I received this presentation of the “Bjerknes Lecture” that Dr. James Hansen gave at the annual meeting of the American Geophysical Union on December 17th. There are the usual things one might expect in the presentation, such as this slide which shows 2008 on the left with the anomalously warm Siberia and the Antarctic peninsula:
Source: James Hansen, GISS
Off topic but relevant, NASA has recently “disappeared”updated this oft cited map showing warming on the Antarctic peninsula and cooling of the interior:
There is also some new information in Hansen’s presentation, including a claim about CO2 sensitivity and coal causing a “runaway greenhouse effect”.
Hansen makes a bold statement that he has empirically derived CO2 sensitivity of our global climate system. I had to chuckle though, about the claim “Paleo yields precise result”. Apparently Jim hasn’t quite got the message yet that Michael Mann’s paleo results are, well, dubious, or that trees are better indicators of precipitation than temperature.
In fact in the later slide text he claims he’s “nailed” it:
He adds some caveats for the 2xCO2 claim:
Notes:
(1)
It is unwise to attempt to treat glacial-interglacial aerosol changes as a specified boundary condition (as per Hansen et al. 1984), because aerosols are inhomogeneously distributed, and their forcing depends strongly on aerosol altitude and aerosol absorbtivity, all poorly known. But why even attempt that? Human-made aerosol changes are a forcing, but aerosol changes in response to climate change are a fast feedback.
(2)
The accuracy of our knowledge of climate sensitivity is set by our best source of information, not by bad sources. Estimates of climate sensitivity based on the last 100 years of climate change are practically worthless, because we do not know the net climate forcing. Also, transient change is much less sensitive than the equilibrium response and the transient response is affected by uncertainty in ocean mixing.
(3)
Although, in general, climate sensitivity is a function of the climate state, the fast feedback sensitivity is just as great going toward warmer climate as it is going toward colder climate. Slow feedbacks (ice sheet changes, greenhouse gas changes) are more sensitive to the climate state.
Hansen is also talking about the “runaway” greenhouse effect, citing that old standby Venus in part of his presentation. He claims that coal and tar sands will be our undoing:
Hansen writes:
In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect. If we also burn the tar sands and tar shale (a.k.a. oil shale), I think it is a dead certainty.
That would be the ultimate Faustian bargain. Mephistopheles would carry off shrieking not only the robber barons, but, unfortunately and permanently, all life on the planet.
I have to wonder though, if he really believes what he is saying. Perhaps he’s never seen this graph for CO2 from Bill Illis and the response it gives to IR radiation (and thus temperature) as it increases:
It’s commonly known that CO2’s radiative return response is logarithmic with increasing concentration, so I don’t understand how Hansen thinks that it will be the cause of a runaway effect. The physics dictate that the temperature response curve of the atmosphere will be getting flatter as CO2 increases. Earth has also had much higher concentrations of CO2 in past history, and we didn’t go into runaway then:
Late Carboniferous to Early Permian time (315 mya — 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ).
There’s lots more in this paper to behold in wonderment, and I haven’t the time today to comment on all of it, so I’ll just leave it up to the readers of this forum to bring out the relevant issues for discussion.
I’m sure Steve McIntyre at Climate Audit will have some comments on it, even though his name is not mentioned in the presentation. My name was mentioned several times though. 😉
this post coincides with me being more aware of a localised possibly micro-climatic change that’s occurring in my freezer. Unfunded research reveals that the ice is disappearing!!! I blame a Scottish distiller . . .
Peter
December 21, 2008 2:24 pm
PeteM:
This can be explained by a run away greenhouse effect on Venus
Nothing to do then with the fact that: a) the atmospheric pressure of 90 atmospheres, b) it has no magnetic field and c) it rotates extremely slowly.
If the runaway CO2 effect could exist on Earth then, by constructing huge glass domes, filling them with CO2 and using the resultant heat to generate electricity, we could solve the worlds energy problems and stop using fossil fuels altogether.
Except for one small problem – it won’t work.
foinavon
December 21, 2008 2:28 pm
Re Bill Illes:
Yes it is. It reproduces the temperature response resulting from raised atmospheric CO2 according to a climate sensitivity of 3 oC of warming per doubling of atmospheric CO2. It essentially reproduces your graph. Of course I may not have got there in exactly the same way that you did, but it’s straightforward to derive an equation for the logarithmic relationship of temperature to raised CO2 according to a climate sensitivity of 3 oC. My graph gives the absolute surface temperature at equilibrium assuming that the earth’s temperature was 15 oC at a pre-industrial concentration of 280 ppm.
The main point is that the representation in the introductory post is highly misleading since is is dominated by the very very large temperature response over the completely unrealistic region of the CO2 concentration (e.g. 0 – 50 or even 100 ppm).
If someone wants to get a proper feel of the earth’s temperature response to raised CO2 during contemporary periods and in the future then the graph in the introductory post is pretty useless. Likewise if one wants to address Hansen’s scenario properly (that’s the point of this thread Ibelieve!), then one should use a proper representation of the earth’s temperature response over the range of CO2 concentrations relevant to the discussion.
And your reproduction of Raymond Pierrehumbert’s statement is entirely compatible with my equation (and your graph). But it’s not very relevant. We’re considering the earth’s warming response to very large increases in atmospheric CO2 concentrations, not the effect of eliminating atmospheric CO2 entirely (we don’t want to go there either!).
@Grant Hodges
I agree with you. Mr Hansen’s activity may be sort of interesting but the “true” phenomena of our times went off from this site’s radar.
Regards
PeteM
December 21, 2008 2:30 pm
Smokey (13:59:44) :
Your Mercury example has unique problems because Mercury’s day and year are the same, and Mercury has essentially no atmosphere. Your implication that the day side and night side should be averaged is incorrect.
> I didn’t say they should be averaged — Mercury’s temperature varies like this because it has no atmosphere to avoid the consequences of its rotation and distance form the sun . Venus ( despite being further from the sun) achieves higher temperatures because it has an atmosphere.
If CO2 were the scary greenhouse gas that AGW proponents believe it is, then Mars, with 95%+ CO2 [compared with Earth’s tiny .038] would have an average temperature greater than eighty degrees below zero, despite its thin atmosphere. But as we now understand, the heat retention of CO2 begins to fall off logarithmically after the first 20 ppmv. So Mars remains a very cold place, and 95% CO2 does not make a difference.
> 95% of a much,much thinner atmosphere than Earth . On Venus high greenhouse gases make a difference because there is a much thicker atmosphere.
I can’t speak for Hansen about why he didn’t mention it so I’m only responding to your point.
“When you refer to ice core data; just what “data” do you mean ?”
George E Smith
George, thanks for your very comprehensive response. In my trawling over time, I cannot remember exactly which study, by whom or when…which isn’t very helpful I know.
However the studies to which I refer make use of ice cores by measuring phylo-plankton sediment (or lack of it) as evidence of periods when polar regions were relatively ice free. As I understand it, the claim is that because there is little or no evidence of such sediment within ice cores over the past 10,000 years, this suggests that the northern ice cap has remained more extensive than it is currently over that period.
I am aware that ice core measurements are used in a multitude of ways, but this one is of interest to me in particular because of the work of Prof. Easterbrook’s in proposing that there have been a number of warm periods with the last 10 millennia – or certainly since the end of the last ice age.
foinavon
December 21, 2008 2:47 pm
That’s not really true crosspatch. The fact that enhanced CO2 concentrations result in enhanced warming of the earth has got very little to do with models. It’s the result of a whole load of empirical (and theoretical) analyses.
In fact the role of CO2 in warming the earth has been known since the middle of the 19th century, and already by the end of the 19th century Arrhenius had established that the earth’s temperature rose as the logarithm of the enhanced CO2 concentration.
There is a whole load of data that bears on the quantitative relationship between enhanced CO2 and enhanced temperature. This has been obtained by examining the temperature response during ice age cycles…. the relationship between atmospheric CO2 and temperature in the deep past (last 500 million years)…the analysis of ocean heat uptake….the temperature response following volcanic eruptions….the temperature response to the solar cycle and so on…
…these generally give a result near 3 oC of warming (plus/minus a bit) per doubling of atmospheric CO2. Hansens’ recent analysis of the ice age cycles illustrated in his powerpoint presentation discussed on this thread is yet another example..
That’s not to say that this isn’t also found by modelling. However that’s because the models are parameterized according to our empirical understanding of the real world. But it’s the empirical analyses, measurements and so on that inform the models and not the orher way round….
And yes, we all know that the response is not linear. It’s logarithmic. You can make a very simple calculation of the earth’s temperature response to enhanced CO2 within a climate sensitivity of 3 oC of warming per doubling of atmospheric CO2 using the equation I dumped in my post above:
see post at: 12:52:53
and as Bill Illes points out (post at 14:00:54) in his reproduction of Raymond Pierrehumbert’s quotation from the paper he links to:
“Eliminating the 50W/m2 of tropical CO2 greenhouse effect would drop the tropical temperature by about 25 K, once amplified by water vapor feedback.”
it would be extraordinary to propose that raising atmospheric CO2 levels further (rather dramatically according to the “all the coal and tar shale’s burnt” scenario being discussed on this thread) wouldn’t result in a very large temperature rise (it would be at least 10 oC according to a climate sensitivity of 3 oC, without any rather unpleasant unforseen feedbacks like methane hydrate release and widescale deforestation…)
I don’t think your point about hot spots in models is correct, and they certainly don’t depend on an infinitely deep atmosphere. In fact raising atmospheric CO2 levels results in an increase in height at which longwave radiation is radiated into space. That’s an essential part of the greenhouse effect, and as far as I’m aware it’s represented in models, predicted by theory and observed in reality…
Alan Peakall
December 21, 2008 2:51 pm
Smokey,
Mercury’s day and year are *not* the same length. The tidal influence of the Sun is insufficient to prevail over the 3:2 resonance (sidereal day=58 Earth days, year=88 Earth days) to yield synchronous locking. This knowledge dates from the late 1950s.
That said, the resulting longer solar day of Mercury 176 days (like the long solar day of Venus 117 Earth days) must militate against the establishment of a stable climate as you suggest.
Stefan
December 21, 2008 2:55 pm
How on earth can so many of these eminent scientists be wrong?
Or are they just human like everyone else?
Dave Dodd
December 21, 2008 3:10 pm
If this is OT I apologize, but it certainly is not off subject of the blog. The AGW hypothesis is based on a single premise, namely: Pre-industrial CO2 levels were approximately 280 ppm — present CO2 levels are apporximately 380 ppm, the increase “obviously” human induced. I do not know Ernst-Georg Beck, but he seems well respected in his field. His paper, “180 Years accurate CO2-Gas analysis of Air by Chemical Methods (Short Version)” makes the case that pre-industrial CO2 levels were approximately 355 ppm and temperature dependent, rather than forcing, seemingly blowing the entire AGW argument out the window. He further makes a very strong argument that the 280 ppm value was “cherry picked” by ignoring 90% of known research data. Any comments?
A copy here: http://www.anenglishmanscastle.com/archives/003818.html
crosspatch
December 21, 2008 3:19 pm
“Eliminating the 50W/m2 of tropical CO2 greenhouse effect would drop the tropical temperature by about 25 K, once amplified by water vapor feedback”
The impact of water vapor certainly seems to be something that could cause a drastic change over a short period of time. From my reading of that paper, a reduction of oceanic evaporation rate could reduce atmospheric water vapor and result in a drastic cool down in a short period of time. And in fact we see severe drought in the equatorial region during Northern Hemisphere glaciations to the extent where rain forest is replaced by grasslands. That could be a self-reinforcing mechanism that keeps the system stable in the cold state.
Frank Ravizza
December 21, 2008 3:32 pm
I wonder if Hansen took any critical questions following this presentation? I would have several.
jarhead
December 21, 2008 3:51 pm
to Ben Kellett
re ice cores….google zbigniew jaworowski
Joseph
December 21, 2008 4:09 pm
What!? Multiple references to Hades? Destroying creation? Preserve creation? This, in a lecture at a scientific conference? That’s not science! Pastor Jim is really going off the deep end now. Methinks he has reached his own personal “tipping point”.
foinavon
December 21, 2008 4:11 pm
Dave Dodd,
I suspect you’ll find with deeper investigation that Beck’s data is not a reliable atmospheric CO2 record, although it is interesting in the historical sense…
Beck has complied all of the atmospheric CO2 measures that he has been able to find covering the past nearly 200 years. Unfortunately as acknowledged by many of the scientists that made these measurements, the data were often heavily contaminated by measuring in laboratories in cities (e.g. Vienna, Giessen, Kew gardens London, Frankfurt, Poona India, Belfast, Clermont Ferrand, Copenhagen, Paris, Bern, Rostock in Denmark, Ames Iowa….and so on).
These values are woefully inadequate as measures of atmospheric CO2, since cities give very high CO2 levels as they’re close to emission sources. So, for example, one of the sets of data that Beck uses is that of W. Kreutz in 1939/40 in Geissen.
Kreutz’s laboratory was not far from the railway station, and Kreutz himself pointed out that his data were affected by soil and industrial/urban sources. He found values that were 40 ppm higher in the afternoons than mornings, and higher CO2 on windless days than windy days (when high emissions were dispersed) and so on… That’s what we find today if we measure CO2 levels in cities.
To put that into perspective, a 40 ppm change in 1/2 a day, is around the change in atmospheric CO2 occurring in 2000 years during an ice age transition…!
Unfortunately Beck is misleading the unwary through assertions of “Accuracy” (as in his title). The measures he quotes are not accurate with respect to the atmospheric CO2 concentrations, even if they were precise with respct to a valid determination of local urban/industrial CO2 levels.
Some early practitioners recognisied the problem of massive contamination of CO2 data from urban measurements and made great efforts to obtain data from uncontaminated sources. Jules Reiset, for example, made measurements in the late 19th century on the windy N. Atlantic coast, far from urban centres. His values were rather similar to those obtained from ice cores for that period (around 290-300 ppm). We can also be more confident of his data since he identified the clear cyclic variation in atmospheric CO2 resulting from N. hemispheric plant growth/decay cycles…
foinavon
December 21, 2008 4:14 pm
Frank Ravizza,
why not put your questions here. Perhaps some of the posters can address them..!
Patrick Henry
December 21, 2008 4:16 pm
Mars’ atmosphere is 90% CO2, and it is extremely cold there. Must be the runaway greenhouse effect caused by the dominant greenhouse gas.
Alan Peakall, I appreciate your explanation of Mercury’s rotation. Dave Dodd:
Beck… makes the case that pre-industrial CO2 levels were approximately 355 ppm and temperature dependent, rather than forcing, seemingly blowing the entire AGW argument out the window.
And that is why the AGW contingent went absolutely ballistic when they understood what Beck was saying. They know that if Beck is even somewhat correct, their AGW hypothesis is defenestrated.
Lansner, Frank
December 21, 2008 4:30 pm
@Smokey and Pete M
Temperature at Venus:
Not only is the temperature dependent on distance to the sun , it also a function of pressure:
Temp = F(Distance to sun, pressure)
See here the stunning similarities between planets, for pressures over 0,3 atm: http://www.glar.gl/planet.jpg http://zebu.uoregon.edu/~imamura/121/images/FG09_007.jpg
And “ladies and gentlemen”, if you check the temperature at Venus at 1 atm pressure, you find 330 K.
That is, just around 45 K more than earth at 1 atm. In K that is around 15% warmer af Venus, which is explainable by distance.
Now – il grande experiment to show real-world effect of greenhouse gasses:
Imagine a planet with no greenhouse gasses but still a thich atmosphere.
Arrhenius gave greenhouse gasses all “blame” for the atmospheres isolation effect.
So?
Well, a planet without greenhouse gasses should then have a temperature profile with no isolation effect… This planet should have a temperature-pressure curve totaly vertical.
The pressence of greenhouse gasses are very different from planet to planet. But they all have a quite similar slope in their temp-presseure graph. No planets seems to have different temperature characteristic due to atmosphere contents?
Mike C
December 21, 2008 4:31 pm
My first point is that Hansen is backing off on coal and is now targeting shale sands.
My second point is that PeteM has not thought much through when it comes to comparrisons involving Venus. Not only is Venus closer to the sun, it has a super rotating upper atmosphere of sulphur gases that act like a blanket. Venus also has no magnetic field so it is directly impacted by the solar wind. Nor does Venus have any water at the surface. Comparing Venus and Earth is like comparing an apple to a Mac Truck, there is no comparrison. Hansens efforts to the same, especially since he comes from that field, is idiotic.
Graeme Rodaughan
December 21, 2008 4:31 pm
Some entertainment (from my CO2 Fevered imagination) – perhaps? Climate Zombie.
Headline From the “The Herald” Newspaper, circa sometime in 2009. “Climate Zombie Haunts Town”…
Meanwhile in the Sceptic household, Arthur and Martha prepare for battle.
Martha: “Arthur, have you got the shotgun?”
Arthur: “Yes Martha.”
Martha: “Have you got the special shells that are effective against the Climate Zombie?”
Arthur: “Yes Martha.”
Martha: “Are you sure – let’s list them and make sure.”
Arthur: “There’s the following shells”
– Arthur reads from the blurb on the shell box.
“1. Vostok Ice Cores show CO2 Trailing Temperature Rises SHELL.
2. No Troposphere HotSpot AGW Fingerprint SHELL.
3. Climate Models not Empirically Validated SHELL.
4. One Fact Kills Consensus SHELL.
5. Poorly Sighted and Calibrated Temperature Instruments SHELL.
6. Data Mismanagement SHELL.”
Martha: “Good – at least we are prepared with some real science.”
Arthur: “And your’ve got the Razor?”
Martha: “Occam’s best and at hand.”
– Glass shatters loudly.
Martha: “The back window…”
– Arthur and Martha rush to the back room and burst through the door. The Climate Zombie is inside the house. They both gag from the reek of corruption that has filled the room. Arthur recovers first – and fires from the hip.
Arthur: “Take that – fiend”
– Arthur lets rip with 6 body shots from his pump action shot gun. The Zombie staggers backwards from the impact of the scientific arguments embedded into the shells. Then it lurches forward, with a leering grin.
Zombie: “Ha, you fool – Science cannot refute me – I’m invincible”.
– The zombie lashes out and throws Arthur against the wall where he crumples into a broken heap.
Martha: “Art!”
Martha leaps forward – Occams Razor firmly in hand, first feinting with a simpler hypothesis before going with a deadly “Climate Change by Natural Variation” Manoeuvre.
The Climate Zombie, moves quickly with a “Stacking the Peer Review Board” counter and Martha’s Occams Razor clatters to the floor.
Zombie: (Scornfully) : “Occam’s Razor – What next – will you quote Sir Karl Popper at me, or try a falsification manoeuvre?”
– The Zombie seizes the now defenceless Martha, and drags her off her feet as he sneers into her face.
Zombie: “Never mind… – the pain will not last for long.”
Martha: (Defiantly) “Do your worst!”
– Martha gives the Zombie the finger.
– Zombie kills Martha.
The Climate Zombie looks at the pair of lifeless sceptics. Nodding to himself and contemplating the feast of sceptic brains that is about to begin.
Zombie: “They keep trying science – don’t they know that I am a multi-faceted Politico-Religious Meme backed by vested interests in Government, Industry and a host of NGOs seeking wealth and power.”
– Then the Zombie shivered.
Zombie: “Thankfully – they haven’t tried Parody – it’s my Achilles heel –it’s hard to be serious and frightening if people are laughing at you.”
(end)
davidc
December 21, 2008 4:36 pm
“Now we can look at 800,000 years. The same sensitivity fits for the earlier times, even better. Bottom line: The fast feedback climate sensitivity is nailed. It is 3 C for doubled CO2, plus or minus half a degree.” (p7/39).
Since it is nailed at 3C over all time periods under consideration it’s clear that Hansen is claiming a linear relation between T and CO2. That is,
T = A + B*CO2
where A and B are constants. If we take an arbitrary reference point as CO2 concentration C1 at temperature T1 and take Hansen’s sensitivity figure of 3C for a doubling of CO2 we get
T = T1 – 3 + (3/C1)*CO2 [1]
Check: take CO2 = 2*C1 we get T= T1+3.
It seems to me that Hansen gets his sensitivity number from the CO2 and T estimates from the ice core data on p7/39 (eg C1=200ppm at T1 = -4C; C2=250ppm at T2 = -1C) but I get different results. Any suggestions?
But taking Hansen’s result in the form of eq[1] all we need to do (following Hansen) to predict future temperature is to predict future CO2 (the data is so regular that a simple extrapolation would be enough) and substitute in eq[1]. Why bother with GCMs, forcings and all sorts of complications when it is a simple as this?
Well, it seems that Hansen is referring here to an “equilibrium” or “fast feedback “sensitivity” and maybe the detailed modeling is needed to track the time-course of the approach to this equilibrium.
My first question is: based on the proposed greenhouse mechanism wouldn’t the response of temperature to current CO2 concentrations be very rapid (a few days at most?)?. I know that long times are involved in recycling via the deep ocean, but that is irrelevant if we have a reliable estimate of CO2 “now”. If you want to predict the atmospheric CO2 resulting from current CO2 production it would be necessary to model those factors; but firstly, I don’t think that’s being done (anyone know?) and secondly the one data set that seems to be reliable and predictable (so far) is the recent CO2 rise. Much better to simply extrapolate.
My second question is: why not use the same data as used for the sensitivity estimate to estimate lag-times. If the data he’s using is the Vostok ice core data I think I know why, that the change in T precedes the change in CO2 and the whole story falls apart. Is the sole reason for the GCMs, forcings etc, to estimate lag-times involved in approach to equilibrium?
I know that what I’m saying here is a gross oversimplification of a complex issue, but it seems to me to be what Hansen is saying when he nails sensitivity at 3C per doubling (without reference to the many other potentially significant variables). What else is there to know?
old construction worker
December 21, 2008 4:46 pm
PeteM (13:54:55) :
‘The information I provided shows that is not always a dominant factor .
Venus is suffering from a strong green house effect’
Venus is suffering? It seems to me the green house effect on Venus is normal for Venus.
You have to remember Hansen’s run-a-way green house effect on Venus is still an unproven theory.
foinavon
December 21, 2008 4:47 pm
Smokey,
I don’t think anyone went ballistic over the Beck stuff. It’s clearly nonsense, as a little bit of investigation and clear thinking will illustrate. In general it was noticed and essentially ignored.
The aim in science is to establish supportable explanations for observations. That’s how we learn stuff and make progress (not to mention policy decisions). Things that are clearly erroneous do not need dwelling on.
this post coincides with me being more aware of a localised possibly micro-climatic change that’s occurring in my freezer. Unfunded research reveals that the ice is disappearing!!! I blame a Scottish distiller . . .
PeteM:
Nothing to do then with the fact that: a) the atmospheric pressure of 90 atmospheres, b) it has no magnetic field and c) it rotates extremely slowly.
If the runaway CO2 effect could exist on Earth then, by constructing huge glass domes, filling them with CO2 and using the resultant heat to generate electricity, we could solve the worlds energy problems and stop using fossil fuels altogether.
Except for one small problem – it won’t work.
Re Bill Illes:
Yes it is. It reproduces the temperature response resulting from raised atmospheric CO2 according to a climate sensitivity of 3 oC of warming per doubling of atmospheric CO2. It essentially reproduces your graph. Of course I may not have got there in exactly the same way that you did, but it’s straightforward to derive an equation for the logarithmic relationship of temperature to raised CO2 according to a climate sensitivity of 3 oC. My graph gives the absolute surface temperature at equilibrium assuming that the earth’s temperature was 15 oC at a pre-industrial concentration of 280 ppm.
The main point is that the representation in the introductory post is highly misleading since is is dominated by the very very large temperature response over the completely unrealistic region of the CO2 concentration (e.g. 0 – 50 or even 100 ppm).
If someone wants to get a proper feel of the earth’s temperature response to raised CO2 during contemporary periods and in the future then the graph in the introductory post is pretty useless. Likewise if one wants to address Hansen’s scenario properly (that’s the point of this thread Ibelieve!), then one should use a proper representation of the earth’s temperature response over the range of CO2 concentrations relevant to the discussion.
And your reproduction of Raymond Pierrehumbert’s statement is entirely compatible with my equation (and your graph). But it’s not very relevant. We’re considering the earth’s warming response to very large increases in atmospheric CO2 concentrations, not the effect of eliminating atmospheric CO2 entirely (we don’t want to go there either!).
@Grant Hodges
I agree with you. Mr Hansen’s activity may be sort of interesting but the “true” phenomena of our times went off from this site’s radar.
Regards
Smokey (13:59:44) :
Your Mercury example has unique problems because Mercury’s day and year are the same, and Mercury has essentially no atmosphere. Your implication that the day side and night side should be averaged is incorrect.
> I didn’t say they should be averaged — Mercury’s temperature varies like this because it has no atmosphere to avoid the consequences of its rotation and distance form the sun . Venus ( despite being further from the sun) achieves higher temperatures because it has an atmosphere.
If CO2 were the scary greenhouse gas that AGW proponents believe it is, then Mars, with 95%+ CO2 [compared with Earth’s tiny .038] would have an average temperature greater than eighty degrees below zero, despite its thin atmosphere. But as we now understand, the heat retention of CO2 begins to fall off logarithmically after the first 20 ppmv. So Mars remains a very cold place, and 95% CO2 does not make a difference.
> 95% of a much,much thinner atmosphere than Earth . On Venus high greenhouse gases make a difference because there is a much thicker atmosphere.
I can’t speak for Hansen about why he didn’t mention it so I’m only responding to your point.
JimB (13:59:24) :
World Coal figures — an article from New Scientist (Jan 2008)
http://www.newscientist.com/article/mg19726391.800-coal-bleak-outlook-for-the-black-stuff.html
(All – I didn’t write the headline or article so don’t complain at me about it)
“When you refer to ice core data; just what “data” do you mean ?”
George E Smith
George, thanks for your very comprehensive response. In my trawling over time, I cannot remember exactly which study, by whom or when…which isn’t very helpful I know.
However the studies to which I refer make use of ice cores by measuring phylo-plankton sediment (or lack of it) as evidence of periods when polar regions were relatively ice free. As I understand it, the claim is that because there is little or no evidence of such sediment within ice cores over the past 10,000 years, this suggests that the northern ice cap has remained more extensive than it is currently over that period.
I am aware that ice core measurements are used in a multitude of ways, but this one is of interest to me in particular because of the work of Prof. Easterbrook’s in proposing that there have been a number of warm periods with the last 10 millennia – or certainly since the end of the last ice age.
That’s not really true crosspatch. The fact that enhanced CO2 concentrations result in enhanced warming of the earth has got very little to do with models. It’s the result of a whole load of empirical (and theoretical) analyses.
In fact the role of CO2 in warming the earth has been known since the middle of the 19th century, and already by the end of the 19th century Arrhenius had established that the earth’s temperature rose as the logarithm of the enhanced CO2 concentration.
There is a whole load of data that bears on the quantitative relationship between enhanced CO2 and enhanced temperature. This has been obtained by examining the temperature response during ice age cycles…. the relationship between atmospheric CO2 and temperature in the deep past (last 500 million years)…the analysis of ocean heat uptake….the temperature response following volcanic eruptions….the temperature response to the solar cycle and so on…
…these generally give a result near 3 oC of warming (plus/minus a bit) per doubling of atmospheric CO2. Hansens’ recent analysis of the ice age cycles illustrated in his powerpoint presentation discussed on this thread is yet another example..
That’s not to say that this isn’t also found by modelling. However that’s because the models are parameterized according to our empirical understanding of the real world. But it’s the empirical analyses, measurements and so on that inform the models and not the orher way round….
And yes, we all know that the response is not linear. It’s logarithmic. You can make a very simple calculation of the earth’s temperature response to enhanced CO2 within a climate sensitivity of 3 oC of warming per doubling of atmospheric CO2 using the equation I dumped in my post above:
see post at: 12:52:53
and as Bill Illes points out (post at 14:00:54) in his reproduction of Raymond Pierrehumbert’s quotation from the paper he links to:
“Eliminating the 50W/m2 of tropical CO2 greenhouse effect would drop the tropical temperature by about 25 K, once amplified by water vapor feedback.”
it would be extraordinary to propose that raising atmospheric CO2 levels further (rather dramatically according to the “all the coal and tar shale’s burnt” scenario being discussed on this thread) wouldn’t result in a very large temperature rise (it would be at least 10 oC according to a climate sensitivity of 3 oC, without any rather unpleasant unforseen feedbacks like methane hydrate release and widescale deforestation…)
I don’t think your point about hot spots in models is correct, and they certainly don’t depend on an infinitely deep atmosphere. In fact raising atmospheric CO2 levels results in an increase in height at which longwave radiation is radiated into space. That’s an essential part of the greenhouse effect, and as far as I’m aware it’s represented in models, predicted by theory and observed in reality…
Smokey,
Mercury’s day and year are *not* the same length. The tidal influence of the Sun is insufficient to prevail over the 3:2 resonance (sidereal day=58 Earth days, year=88 Earth days) to yield synchronous locking. This knowledge dates from the late 1950s.
That said, the resulting longer solar day of Mercury 176 days (like the long solar day of Venus 117 Earth days) must militate against the establishment of a stable climate as you suggest.
How on earth can so many of these eminent scientists be wrong?
Or are they just human like everyone else?
If this is OT I apologize, but it certainly is not off subject of the blog. The AGW hypothesis is based on a single premise, namely: Pre-industrial CO2 levels were approximately 280 ppm — present CO2 levels are apporximately 380 ppm, the increase “obviously” human induced. I do not know Ernst-Georg Beck, but he seems well respected in his field. His paper, “180 Years accurate CO2-Gas analysis of Air by Chemical Methods (Short Version)” makes the case that pre-industrial CO2 levels were approximately 355 ppm and temperature dependent, rather than forcing, seemingly blowing the entire AGW argument out the window. He further makes a very strong argument that the 280 ppm value was “cherry picked” by ignoring 90% of known research data. Any comments?
A copy here: http://www.anenglishmanscastle.com/archives/003818.html
“Eliminating the 50W/m2 of tropical CO2 greenhouse effect would drop the tropical temperature by about 25 K, once amplified by water vapor feedback”
The impact of water vapor certainly seems to be something that could cause a drastic change over a short period of time. From my reading of that paper, a reduction of oceanic evaporation rate could reduce atmospheric water vapor and result in a drastic cool down in a short period of time. And in fact we see severe drought in the equatorial region during Northern Hemisphere glaciations to the extent where rain forest is replaced by grasslands. That could be a self-reinforcing mechanism that keeps the system stable in the cold state.
I wonder if Hansen took any critical questions following this presentation? I would have several.
to Ben Kellett
re ice cores….google zbigniew jaworowski
What!? Multiple references to Hades? Destroying creation? Preserve creation? This, in a lecture at a scientific conference? That’s not science! Pastor Jim is really going off the deep end now. Methinks he has reached his own personal “tipping point”.
Dave Dodd,
I suspect you’ll find with deeper investigation that Beck’s data is not a reliable atmospheric CO2 record, although it is interesting in the historical sense…
Beck has complied all of the atmospheric CO2 measures that he has been able to find covering the past nearly 200 years. Unfortunately as acknowledged by many of the scientists that made these measurements, the data were often heavily contaminated by measuring in laboratories in cities (e.g. Vienna, Giessen, Kew gardens London, Frankfurt, Poona India, Belfast, Clermont Ferrand, Copenhagen, Paris, Bern, Rostock in Denmark, Ames Iowa….and so on).
These values are woefully inadequate as measures of atmospheric CO2, since cities give very high CO2 levels as they’re close to emission sources. So, for example, one of the sets of data that Beck uses is that of W. Kreutz in 1939/40 in Geissen.
Kreutz’s laboratory was not far from the railway station, and Kreutz himself pointed out that his data were affected by soil and industrial/urban sources. He found values that were 40 ppm higher in the afternoons than mornings, and higher CO2 on windless days than windy days (when high emissions were dispersed) and so on… That’s what we find today if we measure CO2 levels in cities.
To put that into perspective, a 40 ppm change in 1/2 a day, is around the change in atmospheric CO2 occurring in 2000 years during an ice age transition…!
Unfortunately Beck is misleading the unwary through assertions of “Accuracy” (as in his title). The measures he quotes are not accurate with respect to the atmospheric CO2 concentrations, even if they were precise with respct to a valid determination of local urban/industrial CO2 levels.
Some early practitioners recognisied the problem of massive contamination of CO2 data from urban measurements and made great efforts to obtain data from uncontaminated sources. Jules Reiset, for example, made measurements in the late 19th century on the windy N. Atlantic coast, far from urban centres. His values were rather similar to those obtained from ice cores for that period (around 290-300 ppm). We can also be more confident of his data since he identified the clear cyclic variation in atmospheric CO2 resulting from N. hemispheric plant growth/decay cycles…
Frank Ravizza,
why not put your questions here. Perhaps some of the posters can address them..!
Mars’ atmosphere is 90% CO2, and it is extremely cold there. Must be the runaway greenhouse effect caused by the dominant greenhouse gas.
Alan Peakall, I appreciate your explanation of Mercury’s rotation.
Dave Dodd:
And that is why the AGW contingent went absolutely ballistic when they understood what Beck was saying. They know that if Beck is even somewhat correct, their AGW hypothesis is defenestrated.
@Smokey and Pete M
Temperature at Venus:
Not only is the temperature dependent on distance to the sun , it also a function of pressure:
Temp = F(Distance to sun, pressure)
See here the stunning similarities between planets, for pressures over 0,3 atm:
http://www.glar.gl/planet.jpg
http://zebu.uoregon.edu/~imamura/121/images/FG09_007.jpg
And “ladies and gentlemen”, if you check the temperature at Venus at 1 atm pressure, you find 330 K.
That is, just around 45 K more than earth at 1 atm. In K that is around 15% warmer af Venus, which is explainable by distance.
Now – il grande experiment to show real-world effect of greenhouse gasses:
Imagine a planet with no greenhouse gasses but still a thich atmosphere.
Arrhenius gave greenhouse gasses all “blame” for the atmospheres isolation effect.
So?
Well, a planet without greenhouse gasses should then have a temperature profile with no isolation effect… This planet should have a temperature-pressure curve totaly vertical.
The pressence of greenhouse gasses are very different from planet to planet. But they all have a quite similar slope in their temp-presseure graph. No planets seems to have different temperature characteristic due to atmosphere contents?
My first point is that Hansen is backing off on coal and is now targeting shale sands.
My second point is that PeteM has not thought much through when it comes to comparrisons involving Venus. Not only is Venus closer to the sun, it has a super rotating upper atmosphere of sulphur gases that act like a blanket. Venus also has no magnetic field so it is directly impacted by the solar wind. Nor does Venus have any water at the surface. Comparing Venus and Earth is like comparing an apple to a Mac Truck, there is no comparrison. Hansens efforts to the same, especially since he comes from that field, is idiotic.
Some entertainment (from my CO2 Fevered imagination) – perhaps?
Climate Zombie.
Headline From the “The Herald” Newspaper, circa sometime in 2009.
“Climate Zombie Haunts Town”…
Meanwhile in the Sceptic household, Arthur and Martha prepare for battle.
Martha: “Arthur, have you got the shotgun?”
Arthur: “Yes Martha.”
Martha: “Have you got the special shells that are effective against the Climate Zombie?”
Arthur: “Yes Martha.”
Martha: “Are you sure – let’s list them and make sure.”
Arthur: “There’s the following shells”
– Arthur reads from the blurb on the shell box.
“1. Vostok Ice Cores show CO2 Trailing Temperature Rises SHELL.
2. No Troposphere HotSpot AGW Fingerprint SHELL.
3. Climate Models not Empirically Validated SHELL.
4. One Fact Kills Consensus SHELL.
5. Poorly Sighted and Calibrated Temperature Instruments SHELL.
6. Data Mismanagement SHELL.”
Martha: “Good – at least we are prepared with some real science.”
Arthur: “And your’ve got the Razor?”
Martha: “Occam’s best and at hand.”
– Glass shatters loudly.
Martha: “The back window…”
– Arthur and Martha rush to the back room and burst through the door. The Climate Zombie is inside the house. They both gag from the reek of corruption that has filled the room. Arthur recovers first – and fires from the hip.
Arthur: “Take that – fiend”
– Arthur lets rip with 6 body shots from his pump action shot gun. The Zombie staggers backwards from the impact of the scientific arguments embedded into the shells. Then it lurches forward, with a leering grin.
Zombie: “Ha, you fool – Science cannot refute me – I’m invincible”.
– The zombie lashes out and throws Arthur against the wall where he crumples into a broken heap.
Martha: “Art!”
Martha leaps forward – Occams Razor firmly in hand, first feinting with a simpler hypothesis before going with a deadly “Climate Change by Natural Variation” Manoeuvre.
The Climate Zombie, moves quickly with a “Stacking the Peer Review Board” counter and Martha’s Occams Razor clatters to the floor.
Zombie: (Scornfully) : “Occam’s Razor – What next – will you quote Sir Karl Popper at me, or try a falsification manoeuvre?”
– The Zombie seizes the now defenceless Martha, and drags her off her feet as he sneers into her face.
Zombie: “Never mind… – the pain will not last for long.”
Martha: (Defiantly) “Do your worst!”
– Martha gives the Zombie the finger.
– Zombie kills Martha.
The Climate Zombie looks at the pair of lifeless sceptics. Nodding to himself and contemplating the feast of sceptic brains that is about to begin.
Zombie: “They keep trying science – don’t they know that I am a multi-faceted Politico-Religious Meme backed by vested interests in Government, Industry and a host of NGOs seeking wealth and power.”
– Then the Zombie shivered.
Zombie: “Thankfully – they haven’t tried Parody – it’s my Achilles heel –it’s hard to be serious and frightening if people are laughing at you.”
(end)
“Now we can look at 800,000 years. The same sensitivity fits for the earlier times, even better. Bottom line: The fast feedback climate sensitivity is nailed. It is 3 C for doubled CO2, plus or minus half a degree.” (p7/39).
Since it is nailed at 3C over all time periods under consideration it’s clear that Hansen is claiming a linear relation between T and CO2. That is,
T = A + B*CO2
where A and B are constants. If we take an arbitrary reference point as CO2 concentration C1 at temperature T1 and take Hansen’s sensitivity figure of 3C for a doubling of CO2 we get
T = T1 – 3 + (3/C1)*CO2 [1]
Check: take CO2 = 2*C1 we get T= T1+3.
It seems to me that Hansen gets his sensitivity number from the CO2 and T estimates from the ice core data on p7/39 (eg C1=200ppm at T1 = -4C; C2=250ppm at T2 = -1C) but I get different results. Any suggestions?
But taking Hansen’s result in the form of eq[1] all we need to do (following Hansen) to predict future temperature is to predict future CO2 (the data is so regular that a simple extrapolation would be enough) and substitute in eq[1]. Why bother with GCMs, forcings and all sorts of complications when it is a simple as this?
Well, it seems that Hansen is referring here to an “equilibrium” or “fast feedback “sensitivity” and maybe the detailed modeling is needed to track the time-course of the approach to this equilibrium.
My first question is: based on the proposed greenhouse mechanism wouldn’t the response of temperature to current CO2 concentrations be very rapid (a few days at most?)?. I know that long times are involved in recycling via the deep ocean, but that is irrelevant if we have a reliable estimate of CO2 “now”. If you want to predict the atmospheric CO2 resulting from current CO2 production it would be necessary to model those factors; but firstly, I don’t think that’s being done (anyone know?) and secondly the one data set that seems to be reliable and predictable (so far) is the recent CO2 rise. Much better to simply extrapolate.
My second question is: why not use the same data as used for the sensitivity estimate to estimate lag-times. If the data he’s using is the Vostok ice core data I think I know why, that the change in T precedes the change in CO2 and the whole story falls apart. Is the sole reason for the GCMs, forcings etc, to estimate lag-times involved in approach to equilibrium?
I know that what I’m saying here is a gross oversimplification of a complex issue, but it seems to me to be what Hansen is saying when he nails sensitivity at 3C per doubling (without reference to the many other potentially significant variables). What else is there to know?
PeteM (13:54:55) :
‘The information I provided shows that is not always a dominant factor .
Venus is suffering from a strong green house effect’
Venus is suffering? It seems to me the green house effect on Venus is normal for Venus.
You have to remember Hansen’s run-a-way green house effect on Venus is still an unproven theory.
Smokey,
I don’t think anyone went ballistic over the Beck stuff. It’s clearly nonsense, as a little bit of investigation and clear thinking will illustrate. In general it was noticed and essentially ignored.
The aim in science is to establish supportable explanations for observations. That’s how we learn stuff and make progress (not to mention policy decisions). Things that are clearly erroneous do not need dwelling on.