2010-12-25 05:36:23Basic rebuttal #143: Clouds provide negative feedback
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.107.107

Below is my draft of the basic rebuttal to "clouds provide negative feedback".  I also drafted up an Intermediate version if anybody wants to comment on that.  It's just a slight modification to my two recent "cloudy outlook for low climate sensitivity" blog posts.

____________________________________________________

The effect of clouds in a warming world is a difficult one to predict.  One challenge is that clouds have both warming and cooling effects.  Low-level clouds in particular tend to cause a cooling effect by reflecting sunlight, while high-level clouds tend to cause a warming effect by trapping heat.

So as the planet warms, clouds can have a cooling effect if the amount of low-level clouds increases and/or if the amount of high-level clouds decreases.  Clouds will have a warming effect if the opposite is true.  Thus it becomes complicated to figure out the overall effect of clouds, because scientists need to determine not only if the amount of clouds increases or decreases in a warming world, but which types of clouds are increasing or decreasing. 

For climate scientists who are skeptical that anthropogenic greenhouse gas emissions will cause a dangerous amount of warming, such as Richard Lindzen and Roy Spencer, their skepticism hinges mainly on this cloud cover uncertainty.  They tend to believe that as the planet warms, low-level cloud cover will increase, thus increasing the overall reflectiveness of the Earth, offsetting the increased greenhouse effect and preventing a dangerous level of global warming from occurring.  However, some recent scientific studies have contradicted this theory.

Most of the cloud feedback uncertainty is due to cloud changes near the equator, in the tropics and subtropics (Stowasser et al. 2006).  Studies by Lauer et al. (2010) and Clement et al. (2009) both looked at cloud changes in these regions in the east Pacific, and both concluded that based on a combination of ship-based cloud observations, satellite observations, and climate models, the cloud feedback in this region appears to be positive, meaning more warming.

Dessler (2010) used cloud measurements over the entire planet by the Clouds and the Earth’s Radiant Energy System (CERES) satellite instruments from March 2000 to February 2010 to attempt to determine the cloud feedback.  Dessler concluded that although a very small negative feedback (cooling) could not be ruled out, the overall short-term global cloud feedback is probably positive (warming), and may be strongly positive.  His measurements showed that it is very unlikely that the cloud feedback will cause enough cooling to offset a significant amount of human-caused global warming.

So while clouds remain a significant uncertainty and more research is needed on this subject, the evidence is piling up that clouds will probably cause the planet to warm even further, and are very unlikely to offset a significant amount of human-caused global warming.

2010-12-25 07:37:26
nealjking

nealjking@gmail...
84.151.47.237

"evidence is piling up" sounds a little too strong.

Maybe "current studies are leaning in the direction" would be fairer?

 

With regard to the Intermediate: a lot of information in tables and pictures, but I feel a lack of guidance to the reader as to what to make of it. Can you unpack that a bit more?

2010-12-25 09:40:39too strong?
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.107.107

Too strong you think?  It seems like an accurate assessment to me.  Anybody else have an opinion on that?

I'll look over the Intermediate one and try to clarify a bit.

2010-12-25 16:34:38
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
68.188.192.170

How about tying in the phraseology into your theme:

"the evidence is becoming clear..."

  or

"the view is clearing that clouds..."

 

or just go with your original, which is probably OK.

 

The Yooper

2010-12-26 13:23:03Graphic added
John Cook

john@skepticalscience...
123.211.206.13

Dana, I've added an amended version of the Guide graphic. Let me know if you'd like any changes.

If you'd like wording that is slightly less strong, what about "The evidence is building". Just a tad gentler than "piling up".

2010-12-27 06:02:19phrasing
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.107.107

Thanks John, the graphic looks good.

Good ideas on the phrasing by Daniel and John.  I kind of like 'the evidence is building'.  Any other comments before I publish?

2010-12-27 07:03:09
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.231.11
Basic version looks good. Intermediate version seems somewhat advanced.
2010-12-27 07:35:56
nealjking

nealjking@gmail...
84.151.50.2

"Building" is OK; that language should also be propagated to the Intermediate.

 The Intermediate still needs leavening with more explanation. The graphics by themselves are colorful but don't convey anything to me. What's the message from them?

As a general practice, it would be good to settle the Intermediate before finalizing the Basic. When the Intermediate is stable, you know that all the concepts are in-line.

2010-12-27 08:40:42One thought re cloud feedback
John Cook

john@skepticalscience...
123.211.206.13
The way I think about cloud feedback is regardless of whether it's positive or negative, the important thing is the overall net feedback from all feedbacks. And we have many lines of evidence that net feedback is positive. So I liken it to watching James Cameron's Titanic. We know how it ends - the boat sinks. But we don't know exactly how we get there - do Kate and Leo get together? Does Leo sink to the bottom of the ocean? Similarly, we know the climate has positive feedback - that's the end result - so there very little chance that cloud feedback is going to provide a get out of jail free card. Anyway, just a thought.
2010-12-28 09:47:50
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252
I added a point about other feedbacks and link to the climate sensitivity is low rebuttal at the end.  I tried to add a bit more explanation about the figures per neal's comments, but I thought they were already explained pretty well, so I didn't have much to add.  Rob has a valid point that the Intermediate may be a bit too in depth.  Maybe if somebody does an Advanced version sometime we can pare down the Intermediate a bit.
2010-12-28 12:49:58
nealjking

nealjking@gmail...
91.33.124.204

Incomprehensibilities in the Intermediate version's figures:

"Figure 1 shows the results of the 16 GCMs, iRAM (bottom center), and satellite observations (bottom right).  A clearer version of this figure can be seen in Figure 1 on Page 6 of Lauer et al. (2010)."

When I look at Figure 1, I cannot tell what you mean by "bottom center" and "bottom right".  The bottom row seems to be missing its right-hand end; so what do you mean by the center of that row? (Yes, I see that you have taken this description from the figure caption - but that doesn't make it any more comprehensible to the reader.)


"As demonstrated by this figure, iRAM simulates recently observed cloud cover changes in this the eastern Pacific more accurately than the GCMs, and iRAM also successfully simulates the main features of the observed interannual variation of clouds in this region, including the evolution of the clouds through the El Niño Southern."

How does this figure demonstrate comparative accuracy? I see no qualitative distinction among these graphs. If I had to describe them, it would be as a false-color rendition of a Klingon war vessel (either off-screen to the left or in cloaked mode) firing photon torpedoes into a wrecked starship on the right. I don't have any clue as to why you think it has anything to do with the climate.

 

 

2010-12-28 14:22:32Thumbs up for basic version
John Cook

john@skepticalscience...
123.211.206.13
Basic looks good to me.
2010-12-28 15:01:38Intermediate looks good also
John Cook

john@skepticalscience...
123.211.206.13
I can see what Neal is saying but the fact that we have a basic version gives us some leeway so we don't have to get too simple with the intermediate version. Re the bottom middle/right, its not immediately obvious which is the middle but once you see the reference 'bottom right', it makes it clear which is middle. Similarly, I think the comparisons show iRAM matches observations better than the others (although UKMO is not too shabby either). So Dana, this looks good to go to me. I think this is a great resource to address the cloud argument which is one of the last almost credible arguments of skeptics (only credible in the sense that it has a smattering of peer review behind it).

Dana, when you go live with this, I'd suggest making the basic rebuttal the blog post then do a green box at the bottom that mentions this is the basic version, feature a link to the intermediate version and possibly even mention and link to your previous two blog posts.

2010-12-28 20:05:02
nealjking

nealjking@gmail...
84.151.33.248

John,

- The issue I am raising with the Intermediate version is not "lack of simplicity," but lack of comprehensibly. Providing a good Basic rebuttal does nothing to help me understand figures that are only in the Intermediate version.

-  "Re the bottom middle/right, its not immediately obvious which is the middle but once you see the reference 'bottom right', it makes it clear which is middle. Similarly, I think the comparisons show iRAM matches observations better than the others (although UKMO is not too shabby either)." Sorry, but neither of these points are clear to me at all. For me, they are a non sequitur. We are supposed to be writing not for ourselves, but for our readers; and in this case, I feel left out as a reader. I have no idea of what you and Dana are talking about. (And I mean that, in fact, not just as a hypothetical reader: I have no idea how you are coming to any conclusion about relative accuracy from looking at this figure.)

- Specifically, if we impose a numbering scheme on the parts of Figure 1, starting with #1 on the upper left-hand side, going to #5 on the upper right-hand side; #6 on the 2nd-row left-hand side, going to #10 on the 2nd-row right-hand side; and so on, ending with #18:

a) Which # is indicated by "bottom center"? Which by "bottom right"?

b) How can one derive any impression about relative accuracy from looking at these graphics?

2010-12-29 02:39:44
Ari Jokimäki

arijmaki@yahoo...
91.154.99.160

I think there are some aspects of the cloud issue missing from these rebuttals. While it is indeed important what type of clouds are increasing (or decreasing), it is also important where and when they are doing so. Excellent example is given in recently published Palm et al. (2010):

http://www.agu.org/pubs/crossref/2010/2010JD013900.shtml

They found that cloudiness increased in the Arctic due to sea ice loss. The increased cloud type was low level clouds so one would expect it to have cooling effect. However, in this case the clouds increased especially in the winter to which they said: "Because longwave radiation dominates in the long polar winter, the overall effect of increasing low cloud cover is likely a warming of the Arctic and thus a positive climate feedback, possibly accelerating the melting of Arctic sea ice."
Here's a conference paper on this study:

http://ams.confex.com/ams/10POLAR/techprogram/paper_152700.htm

I don't know if these issues need to be included to the rebuttals or not, it depends on how thorough you want to make them, but at any case the Palm et al. study seems to fit to the section on regional studies in the intermediate rebuttal. By the way, I recently bumped into this quite nice paper of basics of clouds as feedback by Schneider (1972) (this is open access paper so PDF link should work for everyone):

http://journals.ametsoc.org/doi/abs/10.1175/1520-0469%281972%29029%3C1413%3ACAAGCF%3E2.0.CO%3B2

2010-12-29 03:54:52
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

John - sounds like a good plan on publishing the blog post.

neal - as there are only 3 images in the bottom row, by "bottom-center" I mean #15, and "bottom-right" is #16.  It's the center image and the rightmost image in the final row.  I know the figure isn't clear, which is why I said that a clearer version could be found by clicking the link to the study.

The relative accuracy is determined by looking at the color patterns.  In the real world observations (#16), there's red in the bottom left and top right.  The closest figure matching that pattern is #15 (though as John notes, #14 isn't bad either).  Perhaps I'll clarify the text a bit to note that the purpose of the figure is to compare these color (shortwave cloud forcing) patterns.

Ari - perhaps the Palm study could be added for the Advanced version of the rebuttal.  I'll take a look and see if I can fit it into Intermediate as well, when I get the time.

2010-12-29 06:48:38
nealjking

nealjking@gmail...
84.151.33.248

dana1981:

- I assumed that "left", "center" and "right" were associated with the frame, so I didn't see a "right".

- How am I supposed to know that #16 is the "real world" observation, whereas #14 and #15 are simulations results?


 

2010-12-29 10:14:17
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252
There's a label on each of the 16 frames.  You can't read them in my jpeg, but that's why I suggested clicking the link to the paper itself, where the figure is much clearer.  #15 says iRAM and #16 says observations (CERES).
2010-12-29 20:19:18
nealjking

nealjking@gmail...
84.151.61.211

dana, if you include the figures in the posting, as a reader, I assume there is enough information to understand the article. There isn't'.

What's the purpose of these write-ups, if the reader is supposed to do detective work to understand what is going on?

If it's necessary to follow a reference to understand what is already in the article, then either the required information should be provided (preferable), or you ought to tell the reader that s/he must look at the reference to understand what is going on. Maybe it would be better to simply omit Figure 1 in the write-up and tell the reader to go to the reference.

2010-12-29 21:21:42One possible solution
John Cook

john@skepticalscience...
123.211.206.13
Here's one possible solution. Only include the last two boxes in your figure 1: iRAM and observations. Blow them up nice and big. If you really want to spell it out, add titles above each box like "model results", "observations". If you need help with the diagram, email me the paper and I'll create it for you (I had the paper somewhere but can't find it right now)
2010-12-30 03:39:57
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252

The purpose of Figure 1 is to show that iRAM matches the observations better than the other models, so it's important to show all the boxes.

Anyway I really don't think that clicking a link (which I specifically suggest if the reader thinks the figure is too legible) is too much 'detective work'.  John, do you know of a way to make the figure clearer?  My method is to open the paper in Acrobat, take a snapshot of the figure, paste it into Word, and convert that to a jpeg.  There's probably a better way to do it that I'm not aware of.

2010-12-30 06:24:28Try this
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
64.134.163.210

If you have access to Adobe Illustrator, Adobe Acrobat or even one of the freebies like PDFCreator you should be able to open the PDF and extract the raw graphic itself.  Much cleaner that way.

 

If not, try a PNG.  Cleaner image quality than a JPG.

 

I use MWSnap (freeware, v.3.0.0.74) in much the same fashion as your process.  High quality PNG's result.  Good enough for online use, anyway.