Strong Negative Feedback from the Latest CERES Radiation Budget Measurements Over the Global Oceans
By Dr. Roy W. Spencer, Ph. D.
Arguably the single most important scientific issue – and unresolved question – in the global warming debate is climate sensitivity. Will increasing carbon dioxide cause warming that is so small that it can be safely ignored (low climate sensitivity)? Or will it cause a global warming Armageddon (high climate sensitivity)?
The answer depends upon the net radiative feedback: the rate at which the Earth loses extra radiant energy with warming. Climate sensitivity is mostly determined by changes in clouds and water vapor in response to the small, direct warming influence from (for instance) increasing carbon dioxide concentrations.
This can be estimated from global, satellite-based measurements of natural climate variations in (1) Earth’s radiation budget, and (2) tropospheric temperatures.
These estimates are mostly constrained by the availability of the first measurement: the best calibrated radiation budget data comes from the NASA CERES instruments, with data available for 9.5 years from the Terra satellite, and 7 years from the Aqua satellite. Both datasets now extend through September of 2009.
I’ve been slicing and dicing the data different ways, and here I will present 7 years of results for the global (60N to 60S) oceans from NASA’s Aqua satellite. The following plot shows 7 years of monthly variations in the Earth’s net radiation (reflected solar shortwave [SW] plus emitted infrared longwave [LW]) compared to similarly averaged tropospheric temperature from AMSU channel 5.
Simple linear regression yields a net feedback factor of 5.8 Watts per sq. meter per degree C. If this was the feedback operating with global warming, then it would amount to only 0.6 deg. C of human-caused warming by late in this century. (Use of sea surface temperatures instead of tropospheric temperatures yields a value of over 11).
Since we have already experienced 0.6 deg. C in the last 100 years, it would also mean that most of our current global warmth is natural, not anthropogenic.
But, as we show in our new paper (in press) in the Journal of Geophysical Research, these feedbacks can not be estimated through simple linear regression on satellite data, which will almost always result in an underestimate of the net feedback, and thus an overestimate of climate sensitivity.
Without going into the detailed justification, we have found that the most robust method for feedback estimation is to compute the month-to-month slopes (seen as the line segments in the above graph), and sort them from the largest 1-month temperature changes to the smallest (ignoring the distinction between warming and cooling).
The following plot shows, from left to right, the cumulative average line slope from the largest temperature changes to the smaller ones. This average is seen to be close to 10 for the largest month-to-month temperature changes, then settling to a value around 6 after averaging of many months together. (Note that the full period of record is not used: only monthly temperature changes greater than 0.03 deg. C were included. Also, it is mostly coincidence that the two methods give about the same value.)
A net feedback of 6 operating on the warming caused by a doubling of atmospheric CO2 late in this century would correspond to only about 0.5 deg. C of warming. This is well below the 3.0 deg. C best estimate of the IPCC, and even below the lower limit of 1.5 deg. C of warming that the IPCC claims to be 90% certain of.
How Does this Compare to the IPCC Climate Models?
In comparison, we find that none of the 17 IPCC climate models (those that have sufficient data to do the same calculations) exhibit this level of negative feedback when similar statistics are computed from output of either their 20th Century simulations, or their increasing-CO2 simulations. Those model-based values range from around 2 to a little over 4.
These results suggest that the sensitivity of the real climate system is less than that exhibited by ANY of the IPCC climate models. This will end up being a serious problem for global warming predictions. You see, while modelers claim that the models do a reasonably good job of reproducing the average behavior of the climate system, it isn’t the average behavior we are interested in. It is how the average behavior will CHANGE.
And the above results show that not one of the IPCC climate models behaves like the real climate system does when it comes to feedbacks during interannual climate variations…and feedbacks are what determine how serious manmade global warming will be.
Skye,
BTW, I should have pointed out that climate sensitivity cannot be estimated from paleo records as there are too many confounding factors and feedbacks, such as clouds and aerosols. In essence, those estimates were performed as though natural variability is unimportant. Climate sensitivity estimates bases on ice cores or tree rings can be dismissed for those reasons. Of the remaining estimates, they use surface temp data which looks to have a consistent warming bias will which exaggerate climate sensitivity by a factor of 3-6.
I am of the opinion that the physics exist to explain why a weather related cold streak can overwhelm a warm streak based entirely on weather systems and that these systems have cyclical/oscillating components. What is interesting is that the cold phases of these cycles can overwhelm a drought and heat stroke causing warm phase within days. The tiny bit of warming that AGW greenhouse gas adds is easily and handily taken care of by cold streaks without working up so much as a sweat and without being detected (as I am of the opinion that linear trends are an artifact of statistical analysis of weather related patterns on an oscillating scale, nothing more).
jorgekafkazar says: “The fires stop generally when they run out of fuel or when the weather changes.” May 7, 2010 at 5:54 pm
Gilbert says: “I think these are what’s called negative feedbacks.” May 8, 2010 at 1:39 am
No, those are called running out of fuel and changing weather. Running out of fuel is not a feedback, that is, it’s not caused by the fire itself. Running out of fuel is caused by the size of the forest not being infinite. Changing weather? That’s caused by several factors ordinarily not related to the fire.
“As a side note, one thing that is not generally recognized is that the poles during summer get the highest daily average insolation of anywhere on earth. This is because, although they don’t get a lot of insolation even during the summer, they are getting it for 24 hours a day. This makes their daily average insolation much higher than other areas. But I digress …)”
So, explain why this does not translate into no ice every summer??
kuhnkat says: How about cold ocean and high albedo even with melted ice due to the low angle of the insolation to the surface…
Yes, water sometimes has a higher albedo than ice at high zenith angles. Also, the emittance of seawater is almost 0.993, much higher than ice. But, as stated, the theoretical daily average heat rate is highest at the Arctic poles. However, there’s also a problem that most insolation charts I’ve seen don’t account for: the greater atmospheric thickness sunlight passes through at the poles.
I have yet to locate any tables showing actual measurements of net energy received everywhere on the Earth’s surface. However, at the summer solstice, the Arctic sunlight passes through roughly 2.5 times as much air depth as at the equator. The transmittance of sunlight at the equator is about 75%; this should be much lower at the poles.
If the theoretical top-of-atmosphere insolation at the North Pole is 550 watts per square metre (per Figure 1 of http://wattsupwiththat.com/2010/02/28/sense-and-sensitivity/), and if the corrected atmosphere transmittance is 75%^2.5 ≈ 46%, then the sunlight received at the Arctic during the annual Solstice Parade would be about 0.46 * 550 w/m² ≈ 252 w/m², which is quite a bit lower than in the tropics. Don’t bother sending Santa and his elves any Coppertone™ this Christmas.
[This is just an estimate; the actual calculation is more complex because of increased refraction and scattering at the pole, plus spectral considerations. I’m open to honest input, but I’d prefer a link to actual data.]
Although I am repeating myself from a comment earlier in the day, the day’s progress of blogg-comments serves to underscore my irritation and “issue” with so many sites dedicated to exposing the “truth” behind the global warming scare. We are treated to genuine scholarly views that contradict or modify at a significant level the assumptions which underlie the erroneous (in my opinion) conclusions drawn by the warmists. Unlike the IPCC and the Suzuki school of thought that says that once peer-reviewed a position is fact until peer-reviewed (and acknowledged by the initial authors) contrary “facts” are published, the blog review attempts to nail inconsistencies, contradictions and “lies” as they arise. This is commendable as public policies are being determined on the fly, not after sustained and argued debates, and we must respond on the fly. Yet to use the arguments as Dr. Spencer raises is impossible in this environment unless the criticisms and calls for clarity are addressed. The current paper – to use the term in an e-sense – has, as many other such works, cogent and significant points to use as both attack and defense points with those who wish to scare us into bad social actions on the basis of shoddy science and well-constructed fear. But more than 125 comments, back and forth, disputing this and that! So, what can be used, and what cannot? If we are trying to educate the skeptics and provide indefensible arguments to present to the alarmists, we must have our own “consensus”. Which criticisms are valid, and which not? As many trolling the internet and purchasing book after book, I find much simple chemistry and physics and statistical analysis compelling and telling against the AGW hypotheses. Yet the comments – replacing peer-review in this “post-normal” science environment, must be addressed if the original views are to advance. I realize that keeping up these blogs is not a job-for-money. That is where Gore and Suzuki/WWF, etc. have the skeptics at a disadvantage, as they can pour time into rebuttals and positions. But creating a cleaned-up, “consensus” report (or at least a Response to Comments section) is the only way that this work can be gainfully used. Otherwise all the warmist needs to do is to point to Comment #123 and say, “See? Even you guys don’t agree.” I hope you see that my thoughts here are not criticisms of the thinking/work done, but of the end result: muddy water and confusion. This is what the earliest opponents of true democracy feared: a cacophony of opinion with a clarifying process. The internet has given us the freedom of opinion, but not the way to sort out through the mess that comes with it.
Could be, with the right instrumentation, that seven hours is enough (or seven pico seconds if you like that kind of thing) to provide good supporting evidence for your hypothesis.
AGW-Skeptic99 says:
May 7, 2010 at 11:01 pm
“…What makes the skeptic position move into the mainstream media and ends the world wide diversion of human energy and money into the AGW sinkhole? More research or Republican control of a House or Senate committee or Australian politics?
What does it take to make the tide start going the other way. As of now most of the people controlling money and politics treat skeptics like lepers. They don’t want to converse with us or be seen in our company.”
We are treated like lepers because those at the top know they are peddling the world’s largest swindle and we are making it difficult for them. They almost had a done deal until someone published the e-mails (climategate) and someone else leaked the Danish text at Copenhagen. Conmen always hate the people who expose their cons. It remains to be seen whether the Bankers who are behind the Con have enough dirt and other leverage on the various Congress critters to make them vote yes on a Cap and trade bill that will probably oust them out of office.
#
North of 43 and south of 44 says:
May 8, 2010 at 8:17 am
DR says:
May 7, 2010 at 4:53 pm
Next thing you know, Nick Stokes will be convincing us the oceans really do warm from the bottom up 🙂
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Perhaps Nick has found the missing heat, aka, the the earth’s induction heater ;).
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Nick DID find the missing heat AND the oceans DO heat from the bottom up….. as long as there is an active volcano at the bottom that is. … Hundreds of thousands of them are dispersed through the ocean basins….” http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/23_1/23-1_staudigel2.pdf
Ron Cram says:
What? Skye lists 7 estimates, of which 4 have absolutely nothing to do with the instrumental temperature record. Of the 3 that do: One involves the Mt. Pinatubo eruption (surely, you don’t think that any bias is strong enough to corrupt changes that occur on a timescale of a couple of years, besides which the corruption would be in the wrong direction. One involves an analysis looking at the climate response to the 11 year solar cycle…again, I don’t see how any such bias that you speak of (which is far from demonstrated at any rate) would significantly impact the results. And, one involves ocean heat content and I would have to look at it more to understand whether any purported bias would impact it.
So, in fact, only one of the 7 estimates could even have a conceivable chance of being significantly impacted by any supposed bias in the surface temperature record of CRU or GISS.
Oh…And, in regards to Schwartz: In his replies to comments on his paper, he updated his estimate of climate sensitivity ( http://www.ecd.bnl.gov/pubs/BNL-80226-2008-JA.pdf ) and it now significantly overlaps the IPCC range and is not very compatible with the sort of numbers Spencer is talking about here. (Schwartz’s best guess is 1.9 C, with an uncertainty of something like +- 1.0 C. And, I believe some of his detractors would argue that his method still is likely to produce numbers biased low.)
Tilo Reber says:
No. The studies of the last glacial maximum make estimates of all the radiative forcings that occurred and use this to derive a climate sensitivity in units of K per (W/m^2). Then using the known value of radiative forcing due to doubling of CO2 (that even Spencer and Lindzen don’t dispute), it converts this to a climate sensitivity for a CO2 doubling. If you were to assume that the radiative forcing due to CO2 were negligible, then you would have the same temperature change caused by a smaller forcing, which would imply a larger climate sensitivity (although the result would not be self-consistent because the estimates of the forcings imply that CO2 contributes about 1/3 of the total temperature change).
Needless to say, the estimates based on the Mt. Pinatubo eruption or the solar forcing do not use CO2 whatsoever in determining the climate sensitivity. The only one that might consider CO2 as the dominant forcing for the calculation is Gregory 2002 (although for all I know it may not either…I’d have to look at it).
Ron Cram says:
May 9, 2010 at 5:52 am
Skye,
You list out a number of climate sensitivity estimates (ignoring the one by Schwartz which is at the low end of your range) and ask how Dr. Spencer’s results compare to them. Most of these estimates are based on surface temp records by CRU or GISS. If these surface temp records have a warming bias, as Anthony’s SurfaceStations.org project suggests they might, then the estimates of climate sensitivity will be hugely exaggerated. Spencer’s work is based on tropospheric temps as measured by satellites. I hope this helps.
________________________________________________________________________
Here are examples of said bias in the US temperature
http://i31.tinypic.com/2149sg0.gif
http://i31.tinypic.com/5vov3p.jpg
Girma says:
May 9, 2010 at 5:10 am
You get a forcing of 3.7 W/m2 for a a sustained doubling of CO2 concentration in the air which translates into +1.1°C according to the IPCC. This finding is not being disputed by Dr. Spencer.
With my limited knowledge, I deduce there are positive and negative feedbacks on a timescale of months. A gross negative feedback of 5.8W/m2 for ~1.4x Co2 would result in less warming during the 20th century, less than 0.6°C. Does this make sense? I leave the technical details up to the experts. But one thing I know. If 3.7W per square meter forcing translates into 1.1°C and we have for instance 3.7W per square meter less warming from short-term feedbacks. This would mean at least that the model avereage should show 1.1°C less projected warming for the 21st century in the sensitivity scenarios resulting from this negative short-term feedback.
I suppose this also results in less ocean heat uptake which accounts for most of an additional negative long-term feedback. Moreover, the effect on Sea ice has been discussed here lengthily.
Reading some of the comments, I have to ask how is Dr Spencers hypothesis testable? And just what exactly is the hypothesis we want to test anyways. It seems to me he is simply accepting the hypothesis that the CO2 increase is or may be responsible for global warming, and concluded it does, just not as much as the IPCC models say it will.
Basically what he has done is to look at outgoing radiative flux changes from 2002-2009, a period in which temperatures have not been increasing and where there has been an extended solar minimum, and incoming radiation flux is lower than normal. Will the slope remain the same when solar activity increases?. For example, we know cosmic rays increase during low solar activity, and increase in periods of high solar activity, and these cosmic rays may have some effect on cloud formation, which affect feedbacks (positive and negative). It seems to me you would need data that covers at least 1-2 normal solar cycles to be very convincing that this slope is not variable . That said, it does suggest effectively that the IPCC models are missing negative feedbacks.
“Will increasing carbon dioxide cause warming that is so small that it can be safely ignored (low climate sensitivity)? Or will it cause a global warming Armageddon (high climate sensitivity)?”
The assumption that increased CO2 is responsible for all the warming we have experienced is not proven as the AGW proponents would like us to believe, and given that IR measurements have only been made for 50 years, and the nature of estimations of past CO2 concentrations using ice cores obtained from the Antarctic (source of the biggest CO2 sink in the world, and samples with great age uncertainty) and comparing them to samples from Mauna Loa (source of one of the biggest CO2 source in the world where 85% of the data is discarded due to wind causing high or low readings) mean the actual CO2 increase over 100 years is actually uncertain. This is not to deny that CO2 levels are increasing, just that they may have been increasing for longer than we are led to believe .
In the first 20 years of CO2 measurements from MLO demonstrating an increase in CO2, temperatures actually decreased. Despite rising 1-2 ppm per year for the past 10 years, temperatures have not increased. So over the 50 years we have measured CO2 accurately, we have had 30 years of cooling-neutral, 20 years warming, meaning that most of the 0.6 deg C increase in temperature came when mans CO2 emissions were at a much lower level.
By focusing on only 1 hypothesis for the warming, and we are warmer than 100 years ago, and ignoring all other possibilities, they give the hypothesis a validity it does not deserve. We can not say with any certainty that CO2 has caused the warming noted over the last 100 years. Increasing CO2 today may very well be a result of warming that began in 1850 as we came out of the LIA, for reasons nobody has explained. That warming likely had little to do with mans CO2 emissions. I am glad Dr Spencer acknowledged the fact that this warming was likely due to natural causes.
wildred says:
May 7, 2010 at 2:43 pm
Wait, so this paper is making these conclusions from 7 years of data? That doesn’t seem like enough data to make that or any type of conclusion. Notice the 2 figures shown in this post start in 2002.
jeff brown says:
May 7, 2010 at 3:28 pm
I agree with Wildred…only 7 years of data to make these sweeping statements? Interesting how some on this post easily buy into Dr. Spencer’s conclusions w/o the same critical examination given to papers that suggest humans are affecting the climate. Seems very biased.
*****
With respect, I think you may have misunderstood what Dr Spencer has done and presented. He’s not trying to prove whether an increase in CO2 results in multidecadal changes, i.e. the slow build-up of CO2 having measurable long-term consequences. He’s investigating the issue of sensitivity at the monthly frequency level, and thus deriving feedback factor, and for this 87 pairs of measurements from consecutive months is more than enough to establish this, especially with the statistical confidence demonstrated.
What Lindzen, Choi and Spencer demonstrate is that when month-to-month (or season to season) surface warming is detected, there is a correspondingly large increase in outgoing longwave radiation (OLR). If the warming were due to the greenhouse effect, cranked up by positive feedbacks, then increase in OLR would be considerably lower.
Lindzen, Choi and Spencer’s argument seems to me to be that month to month, season to season, or even year to year changes in surface temperatures are not mainly due to the greenhouse effect. Their results prove that beyond any reasonable doubt, and for this they have done us a great service.
However, their weakness is that this does not address multidecadal effects. If I might use an electrical analogy, what they have done is akin to measuring the high frequency AC sensitivity of a feedback system, where the AC signal measured is superimposed on a DC drift (or low frequency AC, if you will). Feedback systems often have different sensitivities to different AC frequencies. It’s perfectly possible to have negative feedback at certain frequencies and positive feedback at other frequencies. For example, oscillators have positive feedback at the frequency of oscillation, but strong negative feedback at other frequencies (I’m not suggesting earth’s climate system is an oscillator, but if you look at typical temperature reconstructions over millions of years covering many ice ages, you could be forgiven for thinking that it is). Likewise, plotting month to month consecutively is effectively filtering out the low frequency information: it’s putting the data through a high pass differentiating filter which eliminates the low frequency components. So, as I understand it, Lindzen, Choi and Spencer have established that relatively short-term (= high frequency) fluctuations in surface temperatures have nothing to do with the greenhouse effect. This doesn’t address the long-term (=low frequency) sensitivity, though.
What needs to be done is to put the data through a low pass filter, or a multidecadal bandpass filter, and look at low frequency sensitivity. This might tell a different story. And, for that, yes, we would need data covering more than 7 years.
ScientistForTruth has said what I was trying to say earlier, perhaps more clearly.
I would add that there definitely is an annual component to the net radiation, and the response to this is highly influenced by thermal inertia, which diminishes the response to an AC forcing compared to a similar amplitude DC forcing. Engineers among you might recognize how any kind of inertia has this effect on amplitude. I think it is wrong to interpret inertia as negative feedback, because given sufficient sustained forcing it goes away. When a CO2-doubling effect is described, it is a steady-state response, and this is where it makes sense to look at feedback. If CO2 doubled tomorrow, net radiation would immediately change, but of course temperature wouldn’t respond so quickly, and it might take several years to reach a new equilibrium. After that you would see what the feedback was.
davidmhoffer,
You have stated it quite succinctly:
“1. The models are based on CO2 causing an energy imbalance of X.
2. The measured imbalance is 0.2X”
Unless some problem is found with Spencer’s work, at the VERY LEAST, the models have a serious diagnostic problem between 60N and 60S. Another instance of correlated error in all the models. Andreas Roesch had already demonstrated correlated positive surface albedo bias in ALL the models at the time of the FAR. Since the FAR, Wentz reported that NONE of the models reproduced more than half the increase in precipitation associated with the recent warming. Camp and Tung and separately Lean reported that none of the models reproduce the amplitude of the signature of the solar cycle seen in the data. And most here are familiar with the potentially definitive contributions of Lindzen, Spencer and others.
I think that we need to point out very specifically, that the range of projections published by the IPCC are just the actual model results for various CO2 scenarios without ANY additional range or confidence level adjustments for model diagnostic issues that were known at the time, even though those errors were known to be far larger than the energy imbalance at issue and at least comparable to the CO2 forcing itself. Of course, the significant correlated diagnostic issues published since then could not have been taken into account.
One of my hopes for next week’s ICCC is that we can highlight the appallingly poor peer review standards being applied to reports of model based results. Regional studies of AGW impact are being published without discussions of the diagnostic literature for the models that were used, and often report, for instance, increased risks of droughts without disclosing that the models fail to reproduce even one-half the increase in precipitation associated with the warming. This will be unpopular with the local scientists, because what regional or state agency is going to want to fund studies, when it is obviously premature to use the models when they are so obviously deficient in this key area.
As Spencer, Lindzen and others have recognized, whether AGW is much of a concern relative to natural variation will rest on whether the net feedbacks to CO2 forcing are as positive as the modelers would have us believe or instead, negative and a barely noticeable perturbation upon the natural variability. The only contemporary model independent evidence seems to be pointing towards the negative. But in the meantime, I think we should press the need for stronger peer review and disclosure of diagnostic implications for any publication of model results. Given the history of high levels of correlated error, publications of new models and versions of models should not read like announcements of an innocent newborn, but should have to discuss specifically whether and how they attempted to address or avoid the documented correlated errors of the past.
JimD and Scientists for truth,
Unless I’m reading Spencer incorrectly, he performed the same analysis on the models as he did on the climate data. The models should have the same thermal inertia behavior as the actual climate, so the diagnostic issue between 60N and 60S is unaffected by this concern. If Spencer has that part right, then the models are wrong. I guess, in a nonlinear system, we can’t rule out that something significant could be happening at the higher latitudes that impact the definitiveness of his results, but the models would still be wrong. In a nonlinear system, having the models be right on some global diagnostic like climate sensitivity in the wrong way is mere serendipity and doesn’t count.
@RockyRoad
From an engineering standpoint, unstable equilibriums just don’t last very long in nature. The point I was trying to make is that the earth probably isn’t approaching a “tipping point”. Looking back at historical data and archeological evidence it would seem that the earths temperature has an upper and lower bound and is somehow self regulated. Anthropogenic influences might be enough to move those boundaries by a fraction of a degree, but even that seems very doubtful. If you look at the amount of CO2 from human sources and the CO2 from natural sources, the difference in magnitude is huge. The human influence on the atmosphere is about like putting a motorcycle engine on the back of a freight train. In theory it should have a measurable effect on the speed or acceleration of the freight train, but in practice it just doesn’t matter.
As a little bit of clarification, I spent some time as a quality engineer and have become very used to dealing in uncertainties. It also made me realize that there is pretty much no such thing as an absolute sure thing. That is why a lot of my explanations have weasel words like probably and may and possibly. And frankly, I don’t understand climate nearly well enough to speak about it in absolutes.
Hope this clears up what I was trying to get at.
IPCC has a confidence range of 1.5 – 6.0C for one of the scenarios for next century temperature change. The midpoint which is commonly used is 3.0C,while alarmists love to focus on the 6C number. More negative feedback not only lowers the 3.0C midpoint down to less than a degree, but much more importantly it cuts the 6.0C completely out. (Boatloads of positive feedback were required to get up to 6.0C.)
Were this scientific work (or follow on articles and work on this “unsettled” science) to completely cut out the 6.0C “edge of the envelope” warming, that seems quite significant. Then you have a 2x co2 climate sensitivity of say 0.6C (take that with a grain of salt, this is crude speculation) and an upper edge of the confidence interval of 2.0C or so.
EG, tightening the confidence intervals in prediction of climate change by lowering the uncertainties in the calculations is a major scientific accomplishment…IF AS ABOVE DISCUSSED the result is a change in the uncertainty from 6C-1.5C = 4.5C to some 2.0C-0.2C = 1.8C.
That’s a third of previous uncertainty in the range of man’s possible detrimental effects on the planet.
“…Look, my articles are not peer-reviewed science, people. I’m just keeping people abreast of progress in research they are paying me to do. 🙂 ”
This quote is from Dr. Roy Spencer May 7, 2010 regarding some criticism of this analysis and I wonder if it will appear with the same conclusions in the Journal of Geophysical Research?
I jumped on Wikipedia and read the article, but it was a lot like walking through pudding: slow going and afterward I felt kinda dirty.
Well I always thought “climate Sensitivity” is defined as the increase in mean earth surface temperature for a doubling of atmospheric CO2; and IPCC says it is 3 deg C per doubling +/- 1.5 deg c per doubling; which means it is 1.4 to 4.5 deg C per doubling; so you can see it changes somewhat with the doubling of CO2; and from that fact that it changes; and the definition you can see that the temperature is a logarithmic function of the CO2 abundance.
Now this must be somewhat theoretical derived from Climatologer’s computer models, because we have never actually observed a doubling of the atmospheric CO2 abundance; and for that matter; we don’t even have a credible way of measuring the average temperature of the earth’s surface; we only have these “anomaly” observations which are differences from what the owl box thermometer read on average over some base time frame. But notice that we don’t have any idea what the true val;ue of the mean earth surface temperature was at any time during that 30 year basetime observation.
It’s like the cop timing you through a five mile long speed trap, and telling the judge you were doing 48 MPH in a 45 MPH zone; except he doesn’t know where in that five miles you were when you were speeding.
And climatologers seem to ignore the fact that the earth surface emitted LWIR thermal radiation; which is the driving Voltage behind the CO2 absorption of energy, varies by more than an order of magnitude from place to place and time to time on earth; so it is hardly a suitable variable to be the standard for calculating the logarithmic warming effect of CO2 increases. As bad as out knowledge of anomalies is from place to place; our knowledge of surface radiant emittance is even worse; and we have no global network for monitoring it.
With a 3:1 variation in the best scientific measurments of “Climate sensitivity”; it seems like you can fit the obseved data to almost any formula you like. I’d bet you can fit the temperature/ CO2 data to the function exp(-1/x^2) for some interval of that function.
Charlie K says:
You seem to be confused here about what the claim being made is. An estimate that doubling the CO2 will produce a warming of ~2-4.5 K is not talking about an unstable equilibrium. It is just saying that the feedbacks are such that the warming gets magnified from the ~1.1 K that would occur if CO2 levels changed with no other changes (to water vapor, clouds, snow / ice albedo, etc.) There is some talk about tipping points (such as shutdown of the thermohaline circulation) but these are not true “runaways”…and I don’t understand how your argument addresses them. Yes, the climate system won’t stay at the tipping point for long…that is why they are tipping points.
Finally, when paleoclimate folks look at the past climates, they find evidence that indeed the climate seems pretty sensitive to perturbations…and they find that quite rapid changes (e.g., due to the shutdown of the thermohaline circulation) suggestive of tipping points have occurred in the past. So, in fact, it is your view and not the consensus view that seems to be in contradiction to our current understanding of paleoclimate.
On this point you are also confused. There are large exchanges of CO2 between the atmosphere, the mixed layer of the ocean, the biosphere, and the soils. However, this is just exchanging the same carbon back and forth. In fact, to a good approximation, these systems can all be thought of as subsystems of one larger system that exchanges carbon only quite slowly with the deep ocean; when a new slug of carbon is added to any part of this system (be it atmosphere, mixed layer, biosphere, …), it will rapidly equilibrate amongst these different components but it will only slowly disappear from this system as a whole. Thus, the carbon we are releasing through the burning of fossil fuels is a new source of carbon added to this system. It is a very different beast from the exchanges between the different components of this system.
This is why our emissions have already caused the level of CO2 to increase by close to 40% relative to the pre-industrial level, even though the amount of our emissions is fairly small compared to the exchanges back and forth between the atmosphere and the mixed layer and biosphere.
Then you should try to understand the science first before you critique it. There is a reason why most scientists have come to the conclusions that they have and it is not because they are stupid or part of a grand conspiracy.
George E. Smith said
May 11, 2010 at 3:26 pm
Reminds me of the story of the cop who pulled Werner Heisenberg over for speeding.
“Do you know how fast you were going?”, the cop asked.
“No,” said Werner, “… but I know where I was.”
Joel Shore says:
May 11, 2010 at 5:33 pm
Interesting post, right up to the end where you say:
Fallacy of the excluded middle. There was also a reason that most scientists came to the conclusion that the continents weren’t moving, and that ulcers were caused by stress, and it was not because they were stupid or part of a grand conspiracy.
However … they were still wrong …