I’ve gotten into a bit of a squabble at Georg Hoffmann’s blog concerning Henrik Svensmark’s cosmic ray cloud-seeding hypothesis.
Hoffmann cites two recent papers that investigate Forbush decreases and their impacts on clouds, and thus climate. The two papers reach different conclusions.
The first paper is by Calogovic et al. (Jürg Beers Gruppe) in GRL, which analyses the 26 strongest Forbush events beginning in 1989 and compares them to ISCCP cloud data. This Calogovic paper finds nothing. No systematic changes in low cloud cover were associated with Forbush events.
The second paper by a German team, Rohs et al, appeared in the Journal of Geophysical Research and found a faint but detectable correlation that seems to contradict Svensmark’s hypothesis that low, earth-cooling clouds would be produced. Rather, Rohs et al finds that high, earth-warming type cirrus clouds are produced instead.
That would be astonishing because it would mean that periods of low solar activity would cause warm periods, and not cold ones, thus completely flying in the face of the Maunder and Dalton minimums.
The Rohs team used Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) data, which uses so-called limb-viewing of the atmosphere. Six Forbush events over 1.5 years were analysed.
Although Hoffmann admits that 6 Forbush events in 1.5 years is a scant amount of data, he can hardly contain his glee with Rohs’s findings and deems them sufficient enough to openly taunt proponents of Svenmark’s hypothesis. He even singles out the “usual suspects”: THE HOCKEY SCHTICK and GREENIE WATCH, here and here respectively, for claiming Rohs’s paper supported Svensmark. THE HOCKEY SCHTICK and GREENIE WATCH did not mention that the clouds formed in the Rohs paper were of the high, warming kind.
Of course, in a reader comment, I asked why the long periods of long protracted solar inactivity during the Manunder Minimum and Dalton Minimum did not lead to warming. Why was it cold instead? Hoffmann replies with interesting speculation:
Concerning the Maunder Minimum. So IF the Rohs relationship turns out to be robust, it is in fact the wrong sign fo the suggested sun/climate relation. Then you have a couple of other possibilities: 1) Direct forcing (TSI) is sufficient to compensate the Cirrus effect. That means a comparably high climate sensitivity. 2) Volcanoes were mainly responsible for the Maunder Minimum and compensated the Cirrus effect 3) The target is not clear meaning there is no clear relationship between the sun and climate.
For the moment I tkink one has to wait for more MIPAS data. Svensmark idea is by any means not even close to something verfied.
I wonder if he realises what he is saying. If Rohs turned out to be robust ( I doubt it will), then it would turn climate science on its head. Now that would be most interesting.
Note: Georg Hoffmann is a researcher at the LSCE (Laboratory of Sciences of Climate and Environment) in Paris and focuses on various aspects of paleo-climatology. His area of specialty includes climate reconstruction of the last 1000 years and the coupling of carbon cycles to climate development on paleo-timescales.
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UPDATE: HOCKEY SCHTICK REPLIES:
1. The abstract says they only looked at mid and high altitude clouds, so nothing can be concluded from this study about low altitude clouds & GCRs
2. The abstract says “a 15% increase in CNM would result in … an increase in cloud opacity,” so unless the abstract is worded incorrectly, there is no problem with the sign of the correlation. This would also be consistent with earlier statement of a “positive cloud-CNM correlation.”
3. The claim that high altitude clouds warm the planet because they “absorb more IR and reflect less sunlight” seems tenuous at best. Incoming solar energy is 45% IR, so these clouds absorb significant amounts of solar energy BEFORE it reaches the earth, thus acting as a sunshade. Furthermore, high altitude clouds at -18C or less are not capable of heating the earth at 15C because “a cold body cannot heat a warm body” from the 2nd law of thermodynamics.
“Note: Georg Hoffmannis a researcher at the LSCE (Laboratory of Sciences of Climate and Environment) in Paris”
and i bet he likes to keep his nice and cosy job there; i know the university surroundings; nice place to be. And as you have seen, he’s just making stuff up as he goes along, he’s gotta keep the ball rolling to keep that nice flat in Paris paid for by the European taxpayer for as long as he can…
I think you could be right.
He’s a paleo-climatologist specialising in the last 1000 years, yet he still is not sure if valocanoes could have impacted the climate over 400 years (LIA). He also is not excluding the possibility that “there is no clear relationship between the sun and climate.” That’s quite amazing.
1. The abstract says they only looked at mid and high altitude clouds, so nothing can be concluded from this study about low altitude clouds & GCRs
2. The abstract says “a 15% increase in CNM would result in … an increase in cloud opacity,” so unless the abstract is worded incorrectly, there is no problem with the sign of the correlation. This would also be consistent with earlier statement of a “positive cloud-CNM correlation.”
3. The claim that high altitude clouds warm the planet because they “absorb more IR and reflect less sunlight” seems tenuous at best. Incoming solar energy is 45% IR, so these clouds absorb significant amounts of solar energy BEFORE it reaches the earth, thus acting as a sunshade. Furthermore, high altitude clouds at -18C or less are not capable of heating the earth at 15C because “a cold body cannot heat a warm body” from the 2nd law of thermodynamics.
During the past thousand years only 17% of the time we had solar minimum conditions which always have coincided with a colder climate.
This for fact and the link between solar minimum and cold events have been confirmed by historic events.
Scientist’s can attack Svensmark’s theory but they can’t deny historic facts.
Volcanic activity was much higher during the Little Ice Age, although we have seen long cold periods that saw solar minimum conditions without major volcanic eruptions. There are scientist’s who think solar minima coincide with a rise in volcanic activity and quakes, but so are solar maxima.
However, I am convinced of Svensmark’s theory (because of the satellite cloud cover maps documenting his study that show increased cloud coverage) but I also think that changes in jet stream patterns and blocking high’s play a big role too.
Through out the Little Ice Age, historic records have been found describing long and intense heat waves like the year of the big fire that destroyed London in 1666 followed by an incredibly cold winter, a weather pattern similar to the weather patterns we have have seen for the past few years that caused the recent year without out summer in the USA last year, the Russian Heat (and Cold) wave and the devastating rains in Pakistan, India, China and Australia.
These patterns have also caused the most amazing event of this year, the cold invasion on the Southern hemisphere this summer where freezing temperatures hit the tropical regions very near to the equator.
We currently observe the effects of our current solar minimum and you only have to read the winter predictions of D’Aleo and Bastardi for the upcoming season and 2013, the start of the real brutal weather conditions, predicted by a.o by Bastardi and Dr. Theodor Landscheidt
who’s name will be given to the upcoming minimum to know for sure if there is a link yes or no.
Just keep in mind that non of the upcoming cold events have been predicted by the climate models pushed by the IPCC who predict a continuous warming and also keep in mind that the warmist will do anything to push for the legalization of the climate policies, even if it’s
the last thing they ever do. This includes an attack on the Svensmark papers.
Anyhow, imo the Anthropgenic Global Warming Theory, if not very dead already, will be buried in a very deep grave by 2013.
Also read this latest posting from Dr. Spencer:
http://www.drroyspencer.com/2010/09/five-reasons-why-water-vapor-feedback-might-not-be-positive/
A big motivator for quick and aggressive action on carbon reduction is the climate sensitivity argument.
However, this argument should be dumped into the bin immediately as our planet has seen huge impacts from comets and meteorites, massive volcanic eruptions that caused cold events and massive extinction events.
One of the most recent events 12.900 years ago is documented here:
http://www.pnas.org/content/104/41/16016.full.pdf
And if you have finished reading it, the only conclusion you can make is that one of the most distinguished properties of our climate that enables the return of life on our planet after a gigantic disaster is the fact that “stable” conditions return.
So increasing albedo warms the planet????
“2010/09/16 06:00 Today is the first day for the 64x Wolfcam. I still have some work to do but the result is very close. I think this is very close to what Wolf and Keller would see through the original 64x scope. It is becoming obvious that the modern sunspot count was first inflated by Waldmeier and then continued by better technology to where today we are some distance from what Wolf would have counted.”
http://www.landscheidt.info/images/Sept_16_6.00.png
It’s quite clearly established that the counting of sunspots was not very regular in the past. One Scandinavian reader over at WUWT, unfortunately the name escapes me, was quite knowledgeable on the subject and he wrote a very convincing reply on this topic awhile back.
Important today, with our observational power, sunspot activity is very low. That will have an impact on the earth. Anyone who says that the sun has only a subordinate effect on the earth’s climate is a charlatan. That makes, in my view, most CO2 AGW scientists charlatans and snake oil salespersons.
They have yet to produce any evidence and, moreover, have fled from or lost every debate.
”Anyone who says that the sun has only a subordinate effect on the earth’s climate is a charlatan”
I don’t think any of the climate scientist ever said that. Disinformation reported they did, but what they said is the sun was accounted and predictable.
Predictable in the sense that they know what the sun’s behavior is causing based on past climate data and sun’s observations. Of course the assumptions here is as good has was the observation’s quality. Yet they never said the sun was out of the equation – but let’s face it, there’s not much we can predict about the sun’s behavior on short term scale (less than 100-200 years) beside sun’s spot and the relative position/attitude of the earth from the sun.
Also, it is important to note the difference between warm and warming. Just because something is warming does’nt mean it is warm. It is at most warmer, and that could still be very cold.
The fact that Daleo/Bastardi predicted (on a statistical basis) that 2013 will be colder does’nt mean there’s no warming going on. On a side note i wonder why they keep pushing the cold era from 2011, then 2012, and now 2013. When will they come with 2015.