Guest essay by Ed Hoskins
Using data published by the IPCC on the diminishing effect of increasing CO2 concentrations and the latest proportional information on global Man-made CO2 emissions, these notes examine the potential for further warming by CO2 emissions up to 1000ppmv and the probable consequences of decarbonisation policies being pursued by Western governments.
The temperature increasing capacity of atmospheric CO2 is real enough, but its influence is known and widely accepted to diminish as its concentration increases. It has a logarithmic in its relationship to concentration. Global Warming advocates and Climate Change sceptics both agree on this.
IPCC Published reports, (TAR3), acknowledge that the effective temperature increase caused by growing concentrations of CO2 in the atmosphere radically diminishes with increasing concentrations. This information has been presented in the IPCC reports. It is well disguised for any lay reader, (Chapter 6. Radiative Forcing of Climate Change: section 6.3.4 Total Well-Mixed Greenhouse Gas Forcing Estimate) [1]. It is a crucial fact, but not acknowledged in the IPCC summary for Policy Makers[2].
 |
The rapid logarithmic diminution effect is an inconvenient fact for Global Warming advocates and alarmists, nonetheless it is well understood within the climate science community. It is certainly not much discussed. This diminution effect is probably the reason there was no runaway greenhouse warming caused by CO2 in earlier eons when CO2 levels were known to be at levels of several thousands ppmv. The following simplifying diagram shows the logarithmic diminution effect using tranches of 100ppmv up to 1000ppmv and the significance of differing CO2 concentrations on the biosphere:
§ Up to ~200 ppmv, the equivalent to about ~77% of the temperature increasing effectiveness of CO2. This is essential to sustain photosynthesis in plants and thus the viability of all life on earth.
§ A further ~100 ppmv was the level prior to any industrialisation, this atmospheric CO2 made the survival of the biosphere possible, giving a further 5.9% of the CO2 Greenhouse effect.
§ Following that a further 100ppmv, (certainly man-made in part), adding ~4.1% of the CO2 effectiveness brings the current level ~400 ppmv.
§ CO2 at 400pmmv is already committed and immutable. So CO2 has already reached about ~87+% of its potential warming effect in the atmosphere.
Both sceptics and the IPCC publish alternate views of the reducing effect on temperature of the importance of CO2 concentration. These alternates are equivalent proportionally but vary in the degree of warming attributable to CO2.
The IPCC have published views of the total effect of CO2 as a greenhouse gas up to ~1200ppmv, they range in temperature from +6.3°C to +14.5°C, shown below:
There are other views presented both by sceptical scientists and CDIAC, the Carbon Dioxide Information and Analysis Centre. What these different analysis show the is the amount of future warming that might be attributed to additional atmospheric CO2 in excess of the current level of ~400ppmv. Looking to the future in excess of 400ppmv, wide variation exists between the different warming estimates up to 1000ppmv, see below.
A comparison between these estimates are set out below in the context of the ~33°C total Greenhouse Effect.
This graphic shows in orange the remaining temperature effect of CO2 up to 1000ppmv that could be affected by worldwide global decarbonisation policies according to each of these alternative analyses.
Some of the IPCC data sets shows very large proportions of the temperature effect attributable solely to extra CO2. The concomitant effect of those higher levels of warming from atmospheric CO2 is that the proportion of the total ~33°C then attributable the water vapour and clouds in the atmosphere is displaced so as to be unrealistically low at 72% or 54%.
It has to be questioned whether it is plausible that CO2, a minor trace gas in the atmosphere, currently at the level of ~400ppmv, 0.04% up to 0.10% achieves such radical control of Global temperature, when compared to the substantial and powerful Greenhouse Effect of water vapour and clouds in the atmosphere?
There are the clearly divergent views of the amount of warming that can result from additional CO2 in future, but even in a worst case scenario whatever change that may happen can only ever have a marginal future effect on global temperature.
Whatever political efforts are made to de-carbonize economies or to reduce man-made CO2 emissions, (and to be effective at temperature control those efforts would have to be universal and worldwide), those efforts can only now affect at most ~13% of the future warming potential of CO2 up to the currently unthinkably high level of 1000ppmv.
So increasing CO2 in the atmosphere can not now inevitably lead directly to much more warming and certainly not to a catastrophic and dangerous temperature increase.
Importantly as the future temperature effect of increasing CO2 emissions can only be so minor, there is no possibility of ever attaining the much vaunted political target of less than +2.0°C by the control of CO2 emissions[3].
Global Warming advocates always assert that all increases in the concentration of CO2 are solely man-made. This is not necessarily so, as the biosphere and slightly warming oceans will also outgas CO2. In any event at ~3% of the total[4] Man-made CO2 at its maximum is only a minor part of the CO2 transport within the atmosphere. The recent IPCC report now admits that currently increasing CO2 levels are probably only ~50% man-made.
On the other hand it is likely that any current global warming, if continuing and increased CO2 is:
§ largely a natural process
§ within normal limits
§ probably beneficial up to about a further 2.0°C+ [5].
It could be not be influenced by any remedial decarbonisation action, however drastic, taken by a minority of nations.
In a rational, non-political world, that prospect should be greeted with unmitigated joy.
If it is so:
· concern over CO2 as a man-made pollutant can be mostly discounted.
· it is not essential to disrupt the economy of the Western world to no purpose.
· the cost to the European economy alone is considered to be ~ £165 billion per annum till the end of the century, not including the diversion of employment and industries to elsewhere: this is deliberate economic self-harm that can be avoided: these vast resources could be spent for much more worthwhile endeavours.
· were warming happening, unless excessive, it provides a more benign climate for the biosphere and mankind.
· any extra CO2 has already increased the fertility of all plant life on the planet.
· if warming is occurring at all, a warmer climate within natural variation would provide a future of greater opportunity and prosperity for human development, especially so for the third world.
De-carbonisation outcomes
To quantify what might be achieved by any political action for de-carbonization by Western economies, the comparative table below shows the remaining effectiveness of each 100ppmv tranche up to 1000ppmv, with the total global warming in each of the five diminution assessments.
The table below shows the likely range of warming arising from these divergent (sceptical and IPCC) views, (without feedbacks, which are questionably either negative or positive: but probably not massively positive as assumed by CAGW alarmists), that would be averted with an increase of CO2 for the full increase from 400 ppmv to 1000 ppmv.
The results above for countries and country groups show a range for whichever scenario of only a matter of a few thousandths to a few hundredths of a degree Centigrade.
However it is extremely unlikely that the developing world is going to succumb to non-development of their economies on the grounds of reducing CO2 emissions. So it is very likely that the developing world’s CO2 emissions are going to escalate whatever is done by developed nations.
These figures show that whatever the developed world does in terms of decreasing CO2 emissions the outcome is likely to be either immaterial or more likely even beneficial. The table below assumes that the amount of CO2 released by each of the world’s nations or nation is reduced universally by some 20%: this is a radical reduction level but just about conceivable.
These extreme, economically destructive and immensely costly efforts by participating western nations to reduce temperature by de-carbonization should be seen in context:
§ the changing global temperature patterns, the current standstill and likely impending cooling.
§ the rapidly growing CO2 emissions from the bulk of the world’s most populous nations as they continue their development.
§ the diminishing impact of any extra CO2 emissions on any temperature increase.
§ normal daily temperature variations at any a single location range from 10°C to 20°C.
§ normal annual variations value can be as much as 40°C to 50°C.
§ that participating Europe as a whole only accounts for ~11% of world CO2 emissions.
§ that the UK itself is now only about ~1.5% of world CO2 emissions.
As the margin of error for temperature measurements is about 1.0°C, the miniscule temperature effects shown above arise from the extreme economic efforts of those participating nations attempting to control their CO2 emissions. Thus the outcomes in terms of controlling temperature can only ever be marginal, immeasurable and thus irrelevant.
The committed Nations by their actions alone, whatever the costs they incurred to themselves, might only ever effect virtually undetectable reductions of World temperature. So it is clear that all the minor but extremely expensive attempts by the few convinced Western nations at the limitation of their own CO2 emissions will be inconsequential and futile[6].
Professor Judith Curry’s Congressional testimony 14/1/2014[7]:
“Motivated by the precautionary principle to avoid dangerous anthropogenic climate change, attempts to modify the climate through reducing CO2 emissions may turn out to be futile. The stagnation in greenhouse warming observed over the past 15+ years demonstrates that CO2 is not a control knob on climate variability on decadal time scales.”
Professor Richard Lindzen UK parliament committee testimony 28/1/2014 on IPCC AR5[8]:
“Whatever the UK decides to do will have no impact on your climate, but will have a profound impact on your economy. (You are) Trying to solve a problem that may not be a problem by taking actions that you know will hurt your economy.”
and paraphrased “doing nothing for fifty years is a much better option than any active political measures to control climate.”
As global temperatures have already been showing stagnation or cooling[9] over the last seventeen years or more, the world should fear the real and detrimental effects of global cooling[10] rather than being hysterical about limited, beneficial or now non-existent warming[11].
References:
[1] http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/222.htm
[2] http://www.powerlineblog.com/archives/2014/05/why-global-warming-alarmism-isnt-science-2.php
[3] http://www.copenhagenconsensus.com/sites/default/files/ccctolpaper.pdf
[4] http://www.geocraft.com/WVFossils/greenhouse_data.html
[5] http://www.spectator.co.uk/features/9057151/carry-on-warming/
[6] http://hockeyschtick.blogspot.fr/2013/11/lomborg-spain-wastes-hundreds-of.html
[7] http://www.epw.senate.gov/public/index.cfm?FuseAction=Files.View&FileStore_id=07472bb4-3eeb-42da-a49d-964165860275
[8] http://judithcurry.com/2014/01/28/uk-parliamentary-hearing-on-the-ipcc/
[9] http://www.spectator.co.uk/melaniephillips/3436241/the-inescapable-apocalypse-has-been-seriously-underestimated.thtml
[10] http://www.iceagenow.com/Triple_Crown_of_global_cooling.htm
[11] http://notrickszone.com/2010/12/28/global-cooling-consensus-is-heating-up-cooling-over-the-next-1-to-3-decades/
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
If you have 3 gases within a system 2 absorping IR at the same energy and 1 gas, inert, makes up 94.06%, a second gas 5% and the third 0.04% what will be the effect of changing the relative volumes say from 5% & 0.04% to 4% & 1.04%. Remember both absorp IR at the same energy and the IR is finite.
An excellent perspective. The entire problem is scientists who are convinced they can represent the atmosphere with mathematical equations, then project it with accuracy out 100 years.
Even if you know all the physical laws and can dial in the known numbers the solutions will only confirm your theory.
The blind spot of global climate models is clouds. Increasing low clouds and decreasing high clouds in real world observations are evidence of a negative feedback.
Increasing low level moisture is greatly underestimated by models from evapotranspiration and trillions of gallons pulled out of aquifers for irrigation and other uses. One might think that since H2O is a greenhouse gas, this would increase warming.
Observations of the US Cornbelt over the last 30 years indicate the complete opposite……….a cooling effect. During the growing season, corn plant populations have doubled during that period. This has created a micro climate, adding tremendous low level moisture from evapotranspiration as well as increasing the vegetative density of the surface.
Higher dew points and a lower lifting condensation level has increased low clouds that form earlier in the day. Less SW radiation means less daytime heating. In addition, there is a positive feedback at work. The resulting increase in rainfall goes back into the soils and are taken in by the plants which continue to contribute to the increase in evapotranspiration.
Meteorologists forecasting for this area of world are very familiar with this significant effect during the growing season.
With CO2 boosting vegetative health across the globe, this same effect is happening on a huge scale but of course with less magnitude than what we see in the Cornbelt.
The magnitude/powerful effect seen here, makes this a massive real world/outdoor laboratory that shows an underestimated negative feedback to temperatures that is occurring on a global scale.
I am often loathe to wholly discount the opinion of experts but evidently CO2 is not able in itself to be the main driver of temperature increase in the future.
I can only assume that feedback loops (eg: water vapour) included in climate models anticipating larger increases somehow multiply the impact of increased CO2. As it is evident the scientific community have only a partial understanding of how these feedbacks work then I can only conclude that there should be limited reliance placed on their projections.
Only when previous changes in climate (recent and historical) have been adequately explained and models adjusted accordingly should we give them greater credence. Even then there is a justifiable debate to be had as to whether it would be worth the economic cost to reduce, or simply adapt.
The measurement uncertainty surrounding the global average radiative forcing, the energy that heats &/or cools the earth, is +/- 5 W/sq m. That’s a total uncertainty bandwidth of 10 W and that’s about +/- 1.5% of a total 340 W/sq m.
Hold that thought.
The radiative forcing attributed to mankind’s CO2 output is 1.6 W/sq m, less than 20% of the uncertainty band. And actually less than that and diminishing.
How can anybody model or predict future warming and climate change based on a number that is completely lost in a data Oort cloud of noise, that is trivial in the normal ebb and flow of the global radiative forcing?
It’s pretty obvious by now – they can’t.
Richard Verney,
Yes all the IR is absorbed in the top three microns of the oceans surface. and the radiation difference between clear sky and a completely overcast sky is ~ 130 watts. Almost as much as the 165 watts of SW radiation claimed by NASA and Trenberth from the sun that passes through the surface.
3 microns over a square meter equals 3 cubic centimeters being heated by 130 watts. A watt is a joule per second and the specific heat is around 4 joules/cubic centimeter so the surface of the ocean should warm at a rate of .7 degrees per second or 42 degrees a minute. Just about like turning on a microwave oven.
That much heat should surely measurably warm the surface when clouds pass overhead shouldn’t it?
Well it doesn’t, I have measured it hundreds of times and there is zero difference in the surface temperature between clear and overcast skies.
The only explanation that I can think of is that evaporation increases in direct response to the increased radiation.
RMB says:
August 10, 2014 at 8:23 am
————————————
It is true that DWLWIR does not slow the cooling rate of the oceans, but your “surface tension” explanation is incorrect. LWIR is absorbed by water, but any heating of the first few microns is offset by evaporation as Gengis and Richard Verney point out.
If your explanation was valid my kitchen should be full of steam evaporating. Its not.
@ur momisugly Terry says:August 10, 2014 at 11:33 am
Because the margin of error for temperature measurements is about 1.0°C
and Man-made CO2 is only 3% of the total
and because water vapor has not cooperated with the concept of fossil fuel CO2 emissions=AGW there should be zero acceptance of any climate model projections which have ultimately failed to project global temperature trend.
davidmhoffer says, August 10, 2014 at 9:51 am:
“The IPCC documentation assumes that this effect is subsumed into the 3.7 w/m2 in the first place. If you can point me to where they say otherwise, I’ll read it. AR4 on the other hand states specifically that radiative forcing cannot be directly equated with surface forcing, and then becomes rather vague as to what value surface forcing should be (but obviously less).”
The ‘lifting the effective emission height (EEH)’ version of the AGW hypothesis doesn’t seem to be dependent on the original increased forcing itself being ‘teleported’ to the surface. It is the temperature rise that’s being linearly extrapolated (along an unchanged lapse rate) to the surface from the level where the increased forcing originated.
So, very conceptually, if we move up about 17000 ft, somewhat less than halfway up the troposphere, we will find the air layer emitting Earth’s atmospheric radiation flux freely to space (it couldn’t be of course, this would have to be at/above the tropopause, but that’s different story), at a mean steady-state temperature of 255K. If we suddenly double the atmospheric CO2 content, we would increase the atmospheric optical depth for outgoing IR and hence lift this ‘effective emission height’ about 500 ft higher. To a layer at 254K, that is, one degree cooler than the ‘old’ EEH.
It is at this point that the 3.7 W/m^2 increase in forcing appears. Stated another way, this 254K layer of air presumably absorbs as much IR coming up from the layers below as before, but emits upwards 3.7 W/m^2 less than before. Somehow because of its lower temperature. Meaning, this layer will have to warm about 1 degree to restore the balance. And it does so from the imbalance itself (more in than out). Once the layer at 17500 ft has warmed by its one degree, this warming can simply be drawn down to the surface via the lapse rate.
Ta-da!
I hate to tell you guys but increasing carbon dioxide in the atmosphere has no effect whatsoever on global temperature. You are simply ignoring the real world when you go through contortions to find out what that logarithmic increase of yours might be. Fact is, there is no warming now and there has been none for 17 years while carbon dioxide steadily increased. This is an experimental observation in conflict with any and all greenhouse theories, linear or logarithmic, that predict warming. Arrhenius greenhouse theory, for example, has been predicting warming for all these years and getting nothing. If you are a scientist and your theory predicts warming but for 17 years you get nothing you are justified in tossing that theory into the waste basket of history. There is a spot reserved for it right next to phlogiston, another failed theory. This may look like not leaving us any greenhouse theory to guide us but that is not true. There is the Miskolczi greenhouse theory (MGT) that IPCC has forbidden anyone to refer to ever since it came out in 2007. Its prediction is exactly what we have now: addition of carbon dioxide to the atmosphere does not warm it. It follows that any warming observed in global temperature records is natural and not greenhouse warming. MGT differs from Arrhenius in that it is able to handle several GHGs simultaneously absorbing in the IR when Arrhenius can handle only CO2 and is incomplete. Carbon dioxide and water vapor are the most importand GHGs in the earth atmosphere. According to MGT they establish a joint optimal absorption window in the IR that they control. The optical thickness of this absorption window in the IR is 1.87, determined by Miskolczi from first principles. If you now add carbon dioxide to the atmosphere, it will start to absorb just like Arrhenius says. But this will increase the optical thickness. As soon as it starts, however, water vapor will begin to diminish, rain out, and the original optical thickness is restored. The newly added carbon dioxide will of course keep absorbing but thanks to this simultaneous reduction of water vapor it cannot cause any greenhouse warming that is imputed to it by Hansen and company. This fact should be verified by independent observations and Miskolczi did that in 2011. Using NOAA database of radiosonde observations that goes back to 1948 he studied absorption of IR by the atmosphere over time and found that absorption had been constant for 61 years. Carbon dioxide in the atmosphere simultaneously increased by 21.6 percent. Constant absorption means no warming. Hence, these data constitute an exact parallel to the warming pause/hiatus we are experiencing now. This fact has wide-ranging consequences. First, it makes a runaway greenhouse warming quite impossible. This is why the very high carbon dioxide amount in geologic history has been unable to cause any runaway warming. Hansen has been warning us that if we do not give up burning fossil fuels a runaway greenhouse effect like that on Venus will destroy us. Unfortunately he is ignorant of Venusian geology too despite having worked as an astronomer on the Pioneer Venus project. Venus has no plate tectonics. Excess radioactive heat on earth is constantly vented by plate boundary volcanism. On Venus it just accumulates beneath the crust and so weakens it that it break apart into giant slabs. These sink into the interior and an entirely new crust is formed every 300 to 600 million years. If Venus is the same age as earth there may have been as many as ten such moltings in its past. Its atmosphere is entirely a product of these giant eructations and has nothing to do with boiling oceans of Hansen’s. Secondly, the Miskolczi effect makes the enhanced greenhouse effect also impossible. This enhanced greenhouse effect is said to be the cause of anthropogenic global warming or AGW by IPCC, Hansen, and other experts. Since it is ruled out by MGT it follows that it is nothing but a pseudo-scientific fantasy, conceived by over-eager climate “scientists”to prove that the greenhouse effect is real.
Arno Arrak says:
August 10, 2014 at 12:15 pm
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCkQFjAB&url=http%3A%2F%2Fnige.files.wordpress.com%2F2011%2F02%2Fthe-saturated-greenhouse-effect-theory-of-ferenc-miskolczi.pdf&ei=bsXnU470BsnXiwKy6IG4Dw&usg=AFQjCNHGM-LHU1GLNqCdX3gd6mZ1w9adew&sig2=03MycldsSWC7Sh3sxecWow&bvm=bv.72676100,d.cGE
@Steven Mosher at 8.08pm. This argument is uncomfortably similar to you painting all models with in the same palette. Known knowns within physics pure does not transfer to newer forms of sub-physics, ie. climate physics.
@ur momisugly Ed Hoskins
“The temperature increasing capacity of atmospheric CO2 is real enough”
—————————————-
CO2 can absorb energy from LWIR as shown by Tyndall in 1859
CO2 can also emit LWIR if conductively heated as shown by Tyndall in 1860
In our atmosphere radiative gases are emitting to space more than DOUBLE the net flux of radiative energy being absorbed at lower altitude.
The question is not the ability of radiative gases to absorb and thermalise energy, but rather their net effect in our moving atmosphere. Which is cooling at all concentrations above 0.0ppm.
A very informative piece. Equally enjoyable were all the thoughtful comments.
Of course the sun has an effect.
Excellent article. However, one point was missing:
On time scales from decades to hundreds of thousands of years, all available evidence shows that changes in CO2 are caused by changes in temperature. There is no evidence showing that ∆T is caused by ∆CO2.
The alarmist premise is that a rise in CO2 will cause global warming. But where is the empirical evidence to support that belief? So far, no such evidence has been found, despite more than 30 years of searching.
Ed Hoskins & commentators: Thank you for such a lucid explanation of the role of C02 in the AGW debate.
The oceans control Earth’s atmospheric temperature.
The amount of energy that the oceans can retain at a given level of insolation is determined by the weight of the mass of the atmosphere bearing down on the ocean surface because that is what determines the energy ‘cost’ of the evaporative change of phase from water to vapour.
At very low pressure there is little difference between the energy required to initiate evaporation and the amount of energy required for the phase change but the higher the surface pressure becomes the more energy is required by the phase change from lquid to vapour.
See here:
http://www.newclimatemodel.com/the-setting-and-maintaining-of-earths-equilibrium-temperature/
Steven Mosher,
“notice how the author makes his case from WITHIN the accepted science.
Notice how effective the case is when you start INSIDE the accepted science..
notice that he doesnt have to resort to saying wacky stuff about the sun.
notice how he doesnt have to engage in numerology about the planets
he takes the science as given ( much like Nic Lewis does) and works from the inside. ”
And although he has made his case from within the (suspect) “accepted science”, he shows that “whatever the developed world does in terms of decreasing CO2 emissions the outcome is likely to be either immaterial or more likely even beneficial”. In other words Mr. Mosher the panic that the IPCC and its adherents attempt to generate is baseless even using their own dubious assumptions. Do you agree with his conclusions and if not, why not?
davidmhoffer says:
August 10, 2014 at 9:31 am
“The entire debate should have ended with “CO2 is logarithmic””.
————————-
I agree, the entire debate should have ended 30 years ago …. but not just because of the claim that “CO2 is logarithmic”.
Now unless my logical reasoning abilities have gone completely FUBAR …. then the claim that “CO2 is logarithmic” makes no logical sense to me if it is based in/on this explanation/description of said, to wit:
—————–
Decades ago it was determined that CO2 ‘s ability to trap heat rising from Earth’s surface declines logarithmically or very rapidly (see first figure below). This means that early on, at low concentrations, CO2 does exert a significant warming of the lower atmosphere. But as the absorption bands in which CO2 captures this rising heat begin to get saturated, CO2 can capture less and less heat with each additional unit of CO2”.
Source ref: http://plantsneedco2.org/default.aspx?act=documentdetails.aspx&documentid=365
==============
Now given the above, it is therefore my learned opinion that the claim that “CO2 is logarithmic” is little more than “junk science” and anyone that believes otherwise is living proof of this quoted statement, to wit:
—————–
davidmhoffer said:
“Never before have so many been duped by such simple trickery by so few”.
===============
First of all, concerning the above explanation/description, ….. CO2 has no ability to “trap” heat or …. to “trap” thermal “heat” energy. It has the ability to absorb either “conducted” or IR “radiated” heat energy …. and/or …. the ability to emit either “conducted” or IR “radiated” heat energy.
Secondly, just what the hell does the CO2 absorption bands for absorbing IR energy have to do with the total amount of IR radiation from the earth’s surface?
Thirdly, is not the “saturation of the absorption bands” in which CO2 absorbs IR energy a direct result of the surface temperature which the surface is the source of said IR radiation?
HA, me thinks the absorption bands in which CO2 absorbs IR energy are probably pretty much saturated for 1 or 2 hours in the locales of clear skies relative to the Sun’s zenith position of “High Noon” .
And fourthly, given the fact that the CO2 is constantly emitting its absorbed IR energy …. how is it possible for it to “absorb less and less heat energy ….. just because it is “emitting more and more heat energy”?
My question is, iffen one fills and caps a 10 gallon glass container with 20% CO2 … and then directly point a 200 watt IR light source at it, from 12 inches distance, that is emitting in the “CO2 absorption bands”, …… just how “HOT” will that CO2 get ….. or will it begin to get colder after it got hotter?
davidmhoffer says in part, August 10, 2014 at 11:12 am:
“Here is the money slide from AR4, figure 2.23
https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-9-5.html”
Radiative forcing is change in net radiation flow, assuming surface and troposphere temperature do not change in reponse to the forcing. Surface forcing is the change in net radiation flow, after the surface and troposphere temperatures have responded.
Radiative and surface forcings are equal when the forcing is not affected by surface and tropospheric temperature response, such as a change in solar output.
Since an increase of surface temperature in response to an increase of GHGs causes an increase of outgoing surface radiation, it is expectable that the surface forcing from an increase of GHGs is less than the radiative forcing from GHGs.
A couple comments on presentation:
The figure I think can be improved by rescaling the left bar so that the blue line is flat at 400 ppm (or even 350). Therefore each additional 100 ppm increase in CO2 is connected downward to the middle bar for a miniscule change in forcing and steady state temperature change.
RE: The fourth chart. Purely for psychological, social, and historical reasons, I would reverse the x axis and put IPCC on the left with rebuttals following to the right.
But my biggest problem with the fourth chart, and maybe spill over into the other charts, is this business of ~33°C total Greenhouse Effect.
I have and continue to believe that the ~33°C figure is really about 3 times too big and comes from a mathematical model blunder by treating a ~30% albedo as a one-way mirror, reflecting incoming solar energy away, but playing no part in trapping earth radiated energy. Yes, there are spectral conversion concerns, but that ~33°C figure comes from what I think is sloppy accounting of what is and is not in a GHG energy budget.
richard verney says, August 10, 2014 at 11:09 am:
(Largely, that downwelling longwave radiation hitting water is absorbed within the top 3 microns, and an increase of such radiation hitting water is heavily disiipated by an increase of evaporative cooling)
If the top 3 microns warms up without the 10 micron level warming up, then heat conduction through the extremely thin temperature gradient between 3 and 10 microns down will cool the top 3 microns faster than increased evaporative cooling. Evaporative cooling won’t outpace heat conduction until the temperature gradient expands over a much greater range of depth, at which point mixing becomes significant at transferring heat to deeper levels.
Genghis, you say with respect to the DWLWIR hitting the ocean:
“The only explanation that I can think of is that evaporation increases in direct response to the increased radiation.”
So you agree that the overall earth/ocean/atmosphere energy level is higher with this radiation than without it?
“The temperature increasing capacity of atmospheric CO2 is real enough”
Um, Please don’t speak for me. The “skeptics believe” is not true for all of us.
Below the tropopause, CO2 does exactly nothing to temperature. That is why we have a troposphere and tropopause. In that regime (where we live) water completely dominates and CO2 doesn’t get a chance to play in the radiation game. It’s an opaque atmosphere in the CO2 range.
Above the tropopause, CO2 is a net radiator to space and cools.
In no case does CO2 cause net warming.
http://chiefio.wordpress.com/2012/12/12/tropopause-rules/
Image of CO2 effect with altitude:
http://chiefio.wordpress.com/2012/12/12/tropopause-rules/stratosphere-radiation-by-species-1460/
And yes, as Mosier says, it IS effective to work inside the other guy’s paradigm, but do remember that the paradigm is wrong…
And do note that lunar tidal effects are not ‘numerology’ and account for as much cold / warm layer mixing in the oceans as the wind. That planetary orbits correlate with solar cycle changes and with lunar orbits may just be incidental. Or maybe not. Dismissing it out of hand without evidence is not a path to further understanding. While it is my opinion that the lunar tidal effect is the operative mechanism in that correlation, it is by no means proven that some solar effect is not operative as well (such as UV depth of energy deposition heating / not heating the ocean and stratosphere).
http://chiefio.wordpress.com/2013/01/24/why-weather-has-a-60-year-lunar-beat/
http://www.pnas.org/content/97/8/3814.full
So yes, as a ploy, it is useful to argue from the other side’s premisses. But just be careful you do not embrace them as true, nor imply they are accepted truth.
This s the latest in a series of very good essays on co2 by Ed.
Most of us believe in radiative physics and Also that there is some point at which adding more co2 has little additional effect on temperatures.
I wrote this piece last year in which I examined the extended Central Engand Temperature to 1538 and plotted co2 levels against it.
http://wattsupwiththat.com/2013/05/08/the-curious-case-of-rising-co2-and-falling-temperatures/
Since then I have been researching the CET record back a further 500 years. There is little doubt that there are periods in that extended record at least as warm as today and that is without entering the core years of the MWP, which may well be notably warmer than today. Not having done the detailed research on that yet I remain open to whatever the research may show.
The point is that we have considerable ups and downs over that extended period to temperatures as warm as today and much colder than today at co2 levels from 280ppm pre industrial to around 400 ppm today.
It is impossible to draw any interim conclusion at present other than superficially it appears- subject to much more research – that co2 concentrations appear to lose their ability to cause substantial warming at around the 280 ppm level
Natural variability appears to be the main driving force. Phil jones admitted a few years ago that natural variability was far greater than he had hitherto believed
Tonyb