Support for the saturated greenhouse effect leaves the likelihood of AGW tipping points in the cold

From The Hockey Shtick, word of a new paper that supports Miskolczi’s theory of saturated greenhouse effect. We’ve seen this before, in the form of this graph.

In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic net downward IR forcing effect of carbon dioxide relative to atmospheric concentration:

The flatter portion of the graph gradually smooths out, as the effect of CO2 forcing becomes saturated with increased concentration. And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:

What’s more, in this new paper there appears to be some evidence for a negative climate feedback, in the form of slightly lowered relative humidity trend, which makes climate sensitivity lower. Relative humidity (RH) is the ratio of the actual amount of water vapor in the air to the amount it could hold when saturated expressed as a percentage OR the ratio of the actual vapor pressure to the saturation vapor pressure expressed as a percentage. The amount of water vapor the air can hold increases with temperature. Relative humidity therefore decreases with increasing temperature if the actual amount of water vapor stays the same. While the study found a slight increase in specific humidity (the mass of water vapor per unit mass of air), relative humidity (near the surface, 2 meter measurement) decreased by 0.5% per decade, resulting in an overall slightly drier atmosphere.

If a positive water vapor feedback response existed in the climate system, you’d expect both the specific and relative humidity to increase with time. It didn’t. This ends up putting the kibosh on the idea of tipping points, and a lack of positive water vapor feedback pretty much takes all the scare out of CO2 induced climate change.

Of note is the issue with station inhomogeneity which apparently had been masking the signal in earlier studies. This study looked at stations individually to determining where such inhomogeneity existed. Here’s an example in figure 3 of their paper:

From THS:

A paper published today in the Journal of Climate finds that relative humidity has been decreasing 0.5% per decade across North America during the 62 year period of observations from 1948-2010.

Computer models of AGW show positive feedback from water vapor by incorrectly assuming that relative humidity remains constant with warming while specific humidity increases. The Miskolczi theory of a ‘saturated greenhouse effect’ instead predicts relative humidity will decrease to offset an increase in specific humidity, as has just been demonstrated by observations in this paper. The consequence of the Miskolczi theory is that additions of ‘greenhouse gases’ such as CO2 to the atmosphere will not lead to an increase in the ‘greenhouse effect’ or increase in global temperature.

Journal of Climate 2012 ; e-View

Surface Water Vapor Pressure and Temperature Trends in North America during 1948-2010

V. Isaac and W. A. van Wijngaarden*

Physics Dept., Petrie Bldg., York University, 4700 Keele St., Toronto, ON Canada, M3J 1P3; e-mail: wlaser@yorku.ca

Abstract

Over 1/4 billion hourly values of temperature and relative humidity observed at 309 stations located across North America during 1948-2010 were studied. The water vapor pressure was determined and seasonal averages were computed. Data were first examined for inhomogeneities using a statistical test to determine whether the data was fit better to a straight line or a straight line plus an abrupt step which may arise from changes in instruments and/or procedure. Trends were then found for data not having discontinuities. Statistically significant warming trends affecting the Midwestern U.S., Canadian prairies and the western Arctic are evident in winter and to a lesser extent in spring while statistically significant increases in water vapor pressure occur primarily in summer for some stations in the eastern half of the U.S. The temperature (water vapor pressure) trends averaged over all stations were 0.30 (0.07), 0.24 (0.06), 0.13 (0.11), 0.11 (0.07) C/decade (hPa/decade) in the winter, spring, summer and autumn seasons, respectively. The averages of these seasonal trends are 0.20 C/decade and 0.07 hPa/decade which correspond to a specific humidity increase of 0.04 g/kg per decade and a relative humidity reduction of 0.5%/decade.

The full paper from the Journal of Climate can be viewed at this link.

132 thoughts on “Support for the saturated greenhouse effect leaves the likelihood of AGW tipping points in the cold”

1. Game, set, match.

And in time for IPCC 5.

Oh Dear.

2. Adam Gallon says:

Looking at that chart of relative humidity, there appears to be a step change circa 1970. A precursor to the Great Pacific Climate Shift?

3. Scotish Sceptic says:

This reduction in water vapour fits in with that paper which showed a link between vegetative cover and local warming (which they then went on to say “couldn’t” cause global warming … which is nonsense)

Vegetation grows by evaporation. It sucks up ground water that would otherwise flow into rivers and pushes it into the air. Take away the vegetation, leave a field ploughed for a few months, cut downt the trees for lower vegetation, and the amount of vaporation decreases leading to rising temperature.

That is why “Urban heating” starts at population densities as small as a few 10’s of people per square kilometer. It’s not the people, so much as what the do to the vegetation.

4. The two pillars on which the rotten edifice of Global Warmery totters are (a) Sensitivity and (b) Feedback. The above work hacks away at pillar b.

If the climate’s sensitivity to rising CO2 is dwarfed by other influences (IPCC AR4 says CO2’s the biggie) then that pillar is demolished. If temperature changes have a self-correcting tendency (negative feedback) rather than self-escalating (positive), then the other pillar goes.

In short, the scare story evaporates if CO2 is no big deal and if warm things tend to cool.

5. Mydogsgotnonose says:

The assumption that IR absorbed by GHGs is thermalised locally is wrong. Not only is the energy quantised so it can only be transferred to another GHG molecule, not symmetrical O2 and N2, it is also almost immediately re-emitted in a random direction by another excited molecule which restores Local Thermodynamic Equilibrium and Equipartition of Energy.

The real GHG warming is at second phases, cloud droplets, black carbon etc. The former gives increased convection so accelerates precipitation thus reducing relative humidity, the physical origin of Miskolczi’s observation]

[I’ve solved the cloud physics and the other three major mistakes in climate science are elementary, so should not have been made by professionals! Basically, the game is over and we’#ll have to find employment for all those failures in climate science department.]

6. definitely a post to bookmark and roll out as evidence that AGW theory does not stand up to scrutiny

7. Frans Franken says:

Perfect to see Miskolczi confirmed again by measurements. Now let some “climate-neutral” government spend a couple of million on evaluation of this theory and potentially save trillions on this climate change derangement. And be very grateful to Miskolczi rather than firing him from NASA.

8. I think tipping point is nothing to do with CO2.
The key is the North Atlantic ocean’s circulation on which these 3 forecasts are based:
http://www.vukcevic.talktalk.net/Fc.htm
Changes are first felt in the Europe where climate is controlled by the Gulf stream, while American continent isn’t , except the area under influence of the Florida current.
.

9. KNR says:

Here is a example of the excuses this paper will be meet with.
Ones, this work does not count, as it does not cover ever square inch of the world .
Two, the people behind it once bought fuel, so their clearly in the pay of big oil
Three, these people are not ‘climate scientists’ and certainly not experts as none of these would ever make these claims.
Four, ‘the Team’ reject this so it must be worthless, and no need to actual read it.
Five, its in conflict with the ‘models’ and they are never wrong so this must be.

10. Claude says:

Will read the paper later today, but have to admit there’s something I don’t see, and that’s the disappearance of water vapor feedback.

While it’s true that relative humidity is going down by 0.5% per decade, specific humidity is still going up. So, it seems like there will still be water vapor feedback, just not as much as if SPECIFIC humidity were going down.

11. Scottish Sceptic says:

Unofficial End to Global Warming Scam

For years I’ve been dipping into google search for “Global warming”. OK, they are hugely biased, and vastly exaggerate the pro-warming sites, which is why the best feel for what is actually being created comes from short time slots like the last 24hours or latest news (last hour).

A few years ago I would have been hard pressed to find any substantial sceptic articles.

But, in the last few days (after a time not looking), I started looking again. The first time I saw an overwhelming majority of sceptical articles, I assumed it was a fluke. The next time … I assumed it was an extended fluke. I considered whether there was some common theme which meant that there was a rush of sceptical works … but whilst the European winter features, it is hardly the dominant theme. Sceptic articles not so much are in the majority, … it is more that it is all but impossible to find anything substantial that is pro warming (unless you count something on snails!!!).

This is not a fluke. The tide has turned. Global warming activists might put on a brave face, but in reality they have nothing to say, their enthusiasm is rock bottom … global warming scepticism is not only in the ascendancy, almost all new articles are now sceptical.

OK, hardly scientific, but in terms of my own personal expertise having monitored this quite intensely for many years, the present evidence shows that the scam is over.

So, why are the politicians still acting the way they are? You might ask.

There is a saying … kick a dinosaur between the legs and it will be a long time until the nerve inpulse reaches its brain at it reacts. For politicians that time-scale is around 5-10years. In other words, most of them don’t talk to ordinary people, don’t care about what ordinary people think – until its time to ask us to vote for them. So, for most of the time, they draw their inspiration and beliefs from the other deluded individuals in the same bubble devorced from everyone else.

One election … when no one likes global warming … that’s a fluke. Two elections when people don’t like parties who pursue the idiotic policy of destroying our carbon based economies … that’s a worrying lack of understanding of the electorate …. three elections … and they were always against global warming taxes!

12. Claude says:

Sorry, totally blew the second paragraph of previous comment.

While it’s true that relative humidity is going down by 0.5% per decade, specific humidity is still going up. So, it seems like there will still be water vapor feedback, not the disapperance we’d see if SPECIFIC humidity were going down.

13. Dodgy Geezer says:

@Jay Currie

“…And in time for IPCC 5. Oh Dear….”

I think you will find, if the paper gets into IPCC 5, that it is presented as

“…and it has also been shown that increased CO2 levels cause dessication of the atmosphere, which has the potential to kill every living thing on earth….”

14. Scottish Sceptic says:

Just one last comment … you might ask why I don’t have tabulated figures in a scientific way… the reason is that Google are known to be (have been?) strongly pro-warming and any kind of statistics were likely to be affected by the spin they wanted to put on the figures rather than anything meaningful. That is why e.g. when you search for “global warming”, it will appear that the web is overwhelmingly behind google’s own view on the subject.

Indeed, any attempt to show the decline in support for global warming in the google stats, was likely to result in a change in those stats. Stats can be manipulated, but what is far more difficult to manipulate is the enthusiasm of the source articles for a subject.

And in my judgement, the enthusiasm of pro-warmists is now rock bottom. A few may be going through the actions because that is their job, or their reputations have been hung in this noose. But those with a choice, have found something better.

15. Patagon says:

I am sorry, but I am not that sure about some of the points mentioned here.

I can see a negative feedback in Paltridge (2009) reanalisys study (*), but I don’t think it is that clear in this study.

A very small reduction in relative humidity is compatible with an increase in net water vapour content in the atmosphere (specific humidity), and it is this second which will affect the radiative properties.

The seasonal values are a bit confussing too. Saturation water vapor content increases exponentially with temperature, so it is normal that a smaller positive trend in summer temperature brings about a bigger trend in water vapour pressure when compared to winter.

What is interesting, and the authors repeat it several times in the paper, is that there is not statistically significant increase in water vapour trends. That means that there is no conclusive evidence of positive water vapour feedback, and that one of the fundamental tenets of the AGW hypothesis is still invisible to the human eye.

(*)Trends in middle- and upper-level tropospheric humidity from NCEP reanalysis data
Garth Paltridge, Albert Arking and Michael Pook
Theoretical and Applied Climatology, 2009, Volume 98, Numbers 3-4, Pages 351-359

16. Interestingly, today’s Frankfurter Algemeine carries a lengthy article claiming that solar radiation variations are “irrelevant and constant, that CO2 and water vapour are the only things that matter and IPCC 2007 got everything right …

I’d love to send them an email saying “B*ll*cks” but sadly my written German wouldn’t say it effectively, and they don’t have an email address for responses to this …

17. John Marshall says:

Not more model output!

If the theory of GHG’s worked as advertised then when feeling cold one could get into a freezer to get warm. We all know that this is impossible but people still believe that a colder atmospheric CO2 molecule will radiate heat to a warmer surface. The 2nd law of thermodynamics states that this cannot happen! Another so called greenhouse gas, water vapour, actually causes cooling. Evapouration needs heat which is extracted from the surface cooling it. If it convects then forms cloud then the released heat will exchange with the surrounding atmosphere and be radiated to cooler areas and eventually to space. This cloud formation cools the surface.

It all comes down to whether the use of the SB formula for BB radiation is the correct one to use for a planet. Earth is not a black body with a uniform surface it is the exact opposite. It also assumes that the majority of the heat is lost through radiation it is not. Cloud formation demonstrates that heat is being lost by convection. Within the atmospheric envelope heat distribution is through convection it is only at the atmosphere/space interface that radiation becomes the overriding heat loss method. Heat is also wind distributed around the surface and from day to night sides. Heat is also generated through atmospheric compression and the difference between saturated and dry adiabatic lapse rates, a la Foehne effect, which produces extra heat probably confused with a GHG warming. The Foehne effect is real GHG warming is not.

18. William M. Connolley says:

> Computer models of AGW show positive feedback from water vapor by incorrectly assuming that relative humidity remains constant with warming while specific humidity increases

No. The GCMs make no assumption of fixed relative humidity. That is an emergent property, approximately.

19. Oh, and how do we know that there is not some other cause of the drop in water vapur measurements. Increased urbanisation for example over the USA or air travel (high stmosphere effects), or changes in solar activity.

Or is it a measurement artifact much like UHI for temperatures…..

20. Not a model in sight. Simply observations. How refreshing.

21. Mydogsgotnonose says:
February 8, 2012 at 1:09 am

“The real GHG warming is at second phases, cloud droplets, black carbon etc. The former gives increased convection so accelerates precipitation thus reducing relative humidity, the physical origin of Miskolczi’s observation]”
____________________________________________________

Indeed yes, Mydog … Just what the ‘Slayers’ and I have been saying. Increased convection goes with reduced relative humidity, and vice versa. So, as we know, the moist adiabatic lapse rate is only about two-thirds of the dry adiabatic lapse rate, primarily because of the release of latent heat in the formation of rain drops which then carry the energy back downwards, warming air and sometimes the ocean and land as well

Apart from turbulent weather, this is the only way thermal energy can go downwards in the troposphere, because it cannot do so by convection or radiation – just by those rain drops that “keep falling on my head … ”

Elementary my Dear Watson.

22. Bloke down the pub says:

Does anyone else spot a connection here between this post and the snows of Kilimanjaro?

23. I was a meteorological technician (professional weather observer) at the start of my career. I wonder if the paper’s authors accounted for the following facts…

Many years ago temperatures at Canadian airport stations were measured manually. The dry bulb temperature and wet bulb temperatures were measured with *MERCURY* thermometers. The dry bulb and wet bulb were then used to calculate RH and dewpoint (vapour pressure). The temperatures at Schefferville, QC often do fall below -30 C and colder during the winter. I don’t have a copy of MANOBS (the observing manual) but I vaguely remember that weather observers were supposed to take the mercury thermometers indoors once the temperature fell below -30, to protect them from freezing (mercury freezes at -38.8 C). Under those circumstances, we were to read the hourly “dry bulb temperature” from the minimum thermometer, which uses a column of alcohol. The wet bulb (and therefore the RH and dew point and vapour pressure) was missing during hours when the mercury thermometers were out of service. Therefore there would be a number of hours during the winter when RH and vapour pressure would be missing. This would be 100% biased to hours with dry bulb temperatures below -30 C.

Fast-forward to current times, and temperature+RH+dewpoint are measured by sensors at autostations. The temperature range for valid data depends on which sensor from which manufacturer is used. So in more recent data, the winter data holes would be fewer, and the temperature threshold for missing data would probably be lower.

So we’re looking at at least 2 temp/RD/vapour_pressure data sets with different characteristics during the winter. I’d hate to be the guy analyzing the data.

24. Antonia says:

I just want to tell Willis that we experienced his thunderstorm theory of cooling today. It wasn’t a particularly hot day, but the clouds were building and towering magnificently. As I took the washing off the line I was hit by a squall. Moments later the rain came.

My daughter lives maybe two kilometres from me as the crow flies. She recorded 60 milimetres of rain plus heavy hail (pea sized). From the same storm I recorded 17 milimetres with a bit of hail. And yes, Anthony, we had both emptied our rain gauges in the morning.

So I had to provide cardigans for the family, even though February is generally the hottest month of the year in the you-beaut-land-of-Oz. The storm-deposited ice really cooled things down.

25. I have known about logarithmic saturation of greenhouse effect since the end of 1990s, when information about it was widely publicized by Steven Milloy’s site, JunkScience.com, and other skeptic sites. At that time I didn’t even know about the existence of WUWT.

WUWT is an excellent source of information, better than JunkScience, in my opinion, and it is good to find out that scientific papers supporting this fact are being published.

But why is it necessary to emphasize Mr. Eschenbach’s copying and posting of the graph in 2006? He didn’t develop the theory, he didn’t develop the graph, he was not the first (or the second, or the hundredth) to bring attention to it. Since when it’s always “Willis this and Willis that”? Makes me feel queasy.

26. Folks, I think this article may be the most important yet for reasons explained below..

It is well known that the moist adiabatic lapse rate (when relative humidity is high) is only about two-thirds of the dry adiabatic lapse rate, and so the rate of convection increases when the relative humidity decreases.

The following quote from Wikipedia http://en.wikipedia.org/wiki/Lapse_rate explains how this is the result of the release of latent heat in precipitation.

“The reason for the difference between the dry and moist adiabatic lapse rate values is that latent heat is released when water condenses, thus decreasing the rate of temperature drop as altitude increases. This heat release process is an important source of energy in the development of thunderstorms. An unsaturated parcel of air of given temperature, altitude and moisture content below that of the corresponding dewpoint cools at the dry adiabatic lapse rate as altitude increases until the dewpoint line for the given moisture content is intersected…”

But all this might appear to be just the opposite of what the article is saying has happened if one assumes that a faster adiabatic lapse rate should lead to cooling.

But does it? Does it allow thermal energy to escape more quickly because the temperature gradient is steeper? Does the release of less latent heat mean less warming of the atmosphere? It appears not.

I suggest (backed up by the data in this article) that the opposite is indeed the case, with lower relative humidity leading to warming.

This is what Anthony is saying and it is very significant. We see negative feedback, not positive feedback as the IPCC would like to see.

So, why is it so?

My hypothesis is this:

(1), As you will know from my posts and my ‘Radiation’ page, I agree with Prof Claes Johnson that there can be no transfer of thermal energy by radiation from a cooler atmosphere to a warmer surface. So backradiation from water vapour is a non-event.

(2) Water vapour and trace gases are the only ones doing the radiating and all radiating from the atmosphere helps to rid the Earth system of thermal energy. (None of it is absorbed by the surface, so it all goes to space.) The reduction in the quantity of water vapour has been very small, so that is far outweighed by the additional radiation due to the higher temperatures at any given level which result from lower lapse rates.

(3) So, the lower the relative humidity, the higher the lapse rate and the lower the rate of radiation, this leading to net warming of the atmosphere. If we can assume that the temperature gradient pivots around an average value (determined by SBL) somewhere in the atmosphere, then that could also lead to higher surface temperatures.

So, in conclusion, I still say there is no greenhouse effect due to either backradiation or trapping of thermal energy by carbon dioxide. Only water vapour can have an effect due to its unique phase change which releases latent heat. It’s effect is seen through a variation in the lapse rate, (due to release of latent heat) which in turn affects the rate of radiation and thus the climate.

Whatever is affecting relative humidity may well operate in natural cycles for reasons not yet fully understood. I doubt that mankind can control the process in any way.

27. Mods

For some reason I can’t post a reply on the Clive Best thread. It comes up as ‘error on page.’

Would you be so kind as to remove the following information in its entirety and place it in that thread? Thanks a lot;

“Clive

Most interesting article, thank you. For those that prefer real temperatures rather than anomalies, clicking on my name will take you to my site where I collect (mostly) pre 1860 temperature data sets from around the world expressed in real terms.

http://climatereason.com/LittleIceAgeThermometers/

Anomalies do help to better compare temperature changes between the various data sets so form a worthwhile function. However they have had the side effect of becoming the basis for a meaningless (in my view) single ‘global’ temperature.

A global temperature has a number of problems, not the least of which is that it disguises regional nuances. Around one third of global stations have been cooling for some time as we observed in this linked article. Intriguingly, separating out the individual stations from the composite of stations used to create an ‘average global temperature’ yields some surprising results. It appears that warming is by no means global as there are many hundreds of locations around the world that have exhibited a cooling trend for at least 30 years-a statistically meaningful period in climate terms.

https://wattsupwiththat.com/2010/09/04/in-search-of-cooling-trends/

These general figures were confirmed by the recent BEST temperature reconstruction which reckoned that 30% of all the stations they surveyed were cooling. Many of the rest (but by no means all) are in urban areas, which many of us believe do not reflect the full amount of localised warming caused by buildings/roads etc. Add in that many stations are not where they started out and have migrated to often warmer climes such as the local airport, and that many stations have become replaced by others or been deleted, and we start to see an immensely complex picture emerging where we are not comparing like with like.

There is a further complication with lack of historic context. For reasons best known to themselves GISS began their global temperatures at 1880 and as such do not differentiate themselves enough to Hadley which began thirty years earlier. I suspect this date was chosen as this was when many of the US stations started to be established, but as regards a global reach a start date around 1910 or so would bring in more global stations and have the advantage of greater consistency, as by that time the Stephenson screen was in almost universal use.

The start date of 1880 does not allow the context of the warmer period immediately preceding it, which means the subsequent decline and upward hockey stick effect is accentuated (the hockey stick commenced with instrumental readings from 1900) . I wrote about the 1880 start date here; where I link three long temperature records along the Hudson river in the USA.

http://noconsensus.wordpress.com/2009/11/25/triplets-on-the-hudson-river/#comment-13064

I think the most we can say with certainty is that we have warmed a little since the depths of the Little Ice age, which would surely come as a relief to most of us, but instead seems to be the source of much angst afflicting most of the Western World, who apparently have stopped learning history and are confused by statistics and context.

I hope you will be continuing your work and develop your ideas.

Tonyb “

28. Corey S. says:

If you click to print the document at the link Anthony has to view it, you can download it as a PDF.

29. Louis Hooffstetter says:

The ‘Journal of Climate’ published this blasphemy?
Off with the editor’s head! (As well as Miskolczi’s!)

But seriously, it appears the tide has turned.

30. Bill Illis says:

This is an important paper because it used a large number of actual measurements from stations rather than a gridded dataset (which are subject to various processing biases etc.)

While specific humidity was increasing, it is about 15% of the value that the theory and the climate models are based on.

The theory is that specific humidity should increase by 7.0% per 1.0C increase in temperatures and across North America, there is an average of 18 g/kg or 18 kg/m2 of water vapour in the air. So we should expect to see specific humidity increase by about 1.5 g/kg for the 1.2C these stations increased over the last 6 decades.

It only increased at about 0.24 g/kg over the 6 decades, or 1.0% per 1.0C, mostly flat . Which is also what the other long-term dataset NCEP reanalysis shows the global water vapour changing by over the same period. Almost no positive feedback from water vapour going back 6 decades.

31. John Brookes says:

“If a positive water vapor feedback response existed in the climate system, you’d expect both the specific and relative humidity to increase with time. It didn’t. This ends up putting the kibosh on the idea of tipping points, and a lack of positive water vapor feedback pretty much takes all the scare out of CO2 induced climate change.”

Actually, I think you’d expect the relative humidity to stay constant.

That sudden and dramatic drop in relative humidity in 1970 is fascinating. I wonder if it is world wide?

Since 1970, relative humidity seems to be gradually increasing. But that would be cherry picking…

[Reply: Relative humidity has been decreasing. ~dbs, mod.]

32. LazyTeenager says:

If a positive water vapor feedback response existed in the climate system, you’d expect both the specific and relative humidity to increase with time.
——–
And why would you, or anyone else for that matter, expect relative humidity to increase with time. Even accepting that warming is happening it is not a forgone conclusion.

I have no reason to expect that as I tend to think the cause and effect relationships around this are complex.

My naive expectation is that relative humidity is about cloud formation and has no effect whatsoever on increased greenhouse effect due to water vapour.

At the same time reduced humidity means less cloud and reduced albedo leading to more surface insolation. Naively this means more heating. But clouds can warm or cool depending on altitude and type thus complicating the interpretation.

33. LazyTeenager says:

From The Hockey Shtick, word of a new paper that supports Miskolczi’s theory of saturated greenhouse effect. We’ve seen this before, in the form of this graph.
————-
The MODTRAN graph is classic green house gas theory and the saturation effect is well understood in that framework. It has nothing to do with Miskolczi’s hypothesis which is poorly supported.

34. LazyTeenager says:

Computer models of AGW show positive feedback from water vapor by incorrectly assuming that relative humidity remains constant with warming while specif
——–
I find the claim that it is assumed that relative humidity is constant very hard to credit.

My first expectation would be that relative humidity would be calculated via the physics from first principles. My second expectation would be that if it isn’t then there would be experimental/observation evidence that thus is in fact the case.

“assumption” is not plausible for a key fact like this.

35. LazyTeenager says:

Statistically significant warming trends affecting the Midwestern U.S., Canadian prairies and the western Arctic are evident in winter and to a lesser extent in spring
———–
This claim of a warming trend is curious since it is generally accepted, especially here, that across the continental USA there has been minimal warming trend.

36. Bobl says:

Someone please inform me. I always hear about a constant rise of temperature for a doubling of CO2, but isnt temperature related to the natural logarithm of the CO2 concentration? If so, should it not be a constant rise for a increase in CO2 of e, or put another way a constant temperature rise for each 2.718 times increase in CO2? 2.718 is a far cry from 2 (Ie 35 % error)

Enquiring minds want to know?

37. LazyTeenager says:

The consequence of the Miskolczi theory is that additions of ‘greenhouse gases’ such as CO2 to the atmosphere will not lead to an increase in the ‘greenhouse effect’ or increase in global temperature.
———
If the M. Hypothesis is mediated by temperature, would another consequence be that changes in solar insolation would also not produce a change in global temperature?

38. Ken Harvey says:

What are you going to do next, Anthony, now that AWG is disposed of? Can I suggest statistical mis-analysis as a subject that is in dire need of going under the microscope?

39. All of this continues to be done in the (unrecognized) context of a general, and very basic, scientific incompetence, on the part of all concerned. Climate science is founded upon false theory, whose unwarranted acceptance into science has mis-educated at least one whole generation of scientists. Not only is there no greenhouse effect at all, of increasing atmospheric temperature with increasing atmospheric carbon dioxide, but the radiative transfer theory, which theoretically implies the greenhouse effect, is also clearly false (very obviously, showing that there is no carbon dioxide “greenhouse” warming negates the theory that predicts such warming). The radiative theory is not only wrong to assume the Earth’s surface to be a blackbody, but wrong to assume each differential layer of the atmosphere radiates thermally as a “graybody” (as local emissivity times Planck/blackbody distribution function). These false assumptions necessarily make the calculated radiation the EFFECT of a strict, set temperature distribution (which is physically provided by the hydrostatic lapse rate structure of the atmosphere, as given in the empirical Standard Atmosphere), not the CAUSE of temperature variations. Basically, the radiative transfer theory of the atmosphere does not address the thermodynamics of the atmosphere, but, it appears to me, is just a “light extinction model” (which merely tracks the light removed from, and added to, a highly directional beam of light in traversing a nearly-transparent medium, and does not provide any real insight into the thermodynamic effect of the light, and indeed naively fails to distinguish between a directed beam and omnidirectional thermal radiation). So the naive use of that theory (as shown in the “modtrans results” graphs presented in the article here) is worthless. Everyone needs to re-educate themselves on the fundamental warming of the atmosphere, responsible for the temperature-versus-pressure structure of the Standard Atmosphere (which, note, is a fundamentally stable thermodynamic state, not subject to “runaway climate” at all). Climate science cannot go forward without the fundamental correction provided by the Venus/Earth comparison I have done, and which should have been done, and generally accepted, 20 years ago–if there had been any competent scientists to do it.

40. Tom_R says:

How is RH measured? Could the errors caused by site changes and UHI contribute to the RH apparently decreasing when it actually remains constant but at a lower temperature?

41. John Silver says:

I have said it before and I say it again:
Me and my green friends want 1200 ppm to be comfortable.
Burn, baby, burn.

42. Anthony Scalzi says:

Here’s the Team Approved(TM) version of Fig 3.

[that image is blocked . . kbmod]

43. DirkH says:

“The consequence of the Miskolczi theory is that additions of ‘greenhouse gases’ such as CO2 to the atmosphere will not lead to an increase in the ‘greenhouse effect’ or increase in global temperature.”

That would actually fit quite wonderfully to Beenstock & Reingewertz’ econometric analysis of the possible causation of temperature by CO2 concentrations (which they were able to rule out). Oh, and it should make lukewarmers rethink their position…

44. DirkH says:

LazyTeenager says:
February 8, 2012 at 5:04 am
“If the M. Hypothesis is mediated by temperature, would another consequence be that changes in solar insolation would also not produce a change in global temperature?”

Miskolczi postulates a constant overall transparency of the atmosphere; in other words, increases in CO2 should be offset (with a time lag) by decreases in H2O, the other important greenhouse gas.

He does not postulate a constant temperature. Also, he does not talk about the level of cloudiness.

45. DirkH says:

LazyTeenager says:
February 8, 2012 at 4:57 am
“My first expectation would be that relative humidity would be calculated via the physics from first principles. ”

You really swallowed that Gavin Schmidt line hook, line and sinker, did ya? Google “Convection Parameterization” for some interesting insights into the world of climate and weather models.

46. Steve Keohane says:

Here is a RH% graph at different atmospheric levels, 1948-2008.

Of course there is no “tipping point” induced by CO2–otherwise, the earth’s atmosphere would be filled with most of the ocean’s H2O in response to our ancient world when the CO2 content was 10 times what we currently have. That’s why “climate scientists” have to ignore climate change in the past.

One would think “Epic Fail” Michael Mann, supposedly a “geologist”, would know that. But then, telling the truth in “climate science” doesn’t garner copious grants and favoritism from the UN, now does it?

48. Richard says:

Personally I have decided that I will treat with great caution any model that cannot be initialised to the approximate conditions on Earth 20,000 years ago and run forward in time to today (producing broadly similar conditions what we currently have measured) before I take any notice of what it has to say about the future.

I would like to know that the phenomena that cause 10s of degrees of change are well understood before I concern myself with ones that changes 1/10s of a degree per century.

49. Harry_Dale_Huffman:

You say we need to reeducate ourselves on your “Fundamental Warming of the Atmosphere” hypothesis which claims the Sun mostly just warms the atmosphere (with its near IR radiation) rather than warming the surface (with both near IR and SW radiation) which then warms the atmosphere. (When using “near IR” I refer to that which is higher frequency than any LW IR emitted by the surface.) Fewer still will absorb in the visible spectrum.

Your argument on your website sounds convincing, but I stumble on some points. Relatively few molecules in Earth’s atmosphere are going to absorb Solar infra-red. Spectroscopy does show pockets due to absorption in that part of the spectrum, but by no means all of the IR appears to be absorbed. That which is absorbed by, for example, a carbon dioxide molecule, will not necessarily be shared with O2 and N2, but can be quickly re-emitted and thus go to space just like reflection. Now we do know the Sun warms the surface and we feel the hot sand in the Sun, but not so hot sand in the shade.

We also know the first few meters of the atmosphere are usually a little cooler than the surface, though not much. So the surface is warming the atmosphere by diffusion, not vice versa. There would not be close thermal equilibrium if this were not so.

Then there is evaporation of oceans to form clouds and rain. Where does that energy come from if it wasn’t the result of the Sun warming the oceans? What I cannot accept is any concept of radiation from a cooler atmosphere warming a warmer surface.

So how does any energy get into the surface if none is coming directly from the Sun? We know not all the light is absorbed, or we couldn’t see. We know not all the UV is absorbed or we wouldn’t get sunburnt. Just what percentage of solar insolation did you say is doing all this warming?

50. Claude Harvey says:

So, Willis was right. “It’s turtles all the way down.”

51. Alex says:

More and more science is convincing more and more people, especially the scientifically minded, that AGW/[CAGW]/or_whatever_it_is_called_now, has failed miserably. Time has proven the models(pseudo-science) wrong. Scientific research is debunking the CO2=global warming theory. Meanwhile, 100 Tory backbenchers (UK parliament) have rebelled against Cameron on the wind turbines scam, a German ex-green scientists has turned cold and wrote a book debunking AGW……….
IMHO, the AGW thing is imploding, fast.

52. Near 500 the death toll so far in eastern Europe from the severe cold.

Mann should put his hockey-stick where it belongs…

53. David Ball says:

I stand by my contention that the debate is no longer about “how much Co2 warms the atmosphere”. It has now moved on to “whether or not Co2 warms the atmosphere”.

54. R. Gates says:

This bit:

“What’s more, in this new paper there appears to be some evidence for a negative climate feedback, in the form of slightly lowered relative humidity trend, which makes climate sensitivity lower.”
______

Let’s take it that this “trend” is actually there. Why would relative humidity go down? Because temperatures have gone up! It is the total amount of water vapor in the atmosphere, that matters, as it is the total actual numbers of molecules of water vapor in the atmosphere that will determine the total net greenhouse effect from those molecules. Global atmospheric water vapor has increased over the time period- thus there are more water molecules present.

And then this bit:

“If a positive water vapor feedback response existed in the climate system, you’d expect both the specific and relative humidity to increase with time. It didn’t. This ends up putting the kibosh on the idea of tipping points, and a lack of positive water vapor feedback pretty much takes all the scare out of CO2 induced climate change.”

____

The notion of tipping points isn’t at all related to the logarithmic saturation effect of CO2 in the atmosphere, nor its effect specifically on increase water vapor as a positive feedback effect. Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor. One must look at the whole system to see how just a little nudge can cause a big change– this is the essence of Chaos. Simple plotting the well-known and obvious logarithmic saturation effect on a graph proves nothing about the existenc of tipping points that could exist through the interaction of any certain level of CO2 concentration with various other elements of the system. One obvious one is the interaction of just slight temperature increases caused by increases in CO2 with the cryosphere. The cyrosphere is sensitive to these slight increases, and certainly then changes in the cryosphere (i.e. Ice caps, sea ice, glaciers) can have a ripple effect to other parts of the climate system.

Bottom line: to suggest that the radiational saturation effect of CO2 in any way suggests that tipping points can’t exist in the climate system is wrong thinking, and misses the entire understanding of the complexity non-linear chaotic systems. Certainly tipping points do exist in the system, ice core data proves it (i.e. the Younger Dryas event and many others), and a seemingly small nudge to the system can cause these tipping points.

55. R. Gates says:

David Ball says:
February 8, 2012 at 7:18 am
I stand by my contention that the debate is no longer about “how much Co2 warms the atmosphere”. It has now moved on to “whether or not Co2 warms the atmosphere”.

____
Maybe the debate has move on to this new area of discussion among the woefully uninformed, or willfully ignorant– but that’s it.

56. atmoaggie says:

If there’s one parameter that siting a weather station at a water treatment plant will influence more than temperature, this is it. But, if the siting quality was better early in the period, as usual, the effect would be the opposite of a decrease, thus a larger than found decrease in RH is possible, all else being equal.
-or-
This is an expected result if the stations are of the roof top and runway variety. (I think…)

Any notion as to the station quality of in situ data used in this?
Call me consistently skeptical, if you will. I’d like to know more before simply granting this one potentially undue credibility.

57. Bill Marsh says:

Over/Under on how long it is before the ‘Team’ begins it’s ad hominem attacks?

Much as they ‘had’ to get rid of the Medieval Warm period, they ‘have’ to get rid of this paper.

58. G. Karst says:

I don’t understand how specific humidity (absolute humidity) can be increasing at 6.5% per deg C rise and yet RH can decrease consistently over the time period. What goes up must come down as precipitation (increased RH). I do understand how there can be localized RH anomallies but doesn’t RH eventually have to normalize to increasing absolute measurements (barring any drastic change in pressure, over the 1 deg rise)?

I refer to a paper submitted to the IPCC in 2007, by Dr. Frank Wentz, director of Remote Sensing Systems (RSS) in Santa Rosa, Calif. It was an exhaustive analysis of the data from Special Sensor Microwave Imagers on Earth-observation satellites, over a 20 year period of actual warming (1986 and 2005). Note: These were measured values NOT modeled ones.

Also note that the IPCC and the “team” actively suppressed this data initially because it contradicted their increased desertification meme. It took awhile to work it into a new meme. GK

59. NK says:

60. NK says:

GKarst– that is a very fair question and I’d love to hear a response from AW.

61. Robert Austin says:

R. Gates says:
February 8, 2012 at 7:29 am

“Bottom line: to suggest that the radiational saturation effect of CO2 in any way suggests that tipping points can’t exist in the climate system is wrong thinking, and misses the entire understanding of the complexity non-linear chaotic systems. Certainly tipping points do exist in the system, ice core data proves it (i.e. the Younger Dryas event and many others), and a seemingly small nudge to the system can cause these tipping points.”

R. Gates,
I agree that that the abrupt changes in the paleoclimate record hints at “tipping points” between the glacial and the interglacial regimes. What paleoclimatology does not appear to support is abrupt changes from a warm interglacial regime to a much warmer regime. So the system would seem to have 2 attractors, not 3. The idea that man has changed the environment to the extent of creating a third climate system attractor is just a flight of fancy at the present state of our climate knowledge.

62. DirkH says:

G. Karst says:
February 8, 2012 at 8:09 am
“I do understand how there can be localized RH anomallies but doesn’t RH eventually have to normalize to increasing absolute measurements (barring any drastic change in pressure, over the 1 deg rise)?”

It can’t because of the rising CO2 concentration, according to Miskolczi. On one slide he wrote:
“If the system energetically could increase its
surface temperature, it need not wait for our
anthropogenic CO2 emissions, since another
GHG, water vapor, is available in a practically
infinite reservoir, in the surface of the
oceans.”
(My link to his slides doesn’t work anymore so I can’t give you more…)

63. Steve M. from TN says:

@R. Gates,

“Bottom line: to suggest that the radiational saturation effect of CO2 in any way suggests that tipping points can’t exist in the climate system is wrong thinking”

IF this paper is correct, then there are no “tipping” points from rising CO2, which is the main premise of CAGW (or whatever the nom du jour is). IF CO2 is saturated, or close to saturated, it cannot significanly add to warming. You’ll also be able to stop the mantra of “CO2 vs. low solar output.” I don’t think ice core data does not prove tipping points. It does prove climate can change fast in either direction (although it appears we warm faster than we cool).

You just have to watch this fantasic documentary about earth magnetic field and cosmic rays!

Fantastic animation and science.of the changing magnetic field on our planet. Svensmark is interwiewed about his hypotesis as competitive to the CAGW anyone hos watch this video realies thats its a far more robust hypotesis than CAGW.

If you want the english speaker. I recommend you to start one window with this swedish public service (HD quality) and turn the sound off.

In a second window you open up the best english speaker voice ive found on the WEBB. Low quality but good enough to make you enjoy the documentary and to make it make sense.

For english speaker.:

http://www.youtube.com/watch?v=d56GOgmjWOI&feature=related (start at 1m 41 s) part one

65. Rob L says:

G. Karst says:
February 8, 2012 at 8:09 am

“I don’t understand how specific humidity (absolute humidity) can be increasing at 6.5% per deg C rise and yet RH can decrease consistently over the time period.”

I would guess that it’s because the atmosphere has warmed slightly, and warmer air can hold a lot more water (eg saturation pressure increases from .0234 bar to .0249 bar by about 6% in heating from 20°C to 21°C)

66. Bill Illis says:

G. Karst says:
February 8, 2012 at 8:09 am
I refer to a paper submitted to the IPCC in 2007, by Dr. Frank Wentz, director of Remote Sensing Systems (RSS) in Santa Rosa, Calif. It was an exhaustive analysis of the data from Special Sensor Microwave Imagers on Earth-observation satellites, over a 20 year period of actual warming (1986 and 2005). Note: These were measured values NOT modeled ones.
———————————

Water vapour levels are tightly controlled by the ENSO. A La Nina will drop global water vapour by 5% while an El Nino will raise water vapour levels by 5%. While some of the +/- 5% change is due to the temperature change between a La Nina and El Nino, some of the varibility is also caused by the different evaporation rates and cloud changes that the ENSO produces. It is not temperature only.

So if you start your dataset in a La Nina and end it in an El Nino, you will see a large increase in water vapour levels. All of the pro-AGW studies on water vapour have used this selection criteria in order to say “see, 7% per 1C”. Nope, start and end your dataset in a La Nina and it is 1% (maybe 4%) per 1C.

Wentz has done a few of these studies, do you have a link to the one you are referring to.

67. This is — to the extent that it is eventually verified and found to be predictive (and assuming no problems surface in the theory) — an example of the best of skeptical climate science, and one that appeals directly to the intuition of most scientists as to what to reasonably expect. I mentally established a saturating curve like that five minutes after I learned about the greenhouse effect and the assertion of “catastrophic” positive feedback (which would make the second derivative in the curve positive instead of negative or flat), at least in the second figure. Not the slope, the curvature. It is simply unreasonable to think that a stable system that has resisted “melting down” for a few billion years doesn’t have numerous negative feedback loops with overall negative feedback, and of course the raw physics of gas radiation predicts saturation at or near the tropopause. The only thing that can significantly alter the GHE with CO_2 concentration is lifting and cooling the tropopause, but there is all sorts of atmospheric dynamics — such as the stratosphere — that oppose that, not to mention the ability of the overall system of heat transfer to re-organize to get of heat more efficiently as the ground or ocean temperatures warm a bit.

rgb

68. Phil. says:

Note that the Fig 3 from the paper is given as an example of the type of data that the authors rejected from their analysis because of inhomogeneities. Also they found the biggest drop in RH occurred in those stations which showed the largest increase in temperature (winter in the north where there is a lack of available liquid water).

69. DirkH says:

@R. Gates,
“Bottom line: to suggest that the radiational saturation effect of CO2 in any way suggests that tipping points can’t exist in the climate system is wrong thinking”

You are, of course, right, as we know that glaciations have begun and ended very quickly. Whether this happened due to a climate tipping point or through an outside influence (Milankovic cycles? Cosmic influences? Volcanoes?) is not known by now. But while we have examples of quick onset of glaciation, we don’t have examples of quick onset of, let’s call it “Hothouse Earth” phases. This does not prove that it isn’t possible. But it reduces the likelihood of it happening.

And when relative humidity drops while CO2 rises, this works against the postulated positive water vapor feedback of the IPCC, so it should reduce the risk; and if we are supposed to buy insurance against the CAGW risk, we should now renegotiate the premium.

Also, just to repeat this: positive water vapor feedback should, if it is possible, be possible on regional scales. So, before the entire globe heats up in a giant feedback loop, we should be able to watch small localized outbreaks of positive water vapor feedback – say, in the tropics, at noon.

It hasn’t been observed by now. And I doubt that it will start in the Tundra.

70. commieBob says:

Scottish Sceptic says:
February 8, 2012 at 2:00 am

So, why are the politicians still acting the way they are? You might ask.

I suspect that many politicians have realized the truth. Obama has recently said: “We are the Saudi Arabia of natural gas.”
http://www.lasvegassun.com/news/2012/jan/26/obama-we-are-saudi-arabia-natural-gas/
T. Boone Pickens has realized that windmills aren’t the way to go and is now pushing natural gas. http://www.reuters.com/article/2012/02/01/us-navistar-idUSTRE81011H20120201 The rich and powerful aren’t about to admit that they were wrong about global warming and green energy but their behavior will show that that’s what they are thinking.

71. Joules Verne says:

@Doug Cotton

You are very confused about so-called back radiation. There is nothing a warmer object does that stops a cooler object from radiating. There is no spooky action at a distance telling the cooler object to stop throwing off photons in the direction of a wamer object. Photons flow in both directions. There is simply more of them coming off the warmer object. Energy transfer is thus the net of an unequal bidirectional flow. The cooler object doesn’t increase the temperature of the warmer but it reduces the net rate. In effect we have three considerations. A warm surface, a cooler gas, a very cold cosmos. The cooler gas, so long as it is able to absorb photons emitted from the warmer surface, acts to insulate the warmer surface from the frigid cold of the cosmos. The actual mechanism by which this happens is that a portion of the photons moving away from the warm surface are absorbed by the cooler gas which very quickly re-radiates those photons. The crux is that the gas absorbs photons arriving from below but re-re-radiates them equally in all directions. Those photons emitted downward reduce the net flow of radiation and the effect is a slower rate of cooling.

This is basic physics and contesting it puts one in the scientifically illiterate and/or crank category. If one is comfortable in that place it’s a big group but the average IQ in it is below 100 if you get my drift.

72. John Marshall wrote: If the theory of GHG’s worked as advertised then when feeling cold one could get into a freezer to get warm. We all know that this is impossible but people still believe that a colder atmospheric CO2 molecule will radiate heat to a warmer surface. The 2nd law of thermodynamics states that this cannot happen

No, that’s not the right way to view the GHE. I agree that trying to track e.g. downwelling radiation and so on is confusing (although not necessarily incorrect). The right way to answer the question “Does the GHG-mediated GHE exist and contribute to the temperature of the surface” is really easy.

Look.

If you look at the top-of-atmosphere outgoing radiation spectrum, you can see it. Greenhouse gases in the upper troposphere radiate at a much lower temperature — in the specific bands associated with CO_2 absorption — than the surface does.

Once you look at the actual graphs, and take the time to understand what they mean, the question is no longer “Does CO_2 play a role in warming the surface of the Earth”. Of course it does. You can see it, in almost precisely the same way that you could see where your house was losing energy via radiation by a means of an IR photograph. The more of your house that is losing heat from a cold outer surface rather than the warm interior, the warmer your house is. A well insulated house is cold on the outside; snow doesn’t melt on its roof. A poorly insulated house has a warmer roof.

IR spectra taken by satellites simply let you identify the parts of the spectrum that act as radiative “insulation”, and slow the transmission of heat so that it eventually comes out of the Earth itself from cold matter up high instead of warm matter down low. End of story.

So don’t get hung up on radiation going up or down, convection or conduction, winds or global oscillations, heat going from warmer to cooler or vice versa, or anything like that. Those things may affect the way the GHG-moderated GHE works, but they do not have any bearing on the question of whether it works at all. All that matters for the latter is the picture of the outgoing radiation that actually cools the Earth — and is the only way heat actually leaves the Earth, so you can completely, totally ignore 100% of the details of how heat moves around the Earth’s surface before eventually being radiated away. That picture leaves one with absolutely no doubt that CO_2 in the upper troposphere is part of the “well-insulated roof” (where the water window is part of the “poorly insulated roof” where the entire spectrum is “the roof”) that one way or another slows the flow of input energy out of the troposphere and hence raises the average temperature of the house beneath the roof.

Just look.

rgb

73. G. Karst says:

Bill Illis says:
February 8, 2012 at 8:55 am

Wentz has done a few of these studies, do you have a link to the one you are referring to.

They found that over the two decades(0.4°C), both factors (precipitation and atmos. water vapor) increased by between 1.1% and 1.2% – or roughly 6.5% for each degree of warming.

Journal reference: Science (DOI: 10.1126/science.1140746).

That is all the information, I have in my notes. I am sure you can find more.

I say forget relative humidity. Think of the global atmosphere as storage vessel for water, as you put more water into the atmosphere, the vessel overflows and rain falls to ground. If you increase the temperature you increase the storage capacity, but it quickly fills to overflow again. It only produces a baffle effect.

Water, truly is a miracle substance. One of it’s characteristics that makes it so, is it’s amazing heat capacity (both sensible and latent). This makes it an incredible heat transport mechanism.

Direct solar heating is greatest at the equator. If we increase the water content (absolute humidity), that water will absorb more heat. This water is then transported, via clouds and humidity to other parts of the globe. The more absolute humidity, the greater the effect. This means, more equatorial heat moves into the temperate and polar regions. This is what I mean by homogeneous effects. The equator remains equatorial and the temperate zones less temperate. As delta temps decrease, so does severe weather patterns decrease. We truly become more homogeneous, climate wise. Increased cloud cover also dramatically affects albedo. This is the beauty of a water vapor driven climate. It self regulates.

All of this depends on a warming climate. If we are in fact cooling… then all bets are off. We must then pull out our “ice age” (tiny, little, big) scenarios.

I used to assume, we were indeed warming, however, recent decadal trends have reduced my certainty to a coin flip. I hope we are, because the cooling alternate is not so kind. GK

74. ponysboy says:

I’m with “Claude”.
In this case RH stands for Red Herring.
So what if relative humidity goes down? There’s still a positive correlation between temperature and water vapor…..the AGW alarmists will love it.
The fundamental question which Spencer has been raising for years is: which came first? Spencer has some convincing arguments that say the water vapor came first. But not convincing enough just yet. Does this paper add anything to that debate? I don’t see how.

75. RobW says:

@R. Gates,

“Bottom line: to suggest that the radiational saturation effect of CO2 in any way suggests that tipping points can’t exist in the climate system is wrong thinking”

So once again Mr Gates. Please explain how ancient earth (500 million years ago, and 120 million years ago) atmosphere did not go over any tipping point when the atmospheric CO2 levels were 6-20 times the present levels. The laws of physics did not change over this time period so either the feedbacks are in fact negative or what?

76. Joules Verne says:

If the earth is operating in a saturated greenhouse state it raises the question of how we’re in an ice age with, even in an interglacial period, temperatures substantially cooler than during most of the earth’s history. Perhaps the greenhouse effect becomes saturated at some point but the geologic column which reveals temperate forests covering Antarctica speaks to it not being saturated at the present time.

I think negative feedback from clouds putting a ceiling on temperature is pretty much all the explanation we need for why there’s not a shred of evidence that the earth has ever experienced a runaway greenhouse. Certainly there’s enough water available in the oceans for that to happen if it was possible.

There is a great deal of evidence however for runaway cooling due to feedback from ice and snow which greatly reduce absorption of solar energy by reflecting it away and thus making it even colder which fosters even more and longer lasting snow and ice cover. In fact there is evidence of glaciation right down to the equator and the only real controversy is whether there was any part of the ocean that was not frozen. This happened several times during the earth’s history and persisted for millions of years. No one really knows what reversed it but volcanic activity darkening the surface with volcanic ash and simultaneously belching CO2 with all the CO2 sinks shut down eventually turned the tide back in favor of liquid ocean surface and no permanent ice even over the poles. This also explains why CO2 levels in the past were 10 times greater than today. It rose that high while the earth was frozen and after the melt the carbon cycle was greatly accelerated and stayed that way until events conspired to give ice the upper hand again which IMO was probably a perfect storm of supervolcanoes and/or asteroid/comet strikes that plunged the globe into darkness for enough years to start the runaway freeze going again. These runaway freezes are very rare and very brief compared to the normal state of affairs.

One must have a good understanding of the earth’s history across deep time to understand how cold the past several million years have been. It’s not global warming we have to worry about right now it’s global cooling. The Milankovich cycle is primed for glaciation and getting nothing but more primed for the next several thousand years. One very large volcanic eruption perhaps with a concurrent solar grand minimum and we’ll have the perfect storm which ends the Holocene interglacial. What little CO2 we can add to the atmosphere by burning fossil carbon might give us a bit more margin of safety against the next perfect storm but probably not enough. In any case it’s pure insanity to proactively reduce the margin of safety against the return of the ice.

77. Joules Verne says:

Robert Brown says:
February 8, 2012 at 9:25 am

“Once you look at the actual graphs, and take the time to understand what they mean, the question is no longer “Does CO_2 play a role in warming the surface of the Earth”. Of course it does. You can see it, in almost precisely the same way that you could see where your house was losing energy via radiation by a means of an IR photograph. The more of your house that is losing heat from a cold outer surface rather than the warm interior, the warmer your house is. A well insulated house is cold on the outside; snow doesn’t melt on its roof. A poorly insulated house has a warmer roof.”

A teachable moment? Good luck!

I finished making a very well insulated structure cut into a hillside a year or two ago. The roof is almost flat (1:14 slope) covered with white mineral roofing. It begins at grade on the uphill side and is 10 feet above grade on the downhill side and faces roughly NW so doesn’t get much sun on the single external wall. It’s better than R-30 insulation on the roof. On dry clear nights it will be covered with frost at sunrise with outside air temperature not having fallen below 40F all night long and air temperature inside the structure a constant 72F. This is in sub-tropical south Texas where year-round ground temperature a feet deep is a perfect 72F which inspired the project (I wanted to see how little heating and air conditioning I could get away with without resorting to expensive construction materials). The result was fantastic. Heating/cooling cost is under \$0.50 per square foot annually and even then in the winter it’s little more than using a few incandescent light bulbs left on 24/7 to kill two birds (lighting and heating) with one stone. A dehumidifier is required during the cooler months when the air conditioners aren’t kicking on at all.

So not only does “snow” not tend to melt on a well insulated roof it will form frost on it even when air temperature is far above freezing. This was an object lesson for me in the power of radiative cooling on dry clear nights although I hadn’t quite forgotten many camping trips to the high desert at Joshua Tree National Monument in the 1970’s and 1980’s outside Palm Springs where you’d roast by day and freeze by night.

Good luck trying to teach the rudiments of why these phenomenon happen when your students aren’t paying through the nose to hear you talk. I’ve had no luck at it. As Yogi Berra said “You can observe a lot by just looking.” Most people see without actually looking, it seems.

78. Joules Verne says:

@Robert Browbn

“so you can completely, totally ignore 100% of the details of how heat moves around the Earth’s surface before eventually being radiated away”

I disagree. We live and breathe at the approximate altitude of a Stevenson Screen (4 feet off the ground). I don’t care much what the temperature of the air is far above my head. Therefore the environmental lapse rate is very important. If more CO2 speeds up the water cycle and reduces the environmental lapse rate without actually making the surface air any warmer than otherwise that’s very important. In actuality that’s exactly what happens over the ocean. More GHG’s merely raises the evaporation rate of the ocean surface and lowers the lapse rate with little effect on either water or near-surface air temperature. On dry land it’s a different story where there’s actually a surface that doesn’t immediately reject downwelling long wave infrared in latent heat of vaporization. In the case of dry land the rate of cooling is reduced by additional GHGs and for better or worse (mostly better) we feel the difference.

But hopefully you already knew that.

79. Joules Verne says:

G. Karst says:
February 8, 2012 at 9:33 am

Outstanding.

80. Ged says:

Somehow I think some particular posters don’t fully understand what relative humidity really means.

For there to be a water vapor feedback, relative humidity must stay the same or raise with temperature. Further, the lower the RH, the easier it is for evaporation. One would expect, due to how water works, that RH would remain the same as you vary temperature over a certain range between freezing and boiling, and as long as there is a source of liquid water to vaporize, this is usually true. The fact RH has gone down is the same as saying the planet’s air is getting dryer. Dry air is air with a low RH, as that’s what’s important to the hydrological cycle–evaporation and condensation.

Question is, if this data is true, and it may not be, why would our air be drying?

81. David Ball says:

R. Gates says:
February 8, 2012 at 7:32 am

Maybe the debate has move on to this new area of discussion leaving behind the woefully uninformed, or willfully ignorant.

There, fixed it for you.

82. Bill Illis says:

Total column water vapour was -0.04 g/kg in January 2012. Plotted versus the ENSO back to 1948. Hard to say there is an increase that correlates with the increase in temperatures over the period.

But temperatures, water vapour and the ENSO are all closely tied.

83. Phil. says:

G. Karst says:
February 8, 2012 at 8:09 am
I don’t understand how specific humidity (absolute humidity) can be increasing at 6.5% per deg C rise and yet RH can decrease consistently over the time period.

If the Clausius Clapeyron equation says that specific humidity should increase by 7%/ºC then if it only goes up by 6.5%/ºC the the RH will go down.

84. Joules Verne says:

R. Gates says:
February 8, 2012 at 7:32 am

“Maybe the debate has move on to this new area of discussion among the woefully uninformed, or willfully ignorant– but that’s it.”

The debate has moved on but not from how much to whether or not. It’s moved on from how much to how much where and when. The timing of the movement is more or less aligned with frame changes going from “global warming” to “climate change” to “climate disruption”. It has also moved from whether or not it’s catastophic change to whether or not it’s beneficial change. The next change is going to be the undershorts of the rent seeking climate boffins and political toadies when angry crowds of unwashed masses who realize they’ve been duped start looking for some payback.

85. Russ in Houston says:

Joules Verne says:
February 8, 2012 at 9:13 am

Are you absolutely sure that IR has the same properties of a photon?

86. R. Gates says:

DirkH. said:

“But while we have examples of quick onset of glaciation, we don’t have examples of quick onset of, let’s call it “Hothouse Earth” phases.”
____
Not true at all. The end of 8.2 ky event as well as the warming preceeding and ending the Younger Dryas period were both quite rapid. The switch on and off, into and out of warming and cooling episodes can be just as steep on both sides. Ice core data is pretty clear on this point.

87. R. Gates says:

Ged says:

“The fact RH has gone down is the same as saying the planet’s air is getting dryer.”
____
Again, all that really matters in regards to the greenhouse effect from water vapor is the total number of water vapor molecules in the atmosphere. RH might certainly be correlated (or not, depending on temperature) but it doesn’t tell you what you really want to know. How many molecules of water vapor are in the atmosphere now, versus 50, or 150 years ago?

88. Smokey says:

R. Gates says:

“…the warming preceeding and ending the Younger Dryas period were both quite rapid.”

But CO2 had nothing to do with it. Nothing. And since your entire reason for being here is your belief that CO2 will lead to runaway global warming, where does that leave you?

89. R. Gates says:

RobW says:
February 8, 2012 at 9:43 am
@R. Gates,

“Bottom line: to suggest that the radiational saturation effect of CO2 in any way suggests that tipping points can’t exist in the climate system is wrong thinking”

So once again Mr Gates. Please explain how ancient earth (500 million years ago, and 120 million years ago) atmosphere did not go over any tipping point when the atmospheric CO2 levels were 6-20 times the present levels. The laws of physics did not change over this time period so either the feedbacks are in fact negative or what?

_____
I think you are equating “tipping point” with run-away greenhouse. There are many tipping points in any chaotic system, each one with the potential of sending the climate toward an attractor, or new center of oscillation. These potential attractors will change over time based on the whole nature of the system (i.e. strength of the solar output, location of continents, greenhouse gas concentrations, level of volcanic activity, location of the solar system in the galaxy, etc.). It might be the case that there is no attractor close by now, or any time in Earth’s distant past where a run-away greenhouse Earth is possible. But this really isn’t the issue related to whether or not adding CO2 (in a geologically rapid manner) as humans have done could tip the climate system toward some new (i.e. very non-Holocene like) attractor. This attractor could be beneficial, or not, for the human species. Our large brains and ability to adapt might easily overcome a new climate, or not.

The essential point is that in no way does the radiational logarithmic nature of CO2 saturation imply any certainty that some “tipping point” can’t be crossed by the climate system as CO2 saturation rises. Tipping points are inherent in every non-linear chaotic system, and the climate is not immune.

90. R. Gates says:

Smokey says:
February 8, 2012 at 12:17 pm
R. Gates says:

“…the warming preceeding and ending the Younger Dryas period were both quite rapid.”

But CO2 had nothing to do with it. Nothing. And since your entire reason for being here is your belief that CO2 will lead to runaway global warming, where does that leave you?
____
I’ve never once stated that I believe that CO2 will lead to runaway global warming. Why do you insist on misrepresenting what I say? In regard to the Younger Dryas event, the exact cause of this rapid cooling was related to the rapid warming that preceeded it. To state that CO2 played no roll in this warming is to state something you can’t possible know. CO2 levels were rising at the time as the world was warming from the last glacial period. What roll that the additional CO2 did or did not play in the warming remains to be discovered.

91. Smokey says:

Gates says:

“There are many tipping points in any chaotic system, each one with the potential of sending the climate toward an attractor, or new center of oscillation.”

If Gates knew what he was talking about he could call turns in the stock market. If he doesn’t know what he’s talking about, he can post here.

92. Joules Verne says:

The lack of understanding of basic physics displayed in this commentary is the pigment in the paint climate boffins use to portray AGW skeptics as knuckle-dragging throwbacks to pre-enlightenment times.

Just sayin’…

93. Joules Verne says:

Russ in Houston says:
February 8, 2012 at 11:38 am

Joules Verne says:
February 8, 2012 at 9:13 am

“Are you absolutely sure that IR has the same properties of a photon?”

At the scale of individual CO2 molecules, you bet.

94. Peter Foster says:

This study was conducted on data from land based stations, would you get the same result over the ocean? Logic tells me no, but have any studies been done, particularly from Pacific islands in the tropics ?

95. The water vapour feedback is determined in the upper atmosphere at about the 400 mbar level or 8 km altitude, mainly over the tropic. This is the location of the predicted but missing tropical troposphere “hot-spot” that has been widely discussed.

If you want to know how increasing CO2 affects water vapour at this level, you need a plot of water vapour specific humidity versus CO2. See:
http://www.friendsofscience.org/assets/documents/FOS%20Essay/Climate_Change_Science.html#Water_vapour

Please look at the 8th plot labeled “Specific Humidity at 400 mbar vs CO2 – Tropics Annual Data 1960 – 2011”. The blue curve shows declining specific humidity with an coefficient of determination R2 = 0.713. (The 13-month filtered monthly plot has R2 = 0.719) The high R2 factors show that the data correlates very well with the linear trend. The annual data and the 13-month filter removes the seasonal signal. This confirms that to a large degree, CO2 replaces water vapour in the upper atmosphere, just where it has the greatest effect on out-going radiation.

Compare this to the next graph, labeled “Specific Humidity at 400 mbar vs Temperature – Tropics Annual Data 1960 – 2011”. The climate models assume that water vapour changes only in response to a temperature change. If this were true, this graph should show a very strong correlation of increasing humidity with temperature. The graph is a phase space plot of the data points connected in time sequence. Over short time periods, especially over a season, an increase in temperature causes an increase in specific humidity. The annual data shows linear striations increasing from bottom left to top right, confirming that higher temperatures relate to higher specific humidity over short time intervals. But the overall trend is down, proving that specific humidity is responding to factors other than temperature. This graph which tests the climate model assumption has a very poor correlation of 0.014, and the trend is declining rather than climate model assumption of increasing with temperature. The climate model assumptions are wrong!

To see how this relates to climate sensitivity, see:
http://www.friendsofscience.org/index.php?id=533

Ken Gregory

96. Philip Bradley says:

Scotish Sceptic says:

Vegetation grows by evaporation. It sucks up ground water that would otherwise flow into rivers and pushes it into the air. Take away the vegetation, leave a field ploughed for a few months, cut downt the trees for lower vegetation, and the amount of vaporation decreases leading to rising temperature.

That is why “Urban heating” starts at population densities as small as a few 10′s of people per square kilometer. It’s not the people, so much as what the do to the vegetation.

One curious aspect of the climate debate is that people extrapolate globally what happens locally to them.

Here in Perth, Australia we have the opposite, which I call the Urban Irrigation effect.

People irrigate their gardens, which directly increases atmospheric water vapour and indirectly increases WV by promoting growth of leafy plants and trees that transpire far more than the native plants.

It’s quite striking at this time of year, Gardens are green and lush, but native bushland is brown, grey with just large trees with pale green leaves.

So I agree with the conclusion that urban effects are largely due to what we do to the vegetation.

97. Philip Bradley says:

Statistically significant warming trends affecting the Midwestern U.S., Canadian prairies and the western Arctic are evident in winter and to a lesser extent in spring while statistically significant increases in water vapor pressure occur primarily in summer for some stations in the eastern half of the U.S.

If the warming is in the winter/spring and the WV changes are in the summer, clearly there is no causative relationship. Ie, no evidence for a +ve water vapour feedback.

The only way they can be related is through a common cause and that common cause is likely decreasing aerosols, which would produce both these effects..

98. little polyp says:

response to ged

good question

does dryin’ air mean less precipitation too ?

99. kwinterkorn says:

To those who dispute the notion of Greenhouse gases: The Laws of Thermodynamics only require that net heat energy flow must be from warmer to cooler. The Laws do not require that all energy flow must be in the same direction, only that net flow is from warmer to cooler. There can be a large upward energy flow from a warm surface into cool air by conduction, convection, and radiation, all occuring at the same time. Yet at each point in the air, radiation emission will occur in a spherical pattern—-ie, in all directions equally. That part of the radiation directed at the surface will transfer energy back toward the surface. Some heat will come back toward the surface, even though the net energy flow must be from warmer to cooler.

The overall effect of the various flows of energy cannot be to heat the warm surface by energy from the cool air. Indeed, the warm surface will, on the whole, transfer heat to the cooler air (which will then, overall, radiate that energy to space) as required by the Laws of Thermodynamics. However, the rate of transfer will be slowed somewhat by the “back radiation”, resulting in a longer “dwell time” for that energy in the system. The equilibrium energy content of the surface and air system together will rise. Voila! The Greenhouse effect.

Stated in other words, any process that slows the escape of heat from a system will result in that system having a higher temperature than otherwise. The atmosphere has gases that produce such an effect for the Earth.

This does not mean that the Greenhouse Effect is large nor that rising CO2 is going to cause catastrophic global warming.

100. MODTRANs does not show the full effect of carbon dioxide. The 2.94 W/m^2 per doubling of CO2 is widely said to be low.

Even Dr. Roy Spencer appears to me to go along with the IPCC figure of 3.7 W/m^2 per doubling of CO2.

However, that does not change the logarhythmic nature of how CO2’s effect varies with concentration of CO2.

As for the drop in relative humidity: In the graph here, most of that occurred so abruptly that it suggests a change in instruments or methods. I would not be surprised by a gradual drop in relative humidity, especially if concentrated to a time period from the early 1970’s to the middle of the last decade, should the cloud albedo feedback turn out to be positive. That is one reason I expect the sum of the water vapor and cloud albedo feedbacks to be less than IPCC expectations.
Another is that what they mention for the cloud albedo feedback sounds strangely high to me – higher than the surface albedo feedback last time I checked.

101. R. Gates says:

Smokey says:
February 8, 2012 at 12:38 pm
Gates says:

“There are many tipping points in any chaotic system, each one with the potential of sending the climate toward an attractor, or new center of oscillation.”

If Gates knew what he was talking about he could call turns in the stock market. If he doesn’t know what he’s talking about, he can post here.

_____
If I could call turns in the market, you wouldn’t want me posting here?

Hmmm…

Calling “turns” in the market is a bit of a fools errand. Best to do what the smart money (i.e. insurance companies and other big investors) do and bet both sides of the market, (a straddle) switching your “long bet” based on the over-bought or over-sold condition in the market. The insurance companies love to sell annuities to you, giving you your measely 5, 6, or 7% returns, while they are betting against you all the time with your money. If the market goes up, they’ve made a tidy return, if the market goes down, they make an absurd return. They dine on fine food and wine, and will gladly give you the table scraps.

The smart money doesn’t try to time turns in the market. They know there will be turns, and they’ll be there to collect on them…all the while, using your money to bet with. A pretty good gig. Those of you in the insurance business–especially the business of selling “annuities” know exactly what I’m talking about. They leverage your money into tidy profits, and could give a wit about “timing the market”.

102. Bill Illis says:

Daily UAH lower troposphere temperatures fell to -0.415C on January 21, 2012.

Water vapour levels must have, likewise, fallen off a cliff. The 3 month lag of the ENSO to water vapour levels and temperatures means that the peak low levels should not be reached until the last part of April, 2012.

103. jjthoms says:

Robert Brown says: February 8, 2012 at 9:25 am
IR spectra taken by satellites simply let you identify the parts of the spectrum that act as radiative “insulation”, and slow the transmission of heat so that it eventually comes out of the Earth itself from cold matter up high instead of warm matter down low. End of story.
=========
spectral plot of MEASURED IR up and IR down is here:
http://www.patarnott.com/atms749/powerpoint/ch6_GP.ppt

==========
Doug Cotton says: February 8, 2012 at 6:31 am
Then there is evaporation of oceans to form clouds and rain. Where does that energy come from if it wasn’t the result of the Sun warming the oceans? What I cannot accept is any concept of radiation from a cooler atmosphere warming a warmer surface.
==========
Please have a look at these real world documents and then see if you can still say this.
Figure 3 in this document
shows the measured IR downwards over a few days and nights.
We know the solar output received in the dark is 0
We know that O2 and N2 have very very very little thermal radiation.
So where does all that downward radiation come from (at least 270W/sqm)
It can only be from GHGs.
During the day we receive about 380W/sqm
So the 270W/sqm is additional to the solar irradiance.

Would anyone care to explain where the night time radiation is coming from if GHE is non existent? Note that the nighttime radiation is only 100W/m^2 less than the day (when the sun is beating down!). Since this radiation is positive and hitting earth can you tell me how this does not increase the temperature over what would be present if no GHGs and night time radiation as zero?.
Also have a look at another real world measurement:
Downward longwave irradiance uncertainty under arctic atmospheres: Measurements and modeling
http://www.slf.ch/ueber/mitarbeiter/homepages/marty/publications/Marty2003_IPASRCII_JGR.pdf
Figure 2
sometimes more downwelling radiation at night! Please explain without GHGs.

104. The published paper “Surface Water Vapor Pressure and Temperature Trends in North America during 1948-2010”, which is the subject of this post, is not very useful because it describes water vapour pressure trends, which is the total water vapour in the atmosphere, the vast majority of which is near the surface. But changes of water vapour near the surface has very little effect on out-going radiation, therefore has little effect on the greenhouse effect.

Our test using HARTCODE (a line-by-line radiative code developed by Miskolczi) shows that reducing the amount of water vapour in a layer at the 307 to 423 mbar lever ( 8 to 9 km altitude) by 20% has 31 times the effect on out-going radiation as the same absolute change of water vapour in a layer next to the surface (848 to 1013 mbar). The actual humidity near the surface is about 20 times greater than that in the upper atmosphere layer, so a percent change of specific humidity in the upper atmosphere layer has 50% more effect on out-going radiation than a percent change of specific humidity in the surface layer. It matters where in the atmosphere the water vapour changed. The change of total surface water vapor pressure tells us nothing about where the change occurred!

In the topics 30 N to 30 S, the specific humidity at 400 mbar best fit line has declined by 0.11 g/kg, or 13%, from 1960 to 2011.

105. William M. Connolley says:

Ged> For there to be a water vapor feedback, relative humidity must stay the same or raise with temperature.

No. What matters is absolute humidity, not relative. It is the interactions of the photons with the molecules that matter, which depends on the number of said H2O molecules; the photons don’t care about how many there are relative to how many there could be.

The point about sfc vs upper air is a good one. I think the pic that KG provides from the FoS is dodgy; humidity measurements from radiosondes are difficult, and unlikely to be consistent over time (oh, and “The climate models assume that water vapour changes only in response to a temperature change” is wrong, as is apparently any statement about GCMs made by skeptics here :-).

Total column WV over the oceans is shown here: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-4-2-1.html Upper troposphere is more complex; see http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-4-2-2.html but you won’t like it.

106. maxberanMax Beran says:

I don’t agree with R. Gates when at February 8, 2012 at 7:29 am he writes:

“The notion of tipping points isn’t at all related to the logarithmic saturation effect of CO2 in the atmosphere, nor its effect specifically on increase water vapor as a positive feedback effect. Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor. One must look at the whole system to see how just a little nudge can cause a big change– this is the essence of Chaos. ”

Where the notion of a tipping point enters this current issue is the speculation that the feedback factor (forcing multiplier due to added water vapour molecules per each added CO2 molecule) approaches unity and a runaway ensues. Obviously this paper lends force to the contrary view by reducing the number of water vapour molecules per new CO2 molecule to below where it was previously thought. And in that entirely linear (non chaos) sense a tipping point is even more improbable.

A small nudge causing a big change is the essence of “Catastrophe” rather than Chaos. The point of chaos is that there is no knowing what might lie the far side of a switch to a new attractor; it might equally be benign.

107. Max Beran says:

I don’t think anyone has risen to William M. Connolley’s bait where at February 8, 2012 at 2:36 am he writes:
“No. The GCMs make no assumption of fixed relative humidity. That is an emergent property, approximately.”
It certainly has been my understanding that RH was assumed fixed for want of any better data. Or if it wasn’t explicitly fixed its value was closely predetermined by other assumptions. Anyone here know better? Have things changed as modelling has progressed?

108. William M. Connolley says:

It is amusing that you see information and correction of errors as bait. What, I wonder, will you do when you realise that what you have always assumed – indeed, what everyone here seems to assume – turns out to be wrong? Reject the information, I suppose.

“The sensitivity of free-tropospheric relative humidity to cloud microphysics and dynamics is explored using a simple 2D humidity model and various configurations of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 3 (CAM3) atmospheric general circulation model (AGCM)… Relative humidity R simulated by the AGCM was insensitive to surface warming. Doubling a parameter governing cloud water reevaporation increased tropical mean R near the midtroposphere by about 4% with a realistic circulation”

What is found from the GCMs (and from theoretical studies) is that you expect RH to stay roughly constant. But this is, as I say, an emergent property: it isn’t an assumption. Similarly, the climate sensitivity is emergent, not built in.

> the speculation that the feedback factor… approaches unity and a runaway ensues

It won’t happen.

109. beng says:

****
Robert Brown says:
February 8, 2012 at 9:25 am

So don’t get hung up on radiation going up or down, convection or conduction, winds or global oscillations, heat going from warmer to cooler or vice versa, or anything like that. Those things may affect the way the GHG-moderated GHE works, but they do not have any bearing on the question of whether it works at all. All that matters for the latter is the picture of the outgoing radiation that actually cools the Earth — and is the only way heat actually leaves the Earth, so you can completely, totally ignore 100% of the details of how heat moves around the Earth’s surface before eventually being radiated away. That picture leaves one with absolutely no doubt that CO_2 in the upper troposphere is part of the “well-insulated roof” (where the water window is part of the “poorly insulated roof” where the entire spectrum is “the roof”) that one way or another slows the flow of input energy out of the troposphere and hence raises the average temperature of the house beneath the roof.
****

Good explanation that any engineer should understand. The “back-radiation” aspect is technically correct, but perhaps not intuitive. For me, the “insulation” analogy is much more intuitive.

110. R. Gates says:

maxberanMax Beran says:
February 9, 2012 at 5:18 am
I don’t agree with R. Gates when at February 8, 2012 at 7:29 am he writes:

“The notion of tipping points isn’t at all related to the logarithmic saturation effect of CO2 in the atmosphere, nor its effect specifically on increase water vapor as a positive feedback effect. Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor. One must look at the whole system to see how just a little nudge can cause a big change– this is the essence of Chaos. ”

Where the notion of a tipping point enters this current issue is the speculation that the feedback factor (forcing multiplier due to added water vapour molecules per each added CO2 molecule) approaches unity and a runaway ensues.
_____
If this discussion was about only one specific type of tipping-point, then my apologies. The title of this blog says “tipping points” (plural). There can be many tipping points along the way in the saturation of the atmosphere with CO2. Runaway greenhouse is only one, and probably one of the most unlikely.

111. Don Harvey says:

Joules Verne, Robert Brown; this is an interesting read, the article and the comments included. To Joules point, if you have a wide-mouth Dewar flask (thermos bottle) on a clear night, low humidity, put a few cc’s of water in it, stretch some plastic wrap over the top (polyethylene is best) and set it on a table outside. After a while, the water will freeze solid because the Earth is about 300K and space about 2K. The water in the Dewar becomes essentially an IR detector and reaches some equilibrium with the field of view. Because of water vapor (humidity), Houston stays warmer at night compared to Austin or El Paso.

Regarding the effects of CO2 on warming, the article is correct in that as a GHG, CO2 is nearly saturated, that is to say, more CO2 makes little difference in the effects of the gas. CO2 and water vapor, in the wavelengths that they absorb, also emit. Using a simple NDIR (non-dispersal Infrared) detector with a bandpass filter for CO2 for example (4.26 micron), one can both detect the absorption of the gas in a system and also the emission of the gas. If the gas is warmer than a reference, the signal from the detector goes up which means that the gas is losing heat and perhaps has transferred heat, when the signal goes down it absorbs heat and energy, However, in a system, the heat of the gas is the temperature of the gas times its partial pressure and specific heat. So, perhaps, if there is more CO2 in the upper atmosphere which emits at both 10 microns and 4.26 microns, and since because of the blackbody curve 10 microns is the emission peak of 300K, and since the Earth’s emission peak is also 10 microns, there is a transference of heat from the Earth to the CO2 in the atmosphere, which is then radiated out to space. Warm CO2 will radiate energy out into space and will be a conductor of heat within the system.

Water on the other hand can be a bigger warming gas because it absorbs at many wavelengths at both short and long. Hydrocarbon gases like methane (natural gas) is very dangerous because the atmosphere is not close to being saturated and methane is a efficient absorber of IR. I think it is interesting that Earth, to have survived with life forms for so long, would have a CO2 cycle or mechanism to balance the good v. the harm it can do respecting life. I think water vapor is part of the mechanism.

The anecdote I observed for years now, and since I viewed the graph of water vapor v. relative humidity shows that my observations are in sync with the data, that is, with increasing water vapor and CO2, vegetation growth has been noteworthy in that we have better lawns. I need to prune my orchard more, have better crops, and the general landscape is greener (in New Hampshire) than it was in the late ’60’s when summers were very hot and dry and winters not so much back then. Perhaps with a slight increase in CO2 vegetation growth will sequester carbon as fast as necessary to maintain a healthy balance. I think a study of tree growth in terms of regional volume (which would include stocking) done while taking into the calculation the history of water vapor, rainfall, and total water in the system would be instructive. I think with a slight increase in temperature, water, and CO2 there is much more vegetative growth. Isn’t that what greenhouse managers do? I think in the environment it all balances out or there would be no life on planet Earth presently.

112. phlogiston says:

R. Gates says:
February 8, 2012 at 7:29 am

Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor.

This is patently untrue. While the IPCC pays lip service to chaos / nonlinear theory, tipping points are presented as purely linear positive feedbacks. There is absolutely no formulation of any nonequilibrium system pattern, attractors or jumping between attractors. Mainstream AGW theory ignores nonlinear / nonequilibrium pattern processes entirely. Your musings on the subject consist of arm-waving only and are not part of the central AGW narrative which is rigidly linear.

113. So not only does “snow” not tend to melt on a well insulated roof it will form frost on it even when air temperature is far above freezing. This was an object lesson for me in the power of radiative cooling on dry clear nights although I hadn’t quite forgotten many camping trips to the high desert at Joshua Tree National Monument in the 1970′s and 1980′s outside Palm Springs where you’d roast by day and freeze by night.

Good luck trying to teach the rudiments of why these phenomenon happen when your students aren’t paying through the nose to hear you talk. I’ve had no luck at it. As Yogi Berra said “You can observe a lot by just looking.” Most people see without actually looking, it seems.

One can actually make ice cream at night in the desert, even in the summer, by making your custard and pouring it in a thin layer into a flat pan well-insulated from below, on a very still night with low humidity. The roast by day, freeze by night is nearly standard operating procedure in e.g. the Sahara, where they have 45 degree temperature swings every day.

As for your second remark, I don’t have much luck getting people to learn when what I am teaching fails to coincide with their prior beliefs. Not just on this blog, this is a lifetime observation. I’ve spent — err, really “wasted” — countless hours trying to convince BICCs (Biblically Inerrant Conservative Christians) that the Universe is a bit older than 10,000 years and that we evolved. Trying to explain radiometric dating to them is a real treat, when they are perfectly happy to assert that God just changed the laws of nature so it looks like some rocks are really old and the light of the stars is coming from really far away, but if we really got those laws right we’d get the right answers, namely that the rocks are all antediluvian and perhaps 6000 years old.

Sounds a lot like climate arguments — on both sides. Me, I favor the side(s) supported by the laws of physics the way they are already worked out, until really proven otherwise;-)

rgb

114. R. Gates says:

phlogiston says:
February 9, 2012 at 9:22 am
R. Gates says:
February 8, 2012 at 7:29 am

Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor.

This is patently untrue. While the IPCC pays lip service to chaos / nonlinear theory, tipping points are presented as purely linear positive feedbacks. There is absolutely no formulation of any nonequilibrium system pattern, attractors or jumping between attractors. Mainstream AGW theory ignores nonlinear / nonequilibrium pattern processes entirely. Your musings on the subject consist of arm-waving only and are not part of the central AGW narrative which is rigidly linear.
_____
I was responding to the notion that the plural “tipping points” as used in the title of this blog post only refers to a single thing– runaway greenhouse warming. It is this, that is patently untrue.

115. Bart says:

I’m going to repost this comment from another thread here, because it is very relevant to this thread.
————————————————————–
This is where the analogy gets interesting. Suppose the dam is infinitely high, but it has two rows of floodgates in it. One, at low level, we will call the CO2 floodgates. One, at higher level, we will call the CH4 floodgates.

The water rises until it starts flowing out of the CO2 floodgate. But, the outflow isn’t enough to establish equilibrium before this row is saturated, so the water keeps on rising. Eventually, it reaches the level of the CH4 floodgates. Here, the water has enough of an outlet that the level stabilizes.

Now, we add more CO2 outlets. To make the analogy fit, let’s assume that we had to raise the level of the CO2 floodgates a bit to fit more in. If the CO2 floodgates had previously been sufficient to allow an equilibrium level to be established, that equilibrium level would be pushed higher.

BUT, since the level previously rose to the CH4 gates, and we put more CO2 gates in below that level which are now able to remove higher volumes of water, the equilibrium level will go down.

I hope maybe this analogy will get a read from some people who did not understand what I was talking about on an earlier thread.

Adding CO2 does not necessarily raise surface temperature, because there are other radiative emitters in the atmosphere which have interacted to create the equilibrium temperature.

116. G. Karst says:

jjthoms says:
February 9, 2012 at 3:47 pm

The delay obviously increases the energy in the earth system by TSI*time. Is this insignificant?

That is exactly the question everyone is arguing. The warmist hold that the effect is catastrophically significant while the realistskeptic hold that it is insignificant or made insignificant, by other negative feedback/forcing(s). Since GMT has plateaued effectively 15 yrs, when CO2 emissions are increasing indicates the portion of GHE due to CO2 is insignificant or at least, such a very low sensitivity value, as to appear insignificant.

Water in the atmosphere exists in all phases ice, vapor(gas), liguid, as well as various isotopes – light (H2O), heavy (D2O), and radio (T2O). It is not a trace gas but a overpowering, driving component. In it’s cloud form it will regulate climate on it’s own dynamics. These dynamics may respond to CO2 IR broadening or cosmic ray seeding, but quantification has been a tease so far. You, like everyone else, must decide the weight of evidence or lack of evidence. I think you will find the CO2 “glove” does not fit. GK

117. I was going to ask whether anybody had mentioned Venus. Apparently somebody did, but that mention didn’t make a lot of sense.

The greenhouse effect does not “saturate”. It’s easy enough to demonstrate theoretically using a grey atmosphere approximation. And otherwise you need a really weird woo theory about Venus.

118. Bart says:

Michael Tobis says:
February 10, 2012 at 6:26 am

‘The greenhouse effect does not “saturate”.’

“Saturation” means the sensitivity to additional amounts tends to zero. Venus actually proves that saturation happens. Despite being 97% CO2, the major greenhouse effect comes from the much smaller concentration of SO2.

119. jjthoms says:

Bart says: February 10, 2012 at 9:25 am
“Saturation” means the sensitivity to additional amounts tends to zero. Venus actually proves that saturation happens. Despite being 97% CO2, the major greenhouse effect comes from the much smaller concentration of SO2.
=================
There are 70 atmospheres of pressure broadening the spectral lines of all GHGs on Venus!! “Saturation” will occur later SO2 is one of the GHGs there are many in the venusian atmosphere including H2O at 100ppm

120. Bart says:

jjthoms says:
February 10, 2012 at 3:19 pm

I found a plot a few weeks back of emissions from the Venusian atmosphere. Sorry I cannot provide a link, but I didn’t mark it and cannot find it. But, it showed that the major gap taken out of the underlying blackbody spectrum was in the SO2 range. The CO2 gaps were comparatively negligible.

121. Spector says:

The one critique that I have of the graphs presented above is the use of a linear instead of logarithmic scale on the carbon dioxide concentration factor. Of course David Archibald, in his “The Fate of All Carbon” article indicates that there may not be enough economically recoverable, combustible carbon remaining on Earth to ever bring the carbon dioxide concentration up to 560 ppm–just double the nominal pre-industrial concentration level.

As late as three years ago, many otherwise intelligent people in positions of power believed that there was an urgent need to cut carbon dioxide emissions by eighty percent before 2050 to prevent the destruction of our environment. It looks like resource depletion will eventually do this anyway. I believe we should now be preparing for the gradual loss of fossil or abiotic carbon as a source of energy while we still may have time to make a gentle transition, rather than worrying about a non-existent, super-accelerated, greenhouse effect.

122. The story as I understand it so far:
CO2 main absorption spectral lines are already stopping nearly all the LWIR in those bands from freely escaping the atmosphere.
However, there is spectral broadening caused by pressure and Doppler shift. It is these lobes that are now increasingly absorbing IR giving the presumably log effect.

I don’t think this is the major factor, although I could be mistaken. Pressure broadening depends on absolute pressure, not partial pressure (it’s related to the mean free time between collisions, and the collisions don’t have to be with other CO_2 molecules but with any molecules), and that isn’t really changing at all. Doppler broadening depends on temperature, so this is one degree of feedback removed from the increase in the GHE caused by increased concentration, a second order (but positive feedback) effect.

My understanding is that the increase comes strictly from raising the tropopause — or rather, raising the height above the ground where the atmosphere becomes sufficiently optically transparent to allow radiation from CO_2 molecules to actually escape to space. The higher the cooler, the cooler the greater the net GHE. There is considerable evidence for this — one of the reasons for El Nino warming is that it is a breathing mode atmospheric oscillation that lifts the tropopause and hence actually does increase greenhouse trapping, allowing for positive feedback amplification of the warming itself, for example.

The problem with this is that the tropopause isn’t like a CO_2-trapping plastic balloon between the troposphere and the stratosphere, so that taking partial pressure/net concentration of CO_2 inside the balloon from 280 ppm (0.03%) to 340 ppm (0.03% — ooo, looks like I need more significant figures, don’t I) isn’t going to blow the balloon up by, well, 0.006%, and if it did, the radiation would be cooled by an additional amount determined by the DALR (in the troposphere) of ~9K/km. If we assume the troposphere is a generous 20 km thick, and the tropopause went up linearly with CO_2 concentration (most unlikely), then the entire increase since the beginning of the industrial era would have raised the mean temperature at the tropopause by 0.01 K.

It’s not quite this simple, of course — the direct effect is so low that the second order effects might be comparable. However, those effects are far, far more powerfully modulated by things other than CO_2 concentration. The decadal oscillations move the troposphere up or down by gross amounts compared to the meter or so predicted by a simple linear model. The location of the tropopause and the stratosphere itself is highly multifactorial — in a way it is self-consistently determined just where the CO_2 does indeed start to radiate, producing a cool layer followed by a lateral transport layer in between the warm ground and the hot thermosphere. I have yet to hear a convincing argument (with actual empirical support) for why the GHE should be significantly modulated by further increases in atmospheric CO_2 once saturation has occurred. If the speculations in the top article are correct — and there is reason to think that they are, it isn’t some sort of violation of the laws of physics to think that they might be — the evidence suggests that macroscopic modulators of the Earth’s atmospheric dynamics are far more important for determining the location of the tropopause and optical radiation zone than concentration.

One can photograph the GHE in action in the form of LWIR spectra at the top of the atmosphere. However, we do not have anything like a sufficient baseline of data to identify specific changes wrought by increased CO_2. Everything is confounded by far larger secular oscillations and negative feedbacks throughout the system.

Note well that one needs large changes in the tropopause to significantly change the ground temperature. The CO_2 band is already “cold”, and the rate of power loss per square meter goes like $T^4$ (and is only active in one moderate sized band in the overall radiation spectrum). A tiny increase of radiative temperature at the Earth’s surface can compensate for a far larger decrease of radiative temperature at 20 km. One needs to make the CO_2 at the tropopause many degrees colder, on average, everywhere, to make the surface one degree warmer, on average, everywhere and just the shift from DALR to WALR — which moves the lapse down and warms the tropopause utterly confounds CO_2-based increases; the feedback from more water in the atmosphere due to CO_2 based warming should strictly be negative, warming the CO_2 at the very place where it is radiating away its heat.

This is why I think that it is very, very wrong to try to explain the GHE in terms of “upwelling” or “downwelling” radiation. This is a false heuristic from the beginning. All that matters is the top of atmosphere spectrum, selective spigots on the outflowing radiation, the height/temperature where the atmosphere becomes transparent (enough) to it, and the lapse rate that self-consistently establishes the relation between height and temperature, the location of the tropopause, and so on. One cannot separate out an imagined individual variable in the multivariate nonlinear system like “downwelling radiation”, assert that it is responsible for “warming” the surface, and then solve a detailed balance equation for the surface pretending that what happens there somehow depends on what’s going on at 20,000 meters via a direct process with no complexity.

I think that there is very probably an extremely simple mathematical statement of the GHE that eliminates all of the arguable detail and permits one to directly numerically focus on a semi-empirical heuristic. If I live long enough and every have free time again, maybe I’ll look for it.

rgb

123. Bart says:

Robert Brown says:
February 13, 2012 at 9:03 am

“Doppler broadening depends on temperature, so this is one degree of feedback removed from the increase in the GHE caused by increased concentration, a second order (but positive feedback) effect.”

There is also a potential negative feedback effect in the fact that a broader distribution is able to radiate energy away at lower wavenumber. That means the surface temperature does not have to be as high to balance the energy radiating away from the planet.

And, there is another negative feedback from higher concentration, and that is that less energy needs to radiate away from higher energy emitters like CH4 in order to achieve balance, so again, the surface temperature does not have to be as high to balance the energy radiating away from the planet.

124. There is also a potential negative feedback effect in the fact that a broader distribution is able to radiate energy away at lower wavenumber. That means the surface temperature does not have to be as high to balance the energy radiating away from the planet.

And, there is another negative feedback from higher concentration, and that is that less energy needs to radiate away from higher energy emitters like CH4 in order to achieve balance, so again, the surface temperature does not have to be as high to balance the energy radiating away from the planet.

Yeah, I admit to being frankly puzzled as to how one can believably estimate — not even compute, just estimate — the straight up GHE warming expected in response to CO_2. I’m really puzzled by the assertion that feedback from non-CO_2 channels will produce 3-5x as much warming as the CO_2 alone. This strong positive feedback could hardly fail to leave its mark in the dynamic responses to non-CO_2 related thermal fluctuations, characterized by extremely rapid warming, very slow cooling not just globally but locally. Yet global temperatures flow along according to seasonal norms, and seem if anything remarkably stable given the complexity of the climate system.

But I think the really big error is that they are probably getting the sign wrong for the feedback from water vapor, asserting that it is the big positive when it is really very likely a weak negative (or at worst, weak positive). The bottom line is that the data from the thermometric era alone (the last 150-160 years) suffices to solidly reject the more extreme of the positive feedback hypotheses. The “Catastrophic Window” is steadily narrowing.

rgb

125. Bart says:

Robert Brown says:
February 13, 2012 at 10:36 am

I’m with you all the way, there.

“I’m really puzzled by the assertion that feedback from non-CO_2 channels will produce 3-5x as much warming as the CO_2 alone.”

Confirmation bias. There was warming, and they were sure they had the culprit, so they misapplied the logic of a pulp fiction detective:

When you have eliminated the impossible, whatever remains, however improbable, must be the truth.

Only if you have a full set of potentialities, of course. They’d have been better advised to take heed of another quote from the same source:

It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

126. @jjthoms…

Regarding your comment on backradiation recorded with pyrgeometers, I have been measuring downward radiation during nighttime and daytime and I can assure you that it is not thermal radiation emitted by the atmosphere. Any dome made with polished aluminum produces the same results. I have found serious deffects on the experiment you refered at

http://www.slf.ch/ueber/mitarbeiter/homepages/marty/publications/Marty2003_IPASRCII_JGR.pdf

In brief, the authors do not specify the conditions of the cloudiness. A cloud cover can produce biased results. Any species of clouds damages the results. The objective of the experiment that you referred was not to measure accurately downward longwave radiation, but the efficiency of pyrgeometers. From their results and my results, the sole conclusion is that pyrgeometers are not useful to measure downward radiation.