Here’s an interesting paper that breaks with consensus. The only problem is that it is being ignored for the most part by the mainstream climate community, even going so far as to having a debate over the paper’s source of data (NCEP reanalysis of radiosonde data) and declaring the data to be too “iffy”. You can read all about that debate at Climate Audit called “
A peek behind the curtain“. It is a firsthand account of the attempt at publishing from one of the authors, Garth Paltridge. Here is how he characterized the debate at a conference:
Those ‘against’ (among them a number of people from GISS) simply said that the radiosonde data were too ‘iffy’ to report the trends publicly in a political climate where there are horrible people who might make sinful use of them. Those ‘for’ simply said that scientific reportage shouldn’t be constrained by the politically correct.
Since most of the objections seemed to be coming from GISS, who has a surface data set that one could also describe as “iffy”, I find their argument rather humorous.
What is really interesting though is this graph presented in comments at CA by Ken Gregory:
Ken writes:
“The relevant discussion of the water vapour effect from the IPCC Fourth Assessment Report (Chapter 8 page 632):
The radiative effect of absorption by water vapour is roughly proportional to the logarithm of its concentration, so it is the fractional change in water vapour concentration, not the absolute change, that governs its strength as a feedback mechanism. Calculations with GCMs suggest that water vapour remains at an approximately constant fraction of its saturated value (close to unchanged relative humidity (RH)) under global-scale warming (see Section 8.6.3.1). Under such a response, for uniform warming, the largest fractional change in water vapour, and thus the largest contribution to the feedback, occurs in the upper troposphere.
This means that changes in specific humidity in the upper troposphere (300 – 700 mb) may be very significant even though the amount of water vapour there is low due to the cold temperatures.
If relative humidity remains constant, CO2 induced warming would cause increasing specific humidity and a strong positive feedback. But if relative humidity is actually falling (due to water vapour being displaced by CO2 as per Miskolczi) then water vapour may cause a negative feedback. The specific humidity has declined dramatically in 2008 at ALL levels in the troposphere.
I do not know the accuracy of the NCEP reanalysis data on upper tropospheric humidity, but the direct measurement of humidity by weather balloons seems preferable to the very indirect determination from satellite data.”
I agree. Here is more on the paper and it’s conclusions. – Anthony
New Paper Suggests Long-Term Water Vapour Feedback is Negative
(1) Environmental Biology Group, RSBS, Australian National University, GPO Box 475, Canberra, ACT, 2601, Australia
(2) Johns Hopkins University, Baltimore, MD, USA
(3) Centre for Australian Weather and Climate Research, Hobart, TAS, Australia
The Abstract states:
The National Centers for Environmental Prediction (NCEP) reanalysis data on tropospheric humidity are examined for the period 1973 to 2007. It is accepted that radiosonde-derived humidity data must be treated with great caution, particularly at altitudes above the 500 hPa pressure level. With that caveat, the face-value 35-year trend in zonal-average annual-average specific humidity q is significantly negative at all altitudes above 850 hPa (roughly the top of the convective boundary layer) in the tropics and southern midlatitudes and at altitudes above 600 hPa in the northern midlatitudes. It is significantly positive below 850 hPa in all three zones, as might be expected in a mixed layer with rising temperatures over a moist surface. The results are qualitatively consistent with trends in NCEP atmospheric temperatures (which must also be treated with great caution) that show an increase in the stability of the convective boundary layer as the global temperature has risen over the period. The upper-level negative trends in q are inconsistent with climate-model calculations and are largely (but not completely) inconsistent with satellite data. Water vapor feedback in climate models is positive mainly because of their roughly constant relative humidity (i.e., increasing q) in the mid-to-upper troposphere as the planet warms. Negative trends in q as found in the NCEP data would imply that long-term water vapor feedback is negative—that it would reduce rather than amplify the response of the climate system to external forcing such as that from increasing atmospheric CO2. In this context, it is important to establish what (if any) aspects of the observed trends survive detailed examination of the impact of past changes of radiosonde instrumentation and protocol within the various international networks.
The paper concludes:
It is of course possible that the observed humidity trends from the NCEP data are simply the result of problems with the instrumentation and operation of the global radiosonde network from which the data are derived. The potential for such problems needs to be examined in detail in an effort rather similar to the effort now devoted to abstracting real surface temperature trends from the face-value data from individual stations of the international meteorological networks. As recommended by Elliot and Gaffen (1991) in their original study of the US radiosonde network, there needs to be a detailed examination of how radiosonde instrumentation, operating procedures, and recording practices of all nations have changed over the years and of how these changes may have impacted on the humidity data.
In the meantime, it is important that the trends of water vapor shown by the NCEP data for the middle and upper troposphere should not be “written off” simply on the basis that they are not supported by climate models—or indeed on the basis that they are not supported by the few relevant satellite measurements. There are still many problems associated with satellite retrieval of the humidity information pertaining to a particular level of the atmosphere—particularly in the upper troposphere. Basically, this is because an individual radiometric measurement is a complicated function not only of temperature and humidity (and perhaps of cloud cover because “cloud clearing” algorithms are not perfect), but is also a function of the vertical distribution of those variables over considerable depths of atmosphere. It is difficult to assign a trend in such measurements to an individual cause.
Since balloon data is the only alternative source of information on the past behavior of the middle and upper tropospheric humidity and since that behavior is the dominant control on water vapor feedback, it is important that as much information as possible be retrieved from within the “noise” of the potential errors.
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Gary (09:23:12) : Also, as I understand it, the data from radiosondes are even more tangled and questionable than the surface temperature record.
Can someone educate us on radiosonde data, i.e. what they are and why the data are so tangled?
–Mark
Ken, check your claims and wording-it is indeed true that your graphs (in the excel sheet) show declining specific humidity at many levels, but near the surface they do show an increase (which is exactly what the paper the study we are talking about says). However, I suspect you meant Relative humidity, which your graphs do show as decreasing at all levels (BTW, are the RH data smoothed? They seem unnaturally unchaotic for weather/climate data).
Leif Svalgaard (09:02:44) :
It has warmed, so even with the same amount of water vapor, RH will go down. The change [a couple of per cent] looks reasonable for ~1 degree warming.
I looked at UAH data. At 600 mb 2009 is colder than the 20yr average and approaching the “record” coldest year of 2008. Doesn’t agree with the above.
Opps read the graph wrong. My apologies Lief.
MarkW (09:57:21) :
Mike Abbott (10:03:03) :
So? it simply means that models don’t work. What is so earthshaking about that? Didn’t you assume that from the outset?
D Werme (10:40:16) :
philincalifornia (09:24:51) :
” Is there a single paper in the history of the evolution of AGW theory where it became clear, quantitatively, that CO2 couldn’t do it alone, and where an accomplice had to be invented ?? Anyone ??”
—————————-
Thanks for the link. I will read avidly. I was, however, looking for something a little different – more psychiatry than physical chemistry. Is there an IPCC-type paper (preferably somewhat readable) where the authors explain how there has to be positive feedback from somewhere, because the CO2 calculations don’t cut it, and because water vapor was the nearest bystander, it was arrested and charged as an accomplice of that dastardly CO2 for its crimes against humanity ?? In other words, something akin to a “we-must-get-rid-of-the-MWP”-moment ??
Here is a response
http://chriscolose.wordpress.com/2009/03/05/what-if-relative-humidity-was-not-constant/
Chris
E.M.Smith (12:04:02) :
I like your analogy, but given that the ‘fire’ is a simulated one in a computer, I’d change it to “nicely contained on the movie screen”…
Was that movie perhaps starring Al Gore?
Wow, within your first sentence you set the tone with an ad-hominem. Good job chriscolose! You are obviously just as objective as we all would suspect.
Mark
The rainforests, however, will dry out and cause enormous positive feedbacks…
NPR: A Drying Amazon Could Speed Climate Change
…
Nepstad says as the climate warms, the Amazon could be caught in a feedback loop, whereby warmer Atlantic waters continue to dry out the Amazon, which in turn contributes more carbon to the atmosphere and accelerates warming.
Phillips is cautious about predicting whether the slip from carbon sink to source will become more frequent. But he notes that computer models of how climate may change in the future do predict a drying of the Amazon and says this latest research confirms those models, at least for one year.
The findings are published in this week’s issue of the journal Science.
http://www.npr.org/templates/story/story.php?storyId=101422948
Mark T,
I don’t know what you expect. This is science, not pre-K anymore. We can’t just go around saying whatever we feel like because “we have the right to” and not expect people to be critical. I was critical (maybe overly so)…get over it.
When the data and your model differ. The solution is obvious. Fix the data.
Common sense again: Water vapour and CO2 are after, not before, being in solution, so after heating not before heating.
I’m sure that the AGW side can some up with some upper wind related measurement to shows that the humidity is actually increased not decreased as observational evidence would strongly say, and we shall have radiosone data consigned to the box as “evil observations” calculated with “death balloons”!
Sorry, could not resist that!
Now back to these very serious results that have placed another very large hole in the CO2 positive feed-back theory.
So if there’s an iffy study that shows global warming will cause hurricanes to jump out of smokestacks and attack New Orleans, that is ok to publish and terrorize the public with. But if there is an iffy study that shows a this type of feedback in the climate system is a scientific possibility, it must not be released to the public at all!
Now with arguments like this going on, what does this say about the claimed confidence intervals on IPCC studies. THey can’t even get the signs of major components right, but they’re 95% certain we are all doomed 100 years from now anyways. I’m guessing this means their 95% confidence intervals are BASED ON THEIR ASSUMPTIONS HAVING NO ERROR. What an amazing and utter lack of humility!
I don’t know what you expect. This is science, not pre-K anymore. We can’t just go around saying whatever we feel like because “we have the right to” and not expect people to be critical. I was critical (maybe overly so)…get over it.
Wow, you do it again.
I don’t expect anything, but if you wish to sling ad-hominems don’t expect people to treat you with any more respect than you give out.
If you don’t like Anthony’s site, then leave. If you think the paper is wrong, then post your review. It was reviewed by others that apparently disagree with you, though I don’t know one way or another. However, by beginning your review with an ad-hominem, you instantly cast a shadow on your objectivity. By following up with yet another, you seal the deal.
Mark
Well chriscolose that link added less than nothing to the debate. Why did you think linking to what is clearly a religious screed would illuminate a scientific issue.
Models are not data, they are not science, if they don’t match the data they are garbage pure and simple. Seriously do you expect people to hold on to “improvede theoretical and model based approachs” after they are proven to be without merit. The models need a lot more improving at the moment, right now the actual data suggests that water vapor feedbacks are most likely negative overall. The huge positive water vapor feedback assumed by the IPCC scenarios is clearly not supported by the data. Just because we thought it should happen doesn’t mean it is happening. You need either real data to show that the feedback is as you claim or you need a new model.
Everything you reference goes back to models and as to the specific models… Garbage in garbage out.
Leif Svalgaard (13:14:14) :
MarkW (09:57:21) :
Mike Abbott (10:03:03) :
So? it simply means that models don’t work. What is so earthshaking about that? Didn’t you assume that from the outset?
—–
If the models don’t work, then there is nothing supporting the position of the alarmists.
If there is nothing supporting the position of the alarmists, then there is no reason to commit to limiting CO2 in the atmosphere.
That is a very big acknowledgement, given how much political capital has been sunk into these schemes the last few decades.
Leif Svalgaard (13:14:14) :
MarkW (09:57:21) :
Mike Abbott (10:03:03) :
So? it simply means that models don’t work. What is so earthshaking about that? Didn’t you assume that from the outset?
“Don’t work” is one thing; generating results that may be ass backwards (i.e., putting the wrong sign on the most important feedback) is another…
“”” Bill (12:22:06) :
This is all well and good, but there’s one question I’ve never heard adequately addressed.
However, isn’t the most significant effect of increased evaporation and humidity increased cloud formation?? Doesn’t the reduction of radiation reaching the surface by clouds more than overwhelm any minor increased capacity for absorption? “””
Well you haven’t been reading my stuff Bill; because I have been harping on that very point for ages.
Go and read SCIENCE July 2007. “How much more rain will global warming bring. ” by Wentz et al.
They report from actual real observational satellite measurments (data) that a 1 deg C rise in mean global (surface) temperature gives 7% increase in total global evaporation, total atmospheric water content, and total global precipitation.
In meteorology and climate science there is a tradition to have precipitation usually be accompanied by clouds; and those clouds are more often than not somewhat dark underneath, which has been ascribed to a combination of reflection of sunlight off the top (albedo increase), and absorption of additional sunlight in the middle of the cloud.
From that, one can deduce that more clouds mean less sunlight reaching the surface, which means surface cooling (negative feedback).
Globally over the long haul, the total evaporation and the total precipitation have to be equal, or else we would end up with the oceans over our heads; or the mother of all droughts.
Cloud scientists keep on insisting that there is no increase in clouds when it gets warmer; they omit saying that there is no known method (in use) for monitoring total global cloud cover all over the planet 24 hours a day (at every point on earth); and there certainly isn’t any system in use for measuring the ground level solar irradiance at all points on earth 24 hours a day. Nor is there even a good sampling process for doing that.
The best they can do is gaze at the backside of the moon (not sunlit); which only reports the sunlight reflected from a part of the earth, part of the time.
All that extra rainfall (when its warmer) has to be blocking some sun somewhere sometime.
George
I should have said Julu-7 -2007 SCIENCE
So I’ll bite !
Just what the blazes is 300-700 mb ? Would that be millibarns, or is that some other unit; and unit of what ? and how does it relate to relative humidity ?
Inquiring minds want to know.
I hope to hell the people on this board are not surprised that this kind of attitude not only exists, but controls much of what they read or see in the media about MANY issues.
My question might be a stupid one, but here goes nothing. 🙂
Sure, the data source is iffy – there have been equipment and methodology changes through the years. But the results show a clear downward trend. If the changes in results through the years could be pinned on equipment changes, measuring bias, or other such things, wouldn’t you see step changes in the data? Or is it homogenized over a number of sources that changed gradually at different rates so that the steps are “hidden” in the blend?
Even so, why is there a clear downward trend – wouldn’t all these changes add up to noise with just as much chance as going up as down? I think the real story here is the forest, not all the little factors involved with each tree.
300millibars is 30,000ft above MSL and 700mbs is 10,000ft above MSL.