Seeking Peer-Reviewed Studies of Water Vapor Feedback

One of the key factors in determining the climate sensitivity to the increasing atmospheric concentration of CO2 and other long lived greenhouse gases is the response of water vapor to the relatively small warming induced by these gases. Climate models produce a strong signal of positive water vapor feedback, while actual measurements taken over the past few decades seem to indicate otherwise if some of the popular skeptical blogosphere presentations are to be believed (specific humidity is purportedly shown to be decreasing). Water vapor feedback is indeed positive near the surface in the planetary boundary layer, but what about higher up in the mid and upper troposphere where the critical impact on enhancement to the greenhouse effect would take place? Can anyone here come up with peer-reviewed studies of this issue?
 

ZapperZ

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What about:

1. B.J. Soden et al., Science v.296, p.727 (2002).
2. http://www.gfdl.gov/~gth/netscape/1999/adh9901.pdf [Broken]
3. D. Rind et al. Nature v.349, p.500 (1991)

Zz.
 
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Gokul43201

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I do not know if these are what you are looking for:
The issue is related to something that Forster & Taylor (2006 J. Climate) and Forster & Gregory (also 2006 J. Climate) have previously demonstrated: In order to estimate radiative feedbacks, you must first remove any sources of time-varying radiative forcing from the data. No one has ever bothered to do this for the time-varying radiative forcing due to natural cloud variations in the satellite data. It appears to be the largest source of decorrelation in both the satellite data and the IPCC model output.

http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175/2008JCLI2253.1&ct=1

http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175/JCLI3611.1

http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175/JCLI3974.1
 
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Or maybe this is what you are looking for:
http://ams.allenpress.com/perlserv/?request=get-pdf&file=i1520-0442-21-21-5624.pdf
"Feedbacks are widely considered to be the largest source of uncertainty in determining the sensitivity of the climate system to increasing anthropogenic greenhouse gas concentrations, yet the ability to diagnose them from observations has remained controversial. Here a simple model is used to demonstrate that any nonfeedback source of top-of-atmosphere radiative flux variations can cause temperature variability, which then results in a positive bias in diagnosed feedbacks. This effect is demonstrated with daily random flux variations, as might be caused by stochastic fluctuations in low cloud cover. The daily noise in radiative flux then causes interannual and decadal temperature variations in the model’s 50-m-deep swamp ocean. The amount of bias in the feedbacks diagnosed from time-averaged model output depends upon the size of the nonfeedback flux variability relative to the surface temperature variability, as well as the sign and magnitude of the specified (true) feedback. For model runs producing monthly shortwave flux anomaly and temperature anomaly statistics similar to those measured by satellites, the diagnosed feedbacks have positive biases generally in the range of −0.3 to −0.8 W m−2 K−1. These results suggest that current observational diagnoses of cloud feedback—and possibly other feedbacks—could be significantly biased in the positive direction."
 
Here is a recent study claiming a strong water vapor feedback.

Between 2003 and 2008, the global-average surface temperature of the Earth varied by 0.6°C. We analyze here the response of tropospheric water vapor to these variations. Height-resolved measurements of specific humidity (q) and relative humidity (RH) are obtained from NASA's satellite-borne Atmospheric Infrared Sounder (AIRS). Over most of the troposphere, q increased with increasing global-average surface temperature, although some regions showed the opposite response. RH increased in some regions and decreased in others, with the global average remaining nearly constant at most altitudes. The water-vapor feedback implied by these observations is strongly positive, with an average magnitude of λ q = 2.04 W/m2/K, similar to that simulated by climate models. The magnitude is similar to that obtained if the atmosphere maintained constant RH everywhere.

http://www.agu.org/pubs/crossref/2008/2008GL035333.shtml"
 
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Here was Dr. Roy Spencer's answer to Andrew Dressler:
http://www.drroyspencer.com/2009/02/what-about-the-clouds-andy/
"I’ve been receiving a lot of questions lately about Andrew Dessler’s water vapor feedback paper which supports the positive water vapor feedback exhibited by the IPCC climate models. Dessler and co-authors used AIRS temperature and humidity sounding retrievals from the Aqua satellite during 2003-2008 to compute how the specific humidity changed with warming"
 
No offense Mike, but if I posted this from Dr. Spencer's website I do believe it would be "stricken from the record".

http://www.drroyspencer.com/2009/02/...e-clouds-andy/" [Broken]

Takin’ it To The Street

Unfortunately, our J. of Climate article has been greeted with deafening silence. Apparently, everyone is too busy burning up computer cycles to see how much virtual global warming they can create in their models. I’m sorry for sounding so cynical, but given the importance of this issue policy-wise, you would think that someone besides me would be working on it.

So…my book describing these issues is almost finished…it’s due at the publisher by March 2. Since even the public understands “cause versus effect”, I decided to put it all down in as simple terms as possible.

Maybe there will be some physicists or engineers out there who understand what I’m talking about.
 
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WeatherRusty:
You brought up the Dressler paper and I pointed out a reply.
 

Xnn

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Here is a peer reviewed paper from the National Academy that identifies the human induced increases of atmospheric moisture content:

http://www.pnas.org/content/104/39/15248.full.pdf+html

Single-forcing experiments performed with two different
models (28, 29) suggest that the large increase in Wo is primarily
due to human-caused increases in GHGs (Fig. 5) and not to solar
forcing or the recovery from the Pinatubo eruption.
and

These findings, together with related work on continental-scale
river runoff (15), zonal mean rainfall (16), and surface specific
humidity (17), suggest that there is an emerging anthropogenic
signal in both the moisture content of earth’s atmosphere and in the
cycling of moisture between atmosphere, land, and ocean.
As I understand it, part of the problem is that there is not a lot of agreement between all the various models. After all, there is still a wide range between 2.0 to 4.5 C/doubling of CO2 accepted for climate sensitivity. That said, there is a corresponding differance between what is noise and what is not. What the above study has found is that the increase in moisture content has become significant enough that it can not be just noise.
 

Xnn

555
0
Spencer runs a climate model with a 50m deep swamp instead of oceans.
He finds that earth observations do not match it and then announces that something must be wrong.

Like duh; what did he expect?

Earths oceans are over 3000 m deep and absorb over 90% of the heat of global warming. So obviously, he is modeling the climate of some other planet.
 

mheslep

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Spencer runs a climate model with a 50m deep swamp instead of oceans.
He finds that earth observations do not match it and then announces that something must be wrong.

Like duh; what did he expect?
Where's this coming from? One of his links above?
 
S

Skyhunter

WeatherRusty:
You brought up the Dressler paper and I pointed out a reply.
That is not a reply.

A proper reply would be published in the same journal as the original research article.

And Spencer also believes Intelligent Design is a valid scientific theory.

Not a very good authority to appeal to.
 

mheslep

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...
And Spencer also believes Intelligent Design is a valid scientific theory.
I don't think so. Appears he is saying he finds the scientific basis for both ID and evolution as weak, with evolution requiring imaginative constructions to cover gaps in the evidence.
http://www.tcsdaily.com/article.aspx?id=080805I [Broken]
 
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S

Skyhunter

Perfect illustration of my point that Roy Spencer is not a very good authority to appeal to.

He is claiming that evolution is faith based and that is nonsense. He said he used to believe it was a fact. Not very scientific since facts are not theories and theories are far more scientifically valid than facts since they are derived from the interpretation of facts. Facts can be right or wrong without changing the underlying theory.

The scientific community and the courts have decided that ID is creationism. The strongest evidence being the draft documents and even the final publication where the authors did a search and replace on the word Creator with designer after a court ruling forbid the teaching of creationism in public schools.

Spencer is not a good authority to appeal to. Even his analysis of the MSU data (his area of expertise) is the outlier among all the other global temperature records.
 
Skyhumter:
Actually everything in life is faith based. Ask any philosopher. I see no reason to not rely on Spencer. The issue is water vapor feedbacks and that seems to be an area he is concerned about and has published papers about.

Do you have papers that falsify his theory or just disagree? Disagreement is called debate and I was lead to believe that is how science advances. Unless science has changed recently.
 
S

Skyhunter

Skyhumter:
Actually everything in life is faith based. Ask any philosopher.
That is a logical fallacy known as http://en.wikipedia.org/wiki/Poisoning_the_well" [Broken]

I see no reason to not rely on Spencer. The issue is water vapor feedbacks and that seems to be an area he is concerned about and has published papers about

Do you have papers that falsify his theory or just disagree? Disagreement is called debate and I was lead to believe that is how science advances. Unless science has changed recently.
The Spencer link provided was not about his published research or proposed theories. It was his opinion being masqueraded as a scientific critique. A real critique would be published in the same journal, not on a blog site.

If you wish to discuss his theory about how the water cycle acts as a thermostat to limit global warming, first provide a link to his published research.
 
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mheslep

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I've no particular interest in defending Spence but these criticisms don't follow my reading of his statements:
He is claiming that evolution is faith based and that is nonsense.
No, he explicitly acknowledges natural selection in populations due to environmental pressures, he states that Gould's punctuated equilibriums invented to cover the gaps in the fossil record are based not on observations, but on faith.
Skyhunter said:
He said he used to believe it was a fact. Not very scientific since facts are not theories and theories are far more scientifically valid than facts since they are derived from the interpretation of facts. Facts can be right or wrong without changing the underlying theory.
He said "fact", in quotes. That's making a bit much of it.
Skyhunter said:
The scientific community and the courts have decided that ID is creationism.
The scientific 'community' doesn't 'decide'. Scientists prove, or falsify, by train of evidence.
Skyhunter said:
The strongest evidence being the draft documents and even the final publication where the authors did a search and replace on the word Creator with designer after a court ruling forbid the teaching of creationism in public schools.
C'mon, non-sequitur. Has nothing to do w/ statements by Spencer.
 
S

Skyhunter

I've no particular interest in defending Spence but these criticisms don't follow my reading of his statements.
No, he explicitly acknowledges natural selection in populations due to environmental pressures, he states that Gould's punctuated equilibriums invented to cover the gaps in the fossil record are based not on observations, but on faith.
He said "fact", in quotes. That's making a bit much of it.
The scientific 'community' doesn't 'decide'. Scientists prove, or falsify, by train of evidence.
C'mon, non-sequitur. Has nothing to do w/ statements by Spencer.
I have no particular interest in attacking him.

Is it ID then that you are defending?

If it is I suggest you watchhttp://www.pbs.org/wgbh/nova/id/program.html" [Broken]

Here is a direct quote from Spencer's op-ed you cited.

Does not classical evolutionism, based almost entirely upon faith, violate the same clause?
Here is another.

I was convinced of the intelligent design arguments based upon the science alone.
Clearly in that op-ed he is demonstrating his belief that ID is an equal if not superior theory than evolution. And ID is not a scientific theory.

Not a good authority to base one's appeal when constructing an argumentative fallacy.
 
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Skyhunter:
Actually if you look at posts 4&5 you will find reference to 4 peer reviewed papers. OH and for your information regarding belief see this news article:
http://www.telegraph.co.uk/earth/environment/climatechange/5016185/Sacked-executive-can-sue-for-unfair-dismissal-over-his-green-beliefs.html
"Tim Nicholson's commitment to green causes was enshrined in law by an employment tribunal as a "philosophical belief" under the Employment Equality (Religion and Belief) Regulations."

You are the one that brought up the issue of beliefs.
 
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S

Skyhunter

The Spencer paper is not a study of water vapor feedback.

He constructed a simple model and fed it short term observational data that he then extrapolates that into a long term cloud feedback response.
 
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Dr. Spencer hopes to extrapolate the high ice cloud feedback suspected of altering long wave radiation flux over the short term MJO http://www.cpc.noaa.gov/products/precip/CWlink/MJO/mjo.shtml" [Broken] to the longer time scales associated with global warming.

He hedges his bet on this in his originating paper. He is merely speculating that cloud response to a warming climate involves negative feedback.

The decrease in ice cloud coverage is conceptually
consistent with the ‘‘infrared iris’’ hypothesized by Lindzen
et al. [2001], who proposed that tropical cirroform cloud
coverage might open and close, like the iris of an eye, in
response to anomalously warm or cool conditions, providing
a negative radiative feedback on temperature change.
We caution, though, that the ice cloud reduction with
tropospheric warming reported here is on a time scale of
weeks; it is not obvious whether similar behavior would
occur on the longer time scales associated with global
warming.
http://www.drroyspencer.com/Spencer_07GRL.pdf" [Broken]
 
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