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. 😉
hey foinavon,
I agree with John W. Please present a falsifiable hypothesis for AGW such that it can be tested and it’s validity determined.
We all know you believers are incapable of providing such hypothesis, so in order to save some time, lets ASSUME you have a falsifiable hypothesis. At this point the game is over, but I’ll spot you a BIG one just for fun…
Let me ask you this:
Does the fact that CO2 has increased yet the global temperature anomaly has decreased in the past decade falsify the theory?
If not, Please state EXACTLY what would falsify the theory?
Until AGW believers like yourself answer basic scientific questions like these, your relig.. err.. theory won’t be accepted. Reply: Tone it down please, all the above points could have been made without the religious comparison. ~ charles the moderator
E.M.Smith (19:54:28) :
I’d be happy with knowing what attribution was given to Hansen in the papers published using his software to claim ~’ice age soon’ in the ’70s, but those were not given,
That was done about an hour and a half before you posted this, I suggest you go back and read it. Of course you could have read the paper itself and found out for yourself rather than recycle the misrepresentations (which are refuted whenever they are dragged up, to no avail apparently).
Charles the moderator,
I’d like to make this general observation: for convenience it’s possible to divide most parties interested in this topic into these broad groupings:
“Denier”
Posters who for political, emotional or other reasons tend to use simplistic arguments to dismiss AGW. A person who falls into this category generally deals in ad hominems, non sequiturs and other fallacious arguments designed primarily to appeal to one’s feelings and preconceived world view.
“Sceptic”
Someone interested in the technical arguments and logical form and structure of the theory. Sceptics come in different flavours but the majority of reasonable sceptics fall into the “luke warmer” category. That is, they accept that CO2 should cause some degree of minor warming, but don’t accept there is enough evidence to conclude that catastrophe is upon us.
“Alarmist”
Believes wholeheartedly and completely in AGW and focuses on worst case theoretical outcomes: tipping points, 1000 metre sea level rises, total destruction of the biosphere, etc.
Many of the posts here, unfortunately, fall into the first category. While understandably many posters are critical of foinavon’s arguments, they don’t tend to be critical of equally bad arguments presented by those perceived as being on the “same side.” This is not a good position to adopt because it reflects badly on the serious sceptical position and its arguments, for which there are plenty. The fallacious reasoning is simply not needed and should not be welcomed here or anywhere else. Reply: Sorry, I was out for the evening, and since this was specifically addressed to me as moderator I will offer a reply inline, although normally inline comments are reserved for only moderation comments.
1. There are more flavors of posters than you have noted above including non-alarmist pro-AGW posters who make cogent and quality scientific and technical arguments. They are welcome here as long as they behave courteously.
2. While some anti-AGW posts may be of dubious quality, it is Anthony’s policy, which I agree with, that the term “denier” is specifically prohibited as a pejorative. It is a crude attempt to delegitimize any arguments which go against the “consensus” of AGW. Whether or not the person who takes an anti-AGW position is making a quality argument or not is irrelevant to the prohibition on usage.
3. This site does not prohibit ill-informed people from posting simply because they are ill-informed. Hopefully some will learn from the responses. I myself have corrected ill informed posts myself in my role as poster (separate from moderator-I post as jeez) for people who may generally hold the same position as myself but who have made obviously fallacious arguments.
~ charles the moderator
anna v
December 22, 2008 10:04 pm
John Philip (15:54:27) :
Mainly for Anna V 1) Temperatures do not follow IPCC projections. Here is a plot to remind this: http://icecap.us/images/uploads/ipccchart.jpg
That plot is labelled an update of IPCC TS26, however it is no such thing; it has some significant differences from the IPCC graph, which is here.
The IPCC chart that advises politicians is not that. It resides: http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf
Figure SPM.5. Even I had put in the data after 2000 by hand and saw that they diverged from the projections.
In addition, the errors shown are not real errors ( I gave a link above from the horses mouth) We are honoring these by treating them as predictions that can be falsified. James Annan shows that over the same period the models and the observations are consistent to the 95% level here.
Please. The only way one can treat the IPCC model scenaria seriously is accepting them as lines and seeing how far off they are from experiment by experimental errors. The theoretical bands are not errors, but bet hedging.
In addition I am sure that when the model parameters are twigged to fit the recent data, the catastrophic predictions are off, and this is the reason we are not seeing a fit to the last ten year data.
And it is La Nina that is cooling. El Nino heats. 2) The fingerprint of CO2 in the tropical troposphere as set out in the AR4 report is absent in the data. Here are the links
for models: http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter9.pdf
data: http://icecap.us/images/uploads/GHGModsvsReality.jpg
No it is not, as patiently explained to Lucia by Arthur Smith here…
I am sorry. patient explanation does not turn black to white ( or red to yellow in this case) 3) The oceans are cooling instead of warming and setting off a feedback loop of greenhouse warming: http://www.npr.org/templates/story/story.php?storyId=88520025
The spin is: global warming missing heat. The truth is, nature does not follow the GCM IPCC models.
There are many sources. This was convenient. 4) the specific humidity is not rising as it should in order to create the runaway feedback loop predicated in the models: http://www.cdc.noaa.gov/cgi-bin/Timeseries/timeseries.pl?ntype=1&var=Specific+Humidity+(up+to+300mb+only)&level=300&lat1=90&lat2=-90&lon1=-180&lon2=180&iseas=1&mon1=0&mon2=11&iarea=0&typeout=2&Submit=Create+Timeseries
Here are plots of relative humidity, which also falls: http://icecap.us/images/uploads/GlobalRelativeHumidity300_700mb.jpg
As others have pointed out, a recent paper from Dessler et al observed a very real increase in humidity, the existence of which means that projected business-as-usual greenhousegas emissions over the next century are virtually guaranteed to produce warming of several degrees Celsius. The only way that will not happen is if a strong, negative, and currently unknown feedback is discovered somewhere in our climate system.
As others have pointed out and I read in the summaries available on the web, you are still talking of computer models. There is no hard tie of CO2 warming and humidity rising except through computer models which have been already falsified.
No, I think the four points stand, and they are not the only ones, just the ones that struck me, an experimental physicist with 35 years experience of fitting models to data ( and not vice versa).
anna v
December 22, 2008 10:57 pm
p.s. Here is the quote from the http://www.ipcc.ch site which clearly acknowledges that the errors are an estimate of the modelers.
this is from AR
chapter 8
Climate Models and Their Evaluation,8.1.2.2 Metrics of Model Reliability, partway in the second paragraph:
The above studies show promise
that quantitative metrics for the likelihood of model projections
may be developed, but because the development of robust
metrics is still at an early stage, the model evaluations presented
in this chapter are based primarily on experience and physical
reasoning, as has been the norm in the past.
Note the “as has been the norm in the past”.
John Philip
December 22, 2008 10:57 pm
Does the fact that CO2 has increased yet the global temperature anomaly has decreased in the past decade falsify the theory?
1. 10 years is too short, the WMO definition of ‘climate’ is 30 years.
2. Temperatures have increased substantially in the last 10 years. http://www.woodfortrees.org/plot/uah/last:120/plot/uah/last:120/trend
foinavon:
Thanks for posting the link to the V. Ramanathan & G. Carmichael (2008) Global and regional climate changes due to black carbon article.
“Thus most if not all of the published estimates of black carbon are derived from models.”
“There is a significant uncertainty (factors ranging from 2 to 5) in estimates of emission strengths”
“…the estimated BC [black carbon aerosols] effect is subject to a threefold or larger uncertainty.”
“The logical deduction from this estimate is that, if and when air pollution regulation succeeds in eliminating the emission of these particles, the
surface warming can intensify by about 0.7 to 1.5 K, where the range is due to a range in assumed climate sensitivity of 2 to 4 K due to doubling of CO2. When this range is factored in with the threefold uncertainty in the aerosol masking effect, stopping the emission of anthropogenic aerosols, could result in a global mean warming of about 0.4 ºC to 2.4 ºC.”
A paper that does computer modelling, used to defend computer models.
So basically, all the evidence for the role and significance of aerosols is theoretical at present? Would that be a reasonable assumption?
Hansen says, “the danger that we face is the Venus syndrome. There is no escape from the Venus Syndrome. Venus will never have oceans again.” That is, “If the planet gets too warm, the water vapor feedback can cause a runaway greenhouse effect. The ocean boils into the atmosphere and life is extinguished.”
Now, that’s a fairly alarmist statement. In fact, that’s the MOST alarmist statement I have ever heard. It’s pretty far out there. Is that what the IPCC says? Is that what Gavin, foinavon, et al really believe?
Hansen cribs a little. He says “Our model blows up before the oceans boil, but it suggests that perhaps runaway conditions could occur with added forcing as small as 10-20 W/m2.” Exploding models do not give confidence in either the models or their output. Should we rely on exploding models? Why does Hansen?
Hansen also cribs, “There may have been times in the Earth’s history when CO2 was as high as 4000 ppm without causing a runaway greenhouse effect. But the solar irradiance was less at that time.” What? Is 4000 ppm a realistic prediction? And how does he “know” solar irradiance was less? Those are fairly speculative statements that both require some evidential support.
Further, he says that “to preserve creation” CO2 must be reduced or constrained to less than 350 ppm.
Again, that’s a fairly hyperbolic assertion, and in strong contrast to his prior statements and to reality. First, if, as Hansen claimed, CO2 levels actually were once 4000 ppm, it is quite evident that “creation” was not lost. Creation still exists. Indeed, if current CO2 levels are 385 ppm, and the oceans have not boiled nor has creation been eliminated, one wonders whether Hansen has lost his mind.
But lo! the oceans won’t boil for a few years yet. The lag time is not specified, but one assumes it will be something less than 100 years, right? If we remain at 380 ppm for another century or so, poof, there go the oceans and creation along with them.
This is science? The best available science? This is the consensus?
The fellow is mad. Are Gavin, foinavon, et al in consensus with him. Are they mad, too?
I had to laugh at his examples of global warming. He shows a dry pier many yards from the water on Lake Mead! It’s a reservoir! The water level on Lake Mead is controlled at the dam! By humans, not climate!
He cites US wildfire acreage since 1960, another phenomenon controlled by humans! This may shock you, but people have a great deal to do with how big fires get and how many acres they consume. It is NOT a climate controlled phenomenon, any more than Lake Mead water levels.
Hansen’s presentation is hysterical, in all the meanings of that word. I have enjoyed the discussions in this thread, but some central points have been missed. One, Hansen’s conclusions are insane, and two, warmer is better. The oceans are not going to boil away. Trust me.
Syl
December 23, 2008 12:49 am
John Philip (15:54:27) :
“Actually, the hypothesis is that the positive feedbacks: primarily the increased water vapour, but also the release of methane from permafrosts, melting of summer sea ice, the die-back of the rainforests, etc that amplify the GHG forced warming and instigate the runaway scenario.”
First the rainforests aren’t experiencing ‘die-back’ they’re experiencing ‘cut-back’.
second, you can forget the entire AGW theory, runaway warming or not, because the cut-back of the rainforests alone account for far more CO2 in the air (from loss of photosynthesis) than all our CO2 emissions.
“Carbon emissions due to fossil fuel combustion represent less than 20% of the total human impact on atmospheric carbon levels. Deforestation not only contributes a relatively minor one off carbon emission of some 2.3 gigatons of carbon to the atmosphere, but an ongoing loss of photosynthetic carbon sequestration to around 38 gigatons per annum that is growing at the rate of 500 megatons every year. It is clear from the fact that this amount dwarfs the present 7.8 gigaton fossil fuel combustion contribution, that the cessation of fossil fuel combustion will not halt the rise of atmospheric carbon dioxide because the loss of photosynthesising biota and the corresponding fall in photosynthesis is so much greater.”
( http://deforestation.geologist-1011.net/ )
I think we are trying to solve the wrong problem.
Steve
December 23, 2008 2:19 am
Random comment but seeing as I think Temperature drives CO2 I’d rather we write foinavon’s formula as
Concentration(CO2) = Power(1/3*(T+9.39), 2)
or make CO2 the dependant and T the independant 🙂
PeteM
December 23, 2008 2:19 am
Will Nitschke (21:41:19) :
“Charles the moderator,
I’d like to make this general observation: for convenience it’s possible to divide most parties interested in this topic into these broad groupings:……”
Will Nitschke – I very much agree with this comment .
(IMHO) This is the best thread I’ve read on this forum because of the informed debate (from all sides) – I am looking forward to more like this ..
Perhaps I can suggest a fourth group – between ‘sceptic’ and ‘alarmist’ . This is someone still motivated by logical argument with supportable statements but inclined to ‘agree’ with the idea that there will be negative change (maybe not catastrophic). A ‘supporter’ group ?
John Philip wrote:
“2. Temperatures have increased substantially in the last 10 years. http://www.woodfortrees.org/plot/uah/last:120/plot/uah/last:120/trend”
But it’s trending down for the last 8.5 years: http://www.woodfortrees.org/plot/uah/last:102/plot/uah/last:102/trend
All the time periods are too short, though. They are only suggestive of something if current trends continue for the next few years. Gone are the good old days when the MET office predicted with confidence that ‘next year’ would be the record year to beat all previous years. Hansen is very confident that all records will be broken with 2-3 years, as per his website.
J. Peden (19:25:30)
Really? Which studies does it contradict? In general there is an expectation that as the atmosphere warms under greenhouse forcing so the atmospheric water vapour concentration rises. That’s the essential point. Dessler’s paper is one of a substantial series of papers that confirm this (note that this also works in reverse of course..atmospheric cooling results in a drop in atmospheric water vapour). That’s all pretty much as expected.
I don’t see the problem with the “untethered theoretical statement” (!) that you reproduce from the NASA info page. All this means is that as the atmosphere warms the water vapour feedback amplifies this warming, and because the amplification itself “recruits” more water vapour there is a bit more warming and so in. One could formalise this within an equation of the form T=T+x+x2+x3+x4……. where T is the primary temperature rise (from enhanced greenhouse forcing or solar change or whatever) and x is the temperature rise resulting from a temperature-dependent feedback (water vapour).
Of course this works in the cooling direction to. Dessler et al use all of the data (warming and cooling events) to deduce a value for the strength of the water vapour feedback that is in fact rather consistent with a number of other studies.
You state: Simply ignoring solar input and oceanic oscillation changes and claiming that this “warming” is due solely to CO2’s effect only manages to bring the number of scientific issues which are not anywhere close to being settled to at least six contained in this very post alone.
But one needs to be much more relaxed about the science! Every paper doesn’t address every question! Our understanding of any particular phenomenon is the summation of a very large number of observations, measurements, theoretical understanding and so on. Dessler’s paper is essentially neutral about the cause of any warming (or cooling for that matter). They provide another piece of information about the way that the atmospheric water vapour responds to temperature variation.
foinavon
December 23, 2008 4:13 am
John S. (20:22:39)
your comment: I have read Dessler et al. several times and my characterization of it stands unshaken. Their Eq. 1(which is nothing more than a crude empirical “sensitivity” calculation misrepresented as “feedback”) is taken as a given and is applied to a year’s worth of data–a cooling year at that–without any critical reflection upon system dynamics. By that token any covariation between two variables would constitute proof of “feedback.”
But that’s doubly incorrect. Eq. 1 is not “misrepresented as a “feedback””. It is represented as the strength of the water-vapour feedback…in other words a “sensitivity”, if you wish to call it that.
And it isn’t “applied to a year’s worth of data”. It’s applied to 5 years worth of data. Are you sure you read the paper “several times”?
and this comment: By claiming that this is an “experimental” study and insisting that thermalized energy is amplified by CO2, you’ve convinced me that any further discussion with you would be scientifically fallow. Better luck in modern academia!
Dessler et al take measurements of temperature, tropospheric specific humidity and relative humidity from the Atmospheric Infrared Sounder mounted on the NASA Aqua satellite, and analyze these to establish relationships betwen temperature and relative and absolute humidity and to extract an estimate of the strength of the water vapour feedback.
That’s an experimental study John (unless you’re suggesting that the only experimental study is one in which no analysis is made?)
foinavon
December 23, 2008 4:28 am
Bill Illis (19:52:14) : The Dessler humidity study found a decline in relative humidity as temperatures declined. This is not consistent with global warming theory in which relative humidity is supposed to stay generally constant.
Read the study and see where it does not agree.
Not really Bill. Global warming theory predicts that as the atmospheric temperature rises under an enhanced greenhouse forcing, so the atmospheric water vapour will rise as a feedback amplifying the warming.
Of course this might occur with the retention of roughly constant relative humidity, and this has been observed in models. But the whole point of establishing the strength of the water vapour feedback through experimental analyses like that of Dessler, is to determine exactly how the water vapour feedback occurs and to quantitate this. Dessler et al. is just another of the studies that contributes to our understanding of the subject. “Global warming theory”, as you call it, doesn’t require that RH stays constant.
In fact, Dessler et al actually found that the relative humidity did remain roughly constant averaged globally and at most altitudes. Of course it would be foolish to expect that local fluctuations in specific and relative humidities don’t occur such that in same cases the RH will drop or rise within a dynamic system (the atmosphere) that is continually locally being pushed away from equilibrium.
deepslope
December 23, 2008 4:43 am
OT, but related – from Science Daily: “Solar Activity Between 1250-1850 Linked To Temperature Changes In Siberia” http://www.sciencedaily.com/releases/2008/12/081219180532.htm
I haven’t read the full paper yet, but the review is interesting: A study carried out by a Swiss-Russian team on ice-cores from the Altai reports a strong correlation between regional temperatures and reconstructed solar activity for the period of 1250 and 1850. A time lag of 10 to 30 years is observed between temperature and solar forcing, implying ocean mitigation. The authors point out that the temperature rise between 1850 and 2000 has to be caused by CO2 from anthropogenic sources, rather than by the sun as during the earlier centuries. They do not appear to discuss the reliability of ice core gas measurements as a function of pressure in the core and other sampling artefacts.
Katherine
December 23, 2008 5:09 am
John Philip answered: 1. 10 years is too short, the WMO definition of ‘climate’ is 30 years.
2. Temperatures have increased substantially in the last 10 years.
to the question: Does the fact that CO2 has increased yet the global temperature anomaly has decreased in the past decade falsify the theory?
If 30 years is the requirement for climate, how do you reconcile the 40-year decline in U.S. temperatures from the mid-1930s to the late 1970s when atmospheric CO2 levels were apparently monotonically increasing since 1958? Wouldn’t 40 years of cooling combined with increasing atmospheric CO2 levels support Hansen’s original model of man-made global cooling?
quote What Hansen did was compute the total difference in forcings in W/m^2 between the last glacial maximum and now due to various effects (the two largest being the difference in albedo (1) because of the ice and the difference in CO2 (2) and other greenhouse gas levels, although I believe there is also a small contribution due to a difference in aerosol loading (3) in the atmosphere).unquote
1. We don’t even know the albedo at the moment, let alone during the last glacial maximum. The A train, a collection of climate satellites, is going to put numbers to the present, but the past is going to remain a mystery for a long time to come.
2. CO2 levels in the past are contested, to put it politely.
3. Aerosols are warming or cooling in the recent record — or at least so it seems when they are needed to make a particular scenario work out. I’ve seen the explanations for the post WWII cooling and I’ve seen hotspots explained by aerosols. Aerosols effect clouds: the IPCC states that our scientific understanding of clouds is very low.
quote He also used the available estimates for the difference in average surface temperature between then and now.(4) So, he has a total forcing in W/m^2 and a total temperature change; dividing the first by the second gives him the temperature change per W/m^2 of forcing, which turns out to be about 0.75 C per (W/m^2). Then, using the well-accepted value for the forcing in W/m^2 due to a doubling of CO2, which is about 4 W/m^2 (even Richard Lindzen accepts this value), he multiplies the 0.75 C per (W/m^2) sensitivity by the 4 W/m^2 forcing to get the result that a doubling of CO2 produces approximately 3 C of warming. unquote (5)
4. I would like to see confidence intervals for the measured now and the estimated past. Without them this is not science, it is handwaving. And with them it is an exercise in hubris.
5. If we had some eggs we could have ham and eggs. If we had some ham. SF fans will remember here the Drake equation which, by making a whole chain of assumptions, ‘proved’ that alien civilisations exist. If you want ham and eggs, then begin by wishing for eggs…
It’s tosh. It’s wishful thinking dressed up as science.
Wait for the A-Train — the line of climate satellites still being assembled by NASA — to give a few years results and then we can do science on the climate. Until then there are too many unknowns, and too many things known but wrong, for this whole business to be anything but expensive speculation.
Here’s my (so cheap it’s free and worth every penny) speculation just for Professor Holdren, the new presidential science advisor, who complains that there is no other over-arching theory of climate change which explains everything we are observing. I give Dr Holdren (fanfare) The Kriegesmarine Hypothesis: the isotope signal is nothing to do with burning fossil fuels, it’s down to plankton population changes caused by dust feeding silicaceous diatoms blooming in preference to C3 plankton (1); C3 plankton starving and switching to C4 metabolism dragging down heavy isotope more than expected (2); ocean warming because surfactant and oil pollution of the surface reduces production of cloud condensation nuclei which reduces maritime cloud cover(3); smoothed sea exhibits lower albedo and, when insolated, warms faster; smoothed sea has reduced emissivity so that at night it cools more slowly (4).
1. The opal ocean.
2. The light isotope signal begins too early to be caused by human CO2 emissions, but matches nicely our vast and reckless expansion of dryland farming and spillage of oil and surfactant.
3. The Hadcrut SST graphs, minus the questionable ‘bucket correction’, show the effect of pouring millions of tons of oil onto the Atlantic and Pacific between 1939 and ’45. A graph of oceanic surface wind speed shows a similarly interesting blip at the same time.
4. Arctic warming and the spill rates from the North Slope oilfield and the wells in Sakhalin may be connected.
See? Handwaving for fun and profit. I leave the cod population crash on the Grand Banks as an exercise for the interested reader. My theory explains that as well. If, of course, you wave your hands a lot.
JF
Katherine
December 23, 2008 5:52 am
Mike D. wrote: Hansen also cribs, “There may have been times in the Earth’s history when CO2 was as high as 4000 ppm without causing a runaway greenhouse effect. But the solar irradiance was less at that time.” What? Is 4000 ppm a realistic prediction?
First, if, as Hansen claimed, CO2 levels actually were once 4000 ppm, it is quite evident that “creation” was not lost. Creation still exists.
If you check the last graph Anthony posted above, based on the data of Berner, atmospheric CO2 reached 7000 ppm in the Cambrian period. That’s way higher than 4000 ppm and the oceans survived.
foinavon
December 23, 2008 5:53 am
Hi Steve (12:46:49)
Yes, there’s pretty good evidence that the atmosphere has warmed the oceans. The ocean temperatures have been monitored for around 50 years, and the data demonstrate characteristics of warming via the atmosphere. So, for example, the warming shows a gradient from surface (most warming) to greater depth (least warming) through the top 700 metres…the warming depth distribution is consistent with what’s known about specific ocean mixing (e.g. the N. and S. Atlantic have deep convection and accordingly surface warmth is identified deeper into these oceans; the northern Pacific has a shallow meridional overturning circulation, and accordingly, surface warmth is not conveyed so deeply below the surface)……the N. Indian ocean shows little surface warming as a result of the aerosolic cooling effect of brown clouds – here greatest warming is sub-surface due to advection (warmth flowing from other warmed ocean regions, especially the S. Indian ocean…[***]
All of these are consistent with a dominant atmospheric effect on ocean warming (rather than vice versa, for example). There’s quite a lot more data that that informs our understanding of this.
I don’t think we do know very well the thermal equilibrium time between oceans and the atmosphere. I couldn’t agree more that this is vital for our understanding of climate sensitivity. That’s largely why most analyses of climate sensitivities aim to use periods in the past where the earth’s temperature is more likely to have come towards equilibrium (the extremely slow responses during ice age periods, and the paleo/temp/CO2 relationships in the deep past and such like), or from an analysis of transient responses (tropospheric temperature responses to the solar cycle…temperature responses to volcanic cooling etc.) to determine the strengths of feedbacks for including in the relatively well-characterised CO2 forcing.
Your Siple core point about the temperature rise between the mid 19th century and 1940. Yes, I think it’s accepted that other factors than CO2 contributed to the temperature rise. The solar output as monitored by the sunspot cycles, for example, increased significantly up to around 1940, and this likely supplemented CO2-induced warming somewhat.
Since we know that aerosols produce a nett cooling effect we have to include these in our considerations. Again, I think it’s pretty well recognized that trying to determine climate sensitivity by analysis of 20th century temperature is difficult (poorly constrained by uncertainties in the climate response time and the contribution of aerosols).
I like your paragraph: Surely you must agree statements like “the debate is over” and “science is settled” don’t help in these situations and seems to imply more certainty to Joe public like me than there really is. Then again I guess no one has actually defined what the “debate” was and which “science” has been settled.
since you answer your own point quite well! I agree with you that it depends exactly what the “debate” is about and which “science” one is referring to in relation to our understanding being settled. The main thing is to address the science in a relaxed, skeptical, and most-importantly, an honest manner.
[***] e.g.:
S. Levitus et al. (2003) Warming of the world ocean, 1955–2003 Geophys. Res. Lett., 32, L02604 .
T. P. Barnett et al. (2005) Penetration of Human-Induced Warming into the World’s Oceans Science 309, 284 – 287.
PeteM
December 23, 2008 5:54 am
Syl (00:49:58) :
…
“Carbon emissions due to fossil fuel combustion represent less than 20% of the total human impact on atmospheric carbon levels. Deforestation not only contributes a relatively minor one off carbon emission of some 2.3 gigatons of carbon to the atmosphere, but an ongoing loss of photosynthetic carbon sequestration to around 38 gigatons per annum that is growing at the rate of 500 megatons every year. It is clear from the fact that this amount dwarfs the present 7.8 gigaton fossil fuel combustion contribution, that the cessation of fossil fuel combustion will not halt the rise of atmospheric carbon dioxide because the loss of photosynthesising biota and the corresponding fall in photosynthesis is so much greater.”
Or maybe we should twice as concerned about human activities …
Roy Sites
December 23, 2008 6:46 am
Yes…That would be circular reasoning. However, that is not what Hansen did. What Hansen did was computed the total difference in forcings in W/m^2 between the last glacial maximum and now due to various effects (the two largest being the difference in albedo because of the ice and the difference in CO2 and other greenhouse gas levels, although I believe there is also a small contribution due to a difference in aerosol loading in the atmosphere). He also used the available estimates for the difference in average surface temperature between then and now. So, he has a total forcing in W/m^2 and a total temperature change; dividing the first by the second gives him the temperature change per W/m^2 of forcing, which turns out to be about 0.75 C per (W/m^2). Then, using the well-accepted value for the forcing in W/m^2 due to a doubling of CO2, which is about 4 W/m^2 (even Richard Lindzen accepts this value), he multiplies the 0.75 C per (W/m^2) sensitivity by the 4 W/m^2 forcing to get the result that a doubling of CO2 produces approximately 3 C of warming.
Let me see, we assume that all unexplained temperature change is due to CO2 and then compute the climate sensitivity for a doubling of CO2 and then we show that a doubling of the CO2 causes the temeperature change. Hmmmmmm, sounds like circular reasoning to me. If we cannot think of any natural causes then it must be caused by us humans. This is really good “science”.
For support of Lindzen’s Iris effect see Spencer’s work based on satellite observations that was brought to us by our Host:
http://wattsupwiththat.com/2008/10/19/new-paper-from-roy-spencer-pdo-and-clouds/
hey foinavon,
I agree with John W. Please present a falsifiable hypothesis for AGW such that it can be tested and it’s validity determined.
We all know you believers are incapable of providing such hypothesis, so in order to save some time, lets ASSUME you have a falsifiable hypothesis. At this point the game is over, but I’ll spot you a BIG one just for fun…
Let me ask you this:
Does the fact that CO2 has increased yet the global temperature anomaly has decreased in the past decade falsify the theory?
If not, Please state EXACTLY what would falsify the theory?
Until AGW believers like yourself answer basic scientific questions like these, your relig.. err.. theory won’t be accepted.
Reply: Tone it down please, all the above points could have been made without the religious comparison. ~ charles the moderator
E.M.Smith (19:54:28) :
I’d be happy with knowing what attribution was given to Hansen in the papers published using his software to claim ~’ice age soon’ in the ’70s, but those were not given,
That was done about an hour and a half before you posted this, I suggest you go back and read it. Of course you could have read the paper itself and found out for yourself rather than recycle the misrepresentations (which are refuted whenever they are dragged up, to no avail apparently).
Charles the moderator,
I’d like to make this general observation: for convenience it’s possible to divide most parties interested in this topic into these broad groupings:
“Denier”
Posters who for political, emotional or other reasons tend to use simplistic arguments to dismiss AGW. A person who falls into this category generally deals in ad hominems, non sequiturs and other fallacious arguments designed primarily to appeal to one’s feelings and preconceived world view.
“Sceptic”
Someone interested in the technical arguments and logical form and structure of the theory. Sceptics come in different flavours but the majority of reasonable sceptics fall into the “luke warmer” category. That is, they accept that CO2 should cause some degree of minor warming, but don’t accept there is enough evidence to conclude that catastrophe is upon us.
“Alarmist”
Believes wholeheartedly and completely in AGW and focuses on worst case theoretical outcomes: tipping points, 1000 metre sea level rises, total destruction of the biosphere, etc.
Many of the posts here, unfortunately, fall into the first category. While understandably many posters are critical of foinavon’s arguments, they don’t tend to be critical of equally bad arguments presented by those perceived as being on the “same side.” This is not a good position to adopt because it reflects badly on the serious sceptical position and its arguments, for which there are plenty. The fallacious reasoning is simply not needed and should not be welcomed here or anywhere else.
Reply: Sorry, I was out for the evening, and since this was specifically addressed to me as moderator I will offer a reply inline, although normally inline comments are reserved for only moderation comments.
1. There are more flavors of posters than you have noted above including non-alarmist pro-AGW posters who make cogent and quality scientific and technical arguments. They are welcome here as long as they behave courteously.
2. While some anti-AGW posts may be of dubious quality, it is Anthony’s policy, which I agree with, that the term “denier” is specifically prohibited as a pejorative. It is a crude attempt to delegitimize any arguments which go against the “consensus” of AGW. Whether or not the person who takes an anti-AGW position is making a quality argument or not is irrelevant to the prohibition on usage.
3. This site does not prohibit ill-informed people from posting simply because they are ill-informed. Hopefully some will learn from the responses. I myself have corrected ill informed posts myself in my role as poster (separate from moderator-I post as jeez) for people who may generally hold the same position as myself but who have made obviously fallacious arguments.
~ charles the moderator
John Philip (15:54:27) :
Mainly for Anna V
1) Temperatures do not follow IPCC projections. Here is a plot to remind this:
http://icecap.us/images/uploads/ipccchart.jpg
That plot is labelled an update of IPCC TS26, however it is no such thing; it has some significant differences from the IPCC graph, which is here.
The IPCC chart that advises politicians is not that. It resides:
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf
Figure SPM.5. Even I had put in the data after 2000 by hand and saw that they diverged from the projections.
In addition, the errors shown are not real errors ( I gave a link above from the horses mouth) We are honoring these by treating them as predictions that can be falsified.
James Annan shows that over the same period the models and the observations are consistent to the 95% level here.
Please. The only way one can treat the IPCC model scenaria seriously is accepting them as lines and seeing how far off they are from experiment by experimental errors. The theoretical bands are not errors, but bet hedging.
In addition I am sure that when the model parameters are twigged to fit the recent data, the catastrophic predictions are off, and this is the reason we are not seeing a fit to the last ten year data.
And it is La Nina that is cooling. El Nino heats.
2) The fingerprint of CO2 in the tropical troposphere as set out in the AR4 report is absent in the data. Here are the links
for models:
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter9.pdf
data:
http://icecap.us/images/uploads/GHGModsvsReality.jpg
No it is not, as patiently explained to Lucia by Arthur Smith here…
I am sorry. patient explanation does not turn black to white ( or red to yellow in this case)
3) The oceans are cooling instead of warming and setting off a feedback loop of greenhouse warming: http://www.npr.org/templates/story/story.php?storyId=88520025
The spin is: global warming missing heat. The truth is, nature does not follow the GCM IPCC models.
There are many sources. This was convenient.
4) the specific humidity is not rising as it should in order to create the runaway feedback loop predicated in the models:
http://www.cdc.noaa.gov/cgi-bin/Timeseries/timeseries.pl?ntype=1&var=Specific+Humidity+(up+to+300mb+only)&level=300&lat1=90&lat2=-90&lon1=-180&lon2=180&iseas=1&mon1=0&mon2=11&iarea=0&typeout=2&Submit=Create+Timeseries
Here are plots of relative humidity, which also falls: http://icecap.us/images/uploads/GlobalRelativeHumidity300_700mb.jpg
As others have pointed out, a recent paper from Dessler et al observed a very real increase in humidity, the existence of which means that projected business-as-usual greenhousegas emissions over the next century are virtually guaranteed to produce warming of several degrees Celsius. The only way that will not happen is if a strong, negative, and currently unknown feedback is discovered somewhere in our climate system.
As others have pointed out and I read in the summaries available on the web, you are still talking of computer models. There is no hard tie of CO2 warming and humidity rising except through computer models which have been already falsified.
No, I think the four points stand, and they are not the only ones, just the ones that struck me, an experimental physicist with 35 years experience of fitting models to data ( and not vice versa).
p.s. Here is the quote from the http://www.ipcc.ch site which clearly acknowledges that the errors are an estimate of the modelers.
this is from AR
chapter 8
Climate Models and Their Evaluation,8.1.2.2 Metrics of Model Reliability, partway in the second paragraph:
The above studies show promise
that quantitative metrics for the likelihood of model projections
may be developed, but because the development of robust
metrics is still at an early stage, the model evaluations presented
in this chapter are based primarily on experience and physical
reasoning, as has been the norm in the past.
Note the “as has been the norm in the past”.
Does the fact that CO2 has increased yet the global temperature anomaly has decreased in the past decade falsify the theory?
1. 10 years is too short, the WMO definition of ‘climate’ is 30 years.
2. Temperatures have increased substantially in the last 10 years.
http://www.woodfortrees.org/plot/uah/last:120/plot/uah/last:120/trend
foinavon:
Thanks for posting the link to the V. Ramanathan & G. Carmichael (2008) Global and regional climate changes due to black carbon article.
“Thus most if not all of the published estimates of black carbon are derived from models.”
“There is a significant uncertainty (factors ranging from 2 to 5) in estimates of emission strengths”
“…the estimated BC [black carbon aerosols] effect is subject to a threefold or larger uncertainty.”
“The logical deduction from this estimate is that, if and when air pollution regulation succeeds in eliminating the emission of these particles, the
surface warming can intensify by about 0.7 to 1.5 K, where the range is due to a range in assumed climate sensitivity of 2 to 4 K due to doubling of CO2. When this range is factored in with the threefold uncertainty in the aerosol masking effect, stopping the emission of anthropogenic aerosols, could result in a global mean warming of about 0.4 ºC to 2.4 ºC.”
A paper that does computer modelling, used to defend computer models.
So basically, all the evidence for the role and significance of aerosols is theoretical at present? Would that be a reasonable assumption?
Hansen says, “the danger that we face is the Venus syndrome. There is no escape from the Venus Syndrome. Venus will never have oceans again.” That is, “If the planet gets too warm, the water vapor feedback can cause a runaway greenhouse effect. The ocean boils into the atmosphere and life is extinguished.”
Now, that’s a fairly alarmist statement. In fact, that’s the MOST alarmist statement I have ever heard. It’s pretty far out there. Is that what the IPCC says? Is that what Gavin, foinavon, et al really believe?
Hansen cribs a little. He says “Our model blows up before the oceans boil, but it suggests that perhaps runaway conditions could occur with added forcing as small as 10-20 W/m2.” Exploding models do not give confidence in either the models or their output. Should we rely on exploding models? Why does Hansen?
Hansen also cribs, “There may have been times in the Earth’s history when CO2 was as high as 4000 ppm without causing a runaway greenhouse effect. But the solar irradiance was less at that time.” What? Is 4000 ppm a realistic prediction? And how does he “know” solar irradiance was less? Those are fairly speculative statements that both require some evidential support.
Further, he says that “to preserve creation” CO2 must be reduced or constrained to less than 350 ppm.
Again, that’s a fairly hyperbolic assertion, and in strong contrast to his prior statements and to reality. First, if, as Hansen claimed, CO2 levels actually were once 4000 ppm, it is quite evident that “creation” was not lost. Creation still exists. Indeed, if current CO2 levels are 385 ppm, and the oceans have not boiled nor has creation been eliminated, one wonders whether Hansen has lost his mind.
But lo! the oceans won’t boil for a few years yet. The lag time is not specified, but one assumes it will be something less than 100 years, right? If we remain at 380 ppm for another century or so, poof, there go the oceans and creation along with them.
This is science? The best available science? This is the consensus?
The fellow is mad. Are Gavin, foinavon, et al in consensus with him. Are they mad, too?
I had to laugh at his examples of global warming. He shows a dry pier many yards from the water on Lake Mead! It’s a reservoir! The water level on Lake Mead is controlled at the dam! By humans, not climate!
He cites US wildfire acreage since 1960, another phenomenon controlled by humans! This may shock you, but people have a great deal to do with how big fires get and how many acres they consume. It is NOT a climate controlled phenomenon, any more than Lake Mead water levels.
Hansen’s presentation is hysterical, in all the meanings of that word. I have enjoyed the discussions in this thread, but some central points have been missed. One, Hansen’s conclusions are insane, and two, warmer is better. The oceans are not going to boil away. Trust me.
John Philip (15:54:27) :
“Actually, the hypothesis is that the positive feedbacks: primarily the increased water vapour, but also the release of methane from permafrosts, melting of summer sea ice, the die-back of the rainforests, etc that amplify the GHG forced warming and instigate the runaway scenario.”
First the rainforests aren’t experiencing ‘die-back’ they’re experiencing ‘cut-back’.
second, you can forget the entire AGW theory, runaway warming or not, because the cut-back of the rainforests alone account for far more CO2 in the air (from loss of photosynthesis) than all our CO2 emissions.
“Carbon emissions due to fossil fuel combustion represent less than 20% of the total human impact on atmospheric carbon levels. Deforestation not only contributes a relatively minor one off carbon emission of some 2.3 gigatons of carbon to the atmosphere, but an ongoing loss of photosynthetic carbon sequestration to around 38 gigatons per annum that is growing at the rate of 500 megatons every year. It is clear from the fact that this amount dwarfs the present 7.8 gigaton fossil fuel combustion contribution, that the cessation of fossil fuel combustion will not halt the rise of atmospheric carbon dioxide because the loss of photosynthesising biota and the corresponding fall in photosynthesis is so much greater.”
( http://deforestation.geologist-1011.net/ )
I think we are trying to solve the wrong problem.
Random comment but seeing as I think Temperature drives CO2 I’d rather we write foinavon’s formula as
Concentration(CO2) = Power(1/3*(T+9.39), 2)
or make CO2 the dependant and T the independant 🙂
Will Nitschke (21:41:19) :
“Charles the moderator,
I’d like to make this general observation: for convenience it’s possible to divide most parties interested in this topic into these broad groupings:……”
Will Nitschke – I very much agree with this comment .
(IMHO) This is the best thread I’ve read on this forum because of the informed debate (from all sides) – I am looking forward to more like this ..
Perhaps I can suggest a fourth group – between ‘sceptic’ and ‘alarmist’ . This is someone still motivated by logical argument with supportable statements but inclined to ‘agree’ with the idea that there will be negative change (maybe not catastrophic). A ‘supporter’ group ?
John Philip wrote:
“2. Temperatures have increased substantially in the last 10 years.
http://www.woodfortrees.org/plot/uah/last:120/plot/uah/last:120/trend”
But it’s trending down for the last 8.5 years:
http://www.woodfortrees.org/plot/uah/last:102/plot/uah/last:102/trend
All the time periods are too short, though. They are only suggestive of something if current trends continue for the next few years. Gone are the good old days when the MET office predicted with confidence that ‘next year’ would be the record year to beat all previous years. Hansen is very confident that all records will be broken with 2-3 years, as per his website.
All the time periods are too short, though. They are only suggestive of something if current trends continue for the next few years
Wot – this trend? http://www.woodfortrees.org/plot/uah/last:12/plot/uah/last:08/trend
[I am joking]
J. Peden (19:25:30)
Really? Which studies does it contradict? In general there is an expectation that as the atmosphere warms under greenhouse forcing so the atmospheric water vapour concentration rises. That’s the essential point. Dessler’s paper is one of a substantial series of papers that confirm this (note that this also works in reverse of course..atmospheric cooling results in a drop in atmospheric water vapour). That’s all pretty much as expected.
I don’t see the problem with the “untethered theoretical statement” (!) that you reproduce from the NASA info page. All this means is that as the atmosphere warms the water vapour feedback amplifies this warming, and because the amplification itself “recruits” more water vapour there is a bit more warming and so in. One could formalise this within an equation of the form T=T+x+x2+x3+x4……. where T is the primary temperature rise (from enhanced greenhouse forcing or solar change or whatever) and x is the temperature rise resulting from a temperature-dependent feedback (water vapour).
Of course this works in the cooling direction to. Dessler et al use all of the data (warming and cooling events) to deduce a value for the strength of the water vapour feedback that is in fact rather consistent with a number of other studies.
You state:
Simply ignoring solar input and oceanic oscillation changes and claiming that this “warming” is due solely to CO2’s effect only manages to bring the number of scientific issues which are not anywhere close to being settled to at least six contained in this very post alone.
But one needs to be much more relaxed about the science! Every paper doesn’t address every question! Our understanding of any particular phenomenon is the summation of a very large number of observations, measurements, theoretical understanding and so on. Dessler’s paper is essentially neutral about the cause of any warming (or cooling for that matter). They provide another piece of information about the way that the atmospheric water vapour responds to temperature variation.
John S. (20:22:39)
your comment:
I have read Dessler et al. several times and my characterization of it stands unshaken. Their Eq. 1(which is nothing more than a crude empirical “sensitivity” calculation misrepresented as “feedback”) is taken as a given and is applied to a year’s worth of data–a cooling year at that–without any critical reflection upon system dynamics. By that token any covariation between two variables would constitute proof of “feedback.”
But that’s doubly incorrect. Eq. 1 is not “misrepresented as a “feedback””. It is represented as the strength of the water-vapour feedback…in other words a “sensitivity”, if you wish to call it that.
And it isn’t “applied to a year’s worth of data”. It’s applied to 5 years worth of data. Are you sure you read the paper “several times”?
and this comment:
By claiming that this is an “experimental” study and insisting that thermalized energy is amplified by CO2, you’ve convinced me that any further discussion with you would be scientifically fallow. Better luck in modern academia!
Dessler et al take measurements of temperature, tropospheric specific humidity and relative humidity from the Atmospheric Infrared Sounder mounted on the NASA Aqua satellite, and analyze these to establish relationships betwen temperature and relative and absolute humidity and to extract an estimate of the strength of the water vapour feedback.
That’s an experimental study John (unless you’re suggesting that the only experimental study is one in which no analysis is made?)
Bill Illis (19:52:14) :
The Dessler humidity study found a decline in relative humidity as temperatures declined. This is not consistent with global warming theory in which relative humidity is supposed to stay generally constant.
Read the study and see where it does not agree.
Not really Bill. Global warming theory predicts that as the atmospheric temperature rises under an enhanced greenhouse forcing, so the atmospheric water vapour will rise as a feedback amplifying the warming.
Of course this might occur with the retention of roughly constant relative humidity, and this has been observed in models. But the whole point of establishing the strength of the water vapour feedback through experimental analyses like that of Dessler, is to determine exactly how the water vapour feedback occurs and to quantitate this. Dessler et al. is just another of the studies that contributes to our understanding of the subject. “Global warming theory”, as you call it, doesn’t require that RH stays constant.
In fact, Dessler et al actually found that the relative humidity did remain roughly constant averaged globally and at most altitudes. Of course it would be foolish to expect that local fluctuations in specific and relative humidities don’t occur such that in same cases the RH will drop or rise within a dynamic system (the atmosphere) that is continually locally being pushed away from equilibrium.
OT, but related – from Science Daily: “Solar Activity Between 1250-1850 Linked To Temperature Changes In Siberia”
http://www.sciencedaily.com/releases/2008/12/081219180532.htm
I haven’t read the full paper yet, but the review is interesting: A study carried out by a Swiss-Russian team on ice-cores from the Altai reports a strong correlation between regional temperatures and reconstructed solar activity for the period of 1250 and 1850. A time lag of 10 to 30 years is observed between temperature and solar forcing, implying ocean mitigation. The authors point out that the temperature rise between 1850 and 2000 has to be caused by CO2 from anthropogenic sources, rather than by the sun as during the earlier centuries. They do not appear to discuss the reliability of ice core gas measurements as a function of pressure in the core and other sampling artefacts.
John Philip answered:
1. 10 years is too short, the WMO definition of ‘climate’ is 30 years.
2. Temperatures have increased substantially in the last 10 years.
to the question: Does the fact that CO2 has increased yet the global temperature anomaly has decreased in the past decade falsify the theory?
If 30 years is the requirement for climate, how do you reconcile the 40-year decline in U.S. temperatures from the mid-1930s to the late 1970s when atmospheric CO2 levels were apparently monotonically increasing since 1958? Wouldn’t 40 years of cooling combined with increasing atmospheric CO2 levels support Hansen’s original model of man-made global cooling?
John Philip (22:57:33) :
1) After the last PDO flip (late 1970s, negative to positive), there was a quick response. Therefore we should be looking for a quick reponse to the recent postive to negative flip.
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1972/to:1982/plot/hadcrut3vgl/from:1972/to:1982/trend
Note – I had to use HadCrut data to get a 10 year span.
2) In the last 8 years, things look quite different, and that starts well before the PDO flip.
http://www.woodfortrees.org/plot/uah/last:96/plot/uah/last:96/trend
Haven’t we been through this before?
quote What Hansen did was compute the total difference in forcings in W/m^2 between the last glacial maximum and now due to various effects (the two largest being the difference in albedo (1) because of the ice and the difference in CO2 (2) and other greenhouse gas levels, although I believe there is also a small contribution due to a difference in aerosol loading (3) in the atmosphere).unquote
1. We don’t even know the albedo at the moment, let alone during the last glacial maximum. The A train, a collection of climate satellites, is going to put numbers to the present, but the past is going to remain a mystery for a long time to come.
2. CO2 levels in the past are contested, to put it politely.
3. Aerosols are warming or cooling in the recent record — or at least so it seems when they are needed to make a particular scenario work out. I’ve seen the explanations for the post WWII cooling and I’ve seen hotspots explained by aerosols. Aerosols effect clouds: the IPCC states that our scientific understanding of clouds is very low.
quote He also used the available estimates for the difference in average surface temperature between then and now.(4) So, he has a total forcing in W/m^2 and a total temperature change; dividing the first by the second gives him the temperature change per W/m^2 of forcing, which turns out to be about 0.75 C per (W/m^2). Then, using the well-accepted value for the forcing in W/m^2 due to a doubling of CO2, which is about 4 W/m^2 (even Richard Lindzen accepts this value), he multiplies the 0.75 C per (W/m^2) sensitivity by the 4 W/m^2 forcing to get the result that a doubling of CO2 produces approximately 3 C of warming. unquote (5)
4. I would like to see confidence intervals for the measured now and the estimated past. Without them this is not science, it is handwaving. And with them it is an exercise in hubris.
5. If we had some eggs we could have ham and eggs. If we had some ham. SF fans will remember here the Drake equation which, by making a whole chain of assumptions, ‘proved’ that alien civilisations exist. If you want ham and eggs, then begin by wishing for eggs…
It’s tosh. It’s wishful thinking dressed up as science.
Wait for the A-Train — the line of climate satellites still being assembled by NASA — to give a few years results and then we can do science on the climate. Until then there are too many unknowns, and too many things known but wrong, for this whole business to be anything but expensive speculation.
Here’s my (so cheap it’s free and worth every penny) speculation just for Professor Holdren, the new presidential science advisor, who complains that there is no other over-arching theory of climate change which explains everything we are observing. I give Dr Holdren (fanfare) The Kriegesmarine Hypothesis: the isotope signal is nothing to do with burning fossil fuels, it’s down to plankton population changes caused by dust feeding silicaceous diatoms blooming in preference to C3 plankton (1); C3 plankton starving and switching to C4 metabolism dragging down heavy isotope more than expected (2); ocean warming because surfactant and oil pollution of the surface reduces production of cloud condensation nuclei which reduces maritime cloud cover(3); smoothed sea exhibits lower albedo and, when insolated, warms faster; smoothed sea has reduced emissivity so that at night it cools more slowly (4).
1. The opal ocean.
2. The light isotope signal begins too early to be caused by human CO2 emissions, but matches nicely our vast and reckless expansion of dryland farming and spillage of oil and surfactant.
3. The Hadcrut SST graphs, minus the questionable ‘bucket correction’, show the effect of pouring millions of tons of oil onto the Atlantic and Pacific between 1939 and ’45. A graph of oceanic surface wind speed shows a similarly interesting blip at the same time.
4. Arctic warming and the spill rates from the North Slope oilfield and the wells in Sakhalin may be connected.
See? Handwaving for fun and profit. I leave the cod population crash on the Grand Banks as an exercise for the interested reader. My theory explains that as well. If, of course, you wave your hands a lot.
JF
Mike D. wrote:
Hansen also cribs, “There may have been times in the Earth’s history when CO2 was as high as 4000 ppm without causing a runaway greenhouse effect. But the solar irradiance was less at that time.” What? Is 4000 ppm a realistic prediction?
First, if, as Hansen claimed, CO2 levels actually were once 4000 ppm, it is quite evident that “creation” was not lost. Creation still exists.
If you check the last graph Anthony posted above, based on the data of Berner, atmospheric CO2 reached 7000 ppm in the Cambrian period. That’s way higher than 4000 ppm and the oceans survived.
Hi Steve (12:46:49)
Yes, there’s pretty good evidence that the atmosphere has warmed the oceans. The ocean temperatures have been monitored for around 50 years, and the data demonstrate characteristics of warming via the atmosphere. So, for example, the warming shows a gradient from surface (most warming) to greater depth (least warming) through the top 700 metres…the warming depth distribution is consistent with what’s known about specific ocean mixing (e.g. the N. and S. Atlantic have deep convection and accordingly surface warmth is identified deeper into these oceans; the northern Pacific has a shallow meridional overturning circulation, and accordingly, surface warmth is not conveyed so deeply below the surface)……the N. Indian ocean shows little surface warming as a result of the aerosolic cooling effect of brown clouds – here greatest warming is sub-surface due to advection (warmth flowing from other warmed ocean regions, especially the S. Indian ocean…[***]
All of these are consistent with a dominant atmospheric effect on ocean warming (rather than vice versa, for example). There’s quite a lot more data that that informs our understanding of this.
I don’t think we do know very well the thermal equilibrium time between oceans and the atmosphere. I couldn’t agree more that this is vital for our understanding of climate sensitivity. That’s largely why most analyses of climate sensitivities aim to use periods in the past where the earth’s temperature is more likely to have come towards equilibrium (the extremely slow responses during ice age periods, and the paleo/temp/CO2 relationships in the deep past and such like), or from an analysis of transient responses (tropospheric temperature responses to the solar cycle…temperature responses to volcanic cooling etc.) to determine the strengths of feedbacks for including in the relatively well-characterised CO2 forcing.
Your Siple core point about the temperature rise between the mid 19th century and 1940. Yes, I think it’s accepted that other factors than CO2 contributed to the temperature rise. The solar output as monitored by the sunspot cycles, for example, increased significantly up to around 1940, and this likely supplemented CO2-induced warming somewhat.
Since we know that aerosols produce a nett cooling effect we have to include these in our considerations. Again, I think it’s pretty well recognized that trying to determine climate sensitivity by analysis of 20th century temperature is difficult (poorly constrained by uncertainties in the climate response time and the contribution of aerosols).
I like your paragraph:
Surely you must agree statements like “the debate is over” and “science is settled” don’t help in these situations and seems to imply more certainty to Joe public like me than there really is. Then again I guess no one has actually defined what the “debate” was and which “science” has been settled.
since you answer your own point quite well! I agree with you that it depends exactly what the “debate” is about and which “science” one is referring to in relation to our understanding being settled. The main thing is to address the science in a relaxed, skeptical, and most-importantly, an honest manner.
[***] e.g.:
S. Levitus et al. (2003) Warming of the world ocean, 1955–2003 Geophys. Res. Lett., 32, L02604 .
T. P. Barnett et al. (2005) Penetration of Human-Induced Warming into the World’s Oceans Science 309, 284 – 287.
Syl (00:49:58) :
…
“Carbon emissions due to fossil fuel combustion represent less than 20% of the total human impact on atmospheric carbon levels. Deforestation not only contributes a relatively minor one off carbon emission of some 2.3 gigatons of carbon to the atmosphere, but an ongoing loss of photosynthetic carbon sequestration to around 38 gigatons per annum that is growing at the rate of 500 megatons every year. It is clear from the fact that this amount dwarfs the present 7.8 gigaton fossil fuel combustion contribution, that the cessation of fossil fuel combustion will not halt the rise of atmospheric carbon dioxide because the loss of photosynthesising biota and the corresponding fall in photosynthesis is so much greater.”
Or maybe we should twice as concerned about human activities …
Yes…That would be circular reasoning. However, that is not what Hansen did. What Hansen did was computed the total difference in forcings in W/m^2 between the last glacial maximum and now due to various effects (the two largest being the difference in albedo because of the ice and the difference in CO2 and other greenhouse gas levels, although I believe there is also a small contribution due to a difference in aerosol loading in the atmosphere). He also used the available estimates for the difference in average surface temperature between then and now. So, he has a total forcing in W/m^2 and a total temperature change; dividing the first by the second gives him the temperature change per W/m^2 of forcing, which turns out to be about 0.75 C per (W/m^2). Then, using the well-accepted value for the forcing in W/m^2 due to a doubling of CO2, which is about 4 W/m^2 (even Richard Lindzen accepts this value), he multiplies the 0.75 C per (W/m^2) sensitivity by the 4 W/m^2 forcing to get the result that a doubling of CO2 produces approximately 3 C of warming.
Let me see, we assume that all unexplained temperature change is due to CO2 and then compute the climate sensitivity for a doubling of CO2 and then we show that a doubling of the CO2 causes the temeperature change. Hmmmmmm, sounds like circular reasoning to me. If we cannot think of any natural causes then it must be caused by us humans. This is really good “science”.