Is the positive water vapour feedback "unproven and disputed"?

Deniers alternate between two conflicting arguments: (1) that water vapor is the most important greenhouse gas, and yet scientists ignore it; and (2) that scientists are wrong when they say that increasing the Earth's temperature will increase the amount of water vapor in the atmosphere and increase the greenhouse effect. That their own arguments directly contradict each other doesn't bother them, since they are only trying to deny--not make sense.

The paper that Maxx refers to is not relevant unless he can figure out a way to change land cover globally, and so alter the way sensible and latent heat is partitioned. Without doing that, the paper becomes irrelevant to the argument--clearly water vapor in the atmosphere is the key factor in keeping the Earth from freezing, trying to convince us that adding more of it is going to cool the Earth down is simply not going to fly.

Also, low clouds are a POSITIVE feedback with temperature--the higher the temperature, the fewer lower clouds there will be and the smaller the albedo.

EDIT for Raisin Caine: You said

"Saying that H2O serves a greater factor in the cliamte than CO2, is just common sense. Only the stupid would believe that CO2 would serve a greater effect at 0.04% of the atmosphere, than the H2O does at 1-4%"

Would you like to retract this statement? It has to be one of the sillier statements you have ever made. Do you feel that nitrogen, oxygen, and argon have even bigger effects on climate, since they make up 99+% or so of the atmosphere?

By the way, the volume fraction of water vapor in the atmosphere is substantially less than 1%, and by mass it's even less, so you might be a little more careful throwing figures around.

I do realize that statistics can be a confusing subject.

Water Vapour Feedback

You should look at how the effect of cloud are being calculated. It is solely for the atmosphere.

Where are the oceans being considered? Clearly more clouds would reduce the radiative heating of the oceans, and thus serving as another form of a negative feedback that is not being considered. Given the amount of energy that is being stored in the oceans, this factor could be huge.

Jeff M,

Negative feedbacks would not make the earth an ice box. Indeed, the only way for the ice box scenario, is that there are too many positive, not negative feedback. Negative feedback counteract changes in either direction. Positive feedback magnify changes.

Edit:

This really does explain things though. You think that negative feedbacks would cause an icebox earth. No wonder you never even attempted to understand what I was saying about negative feedbacks.

http://www.thefreedictionary.com/negative+feedback

Here you go. Look at the definition of negative feedbacks, it might help you in understanding WHY I think the models are wrong.

BTW, most of the positive feedback act in both directions. A colder earth means the oceans store more CO2, taking out more water from the atmopshere, all of which would have the effect of causing more cooling. Indeed, your "frozen solid" statement, shows that I am right, and the models are not.

Pegminer,

Saying that H2O serves a greater factor in the cliamte than CO2, is just common sense. Only the stupid would believe that CO2 would serve a greater effect at 0.04% of the atmosphere, than the H2O does at 1-4%. I have not seen many warmers try to make the claim that H2O does not have a large effect. So your first point is STUPID.

Your second point is even more ignorant. Most "deniers" are claiming that the water is a powerful force, but one that serves as a large negative feedback.

We may be wrong about the power and overall direction of the H2O feedback, but whether or not we are wrong, your criticism is stupid. Do you really want to claim the insignifcance of the water cycle in the temp of the Earth. Care to go there buttercup? Do you really want to talk about how powerful of an effect CO2 has had on Mars with its subzero temps and massive amounts of dry ice? You know you can't defend this. The ONLY thing you can say is that the H2O has been properly accounted for. In fact, if you DARE claim that H2O effect is small, that inherently means that ALL of your models are wrong.

Jeff M,

Not a probelm I have been off by a factor of 100 by getting caught up in the moment.

My point still stands though. They do not account for the effect of the clouds on the cooling of the oceans via less direct radiative heating. Just as their problem with the PDO, the major problem with the entire way that they are looking at the atmosphere, is THAT they are looking at the atmosphere. The atmosphere holds little energy and can NOT be the major factor. The atmosphere can be easily changed by small factors, because of the relative small amount of energy it can hold. The oceans, on the other hand, can hold vast amounts of energy. The oceans drive everything and are why the climate is a stable system and not an unstable one. One need only look at the difference between Mars and Earth to see the effect of the oceans.

Edit:

That is what they are trying to do. They are JUST looking at the atmospheric effect. But a cooling of the oceans from less radiative heating has the added effect of less H2O in the atmosphere, serving to strengthen the negative feedback.

>>Kano has attempted to call into question the positive water vapour feedback by posting a graph...<<

So what? Showing a Denier a graph is like showing them a Rorschach inkblot. Whatever "evidence" they claim to see in a graph is just a projection of their subjective beliefs. How can they see evidence in a graph when they do not even understand the concept of scientific evidence?

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Raisin Caine --

>> Prgmine...Saying that H2O serves a greater factor in the cliamte than CO2, is just common sense. Only the stupid would believe that CO2 would serve a greater effect at 0.04% of the atmosphere, than the H2O does at 1-4%. I have not seen many warmers try to make the claim that H2O does not have a large effect. So your first point is STUPID.<<

So, then, what is the difference between common sense and uncommon ignorance? Why do you think there is a simple relationship between the quantity of things and their relative importance? That is like saying a person does not have cancer if most of their cells are not cancerous.

Additionally, Roy Spencer has theorized that the change in cloudiness is itself the cause of the global warming being seen. Also that this is being misinterpreted as clouds are a positive feedback of global warming. The second part is contradicted by your data which shows no change in cloudiness. The IPCC has said that clouds remain very uncertain but does not go into detail. I don't see how you can say it is a fact given this.

Also in line with Roy's theory, you could have the predator and prey paradox. More wolves means fewer sheep as they get eaten. Then fewer sheep means fewer wolves as they have less food to eat. This then leads to more sheep as there are fewer wolves to eat them. So the cycle continues. Modeled in different ways, it is possible that just looking at the data you can reach the conclusion that more wolves leads to more sheep, because of a small phase difference.

Now, a good followup question is what is the difference in sensitivity among the possible water vapor feedback effects? I submit to you that 4.5C can turn into .5C.

Jeff, evaporation actually has a cooling effect, not a warming effect and this effect is global. This was confirmed by a study done in 2011. Dr. Julia Pongratz from Carnegie Institution for Science explains the study in this short 2 minute video. http://www.youtube.com/watch?v=7QScjmDOxYI

Here is the link to the actual paper: http://iopscience.iop.org/1748-9326/6/3/034032

More recent studies have confirmed the negative feedback of water vapor. This paper was published in the Journal of Geophysical Research Atmospheres (Sept 2013) and finds that the negative-feedback from water vapor could almost completely offset warming from CO2. http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50...

Here is another published in Nature Climate Change that finds a negative feedback mechanism of water vapor that may cause global cooling (Oct. 2013) http://www.nature.com/nclimate/journal/v3/n11/full...

Yet another finds that water vapor feedback is strongly negative, I don't know if this one has been peer reviewed yet or not. The paper is by Physicist Clive Best and the entire paper is posted here: http://clivebest.com/blog/?p=3659

I think we all know that humidity increases dramatically when it rains, yet this fast upshot of water vapor in the air does not lead to run-away warming. So yes, I think it's fair to say that positive water vapour feedback as described by Alarmists can accurately be described as "unproven and disputed."

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Jeff, all the papers I linked agree that water vapor is a negative feedback. They dealt not only with the stratosphere but also with the troposphere and evaporation and clouds and the interactions between them. If there is some mysterious water vapor positive feedback that causes more and more warming they sure didn't find it.

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From your first link

<<<Major problems are found in the means, vari-

ability and trends from 1988 to 2001 for both reanalyses

from National Centers for Environmental Prediction

(NCEP) and the ERA-40 reanalysis over the oceans, and

for the NASA water vapor project (NVAP) dataset

more generally. NCEP and ERA-40 values are reason-

able over land where constrained by radiosondes.

Accordingly, users of these data should take great care

in accepting results as real. >>>

That is a pretty major qualifier IMO.

Obviously water vapor is a major greenhouse gas and completely dominates climate when you include cloud formation, etc. That doesn't mean our CO2 emissions are driving water vapor concentrations.

Relative humidity is the % of water, the atmosphere can hold at its temperature (dew point)

Specific humidity is more like the complete amount of water vapor in the atmosphere

http://ph.search.yahoo.com/r/_ylt=A2oKmK7v5gpTxAgA...

http://bobtisdale.files.wordpress.com/2013/05/figu...

The amount of specific humidity in the atmosphere is also at a pause.

Can you describe to me what parts of the water vapour feedback mechanism remain unproven and disputed? my thanks to Maxx for links showing that is definitely not settled

Common sense should tell you water vapor must not be a positive feedback, because our Earth has had an incredible stable temperature for billions of years, even resisting solar changes, land mass movements, orbital changes, surely our climate would have spiraled out of control long ago, or without some form of negative feedback to counter the positive feedback, isn't it reasonable to suspect the negative feedback is water itself. after all it does cover 70% of our planet.

As far as I know, clouds are still more than a bit of a question mark, but the water vapor feedback itself is about as close to a sure thing as you get in science.

The water vapor feedback was reasonably well and correctly understood over a hundred years ago by Arrhenius.

http://www.aip.org/history/climate/co2.htm

"Svante Arrhenius in Stockholm...was attracted by the great riddle of the prehistoric ice ages, and he saw CO2 as the key. Why focus on that rare gas rather than water vapor, which was far more abundant? Because the level of water vapor in the atmosphere fluctuated daily, whereas the level of CO2 was set over a geological timescale by emissions from volcanoes. If the emissions changed, the alteration in the CO2 greenhouse effect would only slightly change the global temperature—but that would almost instantly change the average amount of water vapor in the air, which would bring further change through its own greenhouse effect. Thus the level of CO2 acted as a regulator of water vapor, and ultimately determined the planet’s long-term equilibrium temperature. (Again, for fuller discussion follow the link at right.)"

In the early 1990s, before advancing science forced him to rely more or less completely on trickery and deception, denier Richard Lindzen managed to construct a then still possible alternative model

http://www.aip.org/history/climate/simple.htm#L_08... which challenged "the way modelers allowed for water vapor feedback...Few scientists found Lindzen's technical arguments convincing...But it was only around this time that satellite instruments began to measure with any precision the greenhouse effect feedback between surface temperature and water vapor, and there was plenty of room to debate how clouds formed and moved water around. It took more than a decade to get observations that showed convincingly that moisture varied with temperature just as the models had predicted — the old assumption of constant relative humidity that all the modelers had used was indeed valid. In short, Lindzen's scenario was flat wrong." (Dessler, Andrew E. (2010). "A Determination of the Cloud Feedback from Climate Variations over the Past Decade." Science 330: 1523-27 [doi:10.1126/science.119254] ).

I think what this basically means is that another denier crock, that temperature ALWAYS drives changes in CO2 and never the other way around (as if because all eggs come from chickens therefore chickens cannot come from eggs) http://www.skepticalscience.com/warming-co2-rise.h... actually DOES apply to water vapor. The amount of water vapor in the air apparently depends almost entirely on temperature, whereas changes in the temperature are mainly driven by other greenhouse gases, especially CO2.