Bishop Hill Striking back at Svensmark
Oct 7, 2011 Climate: solar Nigel Calder reports on a new paper that purports to rebut Svensmark's cloud hypothesis.
During recent years, so the story goes, the Sun has been weak, cosmic rays have been relatively intense, and yet the expected increase in low clouds has not occurred. On the contrary, we’re told, low cloud cover has remained relatively sparse. That’s according the International Satellite Cloud Climatology Project, ISCCP, which pools data from the satellites of several nations.
However, the ISCCP data are apparently problematic:
The conspicuous downward trend in the ISCCP cloud data is almost certainly unreal. An expert view is that it results from changes in the operational status of the satellites from which the data are pooled.
In other words, the jury is still out.
Calder is very critical of the authors of the new paper - Agee et al - suggesting that they have cherrypicked the ISCCP figures rather than mentioning any of the other data sources, which tell a different story. He calls the paper "shoddy".
Reader Comments (183)
Shub
See above. You do not convince.
Hi guys
I find you both very interesting to read, and Shub your blog and tweets are particularly interesting from the point of view of politics of climate science (the treatment of Roger Pielke Snr for example - I often agree with much of what you say in that regard) but on the basis of general experience here I must say that BBD's contributions appear to be well-informed on the topic of climate science.
This is not an attempt to support BBD through "argument by authority", it's just an observation that his posts are generally in line with my own understanding of the subject.
As you know, my own qualifications and publication record can be found by clicking on my name below, or on my twitter profile, or by just a simple internet search.
(BBD - I hope this doesn't backfire and get used to shoot you down!)
Just out of interest, why do you both prefer to remain anonymous anyway? Don't have to answer that if you don't want - I'm just curious.
As I say, I find both of you very interesting guys to read.
Off to bed now though - will see whether this has helped this debate or made things worse tomorrow....!
"it's just an observation that his posts are generally in line with my own understanding of the subject"
Oh my. One Warmer's beliefs conform to another's. Didn't see that one coming. Clever clever clever.
Andrew
Richard Betts
This is a classic dammned-either-way moment, but sod it. Thank you. It's been a lonely furrow and I am pathetically grateful for the endorsement.
Others can make of that what they wish.
Shub - interesting sounding background. Your comments usually strike me as straight thinking.
By happy coincidence there is a post up at Judith Curry's from a someone else with a medical perspective:
http://judithcurry.com/2011/10/10/climate-control-theory-feedback-does-it-make-sense/
just wanted to say that I find the metamorphosis of BBD into Trenberth jr. quite amusing - even down to the equivalent attenuating rhetorical power...:)
Richard, again thanks for your participation/comments
the one at Oct 10, 2011 at 12:39 AM I find useful.
like previous comment to BBD, have you read "heaven & earth"? (by I.Plimer, I'm 1/2 way through).
he is a bit naughty at times, but does put CC/ACC in perspective I think.
any comments?
again, thanks for any response.
Hi Dr Betts
You choose to say this:
: "...Shub your blog and tweets are particularly interesting from the point of view of politics of climate science...I must say that BBD's contributions appear to be well-informed on the topic of climate science"
on this thread?
On a thread, where BBD has fallen into the hole of accepting, at least partially, and after great prodding that there are some problems with the current state of available cloud cover data, and using parts of the same data to refute/reject one of his pet peeves?
As far as supporting orthodoxy is concerned, I have always wanted to ask you this:
You must be aware of the Amazongate episode. Perhaps even closely. Let me tell you - if anything, I am quite familiar with the science in this area. I was one of the handful of people (more precisely perhaps, one of the three people) who dug up an awful lot of information during the entire turbulent period of the back-and-forth between Richard North-George Monbiot-Simon Lewis-Dan Nepstad, which established that the IPCC was wrong.
The behavior of the whole Amazon climate establishment was abysmal during this period. Well, almost the whole, is probably more precise. You all closed ranks and defended some very bad science and bad scholarship and bad advocacy by the IPCC, merely to prevent another repeat of Glaciergate, to avoid 'giving succour to the deniers' and to protect the reputation of the IPCC.
Outsiders like me, were able to clearly see what was wrong with the IPCC, simply because we were outsiders and did not have a stake in protection of orthodoxy.
It is the same here. I have no stake in clouds decreasing or increasing.
"For instance, engineering dudes/dudettes are reductionist in approach - and expect everything to fold over into mathematical equations". No wonder I am confused - C.Eng but B.Sc. & M.Sc in physics.
Richard Betts, as you are here - do you have any comment on Huffman's "no greenhouse effect" hypothesis? I only ask because I am curious, with no axe to gring either way. In my opinion all of his work can not be dismissed simply because he has "original" views about Atlantis, If that was the case Newton's laws of gravity would have been dismissed because he was a religious zealot.
RL
God knows what HDH is claiming, but the previous iteration of misunderstanding about the Venusian atmosphere was led by the 'Steven Goddard' blogger (anonym).
Climate modeller Chris Colose discusses the errors here. It's worth reading the comments as well as the main post.
Comparisons between Newton and HDH are ridiculous.
BBD,
Thanks for the link. The for and against comments are intersting and will take some time to digest, but at first sight there is no definitive conclusion. But the link is useful - any comments from others?
Now, I have just been reminded that I have a day job................
Shub
You are a piece of work. I pointed out that there were problems with ISCCP data showing a decline (global and equatorial). A number of people who would sooner die than admit that RF from CO2 is the main cause of warming since the 1970s claim reduced cloud as the cause. They are probably wrong. Calder agrees.
Please stop this deliberate misrepresentation. You've done enough damage to your credibility on this thread already.
Shub
Do you accept that RF from CO2 is:
- real
- a major cause of warming since the 1970s
Richard Betts
Mainly so I can be as rude as I like about UK energy policy and those responsible for its current direction.
RL
When you have more time to go over the argument there, I think you will agree that Goddard was gravely mistaken. As no doubt is HDH.
BBD, my simple question was - if the temperature lapse rates of Earth, Mars and Venus can be correctly calculated solely from atmospheric pressure and insolation, regardless of atmospheric chemistry, why evoke a planetary greehouse effect? Discussions about heat transportation mechanisms are all very well, but Occam's Razor suggests that the basic question should be answered first.
Roger
You appear to be missing something very basic.
Had you taken me up on my suggestion that the genuinely curious should read Lacis' essay and all links, you would have come across this:
Please, no more about Occam's Razor.
BBD,
The quote that you give does not answer my question (particularly note: "regardless of atmospheric chemistry").
As for St. William of Occam, he is my rod and my staff. And please stop being so nasty to Shub - your extreme rudeness only diminishes you in the eyes of those here.
Dr. Betts, please can you give an imformed opinion?
Ockham's sharp axes
Lay waste a forest of thought,
Leaving the forest.
============
I'm amused that the Razor of CO2's radiative effect has been applied to climate, systematically not simple. The Advocates have stabbed themselves.
======================
RL
I give up. Your mind is closed.
In addition to not reading the information above, you have also not read my exchanges with Shub. You think you have, but that is not the same thing.
No further response to you on this thread.
BBD - so you can not consider a simple question and run away. OK, fine by me.
Okay, Roger. One last try. I shouldn't have walked away.
You say:
Where did "solely from atmospheric pressure and insolation" come from?
We are (or should be) talking about the dry adiabat (La). This is set by the local gravity (g) and specific heat (Cp) of atmospheric gasses:
La=g/Cp
So I'm puzzled.
Next, the dry adiabatic lapse rate does not determine surface temperature. That is determined by the solar radiation absorbed at the surface and the IR re-emitted by GHGs in the atmosphere (see Lacis, above).
Oct 11, 2011 at 1:50 AM | Shub
Hi Shub
Some things did go wrong in the WG2 report in AR4, which is why I chose to volunteer for WG2 in AR5 rather than WG1 where I was for AR4 - I wanted to make a contribution to improving matter from the inside.
On "Amazongate", Simon Lewis's point was that there was scientific literature suggesting a potential major threat to the Amazon from climate change (indeed I wrote some of it!) but WG2 cited the wrong literature instead of this.
However we certaintly do not suggest that the Amazon is definitely doomed due to AGW. The impacts of AGW are uncertain (our model gives the worst outcome - others are less severe or even benign). Deforestation is a more immediate threat - but even that seems to be getting more under control at the moment. The combination of climate change and deforestation, through fire, is probably where the real risks lie.
BBD, Thank you for coming back.
I agree that when I first saw the hypothesis it seemed "too good to be true", so several months ago I worked through it, and could not see a flaw. I, also, wondered if it only applied to the dry, adiabatic lapse rate, rather than beneath the troposphere and clouds (if a planet had clouds). However, from what I could see, atmospheric pressure and TOA insolation produced a remarkably good fit. So it is a genuine question. If there is an adequate solution using only athmospheric pressure (itself dependent upon the planets gravity and atmospheric density) and TOA insolation, physical energy transport mechanisms become second order, and the chemical composition of the atmosphere does not seem to be important (Venus and Mars almost all CO2, Earth N2+O2)
I have not checked the fine detail of planetary lapse rates all the way down to the surface. Perhaps someone here could provide a reference?
I will be away for a few days, but would like to resume this at a later date.
Roger
No problem, and I apologise - busy day, short temper.
I was under the impression that the lapse rate was a constant, not variable closer to the surface.
A very quick poke around turned up this table of planetary adiabatic lapse rates from NASA, but I'm not sure if it's exactly what you are looking for. The formatting does not survive cut and paste to comments here, so please follow the link.
Thanks BBD, I'll get back to it.
You may wonder why I am banging on about this - it is simply that if the hypothesis (or call it what you will) is correct, or even largely correct, then it does not matter if Earth's CO2 is 0.04%, 0.05%, 0.06%....... it would have virtually no effect on the surface climate. In fact, the plants would love it and we would not have to wreck our economy.
But I repeat, I simply do not know! It may rely upon bulk gas laws obeying thermodynamic equilibrium, consequent only on insolation and any internal energy.
Need to eat, sleep, up at dawn..... I'll get back to you.
Roger
No need to hurry. There's what may be a useful discussion of this here. As always, the comments are worth a look too.
This is not a simple matter ;-)
BBD - many thanks for the excellent link, and the further links that it provides. At least we have moved on from the HDH stuff. I will examine further, as time permits. As you say, not a simple matter...
BBD,
It seems that we are the only ones left here - a shame, I hoped that Dr. Betts would come back.
I have thought about this and I have two points:
1. I am now sure that the term "greenhouse effect" has different meanings to different people. To some it means the natural consequence of a planet's atmosphere resulting in an understandable altitude/temperature profile, consequent upon the altitude/pressure profile; to others it means the influence of certain atmospheric gasses (even trace gasses), which radically alter the temperature profile.
Conclusion - we must be very careful with semantics!
2. (This is moe speculation). The usual calculation of pressure (or temperature) variation with altitude uses the lapse rate (dry or otherwise). However, the alternative method (the one generally used in my world of aerospace) does not, and gives virtually the same results. This defines pressure only as an exponential function of altitude, the acceleration due to gravity, the universal gas constant, the temperature and the molar mass of the planet's atmosphere (M= 29 kg/kmol for Earth).
If so then would it not be the case that very small variations to Earth's CO2 component (eg 0.04% to 0.05%) would have an insignificant effect upon M, and hence the pressure and temperature profiles?
I would like to open the second point to debate, and I am fully prepared for anybody to shoot it down, as thermodynamics is not my subject.
Roger - re your point 2 - do you have the equations to hand that you use?
NBY -
I am useless at writing eqations in text, but -
for the exponential decrease in density with height from the surface for an atmosphere with a single molecular component of temperature Ti deg K:
rho = rho(0) * exp (-Mi*g*h/kTi)
Mi is the molecular weight of species i and h is the height above the reference surface, where density is rho(0). kTi/Mig, of dimensioal length, is a scale height parameter which indicates the rate of decrease in density.
The equations that use lapse rate are easily found on google.
Does that answer your question?
Yes - that does help. I think you are looking at the impact of CO2 from the point of view of the various gas laws. These are essentially conservation of energy laws relating temperature, mass, pressure, density and heat capacity and they remain valid for energetically static systems.
As I understand it the argument re: CO2 is that, as a radiatively responsive component of the atmosphere, it plays a part in the energetic dynamics of the planet - exposing it to longwave radiation heats it up. This is a separate mechanism to the pressure/temperature relations of the gas laws. Hence your take on the minor impact on molar weight that ppm CO2 changes has is addressing a different argument.
If you want to see a good intro. to the theory with a lengthy and interesting debate I'd suggest this link at the Air Vent:
http://noconsensus.wordpress.com/2010/04/19/radiative-physics-yes-co2-does-create-warming/
or work your way through Science of Doom:
http://scienceofdoom.com/
I should add - nothing I have seen at either site convinces me re: the catastrophic arguments advanced by some.