Jim Hansen's AGU presentation: "He's 'nailed' climate forcing for 2x CO2"

That wasn’t me who pointed you at that graphic. That was someone else, I was simply pointing out that I got a 404 with one of the URL’s he offered.
REPLY: You pointed out it was missing now, that is what I was referring to. – Anthony

Yes, it was Steven Goddard who gets priority on pointing out the missing graphic.
I misunderstood what he was saying. I clicked on the link he had already said was missing and confirmed it, but thought I had found a mistake in what he was saying.
Sorry.

So, if he’s “nailed” it, that means he’s willing to debate, right?

I have seen at least a half dozen empirical estimations of the climate sensitivity done by a variety of different methods, and their range runs from less than 1 to ~ 1.7 deg C for doubling. They use a variey of correlation techniques (e.g., Douglass and Christy) or estimates of the temperature relaxation time (Schwartz, Scafetta). Therefore the ‘consensus’ (ha, ha) is that the climate sensitivity is far less than Hansen’s claim.

Hansen also fails to mention Venus’s atmosphere is 97% CO2… how he can jump from Earth’s atmosphere of .03% CO2 to runaway global warming is beyond comprehension… he’s completely an imbecile…

Web sites, such as WUWT, are dangerous and an impediment to political consensus of AGW.
Read John’s commentary and then consider where the danger lies.
John Holdren Commentary: Convincing the Climate-Change Skeptics
http://www.hks.harvard.edu/news-events/news/commentary/climate-change-skeptics
The extent of unfounded skepticism about the disruption of global climate by human-produced greenhouse gases is not just regrettable, it is dangerous. It has delayed – and continues to delay – the development of the political consensus that will be needed if society is to embrace remedies commensurate with the challenge. The science of climate change is telling us that we need to get going. Those who still think this is all a mistake or a hoax need to think again.

(with apologies to Ernest Thayer)
Somewhere people laugh
Somewhere people shout
There is no joy in Warmville
James Hansen has struck out

“My name was mentioned several times though. ;-)”
Watch your six!

REPLY: That was a tongue in cheek reference to Steve McIntyre’s “he who must not be named” issue. My name is “Watts” which is sprinkled throughout the radiative forcings section.

Lorne Gunter: Thirty years of warmer temperatures go poof
http://network.nationalpost.com/np/blogs/fullcomment/archive/2008/10/20/lorne-gunter-thirty-years-of-warmer-temperatures-go-poof.aspx
In early September, I began noticing a string of news stories about scientists rejecting the orthodoxy on global warming. Actually, it was more like a string of guest columns and long letters to the editor since it is hard for skeptical scientists to get published in the cabal of climate journals now controlled by the Great Sanhedrin of the environmental movement.
An analytical chemist who works in spectroscopy and atmospheric sensing, Michael J. Myers of Hilton Head, S. C., declared, “Man-made global warming is junk science,” explaining that worldwide manmade CO2 emission each year “equals about 0.0168% of the atmosphere’s CO2 concentration … This results in a 0.00064% increase in the absorption of the sun’s radiation. This is an insignificantly small number.”
For nearly 30 years, Professor Christy has been in charge of NASA’s eight weather satellites that take more than 300,000 temperature readings daily around the globe. In a paper co-written with Dr. Douglass, he concludes that while manmade emissions may be having a slight impact, “variations in global temperatures since 1978 … cannot be attributed to carbon dioxide.”
It may be that more global warming doubters are surfacing because there just isn’t any global warming.

I quit reading Hansen’s junk a long time ago. It is a waste of time. He is simply an ex-scientist, who has turned into a looney politicial hack.

REPLY: That was a tongue in cheek reference to Steve McIntyre’s “he who must not be named” issue. My name is “Watts” which is sprinkled throughout the radiative forcings section.
I think the description “peppered” more accurately describes the disbursement of your name in this case.
Andrew ♫

When I was a young whippersnapper if you had ‘nailed’ something empirically it meant that you had indisputable data from a physically reproducable experiment which you could put before you colleaques with total confidence of confirmation and verification.
Sorry Hansie, don’t see that here on anywhere else at NASTY.

DailyKos reports on: Dr. James Hansen: “How do we make them understand how serious this is?” and gives links to other similar 2008 presentations.

TI: Threat to the Planet: Dark and Bright Sides of Global Warming
AU: * Hansen, J E
EM: jhansen@giss.nasa.gov
AF: The Earth Institute at Columbia University, 405 Low Library, 535 West 116th Street, New York, NY 10027, United States
AU: * Hansen, J E
EM: jhansen@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AB: Abstract. Earth’s history reveals that climate is sensitive to forcings, imposed perturbations of the planet’s energy balance. Human-made forcings now dwarf natural forcings. Despite the climate system’s great inertia, climate changes are emerging above the ‘noise’ of unforced chaotic variability, and greater changes are ‘in the pipeline’. There is a clear and present danger of the climate passing certain ‘tipping points’, climate states where warming in the pipeline and positive feedbacks guarantee large relatively rapid changes with no additional climate forcing. The fact that we are close to dangerous consequences has a bright side: we must reduce greenhouse gas emissions to a level that will minimize many impacts that had begun to seem almost inevitable, including ocean acidification, intensification of regional climate extremes, and fresh water shortages. Actions required to stabilize climate, including prompt phase-out of coal emissions, are defined well enough by our understanding of the climate system, the carbon cycle, and fossil fuel reservoirs. These actions would also yield cleaner air and water, with ancillary benefits for human health, agricultural productivity, and wildlife preservation. Yet the actions required to stabilize climate are not being pursued. Denial of climate change by the fossil fuel industry and reactionary governments has been replaced by ‘greenwash’. The policies of even the ‘greenest’ nations are demonstrably impotent for the purpose of averting climate disasters. I conclude that inaction stems in large part from ‘success’ of special financial interests in subverting the intent of the democratic process to operate for the general good. The consequence is intergenerational inequity and injustice, affecting negatively the young and the unborn. The defense of prior generations, that they ‘did not know’, is no longer viable. Indeed, actions by fossil fuel interests that served to deceive the public about the dangers of human-made climate change raise questions of ethics and legal liabilities. Youth, at least those who are not too young or unborn, have recourse through democratic systems, but continued failure of the political process may cause increasing public protests.

The Dark and Bright Sides of Global Warming James Hansen August 13, 2008 YouTube

The Threat to the Planet: Dark & Bright Sides of Global Warming PDF
Jim Hansen, 3 October 2007, presented at conference: Heating Up the Energy Debate, Gustavus Adolphus College, St. Peter, Minnesota
What Hansen critically fails to realize is that liquid fuel is critical to our civilization – and his job. The looking decline in global petroleum production (“Peak Oil”) will enforce rapid reductions in available liquid fuels to fuel importing countries like the US. See:
Robert L. Hirsch The Inevitable Peaking of World Oil Production
Peaking of world oil production: recent Forecasts
US Department of Energy/National Energy Technology Lab., NETL-2007/1263 |
year = 2007, February 5, (The “Hirsch report”), and
Mitigation of maximum world oil production: Shortage scenarios Vol 36 # 2, Feb. 2008, 881-889
Our critical issue is not whether the ocean will warm 1 or 1.5 feet, but whether we will have the fuel to run tractors, trucks and to drive to work.
Note especially the World Export Model. Khebab, Graphoilogy, especially slides 16 and 17.
We can convert oil sands and coal to fuel. Sasol of South Africa has successfully been producing oil from coal since 1955.
I would like to see how Hansen proposes to run cars or planes on sequestered CO2. It is our future and our children’s that Hansen is unwittingly destroying in his zeal. Obama’s buying into Hansen’s perspective means much worse economic times ahead in that the US will be even more unprepared for operating on 75% less fuel than we currently use!

So what happend to “If it looks to good to be true than it probably is ?”
Does he really think that the debate will be over now that he has nailed it? This is pure politics, and he knows it, its all or nothing now.

It’s worth pointing out the essential fallacies represented in the two graphs presented in Anthony’s introductory post:
(i) the Illis temp vs [CO2] graph of Bill Illes (who he?) is very misleading since it is dominated by the very large temperature changes occurring over the very low [CO2] ranges (0-50 ppm) never experienced on earth.
It’s easy for anyone with the most basic graphing program (e.g. Excel) to see this for themselves.
You can construct essentially the same graph presented by Anthony (Illes) using the equation:
T = (3.0/log(2))*(log(C))-9.39
where C is the CO2 concentration.
So set up a column of X values ranging from 2-3000 ppm. This is C the atmospheric CO2 concentration
In the above equation 3.0 is the climate sensitivity, the log(2) value refers to the fact that this is the temperature increase upon doubling, the log (C) indicates the logarithmic relationship between temperature rise and change in CO2 concentration, and the 9.39 “normalises” the earth’s temperature to 15 oC at at pre-industrial CO2 concentration (280 ppm).
If you then expand the data to observe the relevant bits; i.e. CO2 concentration between 280 ppm and 1000 ppm (to give the extreme value that might be realized in the next 150 years if we didn’t address this problem at all) or 3000 ppm that might be realized under the Hansen scenario of burning all of the coal and tar shale, you can see that very dramatic temperature rise will accrue (and that’s without factoring in other potentially large feedbacks like recruiting all of the methane clathrates in the deep oceans).
(ii) The “Scotese” “graph” is nonsense. Where has it come from? It bears no relation to our understanding of the earth’s temperature and atmospheric CO2 levels in the deep past. I think we all know, for example, that the earth’s temperature hasn’t drifted steadily downwards from ~22 oC 25 million years ago to 12 oC now! And are we really supposed to believe that the earth’s temperature “sat” at a rock-steady 22 oC for many 10’s of millions of years in the past? I think not, and that’s certainly not what the science shows.
..oh well….

Slightly off topic…having a little but uncertain hope is worse than having no hope at all. Yet New Scientist, in an article on-line, first says we have reached a tipping point of no return and then says, well, there may yet be a little hope for the Arctic (summer) ice after all. It’s a very confusing article, all based on those infamous oh-so-reliable computerized models.
As you can see from the link, the headline is: Arctic melt 20 years ahead of models. The question nobody seems to be asking, however, is: if this is so, why are the models so incorrect? Could it be that, one way or the other, we really still don’t understand how our complicated planetary climate system works? Like the ending of that tootsie pop commercial says, “the world may never know.”
http://www.newscientist.com/article/dn16307-arctic-melt-20-years-ahead-of-climate-models.html

Hansen cites CO2 in some 16 pages, but only mentions water relating to melting glaciers or ocean level rise.
Hansen fails to clearly show that H2O is 80% of greenhouse gas while CO2 only 20%. Furthermore, we know the least about H2O, especially the precipitation and the water heat conduction mechanisms, especially below the troposphere.

Ben,
When you refer to ice core data; just what “data” do you mean ? I would suggest that there is NO ice core data that is more famous world wide, tha the two graphs in Al gore’s “an Inconvenient Truth (p 66/67), and that is simply purported Temperature Data, and purported CO2 data. My understanding is that the CO2 data is actual measured CO2 composition in the samples, and that the “Temperature Data” relies on an O16/O18 proxy; which I don’t claim to understand. how O16 and O18 can simply transmute into each other (or from something else solely as a function of atmospheric temperature is beyond my understanding of atomic Physics (which I once taught0, but that was way back at the start of the space age.
But I am constantly amazed at the ingenuity of scientists at sensing things remotely. My hat is off to Astronomers, who pretty much derive their entire science from the Electromagnetic spectrum for DC to Cosmetic Rays and beyond to unobservable parallel univerese, where any imaginable lwas of Physics can be found.
Now I know those “ice cores” yield a whole lot more substance that just temperature proxies, and CO2 concentrations, and I also know there is a whole lot of skepticism/ debate about just how reliabl;e that stuff is.
But regardless of doubts about the validity of these proxies; it seems to me, that the one thing you can probably count on with some level of credibility, is THE TIMING of whatever happens in those ice cores. They are very tree ring like in their Timing, although I never heard of one tree ring diffusing into otheres to scramble the data. But I generally believe the event timing; unless the lab technicians sometimes screw up.
And therein lies the crux in my mind. In Al gore’s book he deliberately separated those two graphs vertically for the purpose of hiding the true relative timing of CO2 events, and Temperature events.
Well OK he hasn’t had his day in court so maybe I shouldn’t accuse him of outright fraud; I mean it is also possible that he is just as dumb as a box of rocks, and didn’t realize that if he overlapped the curves, one could really see the relative timing of events; sort of what an 8th grade high school science student would do.
Well I have to admit that I have seen the same data printed in peer reviewed journals and other so-called Scientific publications; and actually I have NEVER ever see them overlapped by any author; but I don’t deny that some author/s may exist who have done that.
Bottom line is it is evidently irrefutable that the temperature changes precede the CO2 changes (that caused them) by intervals of from 500 -1500 years, with 800 years appaerntly yielding the highest correlation coefficient.
So regardless of how hokey other ice core evidence may or may not be (I’m not competent to judge that); I don’t se how you get past the usually fatal conclusion that we don’t like our causes happening 800 years after the effect that they cause.
I actually queried Spenser Weart on that point, in Physics Today for Jan 2005 (letters), and he basically changed the subject in his reply, and by e-mail declined to comment further.
Explain the relative timing “anomaly” to me and I’ll die happy.

@Smokey (11:24:08) : On your point
“After reading Hansen’s comparison of the Earth and Venus, I notice that he made no mention of the fact that Venus is much closer to the Sun than the Earth is. Or that Mars’ atmosphere is mostly CO2, and Mars is freezing cold.
….. ”
(a) I’m not sure if you are suggesting that position from the sun is the dominant reason for the the temperature difference between Venus , Earth and Mars .
Mercury is much closer to the Sun (58 million Km) than Venus (108 million km)
Mercury has a temperature of that varies between about 430 C and -180 C. Venus has a temperature of about 450 C with not much difference between night side and sun side.
This can be explained by a run away greenhouse effect on Venus
(http://en.wikipedia.org/wiki/Venus)
(b) Since atmosphere is important ( comparing Venus and Mercury) …why is Mars cooler . Its atmosphere is so thin (about 100th that of the Earth) that even though the CO2 content is hight ( 95%) there isn’t enough to cause a runaway greenhouse effect or mask the effect of its distance from the Sun .
(http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/temperature_overview.html) . Although the CO2 content does appear to have some effect on Mars.

It’s also curious when making the comparison to Venus, shouldn’t he mention Venus has no no planetary magnetic field? Because of that, the sun has stripped Venus’ atmosphere of most of the lighter gases, leaving an atmosphere of mostly the heavier CO2 and Nitrogen molecules.
If you are going to do science why not do it completely, why not do it in the open?
It’s as if he thinks no one knows what photosynthesis is. Come to think of it, I asked that very same question to a group of people (I won’t say who they really were) and not one in the crowd knew what it was. So obviously they didn’t have a clue what would happen if we were able and reduced the CO2 in the atmosphere to zero.

PeteM:
Did you even read Kasting’s 1988 paper where he uses the term “runaway greenhouse” occurs? Clearly not. He is specifically linking this term to solar activity during the early stages of planetary evolution causing all the water vapor to blow away into space.
The water it seems, in his one-dimensional atmospheric model, acted as a negative feedback untill it dissipated into space.
Try again Pete, but this time follow-up on your “proof”. Don’t just read the buzz words.

“the enhanced CO2 levels result in enhanced warming of the earth”
And that is the point nobody has proved to my satisfaction. All we have are “models” created by people who already wanted to show this fact.
We have no indication that CO2 has added any appreciable amount of warming to Earth. And you have the problem of diminishing return. If you get a certain amount of warming when you add 100ppm of CO2, you get significantly LESS warming when you add the next 100ppm. The response is not linear.
Also I believe the models are completely bogus because they predict a hot spot in the middle of the atmosphere. You can’t do that in real life because they minute you warm air in a given location, it wants to rise and it rises above more of the CO2 in so doing and radiates any heat it gained into space. So an increase in CO2 would maybe increase convection but none of the models take convection into account. They seem to depend on a static and infinitely “deep” atmosphere.
The models aren’t based on reality.

deadwood (13:33:02) :
You have missed the point – Smokey seemed to suggest that distance from Sun was a factor to explain differences in Earth Mars and Venus .
The information I provided shows that is not always a dominant factor .
Venus is suffering from a strong green house effect (http://en.wikipedia.org/wiki/Venus)
Mars doesn’t have a thick enough atmosphere to escape most of the implications of its distance from the sun .

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 . . .

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!).

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.

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.

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

I wonder if Hansen took any critical questions following this presentation? I would have several.

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”.

Frank Ravizza,
why not put your questions here. Perhaps some of the posters can address them..!

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.

“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?

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.

I’m still wondering where Hansen took the figure 3 for 2xCO2. If we increase the mass of carbon dioxide, but the heat source remains constant, then the CO2 would act like a cooler, not like a radiator. I think Hansen resorted to the “Solar Irradiance has increased” for making his fantasy sounds more credible from a scientific standpoint. For the carbon dioxide acted like a warmer, the solar irradiance had to increase, but it has happened just in the opposite way… Heh! On the other hand, sandy lands have always existed on Earth. Perhaps Hansen is trying to blame deforestation on global cooling.

David,
No, Hansen certainly isn’t claiming a linear relation between CO2 and T…far from it.
The relationship is logarithmic. I’ve dumped a simple equation in my post above (see 12:52:53), which can be used to calculate the temperature response to enhanced CO2 within a 3 oC climate sensitivity.
Hansen’s analysis is more complex almost certainly. He’s presumably done a full fit of the ice age record incorporating insolation variations (these can be calculated from analysis of Milankovitch cycles), and the known feedbacks (water vapour, albedo), and optimised the climate sensitivty of the CO2 forcing….something like that.
However if one wants to estimate the earth’s temperature response to enhanced CO2 within a particular climate sensitivity, the equation in my post above will allow you to do that (or you can change the climate sensitivity and see what happens)..
Of course that doesn’t means that’s what’s going to happen! It’s possible that the sun might do something funny…or we might enter a weird volcanic/tectonic stage…or we might get hit by an asteroid…but there’s quite a lot of evidence that the earth’s temperature response to greenhouse gas forcing can be estimated to a first approximation using a climate sensitivity value. Hansens’ study reinforces a lot of other data suggesting that this is somewhere near 3 oC of warming per doubling of atmospheric CO2..

“but there’s quite a lot of evidence that the earth’s temperature response to greenhouse gas forcing can be estimated to a first approximation using a climate sensitivity value”
Can you demonstrate any such evidence using data other than Hansen’s? Can you show a temperature response that rises in step with CO2 rise? I haven’t seen one yet. I have not seen any temperature response that even remotely resembles the increase in CO2. Again, we had the most dramatic increase in CO2 while global temperatures were cooling. In 1998 we had much more CO2 than we had in 1933 yet temperatures during that PDO/ENSO warm cycle didn’t rise as high as they did in 1933.
Sure there are a lot of theoretical models that demonstrate this relationship but none have shown to be an analog to reality.

crosspatch,
Atmospheric CO2 levels rose relatively slowly after the war up through the mid 60’s:
1944ish 310 ppm
1962 320ppm
1973 330ppm
So in the 30 post war years CO2 levels rose around 20 ppm.
In the next 30 years they rose 47 ppm (377 ppm in 2003; 386 ppm now).
The earth’s temperature was pretty flat post war ’til the early 70’s. The evidence indicates that the massive release of very dirty fuels that gave us killing London smogs and acid rain and such like was sufficient to counter the small temperature rise expected from the smallish (in the grand scheme of things!) CO2 rise. As various clean air acts kicked in during the 1960’s especially, the “cooling” effect of our diry aerosols was somewhat diminished. We are still “protected” from the full whack of greenhouse-induced warming by a cooling aerosol effect.
The temperatures haven’t really declined since 2000. As the earth’s temperature responds to enhanced greenhouse warming, the temperature trends slowly upwards (there is quite a large inertia in the climate system, and so it takes a considerable time for the earth’s temperature to eqilibrate with a new forcing). During this rising trend stochastic variations in the climate system may dominate for short periods. 2008 is going to be somewhat short of a record year due to the strong early La Nina, and we’re smack at the bottom of the solar cycle.
it wouldn’t be surprising if the next record temperature year will occur at the next El Nino or two!

foinavon,
Maybe he did all those things but if his sensitivity is a constant the end result is a linear relationship. If not, he should be saying that the sensitivity is a function of a whole range of parameters and variables, not a constant. For example, with your log relationship you would need to specifying the starting concentration of CO2 to be able to state the effect on T of a doubling. No?

Whenever this gentleman’s name appears, an image of the muppets intrudes into my consciousness. At least with those creatures there’s an aura of innocence about their silliness.
Did a quick scan of his lecture and one of the first thing I noticed is how he sets up a strawman of solar irradiance to dismiss solar influence on the climate. TSI, as I understand it, is a relatively stable element. Of more consequence is solar wind and solar/earth magnetic field interactions. To use TSI as he does is to place blinders on science.
And the presumptive arrogance of the man — “to preserve creation.” Give me a break!
And the examples he pulls out of his hat.
Rongbuk glacier — probably less about temperature than a disruption of monsoonal precipitation patterns due to dumping of particulate matter into the atmosphere.
Western wildfires — a consequence of repressing natural fires which resulted in an explosive growth of combustible tinder over the decades.
Western drought with that picture of the Lake Mead pier far from any water — the infrastructure in the Western states was developed and built during an unusually wet period. Now that a more normal, drier period is upon us, there’s much hand wringing.
And he goes on and on.
I’ve saved the file so I can read some of it tomorrow morning to get my blood racing so I can shovel some of that +15″ of global warming {it’s still coming down}.

Bobby Lane
Please rethink your characterization.
The one sending out the massive troops to enforce the decree was Sauron.
Aragon was the one upholding the truth.

SOMEONE PLEASE CORRECT ME IF I’M WRONG, BUT…
CO2 and temps were both higher in the past, so if the planet’s climate is on hair-trigger, how do we not see this happening in the past, and why once the temps go up due to feedback, do they ever come back down. I would thing that if the climate was so unstable that a slight tip could force it to get hot that it would be locked in at the high end, with cold spells being the anomaly. What reset it in the past when humans weren’t here to sacrifice themselves and their wellbeing for the greater good of Ma Nature?

Not really Smokey,
You’ve brought all sorts of extraneous “political” stuuf that’s not really relevant. It’s all about the evidence, I hope we would agree!
i’ve hardly disregarded “many years of work by numerous esteemed scientists like J.S. Haldane”… If you read my post above (16:11:33), you’ll see that i’ve been more than favourable to the early measurers of CO2. And if you read the primary literature on this subject (i.e. the papers of the likes of Kreutz in Giessen or Jules Reiset), you’ll see that they are quite open about the deficiencies of their measurements (Reiset went to great lengths to get relaiable data).
Notice that Beck plays fast and loose with the word accurate. But we need to be clear about what the accuracy refers to. Measurements can be precise but inaccurate. Or they can be inaccurate but not representative of the subject at hand. That’s the case with many of the measurements that Beck complies while removing all reference to the qualifiers of the excellent scientists themselves.
Basically a number of scientists made atmospheric CO2 measurements in heavily contaminated urban environments while developing the methodologies for CO2 collection and analysis. Their measurements were often precise. They were accurate measurements of the CO2 content in the air in the urban locations that they lived. But they were not accurate in relation to the well-mixed atmospheric CO2 levels.
Some scientisits (like Rieset) took great efforts to measure atmsopehric CO2 in uncontaminated settings far from urban centres. Reiset took his apparatus to the windy N. Atlantic coast and obtained atmospheric CO2 values that are pretty close to the ice core data (290-300 ppm) for the late 19th century…
Nobody said that “remained right at 280 ppmv prior to the 1900”
Nobody is trying to “fool” anyone. You’re being overly defensive. It’s all about the evidence Smokey.

No David you don’t actually need to state the starting concentration of CO2. That’s one of the essential features of a logarithmic relationship. It’s a little like the radioactive half life which is also an independent parameter in relation to the starting radioactivity.
So if the atmospheric CO2 concnetration rises from 180-360 ppm the earth’s temperature response is a warming one equivalent to 3 oC
And to get another 3 oC of warming the atmospheric CO2 concentration would have to rise from 360 ppm to 720 ppm.
Or one could take any arbitrary value. 280 ppm (pre-industrial level) to 560 ppm gives 3 oC of warming within a climate sensitivity of 3 oC per doubling.
…and so on…

Not only that, the cooling over this last 12 month period is the greatest since the Pinatubo cooling. We are 1.49 degrees cooler over the last 12 month period than we were over the same 12 month period ending in November 2007. The Pinatubo cooling was 1.87 degrees in one year. El Chichon cooling was even greater in N. America at around 2 degrees. So we have had cooling in one year that has only been matched in the recent past (since the 1970’s) by major volcanic events. And we have had no such major volcanic events.

The global response is similar. More years of cooling than warming since WWII. The exact numbers differ but the trends are the same. North America accounts for most of the land area in the Western half of the Northern Hemisphere so accounts for about 1/4 of the world. Trends in N America should match global trends, and they do.
The problem is in getting accurate data from the other half of the Northern Hemisphere. The data from China and Russia seem spotty and tends to go “missing”. And there is even less data from the Southern Hemisphere.
The satellite global trends and NOAA’s North America trends match.

Smokey, you seem to be linking to stuff that you haven’t really thought about.
The “Scotese” graph is nonsense. I hope you can see what’s horribly wrong with it. Anyway, you’ve linked to this without apparently looking at the paper by Pagani that’s cited there. That paper addresses some of the issues you request guidance on. For example, it highlights the essential link between atmospheric CO2 levels and global temperaure, in this case the slow reduction in atmospheric Co2 (through weathering most likely) that, according to Pagani “likely allowed for a critical expansion of ice sheets on Antarctica”:
Pagani M (2005) “Marked decline in atmospheric carbon dioxide concentrations during the Paleogene” Science 309, 600-603
Abstract: The relation between the partial pressure of atmospheric carbon dioxide (pCO(2)) and Paleogene climate is poorly resolved. We used stable carbon isotopic values of di-unsaturated alkenones extracted from deep sea cores to reconstruct pCO(2) from the middle Eocene to the late Oligocene (similar to 45 to 25 million years ago). Our results demonstrate that pCO(2) ranged between 1000 to 1500 parts per million by volume in the middle to late Eocene, then decreased in several steps during the Oligocene, and reached modern levels by the latest Oligocene. The fall in pCO(2) likely allowed for a critical expansion of ice sheets on Antarctica and promoted conditions that forced the onset of terrestrial C-4 photosynthesis.

Foinavon,
you and other warmers appear to be getting pretty desperate in your level reasoned discourse. Of course, you are also becoming DENIERS!!!
Would you please post the data and models that differ from the IPCC who presented graphs, argument, data, and models showing the infamous HOT SPOT in conjunction with tropospheric cooling and tropopause heightening as the ID of Anthropogenic Global Warming through Greenhouse Gasses??
AR7 is what you must deal with to DENY the hotspot.
I assume you do not agree with the games with models and wind speed measurements to tell us that we can’t EXCLUDE THE POSSIBILITY OF A HOT SPOT??
Personally I am just fine with the IPCC science. They tell us that GG warming will cause the three mentioned data points. We do not have those data points. Therefore we either do not have GG warming (or ANY warming with no hot spot) or they are wrong.
Since we apparently agree that they are wrong, I again urge you to post your theory and data!!
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

“And even then – this may all morph into ‘Man Made Emissions of CO2 cause Global Cooling.'”
Actually, that is where Hansen got his start. His first climate models were used (by Rasool, 1971) to show that burning fossil fuel would plunge us into an ice age. Then when temperatures go the other way, his models show it will boil us alive.

And note that even in 1971 Rasool noted that:

the rate of temperature increase diminishes with increasing carbon dioxide in the atmosphere

So even then they knew the response wasn’t linear. If you increase CO2 by 100ppm you might get some rise. You get less rise when you add another 100ppm and even less rise when you add another. So if we have added, say, 200ppm of CO2 to the atmosphere, adding another 200ppm will have less impact than we have already had. In other words, for a linear increase in CO2, you get a non-linear increase in temperature with a large initial rise that trails off as CO2 increases.

And finally:

“As a scientist and lifelong liberal Democrat, I find the constant regurgitation of the anecdotal, fear-mongering clap-trap about human-caused global warming to be a disservice to science,” Hertzberg wrote in Sept. 26’s USA Today. “From the El Niño year of 1998 until January 2007, the average temperature of the Earth’s atmosphere near its surface decreased some 0.25 C (0.45 F). From January 2007 until the spring of 2008, it dropped a whopping 0.75 C (1.35 F).”

So “fighting” global warming might be rather silly considering there is no “global warming” to fight and hasn’t been since 1998. What I find so amazing is that Mann could take an El Niño temperature rise and project it continuing non-stop into the future and get away with it for this long.

Hansen and the rest… I concerned by the core of Fascism that haunts the AGW Meme like a cancer. After all, anything is justified if you are saving the planet.
Some more pseudo-entertainment from my CO2 fevered imagination – story seems the appropriate vehicle for expressing my concerns with the AGW movement.
When Green Chickens Come Home To Roost.
Somewhere in the USA, Sometime in 2018…
FADE IN.
OUTSIDE: EARLY EVENING – NOVEMBER.
– A weary group of men and women, chained into a gang, trudge along a city road. Their guards carry rifles, and short whips. A light dusting of snow is falling.
– They pass a Primary (Elementary) school where the teachers and students have assembled to watch them pass. The Principle of the school turns and faces the assembled children and staff and raises her arms.
Principle: (Stern Encouragement) “Now children all as one – Sceptics are Septics”.
Assembled Children and Staff: (Chanting) “Sceptics are Septics… Sceptics are Septics… Sceptics are Septics…”
– Some of the chained people steal glances at the children.
Guard: “Eyes Front!”
– The guard smashes his whip across the face of one of the chained men and bright blood splashes onto the snow.
– One of the schoolchildren breaks ranks and staggers forward through the snow.
Schoolboy: (Falteringly Disbelief) “That’s my Dad!?”
– The principle turns abruptly towards the boy and signals to green frocked School Proctors, who leap forward and grab the boy before he can reach the road.
– The struck man slumps to the ground, barely conscious, the man chained next to him, takes his arm and drags him to his feet.
Principle: (Outraged) “Shocking behaviour. Samuel Taylor – A months detention. Proctors remove him to the holding room.”
– The proctors drag the boy away.
Assembled Children and Staff: (Continue Chanting) “Sceptics are Septics… Sceptics are Septics… Sceptics are Septics…”
– Two school cleaners stand quietly to the side of the assembly, not being teaching staff or students they are not required to join in. They talk quietly together.
Cleaner One: “So the Higgs Boson has been found at CERN?”
Cleaner Two: “Yes, the Paper by Peebles gives an excellent demonstration of the existence of the Higgs Boson.”
Cleaner One: “Do you miss the research at MIT?”
Cleaner Two: “Of course – but at least I’m able to feed my little girl. – and what choice did I have, Particle Physics isn’t Environmental Science is it.”
Cleaner One: “Same with Nuclear Engineering – now that all the reactors have been shut down – there’s just no more work for a PHD in Engineering in my field.”
– Cleaner Two nods towards the steadily moving chain gang.
Cleaner Two: “Still it’s better than what that lot are facing.”
Cleaner One: “Which is?”
Cleaner Two: “5 Years Hard Labour in the Pig Methane Plant.”
Cleaner One: “Shovel Pig manure for 18 hours a day and get fed…”
Cleaner Two: “Which would you prefer – that – or the alternative?”
– Cleaner one shivered from more than the cold, and drew his coat more tightly around his thin frame.
Cleaner One: “The fertiliser plant – but that’s just for capital crimes isn’t it?”
Cleaner Two: “Apparently “Carbon Denial” is set to become a capital crime – rumour has it, that it’s to be the next Presidential Emergency Directive.”
Cleaner One: (Quietly) “Oh my god… what have we become?”
– Cleaner Two nods silently in agreement.
– The Principle signals a halt to her students and staff.
Principle: (Smug) “Now everyone – we have todays new mantra, lets chant it together for the benefit of these poor deluded people.”
All: (Chanting in practised unison) “Man Made CO2 Causes Global Cooling… Man Made CO2 Causes Global Cooling… Man Made CO2 Causes Global Cooling…”
FADE OUT.

For those of you who believe that Algore/UN/IPCC/Pachauri are dangerous, I hope are now watching 60 Minutes and listening to the most scientifically ignorant governor ever to be wrongly elected to public office. It is clear that Californians will be lucky to survive this moron.

Steven Goddard says:

Another very troublesome NASA “correction” article came out a few weeks ago.
http://earthobservatory.nasa.gov/Features/OceanCooling/
What could have motivated a bizarre “science” story like that? I’ve never seen anything like that before.

That certainly doesn’t look like science.

I’ve googled bill illis and all I can find is his posts on the various denialist sites. Any credentials? Expertise? Why is there no professional information on Illis?
Cheers
REPLY: On the flip side – Why is there no professional information or even a name for “Tamino”? Why is there no name or professional information from you?
If Bill wants to respond I’m sure he’ll do so.

Another problem with ‘doubling’ is saturation. A graph appeared many threads back that showed the diminishing return of absorbtion. (can’t remember the name, couldn’t find it) With CO2 somewhere above 97% of everything it can absorb, a doubling might get to 98.5%.
That won’t have much effect. The real question is what level of that nasty stuff hit 95%? Or any arbitrary point. We just can’t get many more degrees C from any additional CO2.
Barking up the wrong tree.

“, I also think that the increase in H2O in the atmosphere with temp increases causing an increased albedo (via clouds) is important as well.”
Well, the bottom line is that there currently is no “global warming” and while we did get a period of about 22-23 years of warming that coincides with a positive PDO, the rest of the period since 1933 have been cooling years.
There just isn’t any “global warming” to relate rising global CO2 levels to. I don’t doubt that CO2 is rising, you can clearly see that from the data. I don’t doubt that climate warmed from about 1976 to 1998, that is also clear from the data. What isn’t shown at all by the data is any relationship between that 22 year rise and CO2 rise when the 30 years prior and 10 years since directly contradict that hypothesis. 40+ years of declining temperatures and 22 years of increasing temperatures with CO2 climbing in a nearly linear fashion over the entire time does not exactly cause me to jump to any cause/effect conclusions.

No David you don’t actually need to state the starting concentration of CO2 [in order to have a 3C. temperature increase for each CO2 doubling]./foinavon
Of course you do. Or are you arguing that doubling CO2’s concentration from 1ppm CO2 up to whatever levels we have now would have induced a 3C. degree response each time? In addition, you are ignoring the [relatively small] amount of long wave radiation reflected from the Earth’s surface which is available to be captured only by virtue of CO2’s absorption characteristics – which isn’t very much in comparison to water vapor’s, and, of course the climatic mechanisms which dissipate heat energy, the same ones which have also already kept water vapor from performing at its untethered theoretical maximum here in the real world.

crosspatch (18:38:58) :
“And even then – this may all morph into ‘Man Made Emissions of CO2 cause Global Cooling.’”
Actually, that is where Hansen got his start. His first climate models were used (by Rasool, 1971) to show that burning fossil fuel would plunge us into an ice age. Then when temperatures go the other way, his models show it will boil us alive.
The technique of morphing the ideology to fit the available data – when swamped by that data – has been used once before. We can expect it to be used again in the future.
In all three (2 past, 1 proposed Future) cases the target of restricting CO2 output as a means of constraining the development of Western Civilization remains invariant.

Retired Engineer (20:50:19) :
Another problem with ‘doubling’ is saturation. A graph appeared many threads back that showed the diminishing return of absorbtion. (can’t remember the name, couldn’t find it) With CO2 somewhere above 97% of everything it can absorb, a doubling might get to 98.5%.
Is that the reason that the curve is a logarithmic one – i.e as the absorption spectra for CO2 gets saturated – CO2 faces a diminishing returns relationship for forcing warming?
Just asking?

This year looks pretty similar to 1981 when we did about 1.60 ppm CO2, so it seems likely we’re looking in the 1.50 to 1.60 range this year.
If we averaged adding 1.50 ppm/yr, for the next 30 years (which seems reasonable) we could be looking at flat to lower temps for the cycle with 90 – 100 ppm CO2 added to the atmosphere. That would be roughly 90/340 or an addition of 26% increase in CO2 for the cycle with flat, to slightly lower temps.
How does THAT fit in with 3o C for a double?

Foinavon,
“The earth’s temperature was pretty flat post war ’til the early 70’s. The evidence indicates that the massive release of very dirty fuels that gave us killing London smogs and acid rain and such like was sufficient to counter the small temperature rise expected from the smallish (in the grand scheme of things!) CO2 rise. As various clean air acts kicked in during the 1960’s especially, the “cooling” effect of our diry aerosols was somewhat diminished. We are still “protected” from the full whack of greenhouse-induced warming by a cooling aerosol effect.”
I’ve read all this before on the Realclimate website. What you’re saying may all be true of course, but certainly it is very convenient isn’t it? When the Earth isn’t warming, its due to the cooling effects aerosols. When the Earth is warming, the aerosols have apparently disappeared from the atmosphere? Are places like China and India burning very ‘clean’ fuels now as opposed to what was being burnt in Europe back in the 60’s? Could be so, I don’t know. But it’s a reasonable question to ask I think.
You state: “the evidence indicates..”. If there is evidence and the research is pretty solid I’m happy to accept it as credible. Could you provide links please?
One wouldn’t want to be lead to the conclusion that the aerosal claim is an ad hoc assertion used to save AGW. It seems to me that without invoking aerosols as a massive atmospheric coolant, AGW is in a lot of trouble. So presumably there has to be a lot of very solid science behind aerosols and their effects on the atmosphere and good data on historic atmospheric content. I would also expect that the data would tend to be showing significantly more cooling in those areas of the globe where aerosols were being mostly expelled? And all the empirical data supports this and is (reasonably) consistent with this?
(One of the frustrating thing I find about reading Realclimate is that very very critical points such as this example tend to be lightly skipped over.)
Thanks.

1. The graphic of Antarctica illustrates the period 1982-2004. What would the graphic look like if the period was ’82-’07? What will it look like in January, when we could include data from ’08???
2. The problem with Hansen “nailing” his conclusions by including aerosols, albedo, and water vapor — the IPCC 2007 Summary for Policymakers rates our “Level of Scientific Understanding” (LOSU) for aerosols as “medium-low” for direct effect and “low” for cloud albedo effect. The LOSU is rated “medium-low” for surface albedo forcings. The chart I’m looking at in the report does not quantify the LOSU for water vapor forcing.
My point is that if you have low or medium-low understanding of major components in the final calculation of anthropogenic radiative forcing, how can you claim to have “nailed” anything until you understand all the major factors with reasonable certitude? You can’t. It’s a logical impossibility. Even granting for the sake of argument that understanding of the CO2 factor is very good, you cannot approach certainty by adding in other uncertain factors. Duh!
Dr. Hansen, sit in the corner and put on the dunce cap.

I’d like to encapsulate some conclusions I have from looking at CO2 data, old and new.
CO2 was decided by the present gurus that it should be measured where it is “stable” and at the specific time of day when it is the lowest.
Why so? because it can vary enormously from location to location and height to height and time to time. The AIRS animation maps that show the CO2 bands and the earth breathing with the seasons are the tip of the iceberg, literally, since they are over 5000 meter high. Most of the biosphere is below 1000 meters. In data shown in http://www.ferdinand-engelbeen.be/klimaat/co2_measurements.html we can see variations of 100ppm depending on updrafts etc. Thus it is not surprising that the Beck compiled figures show all this diversity.
What is surprising is why the “stable” choice is considered scientifically robust.
Why not measure as one measures temperatures? hi/low average and thousands of locations avraged, as with temperatures? Because the rise would be smaller?
Of course one might say that temperatures are not robust either. Maybe they should be measured like CO2, on top of Mauna Loa on the cooler time of day and 100 other sites hand picked for stability, all shown independently as confirmations of Mauna Loa temperatures. But then maybe the temperature rise, even when it does rise , would be less dramatic.
There is a smell coming from the whole field as cultivated by AGW.

Retired Engineer wrote:
Another problem with ‘doubling’ is saturation. A graph appeared many threads back that showed the diminishing return of absorbtion. (can’t remember the name, couldn’t find it) With CO2 somewhere above 97% of everything it can absorb, a doubling might get to 98.5%.
Check this post: A Window on Water Vapor and Planetary Temperature – Part 2 The graphs there look like what you describe.

correction- That should have been “Venus receives almost 2 times higher solar insolation due to its closer proximity to the sun”.

If there is – according to Hansen – a “runaway global warming” on Venus, what “on earth” (English is a funny lanhuage 😉 caused it – and again according to Hansen?
Seems like the sun has nothing to do with anything anymore – oh, except with cancer, “of course”…

@Grant I’ve been watching that as well and wondering what to make of it, but it’s not entirely unusual. If you examine the chart, the 2004 data stepped sideways for a bit around the same time last year, as well as the 2003 data later in the month. The 2008 sideways step is lasting longer, however, than the other years depicted.
What I find curious is that NSIDC hasn’t heralded the change in a new press release. They really like to point out warming changes whenever they can. Cooling changes are either ignored or downplayed as far as I’ve observed. If you look at the NSIDC chart (http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png) you’ll see that the growth has not only slowed, but lost mass by a degree.
Anyone have an explanation for why this may be occurring? I was under the impression that this was a colder winter. Is that not the case up north?

re to Will
When you refer to what most of the IPPCC scientist are looking for in response to AGW please add the word negative. As the IPCC takes AGW for granted, they mainly look for negative and often doubtfull effects, and ignore postive effects of increased CO2.

Great thread. People actually discussing math and science.
Question I have is that if the temperature response to CS (Climate Sensitivity) is logarithmic as Dr Hansen and most seem to agree then why:
1) is the temperature increase primarily linear? Only way that happens I think is if CO2 growth is exponential, yes?
2) Given the 2.5 – 3.5C temperature in response to doubling CO2 from 280ppmv and we are currently nearing 400 ppmv (about halfway there) should we not have already seen about 70% of the 2.5-3.5C temp increase?

If Mercury has no atmosphere, how can we talk about its ‘climate’?

Steve,
Yes, your numbers are right. Within a climate sensitivity of 3oC (of warming per doubled CO2) we expect around 1.3 oC of warming at equilibrium for a CO2 increase from 280-380 ppm.
Of course that’s the equilibrium response. Since the earth has a large inertia (largely from the oceans), it takes some time for the planet to come to a new thermal equilibrium with the forcing. So we still have a bit of warming “in the pipeline” even were CO2 levels to stop dead at current levels.
We’re also still pumping out loads of aerosols and these are protecting us somewhat from the full whack of our greenhouse gas emissions. This has been reviewed recently by Ramanathan and Carmichael, who conclude that the 3 W m-2 excess greenhouse forcing is still being countered by around -1.5 W.m-2 of aerosol cooling.
V. Ramanathan & G. Carmichael (2008) Global and regional climate changes due to black carbon; Nature geoscience 1, 221-227.
That’s a costly paper to get hold of, but Ramanathan has made a detailed presentation of this work to the Wegman oversight committee which can be found here:
http://oversight.house.gov/documents/20071018110734.pdf
The papers you cite concerning climate sensitivity are an odd bunch. I couldn’t find this one:
Compo and Sardeshmukh [2008]: Oceans a main driver of climate variability.
Until I realized you’d changed the title! Were you trying to make it sound more interesting?
It’s actually
Compo, G.P., and P.D. Sardeshmukh, 2008: Oceanic influences on recent continental warming. Climate Dynamics, doi: 10.1007/s00382-008-0448-9.
And in fact it’s not particularly controversial. The authors do some modeling and suggest that within their model they can calculate much of the land warming of recent years as a result of ocean warming. They don’t address the cause of the ocean warming, but the evidence is pretty strong that the oceans have warmed due to greenhouse enhancement. Some of the observations of the paper don’t accord with real world observations. For example they question the water vapour feedback to greenhouse warming (which they have eliminated from their model by design), particularly the prediction that the troposphere tends towards a constant relative humidity. However data that identify the predicted change in water vapour feedback and a tendency towards a constant relative humidity has recently been published:
A.E. Dessler et al (2008) Water-vapor climate feedback inferred from climate fluctuations, 2003–2008. Geophys. Res. Lett. 35, L20704,
(a summary can be found here:
http://www.nasa.gov/topics/earth/features/vapor_warming.html)
The “paper” by Douglas and Christy is being prepared for a non-science polemical magazine. That’s unlikely to be very helpful!
The Chylek paper seems O.K. I’ll read it when I get a chance…

Hansen’s Venus comparison is utterly desperate and you’d think somebody working for NASA would actually understand the origins of that planet’s atmosphere. The idea that Venus is an example of ‘runaway greenhouse’ is a common misconception. Venus has always been hot and the reason there is so much carbon dioxide in its atmosphere has nothing to do with volcanic emissions as many people believe.
It all began billions of years ago when Venus and the Earth were much the same; balls of ice and rock. Unfortunately for Venus, its proximity to the Sun meant its ice soon turned to steam and, if there ever were any oceans, they never would have been below boiling point. As the steam reached the upper atmosphere, UV light from the Sun broke the water into hydrogen and oxygen. The hydrogen floated off into space whilst the oxygen sunk back down to the surface and joined with carbon from the super-heated surface rocks thus creating carbon dioxide.
Rather than getting hotter when the CO2 replaced the water vapour, Venus’ surface cooled quite significantly due to it being a much less effective ‘greenhouse’ gas. Venus has only managed to keep its heat due to its incredibly dense atmosphere and extremely slow rotation creating a pressure cooker effect. The atmospheric composition is largely irrelevant. One thing’s for sure though, Venus did NOT heat up as Hansen implies, it just never had a chance to cool down.

“foinavon (14:47:48) :
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.”
Foinavon,
What is the difference between modeling and theoretical analysis?
“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. ”
So 1800s…this was “known”. I think there were quite a few things that were “known” then…but now, maybe not so much.
“There is a whole load of data that bears on the quantitative relationship between enhanced CO2 and enhanced temperature.”
And there’s a whole load of data that doesn’t.
“But it’s the empirical analyses, measurements and so on that inform the models and not the orher way round….”
I agree with this one. I think it’s been proven beyond any question that the models don’t inform the measurements, although some seem to be trying very hard to get them to do exactly that.
“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”
Based on a 5 minute google of “u.s. coal reserves”, it’s pretty clear to me that there is no “consensus” on how much coal is available, so how is it possible to predict the result of buring it “all”. We have no idea what “all” is.
” Stefan (14:55:53) :
How on earth can so many of these eminent scientists be wrong?
Or are they just human like everyone else?”
There is a part of human nature that makes some people seek data that only supports their belief systems. I don’t know anyone who ever got a “bad deal” buying a car…just ask them.
JimB

Cannot help but wonder if some of you folks are related to the creationista/ID folks.
What do ya alls think of comparison of the atmosphere to blood – specifically its function as a buffer? As with blood, it absorbs and absorbs and absorbs until a critical point is reached, whereby it all goes downhill from there.

“It seems Illis is a garage scientist (Links to prof. qualifications appreciated.), so you are probably right. it is so easy to cook a graph, or just get it wrong, or, in the case of the denier folks, get what you are looking for instead of what is. This is why rigorous science is called for: while not perfect, since people aren’t”
The first thing Alarmists resort to is the credentials of those who critique. If that doesn’t work, personal attacks are in order.
How interesting that one of the world’s preminent statisticians (Wegman) is denergenated, and is reduced to a “garage scientists” becuase he failed to toe the line. CCPO, you seem blissfully unaware that Mann’s MBH9X temp reconstructions were nothing more than a statistical analysis of 1300 temp proxies. Those was no “science: involved in crafting the Hockey Stick, as it was purely an excercise in Principle Component Analysis. McIntyre and McKitrick are professional statisticians, and it didn’t take them and many others to find out what Mann was up to. Yet, not one of Mann’s “peers” discovered Mann’s mistakes. So much for Peer Review. Wegman was correct in affixing the label “Social Network” to Climate Science’s peer review process.
BTW, keep a weathered eye on GISS and NOAA’s treatment of December’s Siberian temp anaomalies next month. Should be interesting as Central Siberia has had high temps ranging from -40 to -80 deg F for this month.

J Peden,
You’re right that the climate sensitivity breaks down at very low [CO2] concnetrations, but these aren’t realistic anyway. Anything below around 100-120 ppm isn’t relevant to CO2 levels during any period in the earth’s history of the last billion years or more (except perhaps during the nasty ice house period(s))!
And of course the climate sensitivity as defined in mine or Bill Illis equations doesn’t give the absolute temperature (mine does since I’ve normalised this to 15 oC at 280 ppm) , but the temperature increase above the blackbody (atmosphere-free) temperature of the earth supplemented with whatever residual warming that would exist in a CO2-free world. So as one continues to halve the CO2 concentration within the climate-sensitivity relationship, the temperature tends towards some horrible cold temperature (around 255K-ish?), rather than continuing to plummet with 3 oC of cooling per halved [CO2]!
The point of my analysis ‘though and the equation that I produced (post at 12:52:53) is to highlight the extremely misleading nature of the Bill Illis curve in the introductory article here.
The Scotese graph with a pseudo-“paleotemperature/paleoCO2 evolution” is also horribly incorrect, but that’s another matter!

Forgive me if this has already been said- I hadn’t time to read Hansen’s opus and all comments.
Am I mistaken in my belief- since Hansen’s ignored it- that ice-age inceptions and terminations have everything to do with solar radiation input at over 65 degrees latitude (Milankovitch cycles) and nothing to do with CO2 (which lags temperature changes by up to 800 years).
So let’s see whether I’ve “nailed it” Looking at slide 8 in Hansen’s lecture (We have good records of the long-lived atmospheric gases from ice cores, covering 400,000 thousand years, even 800,000 years.) there is a temperature change of about 7-8 degrees for roughly a 1.6 increase/decrease in C02, or about 4.5 degrees for a CO2 doubling. Dial in the logarithmic “response” and a few other non-solar “feedbacks” and there you are- about 3.5 degrees/CO2 doubling.
Simple- as long as you ignore the big bright yellow ball in the sky.

Sorry, that should say Pagani.

foinavon (16:11:33) :

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…
These values are woefully inadequate as measures of atmospheric CO2, since cities give very high CO2 levels as they’re close to emission sources.

Aren’t the current measures of CO2 from Hawaii close to emission sources, that is, volcanoes?

Higher resolution CO2 and temperature estimates over the last 500 million years can be seen here.
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/All_palaeotemps.png/800px-All_palaeotemps.png
http://www.globalwarmingart.com/images/7/76/Phanerozoic_Carbon_Dioxide.png

Wow Hansen has “nailed it”! I don’t notice any data though, or even an explanation of a logical line of reasoning that doesn’t assume all the effects he is supposed to be measuring?
Hypothesis is not theory, theory is not fact. The burden of proof is supposed to sit squarely on the theory in question.
Computer model runs are not data, corrections to the temperature record also known as WAGs are also not data. I like foinavon waving away all the paleo data. In the past CO2 has clearly not been a major climate driver, nor is it even evident that it is a positive effect despite a prediction based on incorrect assumptions from Arrhenius.
If you think Hansen has any credibility it isn’t because of science. Until he releases his raw data and his methods for doing his calculations the logical conclusion is fraud.

foinavon (05:59:16)…
You wrote:
“The Scotese graph with a pseudo-”paleotemperature/paleoCO2 evolution” is also horribly incorrect, but that’s another matter!”
I’m sorry, but the Scotese graph has been corroborated using other proxies (i.e isotopes and iron stained grains) and it is correct. If you read the references at the bottom of the diagram, you would find other authors who have found the same results.

Anthony Watts says:

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.

Since his argument isn’t based on Michael Mann’s paleo results, I don’t see that this message (assuming it to be true…another whole can of worms) is particularly relevant.
Bill Illis says:

First, where is the solar reduction part of the equation due to the Milankovitch cycle. This formula says it doesn’t even play a part including kicking off the ice albedo in the first place.

Yes, changes in solar insolation kick off the ice albedo changes. However, these changes are in the distribution of solar insolation. The total amount of solar insolation hitting the earth does not change (or not appreciably).

Second, his math is wrong if the sensitivity is 3.0C per doubling because a reduction to 180 ppm from 280 ppm only results in a decline of 1.9C (picky I know but he is the one who says he has nailed it empirically – the formula doesn’t even work).

Your calculation includes only CO2. His presumably also includes methane(and maybe NO2?).
Noblesse Oblige says:

I have seen at least a half dozen empirical estimations of the climate sensitivity done by a variety of different methods, and their range runs from less than 1 to ~ 1.7 deg C for doubling. They use a variey of correlation techniques (e.g., Douglass and Christy) or estimates of the temperature relaxation time (Schwartz, Scafetta).

Actually, Schwartz has revised his estimate in the reply to the comments on his original paper. His new estimate is something like 1.9 C and has large enough error bars to overlap with a good portion of the IPCC range. (And my guess is some of the commenters on his paper would argue his new estimate is still too low based on the problems they identified in his paper.)

Richard deSousa says:

Hansen also fails to mention Venus’s atmosphere is 97% CO2… how he can jump from Earth’s atmosphere of .03% CO2 to runaway global warming is beyond comprehension… he’s completely an imbecile…

That is it’s composition now but the question would be what its composition was before the runaway greenhouse effect got going. In particular, all the water on Venus boiled into the atmosphere when it got very hot, dissociated and then I think it eventually escaped into space. It is also worth noting that although nitrogen only makes up ~3.5% of the current Venus atmosphere, this is not a small amount of nitrogen considering that the air pressure on Venus is currently 92X that on earth.
Since Hansen is one of those responsible for understanding the greenhouse effect on Venus, I think he might know a little more about it than you do. (That said, I must admit that I am also surprised to hear him argue that a runaway effect could occur here on Earth, since most scientists that I know of, such as those at RealClimate, argue that a true runaway on Earth is not in the cards. I would like to hear the arguments on both sides.)

foinavon, would you perhaps indicate where in your opinion correct paleotemperature/CO2 level curves are to be found?
By the way only the paleotemp curve is due to Scotese, as you would have seen if you had bothered to check. Incidentally the original has rather more detail during the Cenozoic, Anthony selected a simplified version.

E.M.Smith says:

Do you have a citation?
….
I’d say a more accurate description would be that “a research associate provided the computer programs that lead to the claim of global cooling.”
All is see is Hansen backpedaling from his earlier model to a newer model.

Hansen explains here that what he gave Rasool was a code to do Mie Scattering calculations. Mie Scattering is something that was worked out around 1900, although the formulas are complicated enough that it would have been a non-trivial task to write code to calculate them back in 1971. (Today, with routines to compute Bessel functions and Legendre Polynomials more readily available, it is much easy to calculate Mie scattering and many people, including myself, have written our own codes.)
To say that Hansen or his model predicted cooling because that is the result that Rasool got is not much different than saying that Newton predicted cooling because Rasool used calculus, invented by Newton, to get his result. (In fact, Newton actually invented, or co-invented, calculus whereas Hansen merely codified the theory already worked out by Mie, so Newton’s connection is more direct.)
It is also worth noting that although the initial paper by Rasool and Schneider in 1971 did predict that cooling due to aerosols would win out over warming due to GHGs, the authors themselves admitted it was a first calculation…and, particularly in response to a comment on their paper, were very clear in noting that their calculation had a variety of potential inaccuracies. Within a few years, Schneider had done further calculations that made him realize that warming would likely win out over cooling. (It is also worth noting that in 1971 it was by no means clear that the U.S. and other Western countries would begin to sharply curtail their emissions of aerosols because of the Clean Air Act and other legislation…and thus that these emissions would not continue to grow exponentially.)

As for the other predictions, our understanding of the greenhouse effect and the consequences of its amplification include enhanced tropospheric water vapour,…./foinavon
Which is also not happening so far, consistent with the fact that water vapor alone has not produced the maximal theoretical “greenhouse” effect it otherwise should have, according in part to the very same energy wave absorption mechanism alleged to operate in the case of CO2 [coupled with water vapor’s increasing concentration per atmospheric temperature increase] – an effectively real damping regulation probably due to the operation of climatic mechanisms involving heat energy blocking and dissipation by means of cloud formation, release of latent heat during water vapor precipitation, and convection.
And why these same mechanisms for regulating water vapor’s “ghg” effect would not also work in the case of CO2’s so as to further blunt the alleged large temperature effect from doubling [a small] atmospheric CO2 concentration, is certainly a mystery to me, again especially noting that water vapor concentration is not increasing, but even instead decreasing with increased CO2 concentration.
Moreover, regarding any alleged correlation between CO2 concentrations and temperature over some range of CO2 concentration, if CO2 concentrations follow/lag temperature increases quickly enough, a relevant correlation between them of some significance could be present but not a CO2–> temperature causation. Apparently, previous concentrations of CO2 much higher than those of today have not abetted warming temperatures nor prevented atmospheric temperature decreases.

Citing Venus as an example is laughable. The Venusian atmosphere is hundreds of times denser than ours. This is like arguing that since the armor on an M1A1 tank can protect one from an RPG, a throw pillow should do the same.
J. Peden,
You are missing the obvious explanation that the CO2 travelled back in time to cause the warming. Surely this makes more sense than doubting global warming orthodoxy.

J. Peden,
I’m surprised that you assert that our understanding of the greenhouse effect and the consequences of its amplification include enhanced tropospheric water vapour,… is not happening. That simply doesn’t seem to accord with the science:
A recent experimental study presents further evidence for the water vapour feedback, and supplements a whole slew of studies identifying warming-induced enhancement of tropospheric water vapour (see following citations):
A.E. Dessler et al (2008) Water-vapor climate feedback inferred from climate fluctuations, 2003–2008. Geophys. Res. Lett. 35, L20704,
a summary can be found here:
http://www.nasa.gov/topics/earth/features/vapor_warming.html)
see also:
Soden BJ, et al (2005) The radiative signature of upper tropospheric moistening Science 310, 841-844
Santer BD et al. (2007) Identification of human-induced changes in atmospheric moisture content. Proc. Natl. Acad. Sci. USA 104, 15248-15253
Buehler SA (2008) An upper tropospheric humidity data set from operational satellite microwave data. J. Geophys. Res. 113, art #D14110
Brogniez H and Pierrehumbert RT (2007) Intercomparison of tropical tropospheric humidity in GCMs with AMSU-B water vapor data. Geophys. Res. Lett. 34, art #L17912
Gettelman A and Fu, Q. (2008) Observed and simulated upper-tropospheric water vapor feedback . J. Climate 21, 3282-3289
etc. etc….

Joel,
“One thing that many people fail to realize is that all functions are locally linear over a small enough range unless you are right at a point of zero slope.”
I don’t consider 118 years (1890 – present) to be a small range? Actually it’s pretty much the entire range so it can’t be ‘small’. Small would be 5-10 years, at least to me.
‘we get that our current concentration of ~385 ppm is 37.5% of the way there whereas if we assume the expected logarithmic relationship, we get that it is 46% of the way there, not that huge a difference.
‘
I’d disagree that it is ‘not that big a difference’, close to a 20% difference is big (46% is ~ 20% larger than 37.5%). Assuming 3C for doubling and accepting the 46% figure, doesn’t that mean that we should have already seen a 1.15 – 1.61C temp increase (and we clearly haven’t seen even the low end of that range). Further if we’ve seen .6C increase (not an accurate figure, it may be lower) over 46% of the range, then doesn’t that mean we might expect to see roughly a 1.3C total increase?

Maybe it is because people are doing “out the backdoor” assessments of the validity of said global warming and are beginning to smell a contrived panic driven agenda.
In the western part of the US we have this: Record lows at both minimum and maximum combined with record snow falls/liquid precip. The humidity is high yet the air temps are freezing my little behind. Until this month, I always thought colder meant dryer. Nope. I forgot my 5th grade lesson on precipitation circulation. The current weather reminds me much more of that little chapter in 5th grade science books about on-shore flow and mountain precipitation. Simple little model. So simple that it should make the current AGW models, that apparently are too complicated for one chapter in a 5th grade science book, literally short circuit and blow fuses on the computers used for said climate models.
http://www.weather.gov/climate/index.php?wfo=pdt
This site = sanity

The Scotese “graph”
Nasif Nahle (07:13:30)
anna v (07:19:27)
tty (08:03:04)
J Peden (08:19:15)
The Scotese graph in the Introductory post should set the alarm bells ringing! Surely a “skeptic” should ask the question “where are the data?”
The main problem can be put in a nutshell:
A true determination of the relationship between atmospheric CO2 concentrations and earth’s surface temperature can only be obtained from paleodata under those circumstances where contemporaneous paleoCO2 and paleotemp data are available”
What you can’t do is take a scattering of sparse data points (which we can’t see since they’re not represented on the childish sketch) and draw straight lines between these encompassing many 10’s of millions of years in some instances, and pretend that all the vast intervening periods are thus defined.
The other problem is that the CO2 data is from Berners GeoCarb model in which a broad brush representation of the major elements of the earths CO2 history are modeled. It’s not really a proxy CO2 measure..it’s more of a proxy-based broad reconstruction.
I have no idea where the sketched temperature data comes from. Does anybody know? It doesn’t seem to be described on Scotese’s site. In the context of Scotese’s rather nice site describing epochal climate histories, it’s perfectly satisfactory as a broadly educational sketchy indication of how things have changed in the past. But I’d be surprised if Scotese was thrilled at seeing his sketch used as historical temperature evolution to compare with modeled broad-brush CO2 evolution.
There is a whole load of data on contemporaneous proxy CO2 and proxy temperature measures. These have been compiled quite recently in a review by Dana Royer and covers the data up to around 2005:
D.L. Royer (2006) “CO2-forced climate thresholds during the Phanerozoic” Geochim. Cosmochim. Acta 70, 5665-5675.
since Royer’s review, quite a number of further studies have been done which continue to highlight a general link between atmospheric CO2 levels and earth’s temperature under conditions where contemporaneous proxy CO2 and proxy temp. relationships have been established:
R.E. Carne, J.M. Eiler, J. Veizer et al (2007) “Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era” Nature 449, 198-202
W. M. Kurschner et al (2008) “The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of the terrestrial ecosystem” Proc. Natl. Acad. Sci. USA 105, 499-453.
D. L. Royer (2008) “Linkages between CO2, climate, and evolution in deep time” Proc. Natl Acad. Sci. USA 105, 407-408
Zachos JC (2008) “An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics” Nature 451, 279-283.
Doney SC et al (2007) “Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene” Ann. Rev. Environ. Resources 32, 31-66.
Horton DE et al (2007) “Orbital and CO2 forcing of late Paleozoic continental ice sheets” Geophys. Res. Lett. L19708 (Oct. 11 2007).
B. J. Fletcher et al. (2008) “Atmospheric carbon dioxide linked with Mesozoic and early Cenozoic climate change” Nature Geoscience 1, 43-48.
and modelling studies of glaciation thresholds for CO2:
DeConto RM et al (2008) Thresholds for Cenozoic bipolar glaciation Nature 455 652-655.
Lunt DJ et al (2008) Late Pliocene Greenland glaciation controlled by a decline in atmospheric CO2 levels. Nature 454, 1102-1104
etc…

Bill Marsh says:

I don’t consider 118 years (1890 – present) to be a small range? Actually it’s pretty much the entire range so it can’t be ’small’. Small would be 5-10 years, at least to me.

For an exponential or logarithmic function, the question of regarding the region of linearity is related to the FRACTIONAL change in the function over the time period in question. I don’t think you can determine anything one way or the other from your intuition on what is a short or long period of time.

I’d disagree that it is ‘not that big a difference’, close to a 20% difference is big (46% is ~ 20% larger than 37.5%).

Well, I won’t quibble with you on what constitutes a large or small difference but considering that you were originally claiming our current CO2 concentrations (being ~37.5% of the way between 280ppm and 560ppm on a linear scale) constituted being >70% the way to a doubling on a log scale, I would say that the fact that it actually is only 46% of the way to a doubling does mean that the linear-to-log conversion doesn’t make nearly the difference that you thought it did.

Assuming 3C for doubling and accepting the 46% figure, doesn’t that mean that we should have already seen a 1.15 – 1.61C temp increase (and we clearly haven’t seen even the low end of that range)…

See the rest of my post there. Given that we are out-of-equilibrium and given the large uncertainty in the value of the negative aerosol forcing, what we have seen is compatible with a very broad range of values for the equilibrium climate sensitivity. The simple fact is that the 20th and early 21st century temperature record just doesn’t provide us with very strong constraints on this value, which is why we have to look at other empirical evidence.