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
doi: http://dx.doi.org/10.1175/JCLI-D-11-00003.1
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.
@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.
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
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
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.
@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?
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.
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.
@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.
G. Karst says:
February 8, 2012 at 9:33 am
Outstanding.
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?
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.
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.
http://img692.imageshack.us/img692/9803/ensotcwv48jan12b.png
But temperatures, water vapour and the ENSO are all closely tied.
http://img26.imageshack.us/img26/6837/tempsensotcwv79jan12.png
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.
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.
Joules Verne says:
February 8, 2012 at 9:13 am
Are you absolutely sure that IR has the same properties of a photon?
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.
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?
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?
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.
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.
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.
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’…
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.
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 ?
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