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. 😉
Peter (09:06:07) :
Joel Shore:
“The reason for this is that, at the end of the day, the earth equilibrates to a new level of greenhouse gases by raising the temperature at the effective level it radiates from”
Are you sure you’ve got that right?
Surely if you increase the temperature at the effective level it radiates from, it will radiate more energy into space?
Or am I missing something?
He has it right, the effective level is a function of the GHG concentration, increase [GHG] and the effective level moves up, that level being initially cooler means that less energy is leaving the planet than is coming in so the temperature must increase until balance is reached. So at equilibrium the effective level is higher and at the same temperature as it was at the lower altitude.
old construction worker
December 24, 2008 10:14 am
to Joel Shore, foinavon and the rest of the AWG crowd
‘Schneider (Stephen), among others, created the appearance that the Summary was representative of the Science Report. However, he provides an early insight into the thinking when speaking about global warming to Discovery magazine (October 1989) he said scientists need, “to get some broader based support, to capture the public’s imagination…that, of course, entails getting loads of media coverage. So we have to offer up some scary scenarios, make simplified dramatic statements and make little mention of any doubts we may have…each of us has to decide what the right balance is between being effective, and being honest.” The last sentence is deeply disturbing–there is no decision required.’
http;//candafreepress.com/indexphp/article/7116
Unless you address the concerns of the NCPA, Anthony,Tim Ball, Steve McIntyre and other who question of How the Science is done and resolve the issues then you and the other AWG crowd have little credibility with this old construction worker.
BTW I let my tax paying peers and my elected representatives know my humble opinion. If it takes count orders to force complete openness needed on “how the science is done” concerning “CO2 Drives the Climate Theory”, paid for by us, the tax payers, so be it.
Let the sun shine in.
Peter (09:59:26)
It seems to be largely down to greenhouse gas concentrations. They were generally far higher in the past and so they countered the effects of a dimmish sun.
But not always. There were ice ages in the past. These correlate to periods in which greenhouse levels drifted below the thresholds that then limited cool or cold periods. For example there are two long-lived glaciation events in the Permian-Carboniferous period, one between 326-312 million years ago (MYA) and 302-290 MYA. The post glacial period up to around 270 MYA was still preety cold. These are very long periods of cold and are associated with drifts of atmospheric CO2 to around 500ppm and lower. Obviously with a weaker sun, the CO2-threshold for glaciation was much lower than now and cold or glacial periods could arise when CO2 levels drifted below around 1000 ppm.
There’s also evidence for an earlier Carboniferous glaciation around 352-350 MYA and a brief late-Devonian event around 360 MYA. There are no contemporaneous CO2 proxies for these periods, but the nearest dated CO2 proxies show low CO2 (1000 ppm).
There’s also evidence for a late Ordovician glacial event dated around 446-444 MYA. Unfortunately we don’t know what the atmospheric CO2 concentrations were at this point in time.
There is evidence for several rather extreme glacial episodes during the Neoproterozoic era (1000-5550 MYA). Some of these were sufficiently extensive to give rise to the theory of a “snowball earth”. Whatever the extent to these glaciations, they are also linked to reduced greenhouse gas concentrations (during these periods all the continents were assembled near the equator promoting very efficient weathering-induced draw-down of atmospheric CO2).
There is goodish evidence for dramatic glaciations during the Archaeon 3,200 MYA and later. This is proposed to be the result of the production of O2 which oxidised the atmospheric methane that was the dominant greenhouse gas during the earlier periods of Earth’s history…..
…and so on.
Data from:
Kasting, JF and Howard MT (2006) Atmospheric composition and climate on the early Earth. Phil. Trans. R. Soc. B. 361, 1733-1742.
Royer, D.L. (2006) CO2-forced climate thresholds during the Phanerozoic
Geochimica et Cosmochimica Acta 70, 5665-5675.
Mike Bryant
December 24, 2008 11:03 am
“Not only that he did it ten years later when he knew that the emissions trajectories necessary for Scenario A had not occurred!”
Have the emissions trajectories necessary for Scenario C occurred?
Aren’t the observed temperatures below Scenario C?
Wattsupwiththat?
foinavon
December 24, 2008 11:05 am
That should be “…Neoproterozoic era (1000-1550 MYA)…”. sorry!
Mike Bryant (11:03:19) :
Have the emissions trajectories necessary for Scenario C occurred?
For the most part yes.
Joel Shore
December 24, 2008 11:23 am
Mike Bryant says:
As I understand it Lucia is a warmer, but a real sweet one that bakes brownies.
Well, I guess how you interpret her position might depend on your own. From where I stand, I would call her quite firmly in the “skeptic” camp, although she is one of the more reasonable and data-driven of the “skeptics”.
old construction worker says:
You may not like what they say but they do make some strong points that you and the IPPc needs to address.
…
Unless you address the concerns of the NCPA, Anthony,Tim Ball, Steve McIntyre and other who question of How the Science is done and resolve the issues then you and the other AWG crowd have little credibility with this old construction worker.
The NCPA is simply a highly-partisan political organization, not a scientific one. Asking me to respond to every piece of idiocy that they come up with is equivalent to asking you to respond to everything that Greenpeace says. But if you want to read what Schneider has to say in response to this attack on him by quoting him out-of-context, here it is: http://www.aps.org/publications/apsnews/199608/environmental.cfm
As for addressing what Anthony (and the commenters here) have to say, well I suppose that is why I hang out here.
I also hold no illusions that I will be able to convince everyone. There are people around (commenting on this very website, in fact) who still don’t believe that CFCs impact the ozone layer. However, eventually, the science becomes so overwhelming that even a lot of the organizations that one would expect to oppose action drop that opposition (as many of the petroleum companies like BP and Shell, automakers like Ford, and ppwer companies have done over the past decade regarding taking action to reduce our GHG emissions). Then, the political will slowly comes about to take effective action, despite the diehards who refuse to be convinced by the scientific evidence.
Thanks to old construction worker for that informative link.
And don’t you just love the typical argument tactic of folks like foinavon:
It seems to be largely down to greenhouse gas concentrations. They were generally far higher in the past and so they countered the effects of a dimmish sun.
But not always. There were ice ages in the past…
They constantly frame and re-frame their arguments, until we hear something ridiculous like: “global warming causes global cooling.”
Face it, the planet is laughing at the impotent hubris of the AGW/runaway global warming contingent.
It’s cold outside! Global warming isn’t gonna getcha. Breezes from the frantic AGW hand-wavers help keep the planet cool. Stop it!
Joel Shore
December 24, 2008 11:29 am
Mike Bryant says:
Have the emissions trajectories necessary for Scenario C occurred?
Aren’t the observed temperatures below Scenario C?
Within the error bars, I believe the trendlines would be compatible with both Scenario B and C. (And, the actual forcings are apparently a little less than was assumed in Scenario B.) As for whether Hansen’s prediction will eventually turn out to be a little high of reality, I certainly hope it will given that his climate model at that time had an equilibrium climate sensitivity of ~4.2 C, which is near the high end of the IPCC range and higher than his own current estimate of 3 +- 0.5 C that he notes in his presentation that Anthony linked to.
Joel Shore
December 24, 2008 11:35 am
Smokey says:
And don’t you just love the typical argument tactic of folks like foinavon:
Yeah…It is pretty annoying how foinavon keeps trying to inject some actual peer-reviewed scientific knowledge into these debates! What a low tactic!
(And, foinavon, just to let you know, at least some of us do appreciate the wealth of knowledge that you bring to this discussion!)
foinavon
December 24, 2008 11:53 am
That’s illogical again Smokey. Attempting to ridicule by wilful misunderstanding (and selective quotation) is not skepticism!
It’s not difficult to underatand Smokey. Here’s a short summary:
In general greenhouse gas concentrations were much higher in the deep past and countered the effect of a weaker sun.
But not always. Occasionally greenhouse gas concentrations drifted downwards below the then thresholds for widespread build up of ice from the poles and during these periods of reduced greenhouse gas concentrations glacial periods did occur.
more details in my post just above (11:02:22)
Mike Bryant
December 24, 2008 12:11 pm
“As for whether Hansen’s prediction will eventually turn out to be a little high of reality, I certainly hope it will given that his climate model at that time had an equilibrium climate sensitivity of ~4.2 C, which is near the high end of the IPCC range and higher than his own current estimate of 3 +- 0.5 C that he notes in his presentation that Anthony linked to.”
I hope so too. And the next time he evaluates the equilibrium climate sensitivity he can always adjust it down again.
Hank
December 24, 2008 12:30 pm
I find foinavon’s commentary always interesting. I wonder if he may have taken a course in physical chemistry and actually passed – I certainly never did. He also has an even way of presenting himself which is refreshing. None the less I find his commentary on percentages a little crafty. Anyone who works with numbers has run into this percentage issue before. I am certain he knows when discussing CO2 that “doublings” is how one typically refers to CO2 concentrations since there is a natural log in the equations. This tends to make the remark about percentages of the minuscule all that more pertinent.
What I also find suspect is the statement “CO2 is the dominant independently variable greenhouse gas.” Notice that it is not said that CO2 is the dominant greenhouse gas, but the “independently variable” greenhouse gas. Water vapor not CO2, is the dominant greenhouse gas, of course, and it will take CO2 percentage increases in the thousand plus range (or several doublings) for it to be on a par with water vapor as a greenhouse gas. Also, I am not even sure what it means to refer to CO2 as an independent variable. CO2 is certainly a variable, but we also have a wildly uncontrolled variable known as water. As a skeptic I think a big thing that global warming proponents have to confront is the role of water. The way I reason: If the earth warms more, more water evaporates into the atmosphere; if more water goes into the atmosphere, more comes out as rain; if more comes out as rain, it is fair to infer there will be more clouds; and more clouds means cooling since clouds cool. And yes I understand that clouds also warm but I am pretty confident that the net effect is a cooling. I am old enough to remember the global cooling scare of the 70’s. At that time the story was exactly this – that clouds and snow cover would raise albedo and drive earth’s climate to what was called “snowball earth.”
Joel Shore
December 24, 2008 1:12 pm
Hank says:
I am certain he knows when discussing CO2 that “doublings” is how one typically refers to CO2 concentrations since there is a natural log in the equations. This tends to make the remark about percentages of the minuscule all that more pertinent.
You have identified the exact reason why it is indeed pertinent to speak in terms of percentages: For a quantity where the dependence of the interesting variable (temperature) on it is logarithmic, what matters is the fractional or percentage increase in that quantity, not the absolute amount of the increase. So, I am not sure why talking in this way makes foinavon or me “crafty”…It simply means we are talking in the way that makes the most sense given the expected behavior of the climate on CO2 concentration.
Also, I am not even sure what it means to refer to CO2 as an independent variable.
It means that it is a variable that we (or some other process) can influence directly by injecting more CO2 into the atmosphere. Water vapor concentration, by contrast is (as you note) determined by the temperature. As a practical matter, we cannot at least at the present time inject water vapor into the atmosphere in sufficient quantities to significantly influence the global climate.
As a skeptic I think a big thing that global warming proponents have to confront is the role of water.
The role of water is something that has been understood to be important going all the way back to the first calculations of the greenhouse effect by Arrhenius around 1900.
The way I reason: If the earth warms more, more water evaporates into the atmosphere; if more water goes into the atmosphere, more comes out as rain; if more comes out as rain, it is fair to infer there will be more clouds; and more clouds means cooling since clouds cool. And yes I understand that clouds also warm but I am pretty confident that the net effect is a cooling.
Actually, the most direct effect of more water vapor in the atmosphere is a positive feedback because of water vapor being a greenhouse gas. The effects on clouds are actually even more complicated than your intuition suggests. First, as you note, clouds can have both warming and cooling effects. Second, it is by no means clear that the effect of higher temperatures is to produce more clouds. Because, although the warmer air will have more water vapor in it, it also has a higher saturation level, i.e., it can hold more water vapor before the water vapor condenses into clouds. To a first approximation, climate models tend to predict that the RELATIVE humidity (the absolute amount of water vapor divided by the amount the air at that temperature can hold) remains constant as the climate warms. And, people on this site are actually skeptical of this claim and often trying to argue that relative humidity is actually decreasing as warming occurs (since they want the positive water vapor feedback not to be there). If the relative humidity remains constant, then one might imagine to a first approximation that the amount of clouds would also remain constant…although admittedly it probably doesn’t have to be quite this simple. If the relative humidity decreases with warming, one might expect the amount of cloudiness to decrease.
At any rate, the feedback effect due to clouds does remain the biggest source of uncertainty in climate modeling. However, our current understanding of empirical data from past events, such as the ice ages, major volcanic eruptions, etc. show that the climate system is quite sensitive to perturbations and thus that a strong negative feedback from clouds is unlikely.
I am old enough to remember the global cooling scare of the 70’s. At that time the story was exactly this – that clouds and snow cover would raise albedo and drive earth’s climate to what was called “snowball earth.”
First of all, while this may have been a “scare” in a few popular magazines like Newsweek and a popular book or two, there was never anything approaching such a scare in the peer-reviewed scientific literature, let alone any consensus that such global cooling was likely. In fact, throughout the 1970s, there seems to have been more papers discussing global warming than cooling and a National Academy of Sciences study in the mid-70s concluded that we did not yet understand climate well enough to predict which of the variously-identified warming and cooling forces would predominate. See here for more details: http://www.realclimate.org/index.php/archives/2008/03/the-global-cooling-mole/langswitch_lang/in
foinavon
December 24, 2008 1:14 pm
Hank,
I’m not quite sure what you mean about percentages. As you say, the temperature dependence on CO2 is a logarithmic one. I gave a simple equation to calculate this within a given climate sensitivity in a post above [21:12 (12:52:53)], and the log is right in there, clear as day!
But in relation to the increase in atmospheric CO2 concentrations that joel and Will were discussing (if that’s what you were referring to) , the issue was about the direct increase in the concentration of CO2 (not the increase in the forcing). Atmospheric CO2 concentrations have increased from 280 ppm to 386 ppm, so it’s mathematically correct to indicate that this is a 38% increase. Does that address your point? If not, spell it out and I’ll try again. Note that atmospheric greenhouse gases are not “miniscule” in their effects, even if their absolute concentrations are small….
Your comment starting: What I also find suspect is the statement “CO2 is the dominant independently variable greenhouse gas.” Notice that it is not said that CO2 is the dominant greenhouse gas, but the “independently variable” greenhouse gas.
Yes, that’s what I meant to say. CO2 is independently variable. It rises due to major tectonic events, or over long periods if volcanic emissions outbalance atmospheric draw-down, or by massive release of long-sequestered greenhouse gases. It falls due to weathering (mainly).
Water vapour is not independently variable. It’s a passive player who’s atmospheric concentration responds to other forcings (cooling or warming). There aren’t any processes that can significantly increase or decrease the water vapour concentration independent of other forcings that affect the atmospheric temperature. Of course it’s the dominant greenhouse gas in terms of its contribution to the greenhouse effect. But even then one has to be careful, since a good bit of the water-vapour forcing can be attributed to CO2 (and other independently variable greenhouse gases…and the sun of course!), since the CO2 that warms the atmosphere sufficiently for water to partition into the atmosphere to the extent that it does.
I hope I haven’t been crafty again! I’m certainly not trying to be…
David Porter
December 24, 2008 1:24 pm
really do not understand why there is this concerted pressure from the likes of Joel and foinavon to force upon us their interpretation of the effects of CO2 on temperature, other than this is the only thing that underscores the theology of AGW. (I also notice that whenever there is a thread on this website that in any way attacks Hansen there is also a fighting defense put up by the more persuasive and articulate believers).
So we have increased CO2 levels from 0.03% to 0.04%, which means that we are safe at 99.97% of everything else but it is disastrous at 99.96% of everything else. To exaggerate, it is put the other way around, CO2 has increased, from whatever source, by 30%, whilst at the same time making no mention, or giving no credit, to the most powerful greenhouse effects provided by water vapour and clouds which completely swamp the CO2 effects. Both of these way outperform CO2 in the absorption of ultraviolet radiation. And please I am aware that moisture doesn’t stay in the atmosphere for very long but I am equally aware that it it is constantly replenished every minute of every day.
As a chemist I really do have difficulty buying into your view of the so called disastrous consequences of CO2.
Peter
December 24, 2008 1:27 pm
Phil:
He has it right, the effective level is a function of the GHG concentration, increase [GHG] and the effective level moves up
Moving it up is not the same thing as increasing its temperature.
that level being initially cooler means that less energy is leaving the planet than is coming in so the temperature must increase until balance is reached.
‘Initially’ cooler? Is that cooler yesterday? Or last year? Or a hundred years ago? Or is it an on-going process? How long does it take to warm a rarefied layer of atmosphere by a fraction of a degree?
hunter
December 24, 2008 2:08 pm
Pretending CO2 controls climate is fun and profitable but it is bs.
Water vapor is, has and will be the dominant GHG, and works with positive and negative feedbacks. If CO2 was some sort of short cut that could ‘tip’ the climate one way or the other in anything like a dramatic fashion, I doubt if we would be here at all.
Again: what Hansen & co. have been able to sell is the idea that their apocalyptic predictions are accurate to within small fractions of a degree utilizing instruments and data procedures that are only accurate to within large fractions of a degree.
The lack of precision and the overwhelmingly subjective nature of their measurements have been well documented.
Their lack of accounting for major non-CO2 positive and negative forcings means that their algorithms were designed with the answer already known.
And the dodge about a cooler sun in the ancient past is only now being dragged out as yet more credibility of apocalyptic bs is stripped away.
Hansen himself ridiculed the idea of a solar influence in a speech in Houston recently.
We are influencing the climate as we always have: positive and some negative forcings, but neither in huge global scales.
That “mold” which covers some spots on the earth, called humanity, can not force anything but confusion. Those guys against the friendly gas in familiar beverages muy try a coke or a beer without gas!
Joseph
December 24, 2008 3:20 pm
foinavon (05:53:07) Wrote
Yes, there’s pretty good evidence that the atmosphere has warmed the oceans.
foinavon, that is impossible. Our planet’s ocean is far too large for that to happen. The heat capacity of the ocean is far, far greater than that of the atmosphere. Heat always flows from the ocean to the atmosphere, not the other way around. There is a terrific article here: http://co2sceptics.com/news.php?id=1562 that explains this in layman’s terms. It’s pretty tough to argue with basic physics.
Merry Christmas to all!
foinavon
December 24, 2008 3:27 pm
David,
The notion that joel and I are “forcing upon” you our “interpretation of the effects of CO2 on temperature” is quite funny!
I would hope that you and everyone here is sufficiently strong-minded to resist our “concerted pressure”…you should certainly come to your own decision on these issues.
I think each of us is just saying it as we see it. joel seems to have a very good appreciation of the science and is indeed articulate (and very gracious with his earlier compliment which was appreciated btw). I work in somewhat related areas (I’m a chemist too just like you as it happens) and know some of the science.
We’re really just presenting some of the relevant science, which one shouldn’t be afraid of. After all the natural world doesn’t defer to one’s prejudices and agendas (King Canute recognised that even if his misguided advisors didn’t), and it’s best to face the evidence on these issues, even if someone else’s false platitudes might appear more comforting.
hunter,
do be careful not to fall for the “dodge” of a cooler sun!
Pretending is indeed fun and can be profitable, but only in the short term. In the end reality is likely to turn up and bite you on your cheeky bottom!
Adolfo,
as a Brit, I quite like flat beer…in moderation of course!
Merry XMas to everyone!
Peter (13:27:12) :
Phil:
“He has it right, the effective level is a function of the GHG concentration, increase [GHG] and the effective level moves up”
Moving it up is not the same thing as increasing its temperature.
Quite, it will actually decrease the temperature at the effective level. “that level being initially cooler means that less energy is leaving the planet than is coming in so the temperature must increase until balance is reached.”
‘Initially’ cooler? Is that cooler yesterday? Or last year? Or a hundred years ago? Or is it an on-going process?
It is an on-going process obviously but the explanation was to illustrate how it works in a discrete step. How long does it take to warm a rarefied layer of atmosphere by a fraction of a degree?
Not very long, the heating/cooling rate in the stratosphere is above 0.05ºC/hr.
foinavon
December 24, 2008 4:22 pm
Joseph,
It’s a very well written article. It’s also tosh unfortunately. It is tough to argue with basic physics, but there’s not much “basic physics” in the article.
I expect it’s well written because Stephen Wilde is a lawer, and is thus well-practiced in presenting nonsense convincingly. He pretends that he’s a Fellow of the Royal Meterorological Society, but that would be unlikely since he doesn’t fulfill their credentials[***], and in any case he’s rather absent from their list of Fellows which can be perused here: http://www.rmets.org/about/people/fellows.php?pageNum_frmets=3&totalRows_frmets=360
Mr Wilde asserts that the greenhouse effect is solely a result of atmospheric density, and that CO2 doesn’t play a significant role. Do you agree?
Mr Wilde asserts that the climate is controlled by the “Hot Water Bottle Effect”. Do you agree?
Mr Wilde asserts that it’s impossible to warm cold tap water in a bathroom to the temperature of a warm bath by heating the air in the bathroom. What do you think?
etc. etc.
In fact the atmosphere has warmed the oceans somewhat. A warmer atmosphere reduces the escape of surface thermal energy into space and thus the surface must warm in order to maintain an equilibrium between the incoming and outgoing radiation.
[***]From the Royal Meteorological Society website page on “Fellows”:
Becoming a Fellow normally requires a formal qualification (eg. a first degree in a science subject and/or post-graduate degree or an NVQ in a relevant discipline) and at least five years of professional experience within or directly related to meteorology. Exceptionally, long experience and performance at a high professional level, suitably attested by peer review, can replace the requirement for a formal academic or vocational qualification. MSc or PhD study in a relevant subject counts as one or two years experience respectively.
Joseph (15:20:46) :
foinavon (05:53:07) Wrote
“Yes, there’s pretty good evidence that the atmosphere has warmed the oceans.”
foinavon, that is impossible. Our planet’s ocean is far too large for that to happen. The heat capacity of the ocean is far, far greater than that of the atmosphere. Heat always flows from the ocean to the atmosphere, not the other way around. There is a terrific article here: http://co2sceptics.com/news.php?id=1562 that explains this in layman’s terms. It’s pretty tough to argue with basic physics.
Indeed, however that article gets a lot of it wrong!
Peter (09:06:07) :
Joel Shore:
“The reason for this is that, at the end of the day, the earth equilibrates to a new level of greenhouse gases by raising the temperature at the effective level it radiates from”
Are you sure you’ve got that right?
Surely if you increase the temperature at the effective level it radiates from, it will radiate more energy into space?
Or am I missing something?
He has it right, the effective level is a function of the GHG concentration, increase [GHG] and the effective level moves up, that level being initially cooler means that less energy is leaving the planet than is coming in so the temperature must increase until balance is reached. So at equilibrium the effective level is higher and at the same temperature as it was at the lower altitude.
to Joel Shore, foinavon and the rest of the AWG crowd
‘Schneider (Stephen), among others, created the appearance that the Summary was representative of the Science Report. However, he provides an early insight into the thinking when speaking about global warming to Discovery magazine (October 1989) he said scientists need, “to get some broader based support, to capture the public’s imagination…that, of course, entails getting loads of media coverage. So we have to offer up some scary scenarios, make simplified dramatic statements and make little mention of any doubts we may have…each of us has to decide what the right balance is between being effective, and being honest.” The last sentence is deeply disturbing–there is no decision required.’
http;//candafreepress.com/indexphp/article/7116
Unless you address the concerns of the NCPA, Anthony,Tim Ball, Steve McIntyre and other who question of How the Science is done and resolve the issues then you and the other AWG crowd have little credibility with this old construction worker.
BTW I let my tax paying peers and my elected representatives know my humble opinion. If it takes count orders to force complete openness needed on “how the science is done” concerning “CO2 Drives the Climate Theory”, paid for by us, the tax payers, so be it.
Let the sun shine in.
Sorry about the link
http://canadafreepress.com/index.php/article/7116
Peter (09:59:26)
It seems to be largely down to greenhouse gas concentrations. They were generally far higher in the past and so they countered the effects of a dimmish sun.
But not always. There were ice ages in the past. These correlate to periods in which greenhouse levels drifted below the thresholds that then limited cool or cold periods. For example there are two long-lived glaciation events in the Permian-Carboniferous period, one between 326-312 million years ago (MYA) and 302-290 MYA. The post glacial period up to around 270 MYA was still preety cold. These are very long periods of cold and are associated with drifts of atmospheric CO2 to around 500ppm and lower. Obviously with a weaker sun, the CO2-threshold for glaciation was much lower than now and cold or glacial periods could arise when CO2 levels drifted below around 1000 ppm.
There’s also evidence for an earlier Carboniferous glaciation around 352-350 MYA and a brief late-Devonian event around 360 MYA. There are no contemporaneous CO2 proxies for these periods, but the nearest dated CO2 proxies show low CO2 (1000 ppm).
There’s also evidence for a late Ordovician glacial event dated around 446-444 MYA. Unfortunately we don’t know what the atmospheric CO2 concentrations were at this point in time.
There is evidence for several rather extreme glacial episodes during the Neoproterozoic era (1000-5550 MYA). Some of these were sufficiently extensive to give rise to the theory of a “snowball earth”. Whatever the extent to these glaciations, they are also linked to reduced greenhouse gas concentrations (during these periods all the continents were assembled near the equator promoting very efficient weathering-induced draw-down of atmospheric CO2).
There is goodish evidence for dramatic glaciations during the Archaeon 3,200 MYA and later. This is proposed to be the result of the production of O2 which oxidised the atmospheric methane that was the dominant greenhouse gas during the earlier periods of Earth’s history…..
…and so on.
Data from:
Kasting, JF and Howard MT (2006) Atmospheric composition and climate on the early Earth. Phil. Trans. R. Soc. B. 361, 1733-1742.
Royer, D.L. (2006) CO2-forced climate thresholds during the Phanerozoic
Geochimica et Cosmochimica Acta 70, 5665-5675.
“Not only that he did it ten years later when he knew that the emissions trajectories necessary for Scenario A had not occurred!”
Have the emissions trajectories necessary for Scenario C occurred?
Aren’t the observed temperatures below Scenario C?
Wattsupwiththat?
That should be “…Neoproterozoic era (1000-1550 MYA)…”. sorry!
Mike Bryant (11:03:19) :
Have the emissions trajectories necessary for Scenario C occurred?
For the most part yes.
Mike Bryant says:
Well, I guess how you interpret her position might depend on your own. From where I stand, I would call her quite firmly in the “skeptic” camp, although she is one of the more reasonable and data-driven of the “skeptics”.
old construction worker says:
The NCPA is simply a highly-partisan political organization, not a scientific one. Asking me to respond to every piece of idiocy that they come up with is equivalent to asking you to respond to everything that Greenpeace says. But if you want to read what Schneider has to say in response to this attack on him by quoting him out-of-context, here it is: http://www.aps.org/publications/apsnews/199608/environmental.cfm
As for addressing what Anthony (and the commenters here) have to say, well I suppose that is why I hang out here.
I also hold no illusions that I will be able to convince everyone. There are people around (commenting on this very website, in fact) who still don’t believe that CFCs impact the ozone layer. However, eventually, the science becomes so overwhelming that even a lot of the organizations that one would expect to oppose action drop that opposition (as many of the petroleum companies like BP and Shell, automakers like Ford, and ppwer companies have done over the past decade regarding taking action to reduce our GHG emissions). Then, the political will slowly comes about to take effective action, despite the diehards who refuse to be convinced by the scientific evidence.
Thanks to old construction worker for that informative link.
And don’t you just love the typical argument tactic of folks like foinavon:
They constantly frame and re-frame their arguments, until we hear something ridiculous like: “global warming causes global cooling.”
Face it, the planet is laughing at the impotent hubris of the AGW/runaway global warming contingent.
It’s cold outside! Global warming isn’t gonna getcha. Breezes from the frantic AGW hand-wavers help keep the planet cool. Stop it!
Mike Bryant says:
Within the error bars, I believe the trendlines would be compatible with both Scenario B and C. (And, the actual forcings are apparently a little less than was assumed in Scenario B.) As for whether Hansen’s prediction will eventually turn out to be a little high of reality, I certainly hope it will given that his climate model at that time had an equilibrium climate sensitivity of ~4.2 C, which is near the high end of the IPCC range and higher than his own current estimate of 3 +- 0.5 C that he notes in his presentation that Anthony linked to.
Smokey says:
Yeah…It is pretty annoying how foinavon keeps trying to inject some actual peer-reviewed scientific knowledge into these debates! What a low tactic!
(And, foinavon, just to let you know, at least some of us do appreciate the wealth of knowledge that you bring to this discussion!)
That’s illogical again Smokey. Attempting to ridicule by wilful misunderstanding (and selective quotation) is not skepticism!
It’s not difficult to underatand Smokey. Here’s a short summary:
In general greenhouse gas concentrations were much higher in the deep past and countered the effect of a weaker sun.
But not always. Occasionally greenhouse gas concentrations drifted downwards below the then thresholds for widespread build up of ice from the poles and during these periods of reduced greenhouse gas concentrations glacial periods did occur.
more details in my post just above (11:02:22)
“As for whether Hansen’s prediction will eventually turn out to be a little high of reality, I certainly hope it will given that his climate model at that time had an equilibrium climate sensitivity of ~4.2 C, which is near the high end of the IPCC range and higher than his own current estimate of 3 +- 0.5 C that he notes in his presentation that Anthony linked to.”
I hope so too. And the next time he evaluates the equilibrium climate sensitivity he can always adjust it down again.
I find foinavon’s commentary always interesting. I wonder if he may have taken a course in physical chemistry and actually passed – I certainly never did. He also has an even way of presenting himself which is refreshing. None the less I find his commentary on percentages a little crafty. Anyone who works with numbers has run into this percentage issue before. I am certain he knows when discussing CO2 that “doublings” is how one typically refers to CO2 concentrations since there is a natural log in the equations. This tends to make the remark about percentages of the minuscule all that more pertinent.
What I also find suspect is the statement “CO2 is the dominant independently variable greenhouse gas.” Notice that it is not said that CO2 is the dominant greenhouse gas, but the “independently variable” greenhouse gas. Water vapor not CO2, is the dominant greenhouse gas, of course, and it will take CO2 percentage increases in the thousand plus range (or several doublings) for it to be on a par with water vapor as a greenhouse gas. Also, I am not even sure what it means to refer to CO2 as an independent variable. CO2 is certainly a variable, but we also have a wildly uncontrolled variable known as water. As a skeptic I think a big thing that global warming proponents have to confront is the role of water. The way I reason: If the earth warms more, more water evaporates into the atmosphere; if more water goes into the atmosphere, more comes out as rain; if more comes out as rain, it is fair to infer there will be more clouds; and more clouds means cooling since clouds cool. And yes I understand that clouds also warm but I am pretty confident that the net effect is a cooling. I am old enough to remember the global cooling scare of the 70’s. At that time the story was exactly this – that clouds and snow cover would raise albedo and drive earth’s climate to what was called “snowball earth.”
Hank says:
You have identified the exact reason why it is indeed pertinent to speak in terms of percentages: For a quantity where the dependence of the interesting variable (temperature) on it is logarithmic, what matters is the fractional or percentage increase in that quantity, not the absolute amount of the increase. So, I am not sure why talking in this way makes foinavon or me “crafty”…It simply means we are talking in the way that makes the most sense given the expected behavior of the climate on CO2 concentration.
It means that it is a variable that we (or some other process) can influence directly by injecting more CO2 into the atmosphere. Water vapor concentration, by contrast is (as you note) determined by the temperature. As a practical matter, we cannot at least at the present time inject water vapor into the atmosphere in sufficient quantities to significantly influence the global climate.
The role of water is something that has been understood to be important going all the way back to the first calculations of the greenhouse effect by Arrhenius around 1900.
Actually, the most direct effect of more water vapor in the atmosphere is a positive feedback because of water vapor being a greenhouse gas. The effects on clouds are actually even more complicated than your intuition suggests. First, as you note, clouds can have both warming and cooling effects. Second, it is by no means clear that the effect of higher temperatures is to produce more clouds. Because, although the warmer air will have more water vapor in it, it also has a higher saturation level, i.e., it can hold more water vapor before the water vapor condenses into clouds. To a first approximation, climate models tend to predict that the RELATIVE humidity (the absolute amount of water vapor divided by the amount the air at that temperature can hold) remains constant as the climate warms. And, people on this site are actually skeptical of this claim and often trying to argue that relative humidity is actually decreasing as warming occurs (since they want the positive water vapor feedback not to be there). If the relative humidity remains constant, then one might imagine to a first approximation that the amount of clouds would also remain constant…although admittedly it probably doesn’t have to be quite this simple. If the relative humidity decreases with warming, one might expect the amount of cloudiness to decrease.
At any rate, the feedback effect due to clouds does remain the biggest source of uncertainty in climate modeling. However, our current understanding of empirical data from past events, such as the ice ages, major volcanic eruptions, etc. show that the climate system is quite sensitive to perturbations and thus that a strong negative feedback from clouds is unlikely.
First of all, while this may have been a “scare” in a few popular magazines like Newsweek and a popular book or two, there was never anything approaching such a scare in the peer-reviewed scientific literature, let alone any consensus that such global cooling was likely. In fact, throughout the 1970s, there seems to have been more papers discussing global warming than cooling and a National Academy of Sciences study in the mid-70s concluded that we did not yet understand climate well enough to predict which of the variously-identified warming and cooling forces would predominate. See here for more details: http://www.realclimate.org/index.php/archives/2008/03/the-global-cooling-mole/langswitch_lang/in
Hank,
I’m not quite sure what you mean about percentages. As you say, the temperature dependence on CO2 is a logarithmic one. I gave a simple equation to calculate this within a given climate sensitivity in a post above [21:12 (12:52:53)], and the log is right in there, clear as day!
But in relation to the increase in atmospheric CO2 concentrations that joel and Will were discussing (if that’s what you were referring to) , the issue was about the direct increase in the concentration of CO2 (not the increase in the forcing). Atmospheric CO2 concentrations have increased from 280 ppm to 386 ppm, so it’s mathematically correct to indicate that this is a 38% increase. Does that address your point? If not, spell it out and I’ll try again. Note that atmospheric greenhouse gases are not “miniscule” in their effects, even if their absolute concentrations are small….
Your comment starting:
What I also find suspect is the statement “CO2 is the dominant independently variable greenhouse gas.” Notice that it is not said that CO2 is the dominant greenhouse gas, but the “independently variable” greenhouse gas.
Yes, that’s what I meant to say. CO2 is independently variable. It rises due to major tectonic events, or over long periods if volcanic emissions outbalance atmospheric draw-down, or by massive release of long-sequestered greenhouse gases. It falls due to weathering (mainly).
Water vapour is not independently variable. It’s a passive player who’s atmospheric concentration responds to other forcings (cooling or warming). There aren’t any processes that can significantly increase or decrease the water vapour concentration independent of other forcings that affect the atmospheric temperature. Of course it’s the dominant greenhouse gas in terms of its contribution to the greenhouse effect. But even then one has to be careful, since a good bit of the water-vapour forcing can be attributed to CO2 (and other independently variable greenhouse gases…and the sun of course!), since the CO2 that warms the atmosphere sufficiently for water to partition into the atmosphere to the extent that it does.
I hope I haven’t been crafty again! I’m certainly not trying to be…
really do not understand why there is this concerted pressure from the likes of Joel and foinavon to force upon us their interpretation of the effects of CO2 on temperature, other than this is the only thing that underscores the theology of AGW. (I also notice that whenever there is a thread on this website that in any way attacks Hansen there is also a fighting defense put up by the more persuasive and articulate believers).
So we have increased CO2 levels from 0.03% to 0.04%, which means that we are safe at 99.97% of everything else but it is disastrous at 99.96% of everything else. To exaggerate, it is put the other way around, CO2 has increased, from whatever source, by 30%, whilst at the same time making no mention, or giving no credit, to the most powerful greenhouse effects provided by water vapour and clouds which completely swamp the CO2 effects. Both of these way outperform CO2 in the absorption of ultraviolet radiation. And please I am aware that moisture doesn’t stay in the atmosphere for very long but I am equally aware that it it is constantly replenished every minute of every day.
As a chemist I really do have difficulty buying into your view of the so called disastrous consequences of CO2.
Phil:
Moving it up is not the same thing as increasing its temperature.
‘Initially’ cooler? Is that cooler yesterday? Or last year? Or a hundred years ago? Or is it an on-going process? How long does it take to warm a rarefied layer of atmosphere by a fraction of a degree?
Pretending CO2 controls climate is fun and profitable but it is bs.
Water vapor is, has and will be the dominant GHG, and works with positive and negative feedbacks. If CO2 was some sort of short cut that could ‘tip’ the climate one way or the other in anything like a dramatic fashion, I doubt if we would be here at all.
Again: what Hansen & co. have been able to sell is the idea that their apocalyptic predictions are accurate to within small fractions of a degree utilizing instruments and data procedures that are only accurate to within large fractions of a degree.
The lack of precision and the overwhelmingly subjective nature of their measurements have been well documented.
Their lack of accounting for major non-CO2 positive and negative forcings means that their algorithms were designed with the answer already known.
And the dodge about a cooler sun in the ancient past is only now being dragged out as yet more credibility of apocalyptic bs is stripped away.
Hansen himself ridiculed the idea of a solar influence in a speech in Houston recently.
We are influencing the climate as we always have: positive and some negative forcings, but neither in huge global scales.
That “mold” which covers some spots on the earth, called humanity, can not force anything but confusion. Those guys against the friendly gas in familiar beverages muy try a coke or a beer without gas!
foinavon (05:53:07) Wrote
Yes, there’s pretty good evidence that the atmosphere has warmed the oceans.
foinavon, that is impossible. Our planet’s ocean is far too large for that to happen. The heat capacity of the ocean is far, far greater than that of the atmosphere. Heat always flows from the ocean to the atmosphere, not the other way around. There is a terrific article here: http://co2sceptics.com/news.php?id=1562 that explains this in layman’s terms. It’s pretty tough to argue with basic physics.
Merry Christmas to all!
David,
The notion that joel and I are “forcing upon” you our “interpretation of the effects of CO2 on temperature” is quite funny!
I would hope that you and everyone here is sufficiently strong-minded to resist our “concerted pressure”…you should certainly come to your own decision on these issues.
I think each of us is just saying it as we see it. joel seems to have a very good appreciation of the science and is indeed articulate (and very gracious with his earlier compliment which was appreciated btw). I work in somewhat related areas (I’m a chemist too just like you as it happens) and know some of the science.
We’re really just presenting some of the relevant science, which one shouldn’t be afraid of. After all the natural world doesn’t defer to one’s prejudices and agendas (King Canute recognised that even if his misguided advisors didn’t), and it’s best to face the evidence on these issues, even if someone else’s false platitudes might appear more comforting.
hunter,
do be careful not to fall for the “dodge” of a cooler sun!
Pretending is indeed fun and can be profitable, but only in the short term. In the end reality is likely to turn up and bite you on your cheeky bottom!
Adolfo,
as a Brit, I quite like flat beer…in moderation of course!
Merry XMas to everyone!
Peter (13:27:12) :
Phil:
“He has it right, the effective level is a function of the GHG concentration, increase [GHG] and the effective level moves up”
Moving it up is not the same thing as increasing its temperature.
Quite, it will actually decrease the temperature at the effective level.
“that level being initially cooler means that less energy is leaving the planet than is coming in so the temperature must increase until balance is reached.”
‘Initially’ cooler? Is that cooler yesterday? Or last year? Or a hundred years ago? Or is it an on-going process?
It is an on-going process obviously but the explanation was to illustrate how it works in a discrete step.
How long does it take to warm a rarefied layer of atmosphere by a fraction of a degree?
Not very long, the heating/cooling rate in the stratosphere is above 0.05ºC/hr.
Joseph,
It’s a very well written article. It’s also tosh unfortunately. It is tough to argue with basic physics, but there’s not much “basic physics” in the article.
I expect it’s well written because Stephen Wilde is a lawer, and is thus well-practiced in presenting nonsense convincingly. He pretends that he’s a Fellow of the Royal Meterorological Society, but that would be unlikely since he doesn’t fulfill their credentials[***], and in any case he’s rather absent from their list of Fellows which can be perused here:
http://www.rmets.org/about/people/fellows.php?pageNum_frmets=3&totalRows_frmets=360
Mr Wilde asserts that the greenhouse effect is solely a result of atmospheric density, and that CO2 doesn’t play a significant role. Do you agree?
Mr Wilde asserts that the climate is controlled by the “Hot Water Bottle Effect”. Do you agree?
Mr Wilde asserts that it’s impossible to warm cold tap water in a bathroom to the temperature of a warm bath by heating the air in the bathroom. What do you think?
etc. etc.
In fact the atmosphere has warmed the oceans somewhat. A warmer atmosphere reduces the escape of surface thermal energy into space and thus the surface must warm in order to maintain an equilibrium between the incoming and outgoing radiation.
[***]From the Royal Meteorological Society website page on “Fellows”:
Becoming a Fellow normally requires a formal qualification (eg. a first degree in a science subject and/or post-graduate degree or an NVQ in a relevant discipline) and at least five years of professional experience within or directly related to meteorology. Exceptionally, long experience and performance at a high professional level, suitably attested by peer review, can replace the requirement for a formal academic or vocational qualification. MSc or PhD study in a relevant subject counts as one or two years experience respectively.
Joseph (15:20:46) :
foinavon (05:53:07) Wrote
“Yes, there’s pretty good evidence that the atmosphere has warmed the oceans.”
foinavon, that is impossible. Our planet’s ocean is far too large for that to happen. The heat capacity of the ocean is far, far greater than that of the atmosphere. Heat always flows from the ocean to the atmosphere, not the other way around. There is a terrific article here: http://co2sceptics.com/news.php?id=1562 that explains this in layman’s terms. It’s pretty tough to argue with basic physics.
Indeed, however that article gets a lot of it wrong!