By Patrick J. Michaels and Paul C. “Chip” Knappenberger
Nic Lewis and Judith Curry just published a blockbuster paper that pegs the earth’s equilibrium climate sensitivity—how much the earth’s average surface temperature is expected to rise in association with a doubling of the atmosphere’s carbon dioxide concentration—at 1.64°C (1.05°C to 4.05°C, 90% range), a value that is nearly half of the number underpinning all of President Obama’s executive actions under his Climate Action Plan.This finding will not stop the President and the EPA from imposing more limits on greenhouse-gas emissions from fossil fuels. A wealth of similar findings have appeared in the scientific literature beginning in 2011 (see below) and they, too, have failed to dissuade him from his legacy mission.
The publication of the Lewis and Curry paper, along with another by Ragnhild Skeie and colleagues, brings the number of recent low-sensitivity climate publications to 14, by 42 authors from around the world (this doesn’t count our 2002 paper on the topic, “Revised 21st Century Temperature Projections”). Most of these sensitivities are a good 40% below the average climate sensitivity of the models used by the U.N.’s Intergovernmental Panel on Climate Change (IPCC).
Lewis and Curry arrive at their lower equilibrium climate sensitivity estimate by using updated compilations of the earth’s observed temperature change, oceanic heat uptake, and the magnitude of human emissions, some of which should cause warming (e.g., greenhouse gases), while the others should cool (e.g., sulfate aerosols). They try to factor out “natural variability.” By comparing values of these parameters from the mid-19 century to now, they can estimate how much the earth warmed in association with human greenhouse gas emissions.
The estimate is not perfect, as there are plenty of uncertainties, some of which may never be completely resolved. But, nevertheless, Lewis and Curry have generated a very robust observation-based estimate of the equilibrium climate sensitivity.
For those interested in the technical details, and a much more thorough description of the research, author Nic Lewis takes you through the paper (here) has made a pre-print copy of the paper freely available (here).
In the chart below, we’ve added the primary findings of Lewis and Curry as well as those of Skeie et al. to the collection of 12 other low-sensitivity papers published since 2010 that conclude that the best estimate for the earth’s climate sensitivity lies below the IPCC estimates. We’ve also included in our Figure both the IPCC’s subjective and model-based characteristics of the equilibrium climate sensitivity. For those wondering, there are very few recent papers arguing that the IPCC estimates are too low, and they all have to contend with the fact that, according to new Cato scholar Ross McKitrick, “the pause” in warming is actually 19 years in length.
Figure 1. Climate sensitivity estimates from new research beginning in 2011 (colored), compared with the assessed range given in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and the collection of climate models used in the IPCC AR5. The “likely” (greater than a 66% likelihood of occurrence)range in the IPCC Assessment is indicated by the gray bar. The arrows indicate the 5 to 95 percent confidence bounds for each estimate along with the best estimate (median of each probability density function; or the mean of multiple estimates; colored vertical line). Ring et al. (2012) present four estimates of the climate sensitivity and the red box encompasses those estimates. The right-hand side of the IPCC AR5 range is actually the 90% upper bound (the IPCC does not actually state the value for the upper 95 percent confidence bound of their estimate). Spencer and Braswell (2013) produce a single ECS value best-matched to ocean heat content observations and internal radiative forcing.
[Note: an earlier version of this posted listed the number 12 in the title – the correct number is 14, and the title has been changed to reflect that]
References:
Aldrin, M., et al., 2012. Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations of hemispheric temperature and global ocean heat content. Environmetrics, doi: 10.1002/env.2140.
Annan, J.D., and J.C Hargreaves, 2011. On the generation and interpretation of probabilistic estimates of climate sensitivity. Climatic Change, 104, 324-436.
Hargreaves, J.C., et al., 2012. Can the Last Glacial Maximum constrain climate sensitivity? Geophysical Research Letters, 39, L24702, doi: 10.1029/2012GL053872
Lewis, N. 2013. An objective Bayesian, improved approach for applying optimal fingerprint techniques to estimate climate sensitivity. Journal of Climate, doi: 10.1175/JCLI-D-12-00473.1.
Lewis, N. and J.A. Curry, C., 2014. The implications for climate sensitivity of AR5 focring and heat uptake estimates. Climate Dynamic, 10.1007/s00382-014-2342-y.
Lindzen, R.S., and Y-S. Choi, 2011. On the observational determination of climate sensitivity and its implications. Asia-Pacific Journal of Atmospheric Science, 47, 377-390.
Loehle, C., 2014. A minimal model for estimating climate sensitivity. Ecological Modelling, 276, 80-84.
Masters, T., 2013. Observational estimates of climate sensitivity from changes in the rate of ocean heat uptake and comparison to CMIP5 models. Climate Dynamics, doi:101007/s00382-
McKitrick, R., 2014. HAC-Robust Measurement of the Duration of a Trendless Subsample in a Global Climate Time Series. Open Journal of Statistics, 4, 527-535. doi: 10.4236/ojs.2014.47050.
Michaels. P.J. et al., 2002. Revised 21st century temperature projections. Climate Research, 23, 1-9.
Otto, A., F. E. L. Otto, O. Boucher, J. Church, G. Hegerl, P. M. Forster, N. P. Gillett, J. Gregory, G. C. Johnson, R. Knutti, N. Lewis, U. Lohmann, J. Marotzke, G. Myhre, D. Shindell, B. Stevens, and M. R. Allen, 2013. Energy budget constraints on climate response. Nature Geoscience, 6, 415-416.
Ring, M.J., et al., 2012. Causes of the global warming observed since the 19th century. Atmospheric and Climate Sciences, 2, 401-415, doi: 10.4236/acs.2012.24035.
Schmittner, A., et al. 2011. Climate sensitivity estimated from temperature reconstructions of the Last Glacial Maximum. Science, 334, 1385-1388, doi: 10.1126/science.1203513.
Skeie, R. B., T. Berntsen, M. Aldrin, M. Holden, and G. Myhre, 2014. A lower and more constrained estimate of climate sensitivity using updated observations and detailed radiative forcing time series. Earth System Dynamics, 5, 139–175.
Spencer, R. W., and W. D. Braswell, 2013. The role of ENSO in global ocean temperature changes during 1955-2011 simulated with a 1D climate model. Asia-Pacific Journal of Atmospheric Science, doi:10.1007/s13143-014-0011-z.
van Hateren, J.H., 2012. A fractal climate response function can simulate global average temperature trends of the modern era and the past millennium. Climate Dynamics, doi: 10.1007/s00382
Global Science Report is a feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”
dbstealey
Ok – done it. It’s 0.7 degrees C. Actually it’s more like 0.8 degrees.
No – scrub the 0.8 figure. It’s just under 0.7 degrees.
So ALL of the global warming over the past century and a half is due exclusively to human emissions?? And the planet would be getting colder if not for the added CO2?
You do understand that no credible scientist or organization on either side of the debate agrees with that extreme position, don’t you?
John, you are just throwing a tantrum because folks are starting to ask for measurements. Up until now you’ve gotten a free ride on your assertions. But those days are over.
Ok – Taking your points in no particular order I’ll give it one more go
1. I made no assertion. You still don’t see that. I used the 3.7 w/m2 for 2xCO2 to demonstrate that with no feedbacks the expected warming will be around ~1.2 degrees C. I also noted that warming over the past century or so supported this figure. You should be aware that the ~1.2 degree estimate is very similar to estimates cited by Richard Lindzen, Garth Paltridge and many others. Lewis & Curry have completed a study from which they deduce estimates of 1.33 deg C (TCR) and 1.64 deg C (ECS) which is in the same ball park as my very roughly calculated no feedback figure.
The main point being: Current warming is closely tracking the trend we would expect for CO2 enhanced warming without feedbacks.
Have I made this clear enough?
2. In your last post, you write this
You are not correct here. While some late 19th century or early 20th century warming may not have originated from additional ghgs, the fact remains that the atmosphere has continued support the elevated temperatures even when the original forcing no longer applies. In other words we should have seen more cooling.
Lewis & Curry find that internal variability for the 1859-1882 period and the 1995-2011 period are very similar. Solar activity, volcanic activity etc were virtually the same (using measurements) therefore the mean global temperature in each period should be the same. The mean temperature for 1995-2011 was ~0.7 degree higher than for 1859-1882.
3. Finally, in an earlier post you talk about about “my side” and the need to to find real world measurements to prove “my” case. Let’s be clear I don’t need to prove anything to you but, more importantly, nor do the scientists who support CAGW . They only need to convince the policy makers within the various governments throughout the world that there’s a problem. If those policy makers believe that, on the balance of probability, AGW represents a significant risk then that’s the endgame. Sorry, pal, your argument about no real world measurements for the ghg contribution is simply not going to cut it.
Sceptics (Skeptics if you’re in the US) have 2 options
(i) Show some convincing evidence that there is an alternative reason for the warming observed to date.
(ii) Show that the warming to date is nothing to be overly concerned about and that it is consistent with a low climate sensitivity.
I’ve spent 10 years looking for (i) and have seen nothing other than hot air and BS about the sun. I believe there is a chance with option (ii).
John Finn,
May I deconstruct? Thank you:
1. You say:
the ~1.2 degree estimate is very similar to estimates… a study from which they deduce estimates … my very roughly calculated… &etc.
There are no empirical, testable measurements in any of your comments. You keep tap-dancing around that critical point. What we need are measurements quantifying the specific fraction of the 0.7ºC total global warming in the current warming step change from the LIA. I understand that you now say it’s all due to human emissions. But still: there are no measurements. Thus, it is only your assertion. Not nearly good enough, John. CAGW is only your conjecture. There are no measurements of CAGW.
2. …a study from which they deduce estimates of 1.33 deg C (TCR) and 1.64 deg C (ECS) which is in the same ball park as my very roughly calculated… &etc. But they don’t measure. Do they? No, they guesstimate. Again, not nearly good enough.
Solar activity, volcanic activity etc were virtually the same (using measurements) therefore the mean global temperature in each period should be the same.
That assumes that you know all forcings and feedbacks, including all unknown unknowns. If that were true, we could make accurate predictions. But you can’t, and neither can anyone else. If you think you can, simply predict the month and year that global warming will resume. Seewhatimean?
The mean temperature for 1995-2011 was ~0.7 degree higher than for 1859-1882.
That is a good example of a complete non sequitur.
3. “…the scientists who support CAGW.” They have been debunked. There is no catastrophic AGW. Yes, it was widely predicted. But in the event, that prediction fizzled just like the rest of the alarmist predictions.
Sorry, pal, your argument about no real world measurements for the ghg contribution is simply not going to cut it.
For someone who has never posted those real world measurements, that amounts to just one more baseless opinion.
Sceptics (Skeptics if you’re in the US) have 2 options…
John, skeptics have nothing to prove. CAGW is YOUR conjecture. Therefore, you have the onus — not skeptics. Climate alarmists are always trying to turn the Scientific Method on it’s head, and demanding that skeptics, in effect, prove a negative. That’s not how science works.
But if it makes you happy, I’ll give you my own reasons:
(i) The planet is naturally recovering from the LIA — one of the coldest times of the entire Holocene. It is simply reverting to normal temperatures, and that is entirely sufficient to explain the rise in global T. There is no need for any magic gas to explain it.
(ii) That’s a two part question, but I’ll try: First, global warming is nothing to be concerned about, because as you can see here, we are currently on the cold side geologically. Global T has been much warmer in the past, when the biosphere flourished with life and diversity. A few more degrees of warming will be most beneficial. Any side effects can be mitigated far more inexpensively that the current proposals to sequester CO2, stop using fossil fuels, construct windmills, etc. Unfortunately, the future may well be colder rather than warmer. That would be very bad. Look at that chart again.
And second: climate sensitivity is a number that varies all over the place, from 3 – 6ºC, to zero, to a negative number. But the generally accepted range has been steadily ratcheting down — toward zero, in fact. No global warming for many years, as CO2 continues to rise, argues strongly in favor of that outcome.
Finally, John, you say:
I’ve spent 10 years looking for… &etc.
Almost as much time as I’ve spent studying this subject. But you should know that some folks spend their entire lives studying astrology, phrenology, or Scientology. The time spent looking for something isn’t important. It’s what you find that’s important.
Me? I’m still looking for verifiable measurements of AGW. Haven’t found any yet.
You still don’t understand the key points so we’ll have to let it drop, but this comment really does need challenging
John, skeptics have nothing to prove. CAGW is YOUR conjecture. Therefore, you have the onus
Are you being serious? If CAGW really was my “conjecture” why would I bother spending hours posting comments to you? I wouldn’t be interested in convincing you about anything. You are nothing. You’re not important. I could dismiss you as a denier who is making completely unrealistic demands about absolute certainty with real-world measurements.
The CAGW crowd do not waste their time arguing the toss with “deniers”. They do, however, put their case very eloquently to government advisers. I told you in the last post that governments will not be looking for absolute proof they will be looking at the balance of probablities
You, as a “sceptic”, are not doing a very good job of presenting the sceptic case. Fortunately there are others who do a much better job.
And you have thermometer measurements to prove this?
I have measurements that show exactly that.
No you don’t.
John Finn
You wrote to dbstealey saying
I really would like you to answer your own question.
Why do you spend hours promoting the disproved CAGW conjecture especially when you claim it is not your conjecture?
And I add two questions of my own that I would welcome you also answering.
Why do you throw such ridiculous insults at dbstealey in response to his asking for empirical evidence supporting your conjecture?
And why are such temper tantrums typical of CAGW supporters when their conjecture is challenged?
Richard
Richard
I’ve spent hours arguing against CAGW advocates – including Michael Mann, Grant Foster and Gavin Schmidt. I’ve been banned from Foster’s Open Mind blog and I’ve had posts which challenge the CAGW position appear on the Realclimate blog then disappear due to “technical glitches”.
Now you and dbstealey can continue to convince yourselves that the CAGW movement is dead in the water if you wish, By all means, carry on patting each other on the back every time one of you makes some totally irrelevant and usually ill-informed criticism of the CAGW case but, if this is the best scepticism can offer, you are simply going to end up as one of a sad, dwindling band of no-hopers while governments around the world introduce potentially crippling policies for the rest of us.
To argue against CAGW sceptics must fully understand the the CAGW argument. They need to know where it is weak but also where it is strong – and it is strong in some areas. Spencer and Lindzen are reasonably effective sceptics. Dbstealey is not. He is easily dismissed as a crank.
Take a lesson from someone like Bob Tisdale. Bob is clearly sceptical of AGW-driven ocean warming and presents accurate data to support his case. But Bob does not tolerate any attempt by the sceptic (or AGW) side to mislead or misinform. He jumped all over Don Easterbrook when it was clear that Don had presented graphs which were inaccurate and misleading.
John Finn
I asked you to explain why you provide insults instead of arguments. As troll red herrings to avoid answering, you provide more insulting falsehoods saying
Say what!?
Nature has disproved the CAGW hypothesis by stopping global warming nearly two decades ago.
Ill-informed? I have been studying this stuff and publishing on it since 1980.
You merely spout erroneous drivel.
And your concern trolling about policies fools nobody.
Not content with that, you write of dbstealey
Bollocks!
If his arguments were “easily dismissed” then you would take pleasure in dismissing them. You attack him as being “a crank” because you cannot answer his points which reveal your irrational ravings for what they are.
And you name drop Spencer, Lindzen and Tisdale as being ‘on your side’ when – in reality – they would not touch you with someone else’s barge pole.
Up your game and you may rise above the level of slime.
Richard
John Finn,
I am not asking for “absolute proof”. I am simply asking for measurements rather than your assertions, which do not take the place of measurements. Assertions in this instance are misdirection.
There are no measurements showing how much — if any — global warming is caused by human emissions. That fact goes right to the heart of the debate. The whole CAGW edifice, and indeed, the AGW edifice itself, is constructed based on the belief that human activity warms the planet.
There is no basis for that, other than belief. We need measurements, John. Measurements showing how much, if any, global warming is caused by human emissions. If measurements show that humans cause most of the warming, then we have a real problem. But if measurements show that, say, only 1% of global warming, or 0%, is caused by human activity, then we can disregard our emissions.
Do you see why measurments are essential? Without them, we don’t know what we are talking about. That is no way to make policy.
The alarmist crowd has been winging it for a long time now, convincing the public that humans are causing global warming. But the fact is that we don’t know that. The only way we can be sure is to measure the degree of warming we are causing, if any. But we have no such measurements. That is the one thing we need in order to make a rational decision.
You do want rational — not emotional — decisions, don’t you? As of right now, the belief in AGW is based on emotional arguments. It would be better if you put your energy into finding verifiable, empirical measurements, instead of going ballistic just because people are finally asking to see the effect, if any, of human activity properly quantified.
dbstealey,
Sorry, but John Finn is correct here. Surely you must realize that we will never, ever be able to directly measure the human contribution to the global temperature record? These figures will always be estimates in one way or another.
So what you are asking is simply not possible, and making the skeptics look bad at the same time by unreasonable requests.
SDK,
Not Possible? ‘Never, ever’? You’re obviously new here. No one else has made that claim, and this debate has been going on for months. I am not the only one asking this question. From upthread:
In this article Lord Monckton quotes Professor David Douglass of Rochester University asking him if anyone has attempted empirical measurements, rather than modeling, to determine the CO2 forcing? Lord Monckton asks:
“Please let us know in comments if you are aware of any atmospheric measurements on the basis of which the CO2 forcing has been quantified.”
Are you saying that a physical process cannot be quantified? Nonsense. That would take us back to witch doctor territory, where unexplained phenomena were dealt with by juju known only to the witch doctors. Come to think of it, the IPCC…
Anyway, measurements of CO2 forcing are entirely possible. We know with very good accuracy how much CO2 is emitted by human activity. But they do not put the time, effort or expense into making those measurements for one very good reason: they would find that human emissions are not a significant cause of global warming.
The fact is that despite steadily rising CO2, global temperatures stopped rising many years ago. Those are two measurements we already have.
In science, everything is measured. They just don’t want to find out something that destroys their entire AGW argument.
Oh, FFS, you really have failed to understand not only what I’ve posted but what many other respected scientists have been saying for years.
YES WE KNOW. The forcing is ~3.7 w/m2 per 2xCO2. The debate concerns the temperature response to that forcing. Do you not understand that?
To what is Douglass or Monckton referring? Do they mean the forcing, i.e. a measurement of power per unit area (w/m2) or do they mean the temperature response (degrees C) to a given forcing.
SDK is right. It’s not possible to measure the temperature contribution directly. You can do something similar to what I showed in an earlier post,. That is, select 2 periods which have similar natural forcings but different ghg forcings and note the temperature difference. I used 1859-1882 and 1995-2011 (from Lewis & Curry) and noted that 1995-2011 was about 0.67 degrees warmer than 1859-1882. Since the only appreciable difference in forcing is the ghg component we should be able to get a reasonable estimate of sensitivity.
John Finn,
I figured you would jump on the bandwagon that SDK started. It is nonsense, but at this point you will grasp at anything, like a drowning man grasps at a stick.
As I reminded SDK, no one else has ever said that the ∆T due to human emissions is unmeasurable. But if it is, then maybe we should consult a witch doctor for advice. There’s a limit to scientific knowledge, dontcha know.
Also, what is “FFS”? Is that another of your insults? People who are losing an argument as badly as you are tend to resort to insults. It’s all they have left.
dbstealey,
Respectfully no. What we are discussing here is attribution. And stuff like human attribution can never be directly measured of course. Only estimated. As per the IPCC estimate of “more than 50%”.
You got to start making scientific arguments like Finn, Motl, Spencer and McIntyre etc. in order to counter CAGW. Instead you’ll just be laughed at.
SDK,
Your claim is wrong. Human-emitted gases and particulates are routinely identified, measured, and quantified. It’s done all the time. To claim that it cannot be done only in this particular case is ridiculous.
Everything else is measured. Doesn’t it bother you that the one thing that would resolve the debate is not measured? Science is all about measurement. If there is no measurement, then you are saying we must take the word of… whom, exactly?
“Experts”? If they can’t measure what is purported to be the human effect, then why would you accept what amounts to their guess? There are other experts who make a very good case that CO2 has no warming effect. Are you now going to select which experts we should listen to, and which experts should be rejected? Are you expert enough to determine that? Without measurements, is anyone?
Human emissions can be measured. Temperature can be measured. The ∆T caused by human emissions can be measured. The fact that they are not measured should set off alarm bells in any scientific skeptic.
Finally, I remind you again that you are the only one who believes that the effect of human emissions is unmeasureable. You should re-think that belief. It is not correct.
dbstealey,
So ok then, if you believe it is possible to directly measure the exact percentage of human contribution, why don’t you bring that special thermometer or yardstick or whatever it is supposed to be out in the woods and start measuring right away?
Of course, such a magical measuring device does not exist, and never will exist. You might as well be counting unicorn droppings as you skip merrily along the path.
Alternatively, you can look at the underlying physics and attempt as best you can to estimate the human fingerprint. Scientists do it all the time. Look it up.
SDK,
I don’t see any point in debating with someone who states that a physical process is unmeasurable. Why don’t you go argue that on Hotwopper? Tell them folks here don’t want to discuss nonsense. They’ll welccome you with open arms.
dbstealey,
Ask yourself this then, if human attribution is so “measurable” why haven’t we measured the crap out of it already? Or are the scientists hiding the magical device from us up in their labs? And why can’t the skeptics get a hold of one? Have you looked on eBay?
Listen, we can measure stuff like CO2 and temperatures at given locations. But when you think about it, the GMST is also an “estimation” of sorts. So how can we then possibly attribute a measurable percentage-wise human contribution?
Same as we know that there is a finite number of physical fish in the oceans, but we can never measure the actual number. All we can do is to provide our best estimate as to the fish population in any given body of water using the scientific tools at our disposal, and then attach a degree of uncertainty to it.
For the record, I am also one that believes the ECS is ultimately low, yet weakly positive. So certainly much closer to Lewis than the IPCC average. And if that is not “good enough” for your little universe, then you’re trouble than I thought…
SDK,
I can’t answer your “What if”–type questions. But I note that money needs to be appropriated for the purpose, and that has never been done. Maybe you can guess why not.
Your silly fish analogy doesn’t …hold water. There are ways to get a very close approximation, if you want to know. No measurement is perfect, there are always error bars. But it can be smapled and measured.
I can’t think of any physical process that cannot be measured. As I wrote above, if you believe that a physical process is unmeasurable, there is no need to continue.
And to repeat: you are the first one I’ve seen who believes that human emissions cannot be measured. Thus, you are alone in your own “little universe”.
dbstealey,
You wrote: “you are the first one I’ve seen who believes that human emissions cannot be measured.”
Yep, this is truly getting hopeless when you start confusing human attribution and human emissions. Not at all the same thing.
And next time you pick up a scientific paper on the subject, you’ll notice that human contribution is always described as being estimated. And always will be.
No, it will not “always will be”. I am sure you think that man is limited to the speed of the horse as well.
SDK, that argument is a non-starter.
If the effect of human emissions cannot be measured [even though human emissions can be measured], then your position debunks the entire AGW argument.
Also, if you are going to cherry-pick which ‘experts’ you want to believe, then what do you say to those who choose differnt experts? Prof. Misckolczi says the effect of CO2 is 0.0ºC, ± 0. He is every bit as much of an expert climatologist as Mann, Lindzen, McManus, Christy, or any other expert.
The fact is that all physical processes can be measured. The reason that the effect of human emissions is not measured is very simple: any such measurement would show only minuscule warming at most. All the grant money that pays for studies is controlled by people who have a vested interest in promoting the catastrophis AGW scare.
Simples.
dbstealey,
Ok, so how much do you reckon this Human Attribution Detection Flux Capacitor Chronoscope X1000 would cost to develop? And why aren’t true skeptical scientists at least making an attempt to develop it? At the very least an early prototype?
It kind of strikes me that being able to accurately measure “human attribution” could be the single-most important scientific discovery of this field in ages. Seriously — if it were at all possible — why aren’t more people trying? Surely a potential Nobel Prize could serve as a motivation?
But look, I am of the opinion as well that guys like Mann have been shown to be serial exaggerators. And my back-of-the-envelop calculations show a low-range ECS. I’ve been downloading climate data since working for the European energy sector in the 90s, so think I have a fair handle on the fundamentals.
But when you keep flogging these conspiracies, you are really doing more harm than good. Sorry for the comparison, but kind of like Al Gore did to AGW. Start making ridiculous arguments, and the other side will only be provided with more ammunition to counter it. So no, this cannot be concluded with “simples”. If it rhymes with “pimples”, then that should give you a clue…
And finally, of course different experts will come to different conclusions. That’s how science works FFS (yes, look up FFS FFS).
You got one thing correct – a question – why are more people not trying? it is not impossible. But the answer may not be what is palatable.
Look for the answer to your question as a major problem with the field itself, not in the people who ask questions.
Don’t think this will be any more fruitful than the previous exchange, but still…
Please, provide any scientist being quoted making the claim that “human attribution” can ever be measured. My prediction is crickets…
Rather, what we will see is a perpetual cycle of scientific estimates on the matter. Look at how many have jumped to your support on your own turf even?
SDK,
I have been commenting here since WUWT began. Occasionally I get into an exchange like this, where the other party continues to ask questions. No matter what I answer, there are more questions.
I have made my position clear, but you continue to ask incessant questions. You cannot accept my answers. Whatever my reply, it only causes you to continue your fruitless argument.
I don’t have time to play this game. If you can’t understand my position, then you can’t understand. That is not for my lack of trying. Others more knowledgeable than I have asked the same questions, which are documented upthread. You cannot, or will not accept them. You are a lone voice in the wilderness, insisting that something can never be measured. I do not see it that way, and apparently others have the same view that I do.
So we part ways here. I remind you that to the best of my knowledge, no one else has ever raised your particular issue. Even John Finn has abandoned your one-man crusade.
I suggest that you take up your argument with the others who have expressed the same concerns that I have. If I can’t get my point across after repeatedly explaining, and responding to more than half a dozen replies from you, I give up. Please pester someone else.
If you don’t believe me, maybe Judith Curry has more whack then:
“The no feedback sensitivity is the direct response of the surface temperature to radiative forcing by the increased CO2, without any feedbacks. Why is this interesting/important? The no feedback sensitivity is in principle much easier to calculate (and can presumably be calculated with certainty) and it provides a reference point for assessing the sensitivities associated with climate feedbacks in the overall climate sensitivity to CO2.
“The CO2 no feedback sensitivity is an idealized concept; we cannot observe it or conduct such an experiment in the atmosphere. Hence, the CO2 no feedback sensitivity can only be calculated using models.”
Off course, “no feedback sensitivity” gets you only half-way to “attribution”, i.e. with feedbacks included. There’s lot more in that thread, including this rather blunt paragraph from the comment section:
“Change of radiative forcing cannot be measured. This is used as an input to an estimation of change of global surface temperature, without feedbacks, which can never be measured. This in turn is used as an input to estimating the effect of feedbacks, which can never be measured.”
And more to the point with a hint towards exactly why this is the case:
“Radiative forcing can’t be measured on a planet with water, but it’s certainly theoretically measurable.”
http://judithcurry.com/2010/12/11/co2-no-feedback-sensitivity/
And not really sure what to make of this…
To recap, you initially linked to this Monckton quote:
“Indeed, Professor David Douglass of Rochester University has recently asked me an interesting question: has anyone attempted empirical measurements, rather than modeling, to determine the CO2 forcing?”
Yet then you have this this paper authored by Monckton himself:
“We cannot measure total radiative forcing, with or without temperature feedbacks, because radiative and non-radiative atmospheric transfer processes combined with seasonal, latitudinal, and altitudinal variabilities defeat all attempts at reliable measurement.”
http://www.aps.org/units/fps/newsletters/200807/monckton.cfm