to warming in tropical ascent regions, which strengthens low-level atmospheric stability. Under these conditions, low-level cloud cover and its reflection of solar radiation increase,

So what do they conclude?

These results suggest that sea surface temperature pattern-induced low cloud anomalies could have contributed to the period of reduced warming between 1998 and 2013, and offer a physical explanation of why climate sensitivities estimated from recently observed trends are probably biased low4.

So having “observed” an increased neg. f/b in the model in a period of increased GHG forcing which would be in agreement with a reduced climate sensitivity as derived by real world observations, they manage to interpret this as being a “bias”.
What is the “long term” feedback that they are presenting as the true, unbiased value we should apparently be believing ? The long term f/b value includes the reduced f/b when GHG were not signficant, so by what contorted logic do they conclude that is a better value and a truer indication of current or future climate.

What they are showing is a non-linearly, increasing neg. f/b to rising CO2 forcing which will render climate far more stable the current alarmist scientists claim. In short we don’t need the Paris agreement.

Maybe they had to put the ” it’s worse than we thought” spin in order to get published but it seems that this result is great news for anyone who is honestly concerned about the dangers of future warming.

MarkW
Reply to  george e. smith
November 1, 2016 6:58 am

Greg, they also admit that negative feedbacks have lessened (pretty much stopped) global warming. But they assure as that the models tell them that soon, CO2 will over whelm these previously unacknowleged negative feedbacks, and things will get worser even faster.

Duster
Reply to  george e. smith
November 1, 2016 9:18 am

Plainly, it will be worse than we thought as soon as it clears up.

Paul of Alexand
Reply to  george e. smith
November 1, 2016 6:59 pm

That’s not the only thing effecting clouds,mthough. Some seed particles are required for nuclear ion.

Reply to  PaulH
November 3, 2016 6:56 am

Exactly. Before they go off extolling how great their new model of clouds works in the models they might want to have a tad of skepticism since the models failed before. The new model may be as flawed as the last with the next datapoint. That’s the problem with fitting. Science is done in the real world by running experiments and predicting results not going back and fitting some new theory and saying : Proved. There are millions of ways to fit the data to some theory. The proof is if it actually predicts what happens. Unfortunately for the computer models everything they predict never happens. So, some of us are a little skeptical this is any better.

October 31, 2016 6:43 pm

So if something as low energy as clouds can impede Global Warming…that claim about the Sun having no impact is put to lie….

October 31, 2016 6:47 pm

What a lame excuse, weak as water. Science has degenerated into mindless piffle.

MarkW
Reply to  Terrel Shields
November 1, 2016 6:59 am

Not science, climate science.

Warren in New Zealand
October 31, 2016 6:55 pm

Correct me if I’m wrong in my assumption, but isn’t this exactly what Willis has been expounding in his Thermostat Hypothesis?

Curious George
Reply to  Warren in New Zealand
October 31, 2016 7:13 pm

Now you have it from dye-in-the-wool scientists. They give no credits.

jorgekafkazar
Reply to  Curious George
October 31, 2016 9:04 pm

Except they’re babbling “worse than we thought.”

george e. smith
Reply to  Warren in New Zealand
October 31, 2016 7:21 pm

Don’t recall what that was. Izzit different from “How much more rain will global warming bring?” from SCIENCE july 13 2007 Wentz et al.
G

stan robertson
Reply to  Warren in New Zealand
October 31, 2016 8:31 pm

And exactly why do they suppose that this will not continue into the future? How are we going to get warmer if more clouds reduce the energy input?

Bruce Cobb
Reply to  stan robertson
November 1, 2016 5:33 am

That’s where the magick effect of CO2 comes into play. It truly is a wondrous molecule.

Trebla
October 31, 2016 6:55 pm

That’s why there hasn’t been the expected warming over the past several decades? I thought the official line was that the heat had gone down and hid in the ocean only to re-emerge at some future date. In other words, the models are right and the heat is in the pipeline.

Reply to  Trebla
November 3, 2016 7:01 am

That is so right. They seem to be confused where the heat went. Now they are admitting as seems most likely that the energy was lost into space. The heat in the ocean they blamed for the lack of warming is almost certainly related to PDO/AMO phenomenon. Of course they have no clue what AMO / PDO is or why it is happening. They said 10 years ago PDO/AMO would stop. Guess again. Huge el nino last year.
The problem with it being lost in space is then they can’t say “it will come back and hurt us.” That heat is gone forever. Which means their miss is something they should adjust all the models DOWN 0.5C since they now admit the heat is gone.

Tom Halla
October 31, 2016 6:55 pm

A very long winded restatement of the fact that Gobal Circulation Models do not model clouds well, and clouds have a significant effect. So why are they still making policy based on GCM’s?

Tom Halla
Reply to  Tom Halla
October 31, 2016 6:56 pm

Global not gobal

TonyL
Reply to  Tom Halla
October 31, 2016 7:28 pm

Are you sure?
How can you tell?

Reply to  Tom Halla
October 31, 2016 7:36 pm

nobody makes policy based on GCMS
the 2C target and the 1.5C targets have nothing to do with GCMs or any specific science.
truth is… GCMs are just window dressing for policies decided on other grounds

ossqss
Reply to  Steven Mosher
October 31, 2016 8:42 pm

comment image

Tom Halla
Reply to  Steven Mosher
October 31, 2016 9:00 pm

I mean used as a piece of sagecraft, to borrrow a term. GCM’s have the sort of use as “expert testimony” as used by liability lawyers.

AndyG55
Reply to  Steven Mosher
October 31, 2016 10:12 pm

Yes, we know policies are not decided on the grounds of anything real to do with climate.
Anything else you want to try and sell, Mosh ?

AndyG55
Reply to  Steven Mosher
October 31, 2016 10:19 pm

@ ossqss
Barn… aim… oops missed… build bigger barn.

Greg
Reply to  Steven Mosher
November 1, 2016 1:24 am

Mosh’ said :

truth is… GCMs are just window dressing for policies decided on other grounds

Thanks. One of the most sensible things you’ve said in a long time.
Like Rumsfelt’s WMD claims, they new it was false but needed a simple message to get the public on side for policies decided on other grounds.
AGW scare is just an attempt at establishing and financing the UN as a de facto, unelected world government..

MarkW
Reply to  Steven Mosher
November 1, 2016 7:03 am

Finally Mosh says something that most of can agree with:
“GCMs are just window dressing for policies decided on other grounds”
Global warming is just the latest excuse to impose the solutions they have always wanted to force on us.

MarkW
Reply to  Steven Mosher
November 1, 2016 7:06 am

I can’t let that lie stand, the did not know that the WMD claims were false. In fact most of them have been verified by discoveries in Iraq.
Some of them have been shown to be false, but that’s not the same as claiming everyone knew they were false to begin with.

graphicconception
Reply to  Steven Mosher
November 1, 2016 8:19 am

“… did not know that the WMD claims were false …”
Quite right. They just planned to murder 100,000 people on the off-chance.

Gerald Machnee
Reply to  Steven Mosher
November 1, 2016 9:07 am

**the 2C target and the 1.5C targets have nothing to do with GCMs or any specific science.**
Mosher got this right. 2 deg C has nothing to do with science. It was pulled out of thin air. Now we can just extend this to most of the CO2 rumours.

Reply to  Steven Mosher
November 1, 2016 9:21 am

“nobody makes policy based on GCMS”
No not GCMs, just the “consensus projections” derived from them.
https://wattsupwiththat.com/2016/10/26/madness-climate-projections-can-now-be-used-as-evidence-to-list-endangered-species/

MarkW
Reply to  Steven Mosher
November 1, 2016 10:13 am

Another lie, nowhere close to 100K were killed.
More would have died had Saddam gotten the bomb.

Phil R
Reply to  Steven Mosher
November 1, 2016 10:49 am

Mosh,
You’re right about the 2C target having nothing to do with any specific science:
http://www.spiegel.de/international/world/climate-catastrophe-a-superstorm-for-global-warming-research-a-686697-8.html

Rarely has a scientific idea had such a strong impact on world politics. Most countries have now recognized the two-degree target. If the two-degree limit were exceeded, German Environment Minister Norbert Röttgen announced ahead of the failed Copenhagen summit, “life on our planet, as we know it today, would no longer be possible.”
But this is scientific nonsense. “Two degrees is not a magical limit — it’s clearly a political goal,” says Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research (PIK). “The world will not come to an end right away in the event of stronger warming, nor are we definitely saved if warming is not as significant. The reality, of course, is much more complicated.”
Schellnhuber ought to know. He is the father of the two-degree target.
“Yes, I plead guilty,” he says, smiling. The idea didn’t hurt his career. In fact, it made him Germany’s most influential climatologist. Schellnhuber, a theoretical physicist, became Chancellor Angela Merkel’s chief scientific adviser — a position any researcher would envy.

Phil R
Reply to  Steven Mosher
November 1, 2016 10:51 am

Gerald Machnee,
Whoops, should have read further. See you got there first! 🙂

Shelley Frost
October 31, 2016 7:08 pm

Unbelievable. They’ve mistaken a natural feedback mechanism for something transitory and ephemeral. This cooling response to tropical warming is one of the things that makes global sensitivity to increased CO2 much less than the alarmists predict.

D. J. Hawkins
Reply to  Shelley Frost
November 1, 2016 9:35 am

Yes, they seem to expect those nasty, interfering clouds will go away any time now and global warming will come roaring back in all it’s demonic glory. Yeesh.

October 31, 2016 7:21 pm

Chen Zhou, Mark D. Zelinka & Stephen A. Klein wrote, “and offer a physical explanation of why climate sensitivities estimated from recently observed trends are probably biased low.”

In other words, we need to continue to disregard reality and the realworld feedback that happens to counteract increasing temperatures.
When reality shows you your overestimates are too high, in Climatism you simply claim the observed temperature undershoots are merely aberrations of what they fervently believe should be happening any day now.
And The cargo planes will be landing any day now for these climatists.

PhilO'Sophist
October 31, 2016 7:24 pm

OMG! Disater! climate feedback is low due to clouds “impeding global warming”
What next? Tipping-Point? Extinction?

TonyL
October 31, 2016 7:27 pm

This looks like a major walkback in progress. Clouds counteract the effects of increased CO2. Not so dangerous after all.
Some years ago, someone here at WUWT calculated that an increase of 0.1% in daily cloudiness in the tropics would counteract the effects of doubled CO2. An increase that for all practical purposes would be impossible to quantify, at least with current capabilities.
Also, as Warren notes above, this is what Willis has been saying for quite a while now.
Possibilities:
1) a major retrenchment is just now starting. Just like we saw with CAGW getting morphed into Climate Change when CAGW was no longer tenable. They are adjusting their position.
2) They are staking out unclaimed ground for “The Cause”. Add it to the list.
Global Warming causes warming!
Global Warming causes cooling!
Global Warming causes clouds!
Global Warming causes nothing much!
And all bases are covered.

Jer0me
Reply to  TonyL
October 31, 2016 8:20 pm

No walkback. It is just another hand-waving fantasy to explain why AGW (let alone CAGW) is not happening.

Editor
Reply to  Jer0me
October 31, 2016 9:35 pm

Don’t hold your breath waiting for a walkback. In the models, clouds are a feedback, ie. clouds react to temperature, period. The modellers still haven’t recognised that clouds can operate in other ways, even though that is what they are describing. The level of understanding of climate is quite simply woeful.

TonyL
Reply to  TonyL
October 31, 2016 10:28 pm

Jer0me + Mike Jonas:
You are both right. At first I missed the importance of the last paragraph.
The all-important metrics of GW are the ECS, equilibrium climate sensitivity, and TCR, transient climate response.
They claim that GW is causing more cloudiness, OK so far. Then they claim that the cloudiness causes a systematic underestimate of ECS and TCR.
SO: GW causes a systematic underestimate of GW! And it is all because of the Pause, no less.
Mark it down as excuse #94 for the Pause.
The long suffering taxpayers deserve better from the great LLNL.

markl
October 31, 2016 7:28 pm

So….the modellers finally discovered there are clouds in the sky? And wouldn’t you know it that they are responsible for ruining their otherwise perfect prognostications. Damned skeptical nature.

Berniea
October 31, 2016 7:36 pm

Here they go using arbitrary cloud changes to try to make their CO2 based models fit the historical data. It is just another parameter that will not behave as they predict in the future and will require frequent re-adjustment to try to hide the fundamental errors in their logic as time goes on.

Phil's Dad
October 31, 2016 7:37 pm

Cart followed by horse.

jorgekafkazar
Reply to  Phil's Dad
October 31, 2016 9:29 pm

And more horse manure than will fill the cart.

Claude Harvey
October 31, 2016 7:39 pm

I think it’s the “fluffy” ones causing all the climate modeling problems.

October 31, 2016 7:45 pm

And another Group gets it wrong! It’s SO2, not CO2. Google it.

Patrick B
October 31, 2016 7:47 pm

I could of sworn the science was settled.

Steve Fraser
October 31, 2016 7:52 pm

I especially loved the part where the ocean surface warms where the air is rising…

Phil's Dad
Reply to  Steve Fraser
October 31, 2016 8:11 pm

Quite

rocketscientist
Reply to  Steve Fraser
November 1, 2016 10:23 am

I was flabbergasted that the researchers seem to have gotten the concept of convective heating taught in elementary school completely backwards. The circulation is caused by heat differential, not the other way around.

Reply to  rocketscientist
November 1, 2016 11:34 am

We’ve spent many hours arguing about whether the heat has been released or retained. ( oh do tell me I’m wrong about thermodynamics, see some of science of doom musings in support of CAGW) So, another question I have is what does this do to the earth’s energy budget ? ( it’s a rhetorical question ) CAGW alledegedly has measured this and it conforms to their math that the earth will warm by so much. Are they saying that, that is in error too ? ( do understand these questions aren’t directed at you, I just thought of it) if they didn’t measure the heat escaping, where did it go ? Is the assumption (1-a) is incorrect ? Are the satellite readings incorrect ? Has there been another instrument failure ? ( like the one for TSI ? )
What appeals to authority or papers will they trot out to prove this isn’t so ? CAGW does have a proven tactic, ignore it.

October 31, 2016 7:55 pm

So what they are saying is that we need to ignore the negative feedback in the climate system because it is doing what it is supposed to do. This is a big problem because it also creates a negative feedback loop with our future funding prospects.

October 31, 2016 8:03 pm

So, cloud patterns changes aren’t incorporated into the models.

markl
Reply to  Sam Grove
October 31, 2016 8:06 pm

Sam Grove commented: “…So, cloud patterns changes aren’t incorporated into the models….”
No clouds at all that I’m aware of much less changes.

Mike Smith
October 31, 2016 8:07 pm

Negative feedback. This is terrible, terrible news. Climate scientists should be very afraid.

Chris Hanley
October 31, 2016 8:13 pm

“… Our results indicate that cloud feedback and climate sensitivity calculated from recently observed trends may be underestimated, since the warming pattern during this period is so unique …”.
=================================
By “recently observed trends” presumably they mean the non-existent ~20 years warming relative slowdown/stasis.
http://www.team5ge.yolasite.com/resources/%E3%85%87%E3%84%B9%E3%85%87%E3%84%B9%E3%85%87%E3%84%B9.jpg
As Prof Humlum explains the cloud cover over the tropical (mostly) oceans is likely to be an important control of the amount of solar radiation reaching the surface and therefore the GAT.
Why do the authors assume that the period of relative temperature stasis is so unique?
On the available satellite evidence it could equally be the period 1979 – ~1997 that is unique, or that neither is unique, that both represent natural system fluctuations.

jorgekafkazar
Reply to  Chris Hanley
October 31, 2016 9:35 pm

“Unique” is synonymous with one-of-a-kind, so warming patterns are either unique or they’re not. They can’t be “so unique,” a dreadful solecism. Academics are not up to the standards of my college days.

Chris Hanley
Reply to  jorgekafkazar
October 31, 2016 10:44 pm

I knew someone would pick that up, thanks all the same.
I don’t understand the reference to “academics”.

mothcatcher
Reply to  jorgekafkazar
November 1, 2016 2:49 am

I’m quite relaxed about the use of ‘so unique’ or ‘almost unique’ and I don’t see why the purists get so upset about it. The sense is fine – the subject under discussion has many facets, some of which may be unique, some not, and the sum of all those facets may be so unique, very unique, somewhat unique, or not at all unique. Language has only one use – if it can be understood, that’s all that matters. The authors can be criticised for hyperbole, but not for wrong use of ‘unique’.
Promised myself I would never get into that sort of argument – sorry!
But I like the ‘horse follows cart’ summary of this work. The inversion of logic and purpose it contains is surely (almost) unique.

AndyG55
Reply to  Chris Hanley
October 31, 2016 10:17 pm

“At the heart of this difference are low-level clouds in the tropics, which strongly cool the planet by reflecting solar radiation to space.”
Yet the graph above shows warming when the cloud % is decreasing. OOPS !!

Reply to  Chris Hanley
October 31, 2016 10:28 pm

That ISCCP plot is directly supported by ERBE+CERES measurements of outgoing (reflected) SW from the Earth system:comment image
And so it’s clear that clouds haven’t been a feedback to the warming at all. They’re the cause. They allowed the mean level of ASR (“absorbed solar radiation”, TSI minus reflected SW) to increase substantially from the last half of the 80s to about 2000:comment image

AGW is not Science
Reply to  Kristian
November 1, 2016 6:10 am

Yes, once again they ASSUME that any recent warming is due to increased CO2, without a scrap of evidence – just their true believer faith – AND assume of course that the reason for increased CO2 is human activities, when all they actually measure in terms of CO2 sources and sinks IS what is emitted from human activities. Observation means nothing if it disagrees with their preconceived conclusions. And they call this drivel “science.” It’s enough to make you nuts.

MarkW
Reply to  Kristian
November 1, 2016 7:11 am

I once debated a warmist who readily admitted that they had no idea what caused the warm period in the past, but that didn’t matter because the models assured us that the current warming was caused by CO2 alone.

October 31, 2016 8:14 pm

It will be fun to watch as the warmistas ‘discover’, one at a time, all the feedbacks and other factors that have been missing from their over-simplified and biased models.
But our joy will be tempered by the knowledge of all the money wasted and damage done by their cult.

Editor
Reply to  StefanL
October 31, 2016 9:02 pm

Sorry to disagree, but it won’t be fun. You can see that, because this is one of them – they are discovering a feedback or factor that has been missing from their over-simplified and biased models. But you see, they don’t actually acknowledge it as such, they say it is “responding differently” for a while, ie. “the trend of low-level cloud cover over the last three decades differs substantially from that under long-term global warming“. In other words, the behaviour now is not as predicted, but in future the climate will be as predicted. No matter what they find missing from their models, nothing that happens in the real world will ever get them to change their predictions. This is not fun. The model predictions are their absolute truth, and everything else is simply interpreted accordingly!

Reply to  Mike Jonas
October 31, 2016 9:35 pm

Mike, I agree that most of them won’t acknowledge their errors. That’s why I put the word ‘discover’ in quotes. Perhaps I should have used the word ‘amusing’ instead of fun, as we watch them make fools of themselves trying desperately to make the data conform to their pre-conceived beliefs.
Nonetheless, my amusement will be tinged with sadness, over the wasted money and the damage done to science.

Jer0me
October 31, 2016 8:17 pm

Trends computed over short time periods are often strongly influenced by factors other than CO2 and can be highly misleading indicators of what to expect under CO2-forced global warming.

And these supposedly educated people really cannot see the obvious potential falicy in that argument? They must be incredibly biased to even think that this is not immediately obvious.
As I keep saying, the feedbacks must be negative, or our climate would be swinging wildly in all directions, and it just does not – the major argument against the feedback argument, without which CAGW cannot exist.

AGW is not Science
Reply to  Jer0me
November 1, 2016 6:24 am

Worse – nut just supposedly educated, but supposedly SCIENTISTS! Agreed on feedbacks – there’s no way Earth’s climate could exhibit stability over long periods (as it has) if the system were dominated by positive feedbacks – it’s ridiculous. The only “CO2 forced global warming” that occurs is the warming in their fantasy world models that ASSUME it occurs. In the real world, it’s meaningless unless they can provide some actual scientific evidence otherwise. (And just for the records, stacks of “peer reviewed” garbage does not constitute “evidence” of anything, any more than this fine example of agricultural commodity does; “because I said so” doesn’t cut it for scientists.) On geologic time scales, CO2 and temperature aren’t even correlated, are often enough REVERSE correlated to reject CO2 as temperature driver, and the Earth’s “average” temperature has fluctuated between two extremes that haven’t changed no matter how much (or little) CO2 is in the atmosphere.

Resourceguy
October 31, 2016 8:25 pm

Must be all that cosmic ray rebounding effort.

October 31, 2016 8:30 pm

How can there possibly be negative feedback ? But what of the retained heat from the latent energy when water vapor condenses? Isn’t co2 suppose to hold on to that heat in a never ending cycle? Isn’t that is were the tipping point is suppose to occur ? 97% of scientist agree ! (Sarc)
I’m sure that this has been argued from the skeptic side of things.

October 31, 2016 8:42 pm

“relying solely on recent observed trends are likely to underestimate how much Earth will warm due to increased carbon dioxide”
the relationship between atmos co2 and surface temperature even in the recent data (actual measurements and not reconstructions) appears to be sensitive to the sample period chosen.
the way around that is to use resampling as demonstrated here:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2861463

hunter
October 31, 2016 8:56 pm

They are simply lying to themselves. The predictions are wrong, so they explain away reality. Pathetic climate fanatics.

AGW is not Science
Reply to  hunter
November 1, 2016 6:46 am

Yes, they are truly deluding themselves at this stage; amazing how they twist things so they can have it both ways – when there’s warming, it’s because of CO2; when there’s not, the Co2 induced warming isn’t going to be seen until some distant future time (conveniently). So which one is it?!

hunter
October 31, 2016 8:57 pm

They are simply lying to themselves. The predictions are wrong, so they explain away reality. Pathetic climate fanatics.

October 31, 2016 9:21 pm

GCMs are both better and worse than they are given credit for.
I was at a talk yesterday about the Antarctic sea ice anomaly:
every single CMIP5 model says that Antarctic sea ice is decreasing,
but it’s increasing.
The speaker said that the group he was in (which I think was basically him and his supervisor) looked at the physics, and asked “how do the models handle the ice shelves”? Turned out that all of the existing models ignored the Antarctic ice shelves completely. They added the ice shelves (and the energy budget for meltwater) to one of the models, and presto chango, the model now showed increasing sea ice, at roughly the way the world had really been.
This says to me that for the things the models include, they are not without merit, BUT that as you might expect, it’s the FIRST step of modelling where you decide what to put in your model and what to leave out where the big errors start.
If I remember correctly, the speaker said that it took 4 days per simulated year
on the supercomputer they were using, and they were simulating the last 30 years. I think he said they were using 1 km square cells with 60 layers for the ocean and 30 layers for the atmosphere, and that the model they were starting from was a million lines of Fortran. These are not things that are easy to work with. Getting the grid down to the scale where you can model clouds well is going to push the state of the supercomputing art.

markl
Reply to  Richard A. O'Keefe
October 31, 2016 9:27 pm

Richard A. O’Keefe commented : “…Fortran… supercomputing….”
Non sequeter

jorgekafkazar
Reply to  Richard A. O'Keefe
October 31, 2016 9:39 pm

A million lines of Fortran? I can just about guarantee you there are ten unrecognized serious errors in that program.

Reply to  Richard A. O'Keefe
October 31, 2016 10:00 pm

“… BUT that as you might expect, it’s the FIRST step of modelling where you decide what to put in your model and what to leave out where the big errors start.”
Back in the day when I was a practicing engineer, we had a rule of thumb that all the truly bad decisions on a program were made in the first 10 minutes (comparable to that first step of modeling).

Kaiserderden
Reply to  Richard A. O'Keefe
November 1, 2016 8:31 am

A model with a million lines of code is not a model of anything but nonsense and most like hardcoded to calculate a predefined result (thus the million lines of fortran code – nobody will ever be able to code review or QA it) easy to hide in that much noise …

D. J. Hawkins
Reply to  Richard A. O'Keefe
November 1, 2016 9:49 am

I think rgb-at-duke estimated that computing power would need to increase by 6 orders of magnitude to accommodate a sufficiently detailed model where you could start thinking about getting something useful with regard to climate. Think quantum computers.

Bob Hoye
October 31, 2016 9:38 pm

I hope someone can confirm this.
Some 15 years ago, purple onions were mild. Nice flavour and mild.
Now they are much hotter.
Must be due to global warming.

Reply to  Bob Hoye
October 31, 2016 10:03 pm

maybe your tastebuds have changed?

Berényi Péter
Reply to  Joel O’Bryan
October 31, 2016 11:05 pm

Worse than we thought.
Headline: “Global Warming Makes Taste Buds Angry”

Berényi Péter
October 31, 2016 11:01 pm

In response to increased carbon dioxide, climate models predict a nearly uniform warming of the planet that favors reductions in highly reflective low clouds and a positive feedback. In contrast, over the last 30 years, tropical surface temperatures have increased in regions where air ascends and decreased where air descends.

Climate models predict nothing, they project. Projections are much better, than predictions, because, due to their wonderful malleability, they can never be falsified by observations. Therefore they are always true. Not.

MarkW
Reply to  Berényi Péter
November 1, 2016 7:16 am

I could have sworn that they used to claim that there would be more warming at the poles than in the tropics, due to the distribution of H2O in the atmosphere.
Now CO2 is supposed to have a uniform affect?

Simon Ruszczak
November 1, 2016 12:01 am

Maybe the clouds that are “impeding global warming”, are caused by global warming (sarc).
;

Asp
November 1, 2016 12:21 am

“…..the trend of low-level cloud cover over the last three decades differs substantially from that under long-term global warming”
So we will disregard what we have observed over the past 3 decades and put our trust in the climate models????? Un-be-lievable!

Rob
Reply to  Asp
November 1, 2016 9:12 am

Yes, that was the bit I reacted to as well. Basically, these were wrong type of clouds therefore we can ignore their effect and when the right type of clouds come back, it will get hotter as the models predict, no, sorry, project.
Google “wrong type of snow” for more hilarity.

November 1, 2016 12:40 am

Post hoc rationalizations. A clear sign of pseudo science.

commieBob
November 1, 2016 1:05 am

This is a result of cooling in tropical regions where air descends, relative to warming in tropical ascent regions, …

Any warming will result in more convection. Heat is removed from regions where the air is moving upward. The air is cooled in the upper atmosphere and cools the region where it moves downward. Surely that is unsurprising.
The increased convection is a negative feedback. It should be pretty linear and should be reliable over all timeframes. I think these researchers have misinterpreted their own evidence.

AGW is not Science
Reply to  commieBob
November 1, 2016 6:52 am

Of course they have – because they begin with the erroneous ASSUMPTION that increased CO2 level pushes the temperature up, when all the “theory” (really just hypothesis) ever said is that “ALL OTHER THINGS HELD EQUAL, doubling the atmospheric CO2 content would increase the average temperature by about 1 degree Celsius.” But all else isn’t held equal, and the feedbacks are negative, and the real world CO2 effect is for all practical purposes nil.

November 1, 2016 2:13 am

Catch up will you, this is your job….
http://www.newclimatemodel.com/new-climate-model/

Admad
November 1, 2016 2:25 am

Just goes to show it’s always even worserer than we thunk.

November 1, 2016 2:57 am

As Roseann Roseannadanna said “It’s always something.”
There will never be an admission they were wrong. If temperatures drop over the next 40 years by 4C , the response will be “Ya but it would have dropped by 7C without AGW.”
It doesn’t matter what the observational data show. The automatic response will be that it would have been colder.

November 1, 2016 3:09 am

Combine this with the clean air acts reducing SO2 which is a cloud nucleator and so letting more insolation in what has been the actual warming caused by CO2?

AGW is not Science
Reply to  son of mulder
November 1, 2016 7:48 am

Same as always…essentially nothing. CO2 has been uncorrelated with temperature, lagging behind but correlated with temperature, and reverse correlated with temperature on geologic time scales. In terms of temperature, CO2 “drives” two things – Jack and “Ship High In Transit.”

arthur4563
November 1, 2016 3:11 am

From my perspective , considering the state of energy technology, and usage to be expected in the fairly near future (sometime this decade), all debate annd fighting over CO2 emissions simply reflects extreme ignorance of what lies ahead, which will prevail regardless of the actions of the advanced Western nations. Points of fact : 1) GM announces that it is paying $150 per kWhr for the lithium batteries it will be installing in its electric cars ths year 2) Tesla Motors announces that it will be paying $190 per Kwhr, which pays for all of the costs of the battery pack, not just the cells, 3) Elon Musk claims his battery “gigafactories” can cut battery costs by a third 4) lithium automotive battery packs can be recharged to 80% in around 20 minutes. 5) Molten salt nuclear reactors can be built very quickly in factories and installed with minimal site preparation and will produce power for less than 2 cents per kWhr, making it the cheapest (and safest) power producer on the planet, and can burn nuclear wastes as fuel, reducing them to relatively low radioactive residues which will return to background radiation levels in less than 5 generations and are cheapy stored till that time.
Battery prices are close to the point where gas powered cars become obsolete as overly complicated and expensive compared to more reliable electric versions, and the promised cost reduction by a third gets them there.
I have faith that the sheer economics of the coming technological changes described will force their adoption, although probably adoption will occur more rapidly in China and other Asian countries first. As usual, Western nations will continue to trail in manufacturing and adoption of new power generation technologies due to political pressures that are stupid, although southeastern states in the U.S may buck this trend, as they are doing at present thru the only new nuclear power construction in the nation and their ability to attract manufacturing.
I consider therefore the war on CO2 emissions to be stupid and pointless and a use of energy and money that should be spent encouraging development advanced technologies. It is criminally insane to pour money into things like wind and solar, destined to be non-sustainable economically
in the face of coming energy technologies. I predict a healthy business removing wind turbines
in the fairly near future. And solar roofs will not be replaced when their solar cells weaken in 20 years or so.

MarkW
Reply to  arthur4563
November 1, 2016 7:20 am

If any of the links in that quite improbably chain of events actually happens, let me know.
The biggest problem with batteries is lack of range and cost of replacement.
The first hasn’t been solved and the second is only marginally impacted by these improvements, assuming they actually occur.

AGW is not Science
Reply to  MarkW
November 1, 2016 8:27 am

I’d agree with your assessment of the problems with battery based electric powered transport, not to mention the more frequent need for charging (equivalent to fueling) which takes 4-5 times as long and is therefore an impractical nuisance. Make your trip at night or in heavy traffic or foul weather and those issues are all magnified.
All of this, of course, also fails to mention the amount of environmental destruction done in the mining of “rare Earth metals” needed for all that battery production, the resources that will be expended on disposal of spent batteries (whether the materials can be recycled or otherwise), and the inefficiency of hauling around the weight of the battery packs, which isn’t reduced as their range is depleted as is the weight of a tank of liquid fuel.
If electric vehicles are going to displace ICE vehicles, the roads will have to have an electric power system that the vehicles can draw electricity from built in.

Rob
Reply to  MarkW
November 1, 2016 9:20 am

The biggest problem with batteries for vehicular transport is low energy density. To carry enough batteries to get a decent range, you make the vehicle very heavy, reducing the range meaning more batteries – and so on. All other problems flow from this. The only place electricity has a major role in transport are electrified trains/trams which don’t need to carry your energy with you. Until energy density gets up somewhere near liquid fuels you can forget it as a serious challenge to current vehicles as it is too wasteful of the energy itself.

MarkW
Reply to  MarkW
November 1, 2016 10:17 am

Rob, don’t forget golf carts.

Rob
Reply to  MarkW
November 2, 2016 7:38 am

Nice one, Mark.
Think how terrible it is when your golf cart runs out of power on the 16th fairway! Somebody should do something about this!

Peta in Cumbria
November 1, 2016 3:14 am

and another example of how the human brain just cannot ‘get its head around’ feedback systems.
For humans, something always has to cause something else – the human mind is compelled to break open the/a/any feedback system to try and understand its workings and in doing so destroys the very thing its looking at.
This whole thing about LWIR and temperature.
Things with temperature radiate – they cannot do anything else. Temperature is radiation, radiation is temperature. You cannot say one causes the other. Not least, if the object with temperature wasn’t radiating, you couldn’t see it. It wouldn’t be there.
Of course where the simple minded human brain gets confused is with the sun radiating and causing the place to warm up. Think about the difference between the dirt you’re standing on and the sun.
An example from Buddhist teaching (Thich Nhat Hanh) He will use the example where people might say “The rain is falling”
But if rain is not falling, its not rain. So, what causes what? Does rain cause the falling or does the falling cause the rain? So it is with radiation and temperature.
Again with clouds and temperature. Folks may notice it seems warmer (esp at night) when its cloudy and in their eagerness to show how clever they are, tell everyone that the clouds are trapping radiation or radiating warmth down to the ground.
Good fooking grief, how is a cloud, say 1,000m above your head and hence 10’C colder than you, going to warm you up? No more than replacing your living room fire with an iceberg will. The iceberg has temperature, it radiates, so why doesn’t it warm your house? Yet we all swallow this garbage.
Cold objects cannot radiate to warm objects so as to raise the temp of the warmer object
Clouds seem to warm you simply because you’ve been overtaken by a big bubble of warm air that’s rolled in from somewhere else. As if the higher temperature didn’t tell you that, a cloud forms where that warm air meets colder air above you. (See how this pathetic understanding of feedback gives totally the wrong answer/understanding) Warmth causes the warmth and also the clouds.
Clouds don’t cause warmth, they are a side-effect of warmth.
The cloud is not trapping radiation. Nothing can trap radiation. Not least because (electromagnetic) radiation is a moving thing, a variation/change of electric and magnetic fields at right angles to each other that moves through space at right angles to that.
It cannot be trapped because no-one has yet puzzled how to trap change.
What we’d need would be a Flux Capacitor (change store) – the very heart of any and all time machines and such devices patently don’t exist. And because they don’t exist now, they never have and they never will.

commieBob
Reply to  Peta in Cumbria
November 1, 2016 4:30 am

An example from Buddhist teaching (Thich Nhat Hanh) He will use the example where people might say “The rain is falling”
But if rain is not falling, its not rain. So, what causes what? Does rain cause the falling or does the falling cause the rain? So it is with radiation and temperature.

That’s not insight, it’s word play.

Reply to  commieBob
November 1, 2016 2:44 pm

It’t the sound of one hand crap.

commieBob
Reply to  commieBob
November 1, 2016 3:58 pm

Please, son of mulder, use the proper technical language. It’s called pseudo-profound bullshit.

swordfish
Reply to  Peta in Cumbria
November 1, 2016 5:58 am

@ Peta in Cumbria:
I think you’re confused. Clouds at night don’t warm you up, they slow down the rate at which you cool. A cloud might be 10 degrees cooler than you are but the alternative radiation target would be space which is only a few degrees above absolute zero. According to your way of thinking, a coat wouldn’t keep you warm because it’s cooler than you are. Coats, clouds, duvets – they’re all just insulation.

DC Cowboy
Editor
November 1, 2016 4:12 am

“Trends computed over short time periods are often strongly influenced by factors other than CO2 and can be highly misleading indicators of what to expect under CO2-forced global warming.”
Correct me if I’m wrong (which I probably am), but, aren’t they implying an expectation that clouds will somehow stop having the effect they have for the last 30 years at some time in the future, for reasons as yet unknown? Seems to me that is the only reason they can say that climate sensitivity is underestimated during the last 30 years. Bill Parcells, a great (American) football coach maintained, “you are what your record says you are”. Applying that logic, climate sensitivity is what it says it is, it can’t be ‘impeded’ by a negative feedback unless that feedback will stop at some time in the future. Isn’t this a tropical cloud version of ‘the missing heat is in the deep oceans and when it comes out it will be bad’ theory?

AGW is not Science
Reply to  DC Cowboy
November 1, 2016 8:32 am

Basically, they’re showing that their so-called “science” is nothing more than pseudo science, because they refuse to accept observations that contradict their preconceived conclusions about CO2 driving temperature.

Bill Illis
November 1, 2016 5:20 am

First. just want to note that it is difficult to tell if they used actual data in this study or just climate model simulations. You can’t really tell.
Second, the CERES satellite is showing that the Cloud Radiative Effect (cloud forcing) has indeed declined since the year 2000. Shortwave solar reflection has remained fairly stable but the long-wave heat-held-in forcing has declined. Overall the Cloud Radiative Effect has increased from -21 W/m2 to about -22 W/m2. The anomaly shown here -1W/m2 change (on top of the ERBE satellite showing something similar prior to 2000).comment image
Overall, however, CERES is not showing any change at all in the Earth Radiation Budget. (Clear Sky is up a little and Cloudy Sky is down a bit). Net Zero overall. Where’s the predicted changes?comment image
But let’s say, this study and the CERES and ERBE satellites (and Willis) are right, that the Cloud Feedback is something like -1.0 W/m2/K (rather than +0.7 W/m2/K in the theory and in the IPCC and in Hansen needing to get to get to 3.0C per doubling therefore all feedback assumptions are carefully chosen to get there rather than measured.
… Global Warming then falls to 1.373C per doubling when calculated with -1.0 W/m2/K Cloud Feedback. Not much to worry about.comment image

RH
November 1, 2016 5:33 am

Sooner or later, Svensmark will be acknowledged as a visionary.

Bruce Cobb
November 1, 2016 5:48 am

It’s always fun when Alarmists “discover” what we’ve always known. And then in their charming way, completely misinterpret what they’ve “discovered”.

Coach Springer
November 1, 2016 5:50 am

[Expletiving] clouds interfere with “normal” feedback?

November 1, 2016 6:22 am

“over the last 30 years, tropical surface temperatures have increased in regions where air ascends and decreased where air descends”
See here:
http://joannenova.com.au/2015/10/for-discussion-can-convection-neutralize-the-effect-of-greenhouse-gases/
Fig 3 shows how, after CO2 has done its work in distorting lapse rate slopes, the surface temperature is warmer than it otherwise would have been below ascending columns and cooler than it otherwise would have been beneath descending columns.
Exactly as observed according to the above paper.
The net effect for the system as a whole being zero.

AGW is not Science
Reply to  Stephen Wilde
November 1, 2016 8:40 am

Which should surprise nobody when you look at the sometimes uncorrelated, sometimes correlated with temperature change leading CO2 change, and sometimes reverse correlated CO2 vs. temperature on geologic time scales. IOW, CO2 doesn’t “drive” temperature, at all, in Earth’s climate history, so why should it suddenly have a power it didn’t have in the past today?!

TjW
November 1, 2016 6:50 am

Does the model include the diurnal cycle of thunderstorms? That is, thunderstorms in the daytime, reflecting energy, clear skies at night radiating energy. I suspect the models don’t model anything that happens on such a short timescale.

MarkW
Reply to  TjW
November 1, 2016 7:24 am

Models don’t handle anything smaller than about 100 miles square. Thunderstorms are way to small to be modeled. So they are parameritized instead. Which just means the modelers tell the model how the clouds would have behaved, had the model been able to handle them. (Of course, they are modeling their assumptions, but they will never admit that.)

MarkW
November 1, 2016 6:53 am

So the missing heat is no longer hiding in the deep ocean, it’s now hiding in negative feedbacks?

Walter Sobchak
November 1, 2016 7:48 am

I can’t resist, besides it has just as much as scientific, and more aesthetic, value:

Reply to  Walter Sobchak
November 1, 2016 9:31 am

Darn, you beat me to it!
But now they only block the sun
They rain and snow on everyone
So many things I would have done
But clouds got in my way
Feedback bias… Or BS?

Richard M
November 1, 2016 8:45 am

This is essentially what was predicted by the late Dr. William Gray years ago. He also showed another negative feedback in high altitude water vapor. The net effect would be a small increase in precipitation and a small warming (CS = .2-.4 C).
https://stevengoddard.wordpress.com/2015/05/09/dr-bill-gray-explains-why-climate-models-dont-work/
Also keep in mind the changes in clouds we have seen are not proof of this negative feedback. There could be other causes which is what these pseudo-scientists are trying to claim. In that sense they are right. Don’t just accept this is feedback without more evidence. Doing that is just another version of the same mistake they are making.

Reasonable Skeptic
November 1, 2016 9:38 am

I do wish warmists would read from the same playbook because when they don’t they really do confuse me.
Deniers claim: The world is not warming that fast
Warmists Rebuttal: Look at GISS jerks!
Deniers claim: The models overestimate warming
Warmists Rebuttal: No they don’t jerks!
This paper basically says that deniers were right that it wasn’t warming that fast and not as fast as the models…. or perhaps what they are saying is that it is warming fast, the models are right BUT the clouds will soon change and the warming will be even more pronounced and the models will have to be adjusted upwards.
So which is it? Are deniers right about current warming observations or are warmists wrong about the models and they are going to have to show more warming?

MarkW
Reply to  Reasonable Skeptic
November 1, 2016 10:20 am

They were wrong for the right reasons.

MikeN
November 1, 2016 11:44 am

Am I mistaken, or is the clear translation of their technical jargon that the reality doesn’t match the models?

Reply to  MikeN
November 1, 2016 2:49 pm

Reality doesn’t match the models at present but reality can be changed when needed.

Svend Ferdinandsen
November 1, 2016 11:58 am

Interesting that some questions the believed cloud effect.
The only problem is, that the cloud cover by all means have to be corrolated to CO2 (warming), so as to call it a responce to CO2. Clouds have their own life and could just as well cause the temperature changes we observe. Even the temperature is not corrolated to CO2.
http://climate4you.com/images/HadCRUT4%20GlobalMonthlyTempSince1958%20AndCO2.gif

November 1, 2016 3:33 pm

Finally, the Mosher said something I can generally agree with: “GCMs are just window dressing for policies decided on other grounds”. It is a memorable day. Global warming / Climate Change is just a cloak for the introduction of damaging policies that the elite want to force on us.

November 1, 2016 7:06 pm

“Global temperature has gradually increased over the instrumental record due to increased greenhouse gas concentrations.”
One little problem here. The amount of temperature increase due to doubling CO2 is only about 0.3C where less than 0.2C has manifested so far. Any additional warming beyond this, if it exists, must have a cause unrelated to CO2. If excess warming is occurring, it would be better to identify other reasons for why it’s happening, rather than trying to explain how excessive GHG warming is still happening, even though we aren’t measuring enough of it.

November 2, 2016 1:36 am

C’mon! These intelligentsia MUST be climate scientists … coming to a conclusion like that!

Reply to  Streetcred
November 2, 2016 9:53 am

It also looks like CYA .

November 2, 2016 9:42 am

“… we found that the trend of low-level cloud cover [observed] over the last three decades differs substantially from that [modeled] under long-term global warming…”
You mean that the misbehaving and unruly data is refusing to follow the lead of the models? With apologies to Berthold Brecht:
Stating that the data
Had forfeited the confidence of the scientists
And could win it back only
By redoubled efforts. Would it not be easier
In that case for the scientists
To dissolve the data
And choose another?
TGB

Barbara
November 4, 2016 4:18 pm

I write this more to explain it to myself than anything else, but I would also like help in understanding what I am misunderstanding about the Zhou paper.
SST = Sea Surface Temperature
EIS = Estimated Inversion Strength
LCC = Low Cloud Cover
“… changes in EIS are well explained (r =0.94) by a linear combination of the tropical mean SST and the difference between SST in tropical strong ascent regions and the tropical mean SST ( see Methods), with the latter explaining more decadal variance in EIS (Fig. 2d).”
“Physically, EIS increases with this SST difference because free-tropospheric temperatures throughout the tropics are controlled by the moist adiabat set by the SST in tropical ascent regions, whereas SSTs in tropical descent regions affect the temperature of boundary layer only locally. As a result, LCC variations over the twentieth century are primarily induced by the SST pattern instead of changes in tropical mean SST (Supplementary Text 1 and Supplementary Fig. 6).“
Me: So, out of all of that, what I take is the oceans do not warm uniformly across space, and so there are something like localized convection cells that occur because of the differential. Does that make sense? And, that this non-uniform warming (what they call the “SST pattern”) causes the EIS to increase (basically, because warm air rises and cold air falls in to take its place).
“The above mechanism explains the abnormal decadal net feedback during the satellite era (1979-present), when surface warming is most pronounced over tropical ascent regions where deep convection occurs, with cooling over tropical descent regions, particularly in the Eastern Pacific where low clouds are common (Supplementary Fig. 7).”
Me: Ummm…I’m pretty sure the ascent is caused by the fact that it is warmer; not vice versa.
“The pronounced warming in the tropical ascent regions causes the tropical troposphere to warm and, in the absence of equivalent warming in descent regions, causes the tropical EIS to increase significantly (Fig. 2d), contributing positively to the LCC trend. Meanwhile, the SST-induced LCC reduction over the broader tropical oceans is not strong enough to compensate the EIS-induced LCC increase (Fig. 2c).”
Me: So, as I understand it, they say:
1) If the EIS goes up, or
2) If the SST goes down,
3) Then, there is more LCC
So, the EIS is high (during the time period studied), creating more LCC, but the SST is going up, which should reduce LLC; and, ultimately, the effect of the EIS overwhelms the effect of the SST (for the time period studied).
Their conclusion is that the LCC is affected more by the “pattern” of SST (i.e., it is different in different places at any given time) than by the steady increase of SSTMean. Essentially, all of this amounts to saying that if the sea doesn’t warm perfectly evenly across space, then EIS will play a role in the amount of LCC. Personally, I think that’s a big, fat “duh,” but I am seriously concerned by the fact that these researchers seem to imagine that the uneven heating (or perhaps simply the magnitude of the differences in the late 20th century) is “abnormal” in some way.
Their evidence for the abnormality of this situation is in the supplementary materials. In Supplementary Figure 2 they compare the EIS anomalies from two datasets and their simulations. Their two simulations are very consistent with one dataset, but wildly inconsistent with the other. I haven’t had time to break it down further, or to examine the rest of the supplementary materials, but their first piece of evidence doesn’t even qualify as weak or suggestive due to the gross discrepancy between the two sets of actual data in my opinion.
I’m also concerned about the assumption that it is valid to compute a long-term average LCC. As the sea surface temperature rises, it is not obvious to me that this will result in more spatially uniform warming, which is what would be required to damp the strength of the EIS impact on LCC. Also, it seems to me that there is no reason to dismiss the possibility that there is a connection between systematically increasing SSTMean, and more extreme SST “patterns” as they call them, thus those darn clouds just might continue to unrelentingly impede global warming.
Thank you for listening.
Barbara