Lindzen on negative climate feedback

NEW 4/10/09: There is an update to this post, see below the “read the rest of this entry” – Anthony

Guest Post by Richard Lindzen, PhD.

Alfred P. Sloan Professor of Meteorology, Department of Earth, Atmospheric and Planetary Science, MIT

This essay is from an email list that I subscribe to. Dr. Lindzen has sent this along as an addendum to his address made at ICCC 2009 in New York City. I present it here for consideration. – Anthony

lindzen1Simplified Greenhouse Theory

The wavelength of visible light corresponds to the temperature of the sun’s surface (ca 6000oK). The wavelength of the heat radiation corresponds to the temperature of the earth’s atmosphere at the level from which the radiation is emitted (ca 255oK). When the earth is in equilibrium with the sun, the absorbed visible light is balanced by the emitted heat radiation.

The basic idea is that the atmosphere is roughly transparent to visible light, but, due to the presence of greenhouse substances like water vapor, clouds, and (to a much lesser extent) CO2 (which all absorb heat radiation, and hence inhibit the cooling emission), the earth is warmer than it would be in the absence of such gases.

The Perturbed Greenhouse

If one adds greenhouse gases to the atmosphere, one is adding to the ‘blanket’ that is inhibiting the emission of heat radiation (also commonly referred to as infrared radiation or long wave radiation). This causes the temperature of the earth to increase until equilibrium with the sun is reestablished.

For example, if one simply doubles the amount of CO2 in the atmosphere, the temperature increase is about 1°C.

If, however, water vapor and clouds respond to the increase in temperature in such a manner as to further enhance the ‘blanketing,’ then we have what is called a positive feedback, and the temperature needed to reestablish equilibrium will be increased. In the climate GCMs (General Circulation Models) referred to by the IPCC (the UN’s Intergovernmental Panel on Climate Change), this new temperature ranges from roughly 1.5°C to 5°C.

The equilibrium response to a doubling of CO2 (including the effects of feedbacks) is commonly referred to as the climate sensitivity.

Two Important Points

1. Equilibration takes time.

2. The feedbacks are responses to temperature – not to CO2 increases per se.

The time it takes depends primarily on the climate sensitivity, and the rapidity with which heat is transported down into the ocean. Both higher sensitivity and more rapid mixing lead to longer times. For the models referred to by the IPCC, this time is on the order of decades.

This all leads to a crucial observational test of feedbacks!

The Test: Preliminaries

Note that, in addition to any long term trends that may be present, temperature fluctuates on shorter time scales ranging from years to decades.

lindzen2

Such fluctuations are associated with the internal dynamics of the ocean- atmosphere system. Examples include the El Nino – Southern Oscillation, the Pacific Decadal Oscillation, etc.

These fluctuations must excite the feedback mechanisms that we have just described.

The Test

1. Run the models with the observed sea surface temperatures as boundary conditions.

2. Use the models to calculate the heat radiation emitted to space.

3. Use satellites to measure the heat radiation actually emitted by the earth.

When temperature fluctuations lead to warmer temperatures, emitted heat radiation should increase, but positive feedbacks should inhibit these emissions by virtue of the enhanced ‘blanketing.’ Given the model climate sensitivities, this ‘blanketing’ should typically reduce the emissions by a factor of about 2 or 3 from what one would see in the absence of feedbacks. If the satellite data confirms the calculated emissions, then this would constitute solid evidence that the model feedbacks are correct.

The Results of an Inadvertent Test

lindzen31

From Wielicki, B.A., T. Wong, et al, 2002: Evidence for large decadal variability in the tropical mean radiative energy budget. Science, 295, 841-844.

Above graph:

Comparison of the observed broadband LW and SW flux anomalies for the tropics with climate model simulations using observed SST records. The models are not given volcanic aerosols, so the should not expected to show the Mt. Pinatubo eruption effects in mid-1991 through mid-1993. The dashed line shows the mean of all five models, and the gray band shows the total rnage of model anomalies (maximum to minimum).

It is the topmost panel for long wave (LW) emission that we want.

Let us examine the top figure a bit more closely.

lindzen4

From 1985 until 1989 the models and observations are more or less the same – they have, in fact, been tuned to be so. However, with the warming after 1989, the observations characteristically exceed 7 times the model values. Recall that if the observations were only 2-3 times what the models produce, it would correspond to no feedback. What we see is much more than this – implying strong negative feedback. Note that the ups and downs of both the observations and the model (forced by observed sea surface temperature) follow the ups and downs of temperature (not shown).

Note that these results were sufficiently surprising that they were confirmed by at least 4 other groups:

Chen, J., B.E. Carlson, and A.D. Del Genio, 2002: Evidence for strengthening of the tropical general circulation in the 1990s. Science, 295, 838-841.

Cess, R.D. and P.M. Udelhofen, 2003: Climate change during 1985–1999: Cloud interactions determined from satellite measurements. Geophys. Res. Ltrs., 30, No. 1, 1019, doi:10.1029/2002GL016128.

Hatzidimitriou, D., I. Vardavas, K. G. Pavlakis, N. Hatzianastassiou, C. Matsoukas, and E. Drakakis (2004) On the decadal increase in the tropical mean outgoing longwave radiation for the period 1984–2000. Atmos. Chem. Phys., 4, 1419–1425.

Clement, A.C. and B. Soden (2005) The sensitivity of the tropical-mean radiation budget. J. Clim., 18, 3189-3203.

The preceding authors did not dwell on the profound implications of these results – they had not intended a test of model feedbacks! Rather, they mostly emphasized that the differences had to arise from cloud behavior (a well acknowledged weakness of current models). However, as noted by Chou and Lindzen (2005, Comments on “Examination of the Decadal Tropical Mean ERBS Nonscanner Radiation Data for the Iris Hypothesis”, J. Climate, 18, 2123-2127), the results imply a strong negative feedback regardless of what one attributes this to.

The Bottom Line

The earth’s climate (in contrast to the climate in current climate GCMs) is dominated by a strong net negative feedback. Climate sensitivity is on the order of 0.3°C, and such warming as may arise from increasing greenhouse gases will be indistinguishable from the fluctuations in climate that occur naturally from processes internal to the climate system itself.

An aside on Feedbacks

Here is an easily appreciated example of positive and negative feedback. In your car, the gas and brake pedals act as negative feedbacks to reduce speed when you are going too fast and increase it when you are going too slow. If someone were to reverse the position of the pedals without informing you, then they would act as positive feedbacks: increasing your speed when you are going too fast, and slowing you down when you are going too slow.

gas-brake-pedals

Alarming climate predictions depend critically on the fact that models have large positive feedbacks. The crucial question is whether nature actually behaves this way? The answer, as we have just seen, is unambiguously no.

UPDATE: There are some suggestions (in comments) that the graph has issues of orbital decay affecting the nonscanner instrument’s field of view. I’ve sent a request off to Dr. Lindzen for clarification. – Anthony

UPDATE2: While I have not yet heard from Dr. Lindzen (it has only been 3 hours as of this writing) commenter “wmanny” found this below,  apparently written by Lindzen to address the issue:

“Recently, Wong et al (Wong, Wielicki et al, 2006, Reexamination of the Observed Decadal Variability of the Earth Radiation Budget Using Altitude-Corrected ERBE/ERBS Nonscanner WFOV Data, J. Clim., 19, 4028-4040) have reassessed their data to reduce the magnitude of the anomaly, but the remaining anomaly still represents a substantial negative feedback, and there is reason to question the new adjustments.”

I found the text above to match “wmanny’s” comment in a presentation given by Lindzen to Colgate University on 7/11/2008 which you can see here as a PDF:

http://portaldata.colgate.edu/imagegallerywww/3503/ImageGallery/LindzenLectureBeyondModels.pdf

– Anthony

UPDATE3: I received this email today  (4/10) from Dr. Lindzen. My sincere thanks for his response.

Dear Anthony,

The paper was sent out for comments, and the comments (even those from “realclimate”) are appreciated.  In fact, the reduction of the difference in OLR between the 80’s and 90’s due to orbital decay seems to me to be largely correct.  However, the reduction in Wong, Wielicki et al (2006) of the difference in the spikes of OLR between observations and models cannot be attributed to orbital decay, and seem to me to be questionable.  Nevertheless, the differences that remain still imply negative feedbacks.  We are proceeding to redo the analysis of satellite data in order to better understand what went into these analyses.  The matter of net differences between the 80’s and 90’s is an interesting question.  Given enough time, the radiative balance is reestablished and the anomalies can be wiped out.  The time it takes for this to happen depends on climate sensitivity with adjustments occurring more rapidly when sensitivity is less.  However, for the spikes, the time scales are short enough to preclude adjustment except for very low sensitivity.

That said, it has become standard in climate science that data in contradiction to alarmism is inevitably ‘corrected’ to bring it closer to alarming models.  None of us would argue that this data is perfect, and the corrections are often plausible.  What is implausible is that the ‘corrections’ should always bring the data closer to models.

Best wishes,

Dick


Sponsored IT training links:

Best quality 70-448 prep material is available for download. Pass the real exam using JN0-350 guide and E20-361 lab tutorial.


Advertisements

  Subscribe  
newest oldest most voted
Notify of

Cool. Good stuff! Nice to see Prof Lindzen make an appearance on WUWT.
PS. Can’t believe I’m the first to comment. That never happens.

John F. Hultquist

Serendipity is the effect by which one accidentally discovers something fortunate, especially while looking for something else entirely.
It isn’t immediately clear why
“Given the model climate sensitivities, this ‘blanketing’ should typically reduce the emissions by a factor of about 2 or 3 from what one would see in the absence of feedbacks.”
Is this because the models generate 1.5 to 5 degrees for the one degree temperature increase of doubling CO2?
Also, “ERBS” is the acronym for “Earth Radiation Budget Satellite”
http://asd-www.larc.nasa.gov/erbe/erbs.html
For non-scanning, see third paragraph here:
http://en.wikipedia.org/wiki/Earth_Radiation_Budget_Satellite

Graeme Rodaughan

Excellent Article. Very Clear – loved it.

anna v

From 1985 until 1989 the models and observations are more or less the same – they have, in fact, been tuned to be so. However, with the warming after 1989, the observations characteristically exceed 7 times the model values.
I would remind here that the models are tuned assuming linear approximations for the majority of variables entering the real equations ( that is what averages are). It is inevitable that as time goes on the fit becomes more and more irrelevant, because the true solutions are drastically non linear.
These data are definitive I would think on the subject of feedback.
It is interesting that the short wave has positive feedback, it ties up with what was discussed in another thread about plankton and UV and possible sun cycle effects.

What a treat, thank you Dr Lindzen.
I have often wondered whether accelerator (gas) pedals and brake pedals are reversed for you chaps who drive on the wrong side of the road. Having seen the picture I’m still unsure. Jeans and expensive shoes, that’s a tricky one for an old fart like me. Big pedal because that’s favoured by gas-guzzling wicked Americans, or big pedal because the brake has to be big to make sure they hit it from time to time? It’s all very confusing.

dhogaza

[snip – juvenile rant]

Ian Schumacher

The fact that always seems to be bypassed in descriptions of the green house effect is that the effect has an upper limit. The greenhouse effect is due to a ‘hole’ in frequency spectrum letting in high frequency light and absorbing outgoing low frequency light. This is similar to if you had only a small hole in a spherical cavity that was the only place light could enter (i.e. a black body). The greenhouse effect essentially increases the equivalent absorptivity of earth (makes it more like a black body). However, the effect is limited. The earth can only reach an ‘equivalent’ absorptivity of 1. The earth can not absorb more light than a black body would. If you look at what the temperature of a theoretical black body would be in the position of the earth, you will see that the earth is already very close to the limit. It is already quite close to a black body and therefore very close to the maximum temperature limit it can achieve.
The first thought one might have about this (what should be obvious concept) is ‘what about Venus’? Venus temperature can not be due to greenhouse effect and must be due to something else. There are a lot of things that are unknown about Venus (such as that it has no magnetic field yet has an atmosphere, that it rotates very slowy backwards). However the concept of a runaway greenhouse effect ramping temperatures up way beyond that of an equivalent black body is false. Such a ‘one-way’ mirror effect is impossible. If it wasn’t they you would have the ability to extract energy from background heat, which you can not.
We do have runaway greenhouse effect all the time when we come out of an ice age? Isn’t it curious how temperature increase very quickly and then suddenly stop at essential the same value every time? This isn’t strange at all when one realizes that this is simple because we have hit saturation.
(see)
http://www.ianschumacher.com/maximum_temperature.html

dhogaza

[snip – off topic, Don you don’t get to run this thread]

dhogaza

[ snip – Let me make this clear, we are not going to talk about smoking and cancer on this thread, call me what you want, complain all you like here or to your buddies over at Tammy or RC, but it is not going to happen. If you have something to say about the science presented here you are welcome to say it. – Anthony]

Phillip Bratby

Excellent work. But is there no data/analysis beyond 1999 to confirm the continuing negative feedback?

Mark N

Great Post, are those Lucchese Ropers on the pedals?

I’m still stuck on the infared effect of a trace gases or even something more significant like water vapor. Where is the empircal data (not more self fulfilling modeling or statistics) showing this is even detectable given all the other interactions?
I believe the feedback is bigger than the effect (GHG) 😉
Certainly, from 2000 forward will be challenging for any purely statistical or ‘model based’ approach to establishing the principal interactions … regardless of the feedback.
Maybe I’m just simple but when analyzing variation in a system it is best to first establish the variation in the inputs and then look at the interactions in the process. In industry its call ‘quality control’. In science its called ’cause and effect’.
At this point I guess I’d like to thank Lindzen for some quality control.

coaldust

There it is – empirical data compared to models. This type of test is a basic check to see if a model is correct. Do the modelers test their models against empirical data? This post gives me doubts.
It seems that none of the models are correct. LW feedback is negative. AGW is not cause for alarm.

Rick Beikoff

Beautiful, just beautiful!

Psi

Dr. Lindzen,
Thank you for a lucid, provocative exploration of one of the critical terms of the AGW debate. You’re a credit to the profession, and that’s saying a lot, because its my distinct impression – as an informed layman – that the profession (climate studies) is currently experiencing a lack of credibility with the general public.
Thanks for posting to WUWT.
Best Regards,
-psi (Fudd, literary studies)

Phillip Bratby

Anthony: I’m pleased you’ve snipped Dhogaza. I’ve been banned from RC, but I’ve seen Dhogaza over at RC say “Richard Lindzen, probably the most scientifically credible skeptic out there (tenured at MIT and all)”, then follow it up by attacks on him re smoking and cancer. There’s far too much attacking the person over at RC (see comments of Ray Ladbury, the arch personal attacker at RC) and far too little open discussion of the scientific facts.
Please feel free to snip this; it’s just my personal agreement with your policy of openly allowing discussion of the science, not the person behind it.

Another Mike D

to Ian @ 21:45;
I think that the main temperature difference between Venus and us isn’t the difference in energy coming from the sun, it’s the surface pressure. I live in Chinook country on the Eastern slope of the rockies I can vouch for a 30 degree centigrade temperature change over about 6 hours when the chinook kicks in (quick version: air cooled over the mountains follows down the mountain slopes, pushes up against valley air and forces compression. The valley air tries to get out of the way, but can’t move fast enough. The wind monitors where I work typically have at least one 90 mph 15-second wind gust per month during the winter.)
The blackbody comparison is a good one, we tend to forget that there are lots of other systems out there we can compare against. The chaotic Jupiter weather and super-storms show that “climate change” isn’t just a terrestrial happening.

Philip_B

Empirical derivation of 0.3C climate sensitivity (to a doubling of CO2) is very close to what some physicists calculate from first principles.
http://www.warwickhughes.com/blog/?p=87
When theory and independant empirical observation are in agreement thats a strong indication you are close to the right number.
BTW, the GCMs (climate models) are not theories and therefore their predictions have no scientific validity. Something the IPCC completely ignores.

Graeme Rodaughan

It’s the Evidence guys….
Hard empirical evidence – not the models, that counts.
The substitution of models as “proof” of Global Warming has corrupted the practice of science with the domain of Climate Science.
Climate Scientists need to get back in touch with Reality by testing their models (hypothesis, theory) against hard, empirical evidence.
Why they refuse to do so – they will have no credibility with me.
The AGW Proponents who read this blog/thread need to wake up to that fact that Negative Feedback is a Global Warming Killing Fact.
They then need to ask themselves why they are backing a movement that is directing resources to solve a non-problem instead of directing resources to solve real problems that matter to real people living real lives, such as poverty, hunger, illiteracy, access to clean water, etc.

John Edmondson

Does this imply that whatever greenhouse gases are added to the atmosphere, there is no way of artificially increasing the Earth’s surface temp?
If this is true, then there is no way of stopping or even delaying the onset of the next ice age, due within the next 1000 years.
Even if the IPCC model were correct, at least AGW would have stopped the next Ice age. 5c colder is much worse then 5c warmer.

Graeme Rodaughan

John Edmondson (22:46:34) :
Does this imply that whatever greenhouse gases are added to the atmosphere, there is no way of artificially increasing the Earth’s surface temp?
If this is true, then there is no way of stopping or even delaying the onset of the next ice age, due within the next 1000 years.
Even if the IPCC model were correct, at least AGW would have stopped the next Ice age. 5c colder is much worse then 5c warmer.

That’s right – Europe and North America do not have a viable future – barring the invention of some amazing new technologies….
Mind you in Australia, Ice Ages provide more water and lush rain forests will cover much of the east coast…

anna v

Ian Schumacher (21:45:21) :
The fact that always seems to be bypassed in descriptions of the green house effect is that the effect has an upper limit. The greenhouse effect is due to a ‘hole’ in frequency spectrum letting in high frequency light and absorbing outgoing low frequency light. This is similar to if you had only a small hole in a spherical cavity that was the only place light could enter (i.e. a black body). The greenhouse effect essentially increases the equivalent absorptivity of earth (makes it more like a black body). However, the effect is limited. The earth can only reach an ‘equivalent’ absorptivity of 1. The earth can not absorb more light than a black body would. If you look at what the temperature of a theoretical black body would be in the position of the earth, you will see that the earth is already very close to the limit. It is already quite close to a black body and therefore very close to the maximum temperature limit it can achieve.
….
(see)
http://www.ianschumacher.com/maximum_temperature.html Ian Schumacher

I went to your link. Interesting pov, and cannot see a logical error.
Would you say that the negative feedback shown by the data here is the beginning of an ice age? :).
What about that the total SW +LW is on the positive feedback side. How does it fit in the way you look at it, with band filters? That there exists another band except green house gases? ( could be the effect of the plankton :))

anna v

Sorry sorry that is ” can see NO logical error”!!!
[Not to worry. Either is correct. ~ Evan]

anna v

John Edmondson (22:46:34) :
Does this imply that whatever greenhouse gases are added to the atmosphere, there is no way of artificially increasing the Earth’s surface temp?
If this is true, then there is no way of stopping or even delaying the onset of the next ice age, due within the next 1000 years.
Even if the IPCC model were correct, at least AGW would have stopped the next Ice age. 5c colder is much worse then 5c warmer.

Never underestimate geoengineering. Badgers have done it and humans won’t be able to?
Ways will be found to decrease albedo or increase incoming sunshine, if we manage to reach that time out of the stone age, where the AGWers are determined to take us.

Evan Jones

The entire debate hangs on two issues: feedbacks and data integrity. Without positive feedback, runaway GW theory crumbles. Same, if the data is biased.
(It seems that for AGW, it’s two strikes, you’re out. More study is needed, of course, but that’s the way the wind seems to be blowing.)

James Gerdts

Anthony and all- Kudos to Dr. Lindzen for a clear, accessible, and enlightening post. Love the surprise ending confirming something many of us have long suspected- that the strong positive feedbacks predicted by IPCC are clearly “non-operable”. Wanted to check if others had seen the full-page Cato Institute sponsored letter to the President signed by many, including quite a few folks who are regular contributors, posters, or topics of discussion here and at CA. Ran into it in today’s LA Times, page A17. Highly recommend. Many who feel as we do are willing to risk the slings and arrows of an entrenched industry of doomsayers. I feel the “tipping point” AGW proponents will have to deal with is not the one they expected. Our point of view is gaining traction, day by day. Thanks Anthony for hosting a major touchstone in the movement to restore reason to the public debate.

Graeme Rodaughan (22:55:26) wrote in part: “Mind you in Australia, Ice Ages provide more water and lush rain forests will cover much of the east coast…”
Steady, Graeme. You could break a lot of hearts with statements like that. Australia is fragile. Australia is doomed. You must imprint that on your mind. Drink only seawater (I think that’s what causes the hallucinations) and get back into the mainstream.

Richard Heg

One thing that puzzles me in the environmental movement with regard to feedback is Gaia theory as proposed by James Lovelock which as defined in wiki http://en.wikipedia.org/wiki/Gaia_theory says:
“The Gaia hypothesis is an ecological hypothesis proposing that the biosphere and the physical components of the Earth (atmosphere, cryosphere, hydrosphere and lithosphere) are closely integrated to form a complex interacting system that maintains the climatic and biogeochemical conditions on Earth in a preferred homeostasis.”
This sounds quite elegant to me, that the biological and geological activity produce a feedback system which unlike our neighbors Mars and Venus has kept the earth in a state which allows life to exist. It goes on to say:
“Some relatively simple homeostatic mechanisms are generally accepted. For example, when atmospheric carbon dioxide levels rise, the biomass of photosynthetic organisms increases and thus removes more carbon dioxide from the atmosphere, but the extent to which these mechanisms stabilize and modify the Earth’s overall climate are not yet known.”
So my reading of Gaia theory says nothing to worry about the earth is full of feedbacks which keep thing relativelyly stable. Problem solved, now lets have a nice cup of tea.
However James Lovelock seems to have a different vision, he seems to see humans as a cancer. Here is a quote from a recent interview:
“Because of this (AGW), the cull during this century is going to be huge, up to 90 per cent. The number of people remaining at the end of the century will probably be a billion or less.”
http://www.newscientist.com/article/mg20126921.500-one-last-chance-to-save-mankind.html
I dont understand how i can look at a theory and come to the exact opposite conclusions of the person who proposed it.

AlexB

So we now have this, and the lack of the tropical troposphere hot spot and the lack of increasing ocean heat content and yet still, flying in the face of correct scientific method, the models are still accepted, because a lot of scientists in key positions really believe them to be true.
Also another thought, if the earth’s climate was inherently unstable and increasing CO2 causes increasing temperature which in turn causes further increasing temperature then, given that the paleoclimate record suggests that temperature drives CO2 increase wouldn’t the climate have spiralled out of control millennia ago?

Stephen Garland

The work of Michael Hammer (Jennifer Marohasy’s site 3rd March) may provide the mechanism for a lack of positive feedback suggested here. He describes how most of the energy lost from the earth is at wavelengths not absorbed by greenhouse gases. He also replies to a comment concerning correlation of his theories with satellite data.
He concludes:
‘Both the analysis from basic spectroscopy and the analysis based on atmospheric lapse rates give similar results and imply that greenhouse gases almost totally block energy loss to space at their absorption/emission wavelengths. That in turn suggests that a very significant portion of the energy loss from Earth’s surface is by direct radiation to space at wavelengths where the greenhouse gases do not absorb.’
‘This is in conflict with the Kiehl & Trenberth model and other similar models which suggest that most of the energy loss to space is from the atmosphere. If the atmosphere emits little energy, and then largely from the tropopause and stratopause, the concept of an equivalent radiation altitude has no meaning. Further, the analysis suggests that most of the radiative energy loss from the atmosphere to space is re-radiation of solar energy absorbed high up in the atmosphere.’
‘Surface temperature will increase with increasing greenhouse gas concentrations due to line broadening. The direct effect of carbon dioxide (in the absence of any feedbacks) using the IPCC quoted sensitivity and their postulated rise in carbon dioxide from 390 ppm to 560 ppm will contribute 0.4 degrees by 2070. The IPCC claim that positive feedback from water vapour will increase that to about 3C would imply a sensitivity of 48 watts/m2 per doubling in water vapour concentration. Such a high sensitivity is not compatible with the observed atmospheric temperature versus altitude profile.’
‘It should be noted that this analysis does not predict no radiation to space at the greenhouse gas absorption lines. There is still energy at these absorption lines emitted to space. For the well mixed greenhouse gases such as CO2 and CH4 this energy largely emanates from the stratosphere and is powered significantly by UV absorption of incoming solar radiation by ozone plus some absorption of surface radiation at 9.6 micron . In the case of water vapour, the energy emanates from near the tropopause and is powered significantly by near infrared absorption of incoming solar radiation by water vapour.

Syl

“The Results of an Inadvertent Test”
Insight is Beauty. Beauty is Insight.
Wow.
Thank you, Dr. Lindzen.

James Gerdts

Probably goes without saying, (but I neglected to). Text and pdf copies of the Cato ad are up on their site, http://www.cato.org, for anyone interested. Thanks- JG

Michael hauber

So why should we expect models forced by ocean temperature changes instead of (or is that on top of) Co2 etc to match what the IPCC models, based on the forcings of Co2, but not including any forcings for SST changes predict?

@FatBigot: In case you were being serious, the americans have their pedals the same way around as us. The big one is there because they tend to drive automatics and need somewhere to put their clutch foot when they’re emergency breaking.
And, is it me, or is the posh shoes guy in the picture going to end up wasting loads of fuel from riding the brakes all the time?

Rick Beikoff

And isn’t it a beautiful wind, evenmjones?

Chris H

Wow, great stuff! (Sorry, can’t offer anything more intelligent to say.)

Jack Simmons

Isn’t this amazing, as the temperature goes up, negative feedback goes up. As the temperature goes down, the feedback starts going positive.
Just like my car; when I see my speed going over the speed limit, I let up on the gas and perhaps, if necessary, apply the brakes. If I’m going too slow, I reverse the process.
I’m sure we could all think of several other systems with built in feedbacks intended to keep some parameter within range.
It almost seems as if the earth, like automobiles and home heating systems, were designed to maintain a comfortable environment for life.

vg

Looks like Hansen has decided that the models are no good after all quoted from
http://www.examiner.com/x-2534-SF-Wellness-Examiner~y2009m3d29-James-Hansen-sets-the-record-straight-on-the-New-York-Times-article-The-Civil-Heretic
“I looked up Freeman Dyson on Wikipedia, which describes his views on “global warming” as below. If that is an accurate description of what he is saying now, it is actually quite reasonable (I had heard that he is just another contrarian). However, this also indicates that he is under the mistaken impression that concern about global warming is based on climate models, which in reality play little role in our understanding — our understanding is based mainly on how the Earth responded to changes of boundary conditions in the past and on how it is responding to on-going changes”.
I would say that the scientist leading the AGW’res have about 12-24 months before their careers are terminated or they will be required to change “research activities” LOL

vg

It would seem that Dr Lindzen is far more qualified as well to make statements about AGW…LOL
http://www.giss.nasa.gov/staff/jhansen.html

Richard Heg

“cloud behavior (a well acknowledged weakness of current models)”
recent research from NASA on clouds and aerosols:
http://www.newscientist.com/article/dn16864-halo-effect-explains-brightest-patches-of-sky.html

Alan the Brit

Excellent, first class. A calm look at reality is what is always needed.
Slightly OT then, IF we’re headed for a new ice age within 1,000 years, is there some organisation that can take the UN & its IPCC & the WMO to task for overt ignorance of this basic fact of life, & sue the hell out of them for shear incompetence! Anyway the south west of England should be realitvely ice free, but rather crowded!!!! I’d better get practicing the flint napping.

Brilliant. A tour-de-force.

James Griffiths

Mike Guerin (23:29:36) :
“Is it just me? Am I that smart and everyone else that stupid. Isn’t it obvious that for life to exist on earth there must be a strong negative feedback effect in place. Without strong negative feedback does anyone sane really think that the climate on earth would remain stable enough long enough for life to evolve and prosper?”
Mike, no you’re not the only one!
If the theory behind AGW is correct, the logical conclusion is that the natural response of the earth to an increase in heat is to effectively “turn the thermostat up”
Clearly, we wouldn’t be here today if that was the case!
Of course, to increase the rate of radiation to space, it is also logical that the atmosphere would increase rapidly in temperature to facilitate this, but this shouldn’t be mistaken for runaway positive feedback.

tmtisfree

The subtlety with AGW propaganda is that it is a self-reinforcing mechanism:
1/ climatologists validate their climate reconstructions by noting that they agree with the models ;
2/ in IPCC’s reports, models are valid because they agree with past climate reconstructions.
They can not be wrong.
Bye,
TMTisFree

Jack Hughes

It’s common sense that there is negative feedback. This is what keeps the climate fairly stable.
If there was positive feedback, then the climate would be unstable – and would have been de-stabilised by now with disastrous consequences.

J.Hansford

Clear, concise…… A bell tolling the end of a hypothesis that should have been falsified ten years ago. Good on you Dr Lindzen.
Now. considering that the reality has been Politics and not Climate….
Is our democracy strong enough to override the massive political impetus that AGW has built up….? After all, there is a whole green Socialist agenda relying on those carbon taxes and emission trading schemes…. and the careers of those that have attached themselves to a lie. Whole industries are gearing up to go green.
It will be an interesting time ahead.

Allan M R MacRae

Another approach with a similar answer.
EXTRAPOLATING OBSERVED WARMING TRENDS
by Jarl Ahlbeck (Turku, Finland) (done in 2005 or earlier)
We should not confuse the word “possibility” with “probability” as some
people do when they compare different simulated results with each other.
Everything is possible, but probability has a mathematical definition and
should not be used when comparing simulated results. These reported
(Nature, 27 Jan 2005) values of 1.9 to 11.5 deg C warming are
possibilities, computerized speculations, nothing else. Also: Let’s not
to talk about percent possibilities. All possibilities are
100% possible.
But of course, a kind of reality check can be made very easily: Say that
half of the observed 20th century warming of 0.8 deg is due to greenhouse
gases (CO2 increase from 280 to-370 ppm) and half is due to increased sun
activity. As the relation is logarithmic, 0.4 deg=k*ln(370/280), giving
k=1.435. For 2*CO2 (560 ppm), an additional warming of 1.435*ln(560/370) =0.59 deg C could be expected. This is a speculation as good as any
produced by a computer climate entertainment program.
In fact, 0.59 deg may be an overprediction as the observed warming has been
partly caused by CFCs and CH4. As we know, the atmospheric concentration of CFC has decreased, and there is no more increase in CH4. This means that
the k-value for CO2 should be lower than 1.435.
k = deltaT/ln(CO2b/CO2a)
deltaT = k*ln(CO2b/CO2a)
For various % of 0.8 degree C temp rise in 20th century ascribed to CO2:
(MacRae calculations and comments below)
k CO2a CO2b deltaT
As Above Case
1.435 280 370 0.4 checks Assumes 50% deltaT
1.435 370 560 0.595 checks due to >CO2.
2.870 280 370 0.8 Assumes 100% deltaT
2.870 370 560 1.189 due to >CO2.
Both 50% and 100% seem too much high, given the better correlations below.
0.718 280 370 0.2 Assumes 25% deltaT
0.718 370 560 0.298 due to >CO2.
From ~1850-1940, NH temperature rose by ~0.6 deg prior to the period of CO2 and fossil fuel growth – is the best correlation a “+25% deltaT” = i.e. plus 0.3 degrees?
0.000 280 370 0 Assumes 0% deltaT
0.000 370 560 0.000 due to >CO2.
Given the excellent correlation between NH temperature and solar activity since at least 1750, it is plausible that temperature is completely insensitive to CO2 level.
-0.718 280 370 -0.2 Assumes -25% deltaT
-0.718 370 560 -0.298 due to >CO2.
From 1940-1975, NH temperature fell by ~0.2 deg during the highest period of CO2 and fossil fuel growth – is the best correlation a “-25% deltaT” = i.e. minus 0.3 degrees?
Informal conclusions:
Best fit approx. 0, +/- 0.3 degrees C for a doubling of CO2.
Even doubling CO2 is a non-issue – dump Kyoto and focus on real problems.
****************************

Graeme Rodaughan (22:55:26) :
quote Does this imply that whatever greenhouse gases are added to the atmosphere, there is no way of artificially increasing the Earth’s surface temp?
If this is true, then there is no way of stopping or even delaying the onset of the next ice age, due within the next 1000 years. unquote
I have seen The Great Slave Lake only on radar, but it has always fascinated me: now I can think of a reason to go there. One can use it to test what’s going on in the Arctic Ocean. Give me a budget of a few tens of millions and this is what I’d do: check the water surface for pollution, particularly light oil and surfactant contamination, either clean it up or dirty it more and check the emissivity as night falls. Oil and surfactant smooth water. Smoothed water should warm faster during daylight and cool slower at night. Easily monitored from the air. It might explain the warming of Lake Superior, even though the experiment is too limited to check the stratocu effect which I’d expect over the open sea.
Then check off the North Slope and around Sakhalin for the same level of pollution. Yes, feedback is probably negative, but e pur si muove — something’s causing the warming and my bet is oil and surfactant.
Count them, four peer-reviewed papers saying that commonsense will eventually prevail. Thank you Professor Lindzen. BTW (insert smily here) you do know that the Met Office graph you used has got the dreaded Folland and Parker bucket correction incorporated and thus suppresses the abrupt warming in 39/40? This hides the…. (covers head, runs, a faint wail of ‘Kriegesmarine effect’ drifts away on the breeze….)
Graeme, if you want to stop an Ice Age, just pump more oil and Tide onto the parts of the ocean which are warming most rapidly — the big gyres look interesting. It’s happened before — I’m not sure how you’d check for a natural breaching of a major oil reservoir during the PETM, but for a few million more I’ll put my thinking cap on.
JF
.3? I’d have bet a pint on .6.

Chris Wright

It does seem that climate feedback is of huge importance, and it is this that may provide the nails for the coffin of strong AGW. But which dominates, positive or negative? The fact that i am sitting at my desk and typing this strongly suggests that negative feedback dominates.
In my professional career spanning several decades I have had a lot of experience with servomechanisms, which use negative feedback to achieve a desired result. A badly designed or faulty system will still broadly achieve the desired result, such as maintaining a commanded position. But it will tend to oscillate, sometimes with a simple harmonic motion or a far more complex and apparently random motion. It will respond badly to external influences. But overall it will maintain the desired result.
Looking at graphs of climate, I’m reminded of a poorly designed servomechanism. The climate often oscillates and responds poorly to outside effects such as earthquakes. When returning to the ‘commanded’ position it will often overshoot quite badly. But it does return, so that the overall global temperature over the last few thousand years has been remarkably stable, with variations measured mostly in fractions of a degree.
Clearly the global climate is a servomechanism. And servomechanisms work by negative feedback. I think Professor Lindzen’s work is of extraordinary importance.
Chris

Mike McMillan

Tech note, mes amis:
You can get the Degree symbol º on a PC keyboard by holding down the Alt key and typing 167 in the numeric keypad. Release the Alt key, and the º appears. Google “alt characters” to find listings of other characters.
.
Ian Schumacher (21:45:21) :
. . . The first thought one might have about this (what should be obvious concept) is ‘what about Venus?’ Venus’ temperature can not be due to greenhouse effect and must be due to something else.

Another Mike D (22:39:57) :
I think that the main temperature difference between Venus and us isn’t the difference in energy coming from the sun, it’s the surface pressure. . . .

Right. Temperature decreases with altitude as the pressure decreases, and vice versa. The temperature lapse rate has to do with the specific heat ratio of the gasses involved, very close to 1.4 for air, and between 1.2 to 1.3 for Venus’ CO2 atmosphere. Venus has 90 times earth surface pressure (90 bar), with a resulting high temp. The odd thing here is that with the different lapse rate, if Venus had a 90 bar AIR atmosphere, its surface temp would be a couple hundred ºC hotter, just the opposite of the runaway CO2 greenhouse image commonly peddled.
As close to the sun as Venus is, I’d guess its high albedo is responsible for the temps not being as high as they might otherwise.
.
Thank you Dr Lindzen. On a related area, CO2 has only an absorption band around 4 microns that it doesn’t share with water. According to the atmospheric transmission charts, there isn’t much energy up or down in that region. Are the satellites like ERBS capable of measuring how much 4 micron radiation is reaching the satellite from earth? That would be how much energy remains for CO2 to capture, and thus an upper limit to how much additional heat the doubling of CO2 could add. From the charts, it doesn’t look like much.