Nigel Calder in the Times
As a prelude to a new book, Nigel Calder (who was the editor of New Scientist for four years in the 1960s) has written an op-ed for the Times (UK) basically recapitulating the hype over the Svensmark cosmic ray/climate experiments we reported on a couple of month ago (see Taking Cosmic Rays for a spin). At the time we pointed out that while the experiments were potentially of interest, they are a long way from actually demonstrating an influence of cosmic rays on the real world climate, and in no way justify the hyperbole that Svensmark and colleagues put into their press releases and more 'popular' pieces. Even if the evidence for solar forcing were legitimate, any bizarre calculus that takes evidence for solar forcing of climate as evidence against greenhouse gases for current climate change is simply wrong. Whether cosmic rays are correlated with climate or not, they have been regularly measured by the neutron monitor at Climax Station (Colorado) since 1953 and show no long term trend. No trend = no explanation for current changes.
12 February 2007 at 13:47
So funny how your dismissive attitude here toward the ideas expressed in the article mirror the dismissive attitude in the article toward your side. This is just the most recent example of this sort of thing.
I am just annoyed that no one seems to be acting grown-up in their rhetoric about this on either side. Hyperbole, alarmism, and sarcasm toward opposing viewpoints prevails on both sides, at least in terms of what the public is treated to in the popular media.
We, the non-scientist public, deserve better from both sides, if this is of such grave import.
12 February 2007 at 13:53
[[So funny how your dismissive attitude here toward the ideas expressed in the article mirror the dismissive attitude in the article toward your side. ]]
Did you miss the fact that the cosmic ray people have a big fat contradiction between their theory and the evidence? Forget who is dismissive of whom, take a look at the facts.
12 February 2007 at 14:02
They say there are no facts Barton. Like all of that particular social persuasion, they seem to think if you just say it, that makes it true and no support is needed. Amazing. My comment there failed to post for some reason.
12 February 2007 at 14:29
I had commented on Nigel’s article yesterday (curously the page seems to show only 10 comments at a time) and basically pointed out three main problems with the argument he presented.
1) Nigel claims that the ‘cooling’ of East Antarctica contradicts the theory that greenhouse gases are causing global warming. For one - and I think RealClimate has made this clear - pointing to East Antarctica is not proof that global warming is not happening (see Davis 2005). Furthermore, how can one infer that it is not greehouse gases causing the recent warming by pointing to East Antarctic cooling, especially considering what the IPCC has already had to say about this.
2) He claims that the global temperature rise reached a plateau in 1999. So far, what I have seen shows the contrary: that it has continued to rise.
3) The argument is based to a large degree on political arguments, rather than scientific analysis. In other words, it is purported that the claim that anthropogenic global warming in recent times is a real and dominant phenomena is weakened because it’s the orthodox position, or it’s somehow not open to new interpretations and theories, and so on. These are arguments from a given political circumstance, not from quantitaive/ qualitative analysis of data.
12 February 2007 at 14:31
Now the bees are dying. Is there any link between the decline in the bee population and climate change? We need those little critters to pollinate the plants.
12 February 2007 at 14:45
>is there any link ….?
Er, probably (wry grin). I’m commenting as another reader here (who did keep bees once), I’m not a climate scientist.
Ask locally if you’re seeing a local problem. There are changes due to climate and weather. There are far greater risks for honeybees (one of hundreds of kinds of bees, which are among dozens if not hundreds of kinds of pollinators).
Got pesticide spraying? Migratory beekeepers? A good bee inspection system in your state watching out for known bee diseases that enforces laws to control them? (Ohio had a very effective bee disease control, decades ago at least; I don’t know of many other good ones.)
If you’re talking honeybees, remember they’re European imports; the natives here called them the “white man’s flies” when they arrived. And if you’re talking native pollinators, remember you’re talking about far more animals besides honeybees.
http://www.google.com/search?q=%2Bpollinators+%2B%22climate+change%22
http://www.google.com/search?q=%2Bpollinators+%2B%22migratory+beekeeping%22+%2Bfoulbrood
http://www.google.com/search&q=%2Bpollinators+%2B%22migratory+beekeeping%22+%2B%22disease+control%22&btnG=Search
12 February 2007 at 14:54
I’m surprised by two things in the article: 1. when he states that researchers who have contrary ideas or evidence are rewarded with impediments to their careers (is Svensmark and his basement his only evidence?), and 2. when he mentions solar physicists in general with no name or organisation or anything. I’m surprised because I would expect a former editor of a science mag to reference evidence for such statements and I’m disappointed that he didn’t.
12 February 2007 at 14:59
Hmm….
So I guess that this graph, linked from the same NOAA FTP site is also a poltical ploy
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_IRRADIANCE/SOHO_VIRGO.v2.pdf
Very good picture of how total solar energy has been increasing.
Data does not lie
12 February 2007 at 15:03
The blogosphere is all abuzz with the reports of galactic cosmic rays. Many seem to think it’s is a new, revolutionary idea, as though we hadn’t known about this for years. What surprises me most (well, actually it doesn’t) is that skeptics are so highly critical of any perceived flaw in the IPCC AR4 SPM, but so eager to embrace (without critical appraisal, or even any appraisal at all) an alternative which has no observational support and a most flimsy theoretical basis.
It’s also very revealing that skeptics constantly harp on the idea that alternative viewpoints are “shut out of the discussion.” Nothing could be further from the truth. Svensmark’s theory, though not really credible, still made its way to publication in the peer-reviewed literature, experiments are now scheduled to study the effect of GCRs on cloud condensation nuclei, and both the blogosphere and the media are making (much too much) a big deal of it. How is this being “shut out” of the discussion?
12 February 2007 at 15:17
Re post 8 I think your link should be
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SOLAR_IRRADIANCE/SOHO_VIRGO.v2.PDF
[Response: Indeed, please look at the time scale- this is just the upswing from solar minimum to solar maximum. To see how that really fits in on the longer time-period, look at the PMOD composite:
http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant -gavin]
12 February 2007 at 15:17
My understanding is that the Sun has been more active magnetically for the last 150 years.
How does a a baseline begun in 1953 disprove anything?
The Sun was more active during the Medieval Warming and less active during the Little Ice Age. Surely, the Medieval Warming and the Little Ice Age aren’t explained by the rise and fall of green house gases. So, unless some one offers a better explanation, these events seem best explained by variations in solar output and/or the magnetic field.
If that is right, then a more active sun would probably have SOME effect even if it does not account for all of our current warming and even if its exact mechanisms are not completely understood.
[Response: Nobody’s saying the sun has no effect. Many of us at RC have published papers on observational and modelling evidence for solar forcing effect on climate. The point of contention which always seems to come up is whether it has anything to do with the current climate change (i.e. the last few decades). The answer there is no (or more precisely, not very much). -gavin]
12 February 2007 at 15:32
Dennis Wingo: data does not lie; it wants to be understood. The graph you point to shows a change from about 1365 to around 1367, with a lot of variability. If it were your average bank balance per month, or Stairmaster average steps per day, would you think you saw a trend with that kind of change and variation?
—-
Pollinators: honeybee colony collapse disease news:
http://www.ento.psu.edu/MAAREC/pressReleases/ColonyCollapseDisorderWG.html
12 February 2007 at 15:36
Re #11 Gavin’s comment
Some where there was link to an article(s) that attempted to measure the effect of solar variation on recent warming. This was article that concluded it wasn’t having much of an effect. Could somebody point me to it?
I can’t remember how the analysis was done but, given that solar variation may have accounted for much of difference between the Medieval Warming and the Little Ice Age, I wonder if it might be underestimating a little.
12 February 2007 at 15:40
The Antarctic sea ice numbers are misleading if not completely wrong. See http://nsidc.org/data/seaice_index/ for the specific numbers.
The only month you can get an 8% increase since 1978 is in March. Feb, Apr, and May give you ~6%. The other months are 3% or less (and December is actually decreasing slightly).
Meanwhile, in the Arctic, the annual mean has decreased by over 10% overall, and summers have declined by over 20%. And most importantly, while the Arctic trends are statistically significant at a 99% level, the Antarctic trends are not even significant at a 90% level.
12 February 2007 at 15:41
Re: #8
Dennis, the graph you reference only covers four years — less than half a solar cycle. Have a look at this graph.
Data does not lie. But showing only a tiny fraction of the data so that it will support your hypothesis…
12 February 2007 at 15:43
PS, New Scientist’s editorial weblog — defending a recent article on a ‘reactionless drive’ — wrote:
“… should New Scientist should have covered this story at all? The answer is a resounding yes: it is, after all, an ideas magazine. That means writing about hypotheses as well as theories….”
http://www.newscientist.com/blog/fromthepublisher/2006/10/emdrive-on-trial.html
12 February 2007 at 15:58
If I go directly to the VIRGO page (I’m a theoretical astronomer who constructs solar models) I get to
http://www.ias.u-psud.fr/virgo/
and I go to total solar irradiance, the relevant place is Figure 2.1 to get the variations in the solar flux.
Nothing much is happening, although there is interesting structure even at small luminosity contrasts.
Your link is broken, by the way; I did eventually find your image, which is taken from one small section of VIRGO data with a 3 year baseline.
Yes, the solar luminosity does vary over a solar cycle, which is longer than 3 years. However, if you
look over longer periods than that (as per the links above) these cycles average out and are too small.
Data doesn’t lie, but people can either misunderstand or misinterpret data. Why did you pick a three year snippet
instead of the more easily found 25-30 year timelines? Because the former shows a linear trend and the latter does not?
12 February 2007 at 16:04
That sure is a brief commentary on Svensmark’s work. You fail to point out that the Climax Station does not measure all cosmic rays, only those in certain energy ranges, which are not the optimum ranges for cloud nuclei formation.
[Response: We’ve done this to death, and sometimes we get bored too. If the argument is that cosmic rays are being modulated by the solar activity (which they clearly are on a 11 yr timescale), then I don’t see any reason why different energy bands will be trending differently than the ones monitored at CLIMAX. I would also point out that this is the same series used by Svensmark and others to demonstrate a cloud link in the first place. -gavin]
12 February 2007 at 16:09
Dennis
Link doesn’t work.
12 February 2007 at 16:44
Nitpicking: data -> plural; datum -> singular
12 February 2007 at 16:53
As an example only…
Global warming: another experiment that demonstrates that increases in atmospheric CO2 will not have any effect on climate…
“Researchers recently carried out an experiment that debunks the central point in the ‘theory’ of global warming. They constructed an experimental model of the atmosphere in a box, and by passing infrared light through this model, they demonstrated that the atmosphere is already saturated with respect to the absorption of infrared light by carbon dioxide. In layman’s terms, this shows conclusively that adding CO2 to the atmosphere will have no effect on the net absorption of infrared light, and thus will not increase the surface temperature of the planet. Global warming has been shown to be a hoax!”
Hope noone takes that seriously, and decides to publish it on the front page of the Wall Street Journal…
I suppose I should include the actual series of events related to that experiment: see http://www.aip.org/history/climate/co2.htm
A few years after Arrhenius published his hypothesis, Knut Angstrom sent infrared radiation through a tube filled with carbon dioxide. He put in as much of the gas in total as would be found in a column of air reaching to the top of the atmosphere. The amount of radiation that got through the tube scarcely changed when he cut the quantity of gas in half or doubled it. The reason was that CO2 absorbed radiation only in specific bands of the spectrum, and it took only a trace of the gas to produce bands that were “saturated” - so thoroughly opaque that more gas could make little difference.
This was all clarified around 1950:
The early studies sending radiation through gases in a tube had an unsuspected logical flaw - they were measuring bands of the spectrum at sea-level pressure and temperature. Fundamental physics theory, and a few measurements made at low pressure in the 1930s, showed that in the frigid and rarified upper atmosphere, the nature of the absorption would change. The bands seen at sea level were actually made up of overlapping spectral lines, all smeared together. Improved physics theory, developed by Walter Elsasser during the Second World War, and laboratory studies during the war and after confirmed the point. At low pressure each band resolved into a cluster of sharply defined lines, like a picket fence, with gaps between the lines where radiation would get through.
As far as the cosmic ray question, one there’s no trend, two there’s no evidence that cosmic rays would increase CCN formation in the atmosphere (as opposed to inside a smoggy box) - see http://rabett.blogspot.com/2006/10/svensmark-stumbles-into-smog-chamber.html , etc. It’s already been rebutted several times… but here we see it again! Incidentally, people were claiming that the above ‘CO2 experiment’ disproved global warming on RC threads about six months ago.
12 February 2007 at 17:19
Re: #10 Gerald, thanks so much for the link to those solar graphs. They will be helpful in my presentations.
12 February 2007 at 17:32
What is the current RC explanation as to why the NH is warming and Antarctica is cooling? The cloud cover theory seems to explain it. Does RC have a different explanation besides cloud cover? Do you disagree that cloud cover can explain it?
thx
[Response: RC search in the upper right corner of the main page is your friend here. A search on “Antarctic cooling” takes you right to our previous post Antarctic cooling, global warming. -mike]
12 February 2007 at 18:11
Re #20: “Nitpicking: data -> plural; datum -> singular”
If you’re writing in Latin, sure. In normal English usage, though, data is a mass noun (I think that’s the correct term, though it’s been a while since I studied English grammar, or Latin), used to refer to a whole collection of stuff - like for example snow or sand. So put that nit back
12 February 2007 at 18:35
Re Nits.
Collective is the word you are looking for. Data is a collective noun. Like sheep.
12 February 2007 at 18:41
I have seen Nigel Calder speak and I am surprised at his op-ed. As written, his op-ed inidcates he is more or less ignorant of the basis of the IPCC findings and the scientific consensus on global warming. Cherry picking at its best!
12 February 2007 at 18:42
gavin: did you ever finish May discussion ( http://www.realclimate.org/index.php/archives/2006/05/thank-you-for-emitting/#comment-13470 ) with Nir Shaviv?
12 February 2007 at 18:47
RE#23 - There are certainly a lot of recent scientific reports on the Antarctic that you might want to look into.
First, consider the tropical glacier record, which includes evidence of the Medieval Warm Period and the Little Ice Age as well as the last 50 years of unprecedented warming; the compilation of global tropical glacier records is discussed at:
http://www.sciencedaily.com/releases/2006/06/060627093233.htm
“First Compilation Of Tropical Ice Cores Shows Abrupt Global Climate Shifts” Jun 27 2006
Thus, the warming is not confined to the Northern Hemisphere, but is a global phenomenon.
The Antarctic cooling issue (as cited in the linked op-ed) is a good example of How Misleading Talking Points Propagate (RC) - that may be the link you’re looking for.
Note also that overall Antarctic snowfall has not increased in 50 years.
See also:
http://www.sciencedaily.com/releases/2006/10/061016105739.htm
“First Direct Evidence That Human Activity Is Linked To Antarctic Ice Shelf Collapse” Oct 16, 2006
http://www.sciencedaily.com/releases/2001/01/010117075358.htm
“Antarctic Ice Shelf Collapse Triggered By Warmer Summers” Jan 19 2001
http://www.sciencedaily.com/releases/2006/03/060330181319.htm
“Rapid Temperature Increases Above The Antarctic” Mar 30 2006
http://www.sciencedaily.com/releases/2005/02/050224115901.htm
“Antarctic Ice Shelf Retreats Happened Before” Feb 28, 2005
http://www.sciencedaily.com/releases/2006/03/060302180504.htm
“Antarctic Ice Sheet Losing Mass, Says University Of Colorado Study” Mar 2, 2006
http://www.sciencedaily.com/releases/2006/11/061109130709.htm
“Climate Changes Are Linked Between Greenland And The Antarctic” Nov 10 2006
http://www.sciencedaily.com/releases/1999/04/990409073216.htm
“Antarctic Ice Shelves Breaking Up Due To Decades Of Higher Temperatures” Apr 9 1999
http://www.sciencedaily.com/releases/2006/03/060312210108.htm
“Study Previews Ice Sheet Melting, Rapid Climate Change” Mar 12 2006
And so on… the take home message seems to be that both rising ocean temperatures and summer air temperatures can have dramatic effects on ice sheets, and the Antarctic ice shelves are sensitive to ocean temperatures (which control the melting rate) and snowfall/ ice flow (the addition rate). As the shelves go away, the glaciers will flow right into the sea. The Medieval Warm Period and the Little Ice Age seem to indicate that the climate is sensitive to various forcings, and we’ve created an unprecedented and increasing atmospheric CO2 forcing due to the use of fossil fuels - estimated to be ~20X that of any potential solar forcing - so we should expect that the observed warming trends will continue. Also note that most of the above papers weren’t discussed in the 2007 IPCC report - too recent.
12 February 2007 at 19:03
Re New Scientist/Nigel Calder, former editor of:
Just highlighting the difference in tone between New Scientist No 2569, 16 September 2006: GLOBAL WARMING - Will the sun come to our rescue?, and the latest issue No 2590, 10 February 2007: GOODBYE COOL WORLD - WHY OUR FUTURE WILL BE HOTTER THAN WE’VE BEEN TOLD. It may be a case of judging the book by its cover, but the second statement is a lot more assertive in its form (exclusive use of capital letters) and content (affirmative mode).
12 February 2007 at 19:12
You will not resolve these disputes with contrasting sorts of data, because there will always be some contradictory evidence for any theory.
Of good help is a little history, and a little meta-science, or a look at scientific method.
Implicit in most of these articles is that because global warming has become the orthodoxy, it brooks no dissent. To prove this, every once in a while, we read some new data set that “contradicts” the whole theory.
This happens all the time. A good example is that Newton’s theory of gravity was not able to precisely model observations of the path of Mercury beyond a certain degree of accuracy. In the end, one of the experiments seen as confirming Einstein’s theory was that it did in fact track Mercury precisely.
But in the meantime, Newton’s theory was not thrown out in toto because of a few flaws. Instead, it was refined.
Here, the idea that science is nothing more than a sort of pyrrhonian skepticism is simply wrong. Science accepts tested theories as a model of truth, not to be discarded without a more compelling, fully working model.
Until the so-called skeptics of global warming can present a model that fully explains all of the observations, they have nothing.
The best they could really hope for is to limit the anthropogenic percentage, but in the end, as long as there is any anthropogenic contribution, there needs to be man-made counter-actions.
Another way to hit home with these (often works with evolution deniers) is to ask if they want their medicine conducted on these breaking shreds of evidence without competent review and long term study.
12 February 2007 at 20:36
Nits:
1. I won’t debate the unpleasant subject of normal English usage, but in scholarly writing the distinction between “datum” and “data” has not disappeared, both because some of us prefer to use Latin words correctly and because it is useful to be able to differentiate between the singular and plural forms.
2. Speaking of differentiation, “the Times” is ambiguous (yes, I know I can follow the link, but I try not to follow too many Murdoch links), especially when the author’s nationality (”group”) is unknown.
3. (Re mike’s comment) I don’t wish to complain about the enlarged search function, since that might be viewed as volunteering for webmaster duties, but I was more inclined to scold people for not using it back when a compound search was not required to restrict the results to RC.
4. Please give us a straight science entry soon - absence has made the heart grow quite fond enough, thank you.
[Response: The UK Times. I’ve edited above to be clearer. If you want to volunteer for websmaster duties, I need someone to program in a branch to each search function from two radio-buttons nicely placed in the above banner. Any and all offers accepted and I’ll send you the details on request! -gavin]
12 February 2007 at 20:45
What seems completely implausible is that variations in solar activity have no impact on Earth’s climate whatsoever.
They obviously do, since virtually all (99.9999%) of Earth’s climate is derived from solar energy.
The next issue is that it is completely implausible that solar activity is a monolith, never changing amount. The Sun clearly has cycles of activity.
The Sun clearly has an 11-year cycle. The variance is very small between those cycles but the fact remains that old Sol is a variable entity.
What other cycles does old Sol have beyond the 11 year one. Well go back to the sunspot figures of the late 1600s if you want evidence that old Sol has more varibility than the minimal variance of the 11 year cycle.
http://en.wikipedia.org/wiki/Image:Sunspot_Numbers.png
What bothers me the most, is that people will go out of their way to discount the variation when the evidence is right there. No one measured total solar irradiance in the late 1600s. So we don’t really know that solar variability caused the Little Ice Age.
We do know, however, that changes in the Earth’s orbit can translate into changes in solar energy impacting the Earth which can cause Ice Ages etc.
What bothers me the most, is that people do not want to investigate this variability any further. And some proxies such as C-14 production indicate old Sol has alot of variability, enough to explain the Medieval Warm Period, the Little Ice Age, the Modern Warming etc.
http://en.wikipedia.org/wiki/Image:Carbon-14_with_activity_labels.png
[Response: Why do you think any of what you said is controversial? Look at my own papers for ample evidence that people are actively researching these issues (most recently, Shindell et al 2006). The reason we are critical here of some of the solar shennanigans is the misuse and logical fallacies that seem to abound whenever solar is discussed. Add in the sorry history of people seeing solar connections where there are none (over and again), you have a situation where, in order to be taken seriously, you have to be extremely scrupulous in doing solar research. Svensmark and colleagues haven’t been, and they have been rightly criticised for hyping their results. As a consequence, it becomes harder to take them seriously. For that, they have only themselves to blame. -gavin]
12 February 2007 at 21:01
re: your response to #23
That link says we need to be careful about short records and instead look for long term trends. May I ask: what is long term? 50 years? 100 years, 1000? 10,000? Is ~150 years of thermometer data enough to pick a trend? Is it still enough when we know that we started in a cold period? What of the coverage? What of the accuracy? You don’t want to be fooling yourself with incomplete data, do you?
12 February 2007 at 21:13
The good thing about the GCR theory is that it if NASA is correct about the cycle 25 slowdown,
GCR climate impact should be very testable within 15 years:
http://science.nasa.gov/headlines/y2006/10may_longrange.htm
12 February 2007 at 21:34
Re. Comment 18:
We need to know more about Galactic CR fluxes. The CR Isotope Spectrometer aboard the ACE satellite has for instance been collecting data at the L1 Point for less than ten years.
It may be that neutron monitoring on earth doesn’t provide the information required to establish a trend. It’s possible that a stonger solar magnetosphere preferentially shields the planet not only from certain energies but even elements & isotopes.
Neutrons are along for the ride with the protons in their nuclei, so may or may not be a valid indicator of the charged particles that actually make it through magnetic diversion, the ionosphere & stratosphere to the lower troposphere.
I hope the Danish team attempts to answer the questions you raised as steps in proof last year. The experimental work at CERN indicates they see the need to try in at least some cases.
12 February 2007 at 22:02
Off Topic, quick question:
What are your opinions (Gavin, David et al.) of Ahilleas Maurellis’ article from a few years back? I tried to research some commentary on it but could not find any…http://physicsweb.org/articles/world/16/5/7/1
Thanks, I love your site!
[Response: Mostly ok. There are a few odd statements (such as “Crude calculations suggest that the two effects approximately balance each other, and that water vapour does not have a strong feedback mechanism in the Earth’s climate” - don’t know where that comes from). However, the main hook, that there is ‘anomalous clear-sky absorbtion’ of solar radiation is no longer a big issue. As far as I recall, the anomaly was mostly associated with aerosol species rather than water vapour exotica. However, there are always ongoing improvements to the HITRAN database with respect to water vapour and so I wouldn’t want to be too dogmatic. -gavin]
12 February 2007 at 22:23
Re 33: Like you I’m a non-climatologists getting my head around all this. It’s a very complex field being addressed by hundreds of scientists who have created a vast body of evidence and interpretation. As will become clear if you look around the articles on this site and elsewhere; readings from the network of thermometer stations around the world are but a small portion of the data being collected, interpreted and used to model the planet’s climate system. And temperature is only one of many interrelated parameters or relevance. Many of the data sets that they are working with go back thousands, hundreds of thousands or even millions of years. Such data are derived from myriad sources including the analysis of the chemistry and structure of layers in polar ice cores, lake sediments, tree rings, stalactites and many many others. The international consensus on what the climate is doing is based on all this and much more, all fitted together to create a coherent picture of what the climate has done, is doing and is likely to do. The picture is not complete and is not perfect, and there are plenty of pundits on the sidelines trying to muddy the picture. But it’s fascinating to watch the climatologists at work, as they polish their theories, incorporating and taking advantage of the flood of new data. Check out the rest of this web-site. It’s really worth trying to get your head around it all.
12 February 2007 at 22:46
Following the GCR debate with great interest. A few questions:
1. Is it the RC view that Solar is essentially an 11 year cycle and that its longer cycles are essentially constant or minimal contrasted against GHG forcing?
[Response:No. There is clearly an 11 yr cycle of small amplitude, and there may be longer term irradiance variations - but there is no positive reason to think they are much larger. In the past, solar forcing may have been important (along with volcanic) on multidecadal to century timescales, however, GHG forcing over the last 50 years dwarfs any concievable solar contribution. -gavin]
2. Is any group trying to reconcile Milankovitch projections (which according to my limited knowlege never fully explained the data previously) in light of new understanding of GCR, i.e., Solar Attenuation?
[Response: I have no idea how these things could be connected. Orbital variations are very well understood and there is no reason to think that GCR changes should be affected by them.]
3. Can GCR be thought of as a stream that could have the analogy of swirls and eddies due to other solar bodies?
Thanks,
12 February 2007 at 23:00
In reply to response: [Response: We’ve done this to death, and sometimes we get bored too. If the argument is that cosmic rays are being modulated by the solar activity (which they clearly are on a 11 yr timescale), then I don’t see any reason why different energy bands will be trending differently than the ones monitored at CLIMAX. I would also point out that this is the same series used by Svensmark and others to demonstrate a cloud link in the first place. -gavin]
Planetary cloud cover can and is being reduced by the process “electroscavenging” which can and has occurred without modulation of GCR. (i.e. No change in CLIMAX, but planetary cloud cover is reduced.)(GCR creates ions which form the nucleous for cloud particles. Electroscavenging clears the cloud of the Ion-mediated Nucleous and causes rain.)
Electrosavenging is increasing due to an increase in the Global Electric current. The Global Electric current is increasing due to “the increased number of high speed streams of solar wind, that are occurring during the declining phase and minimum of sunspot cycle in the last decades.” (The solar southern coronal hole is moving towards the solar equator at the end of the solar cycle. The polar coronal hole is producing cyclic strong solar winds.)
It is a fact that overalll planetary cloud cover has been reduced from 1993 to 2003. See Palle’s attached paper which notes the cloud data is consistent with process “electroscavenging” and refers to Tinsley and Yu’s paper. Palle has written a second paper which use data from earthshine (reflected off of the moon) rather than satellite data which confirms this paper.
http://solar.njit.edu/preprints/palle1264.pdf
(See Tinsley and Yu’s attached paper, sections 5 a-e for details concerning the Global electric current and electroscavenging.)
http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf
Does this make sense? Two separate processes. GCR which creates ions, the ions created cloud nucleous and a separate process that clears and collects ions, hence forming rain.
[Response: ??? Try reading the papers you cite - Palle: “However, there is no clear systematic trend [in the ionization] since the 1960s.” (figure 7 caption). This is exactly what one would expect given the lack of trend in CLIMAX. If there is no trend in the input, you can’t get a trend in the output, whatever the mechanism! - gavin]
12 February 2007 at 23:16
In reply to “2. Is any group trying to reconcile Milankovitch projections (which according to my limited knowlege never fully explained the data previously) in light of new understanding of GCR”
Yes. The hypothesis is that earth’s magnetic field is modulate by the orbital cycle. The cyclic variations of the earth’s magnetic field cyclically modulates GCR which increases or decreases overall planetary cloud cover, which creates the ice age cycle. Also it is hypothesized that GCR cyclically changes in overall magnitude as the solar system moves through the Milky Way’s spiral arms.
http://arxiv.org/pdf/physics/0407005
[Response: You might want to ask yourself why this paper never made into the peer-reviewed literature. What is more likely - that the deposition 10Be is affected by climate changes associated with the ice ages (for instance Field et al, 2006 might be useful in assessing that), or that geomagnetic modulation of cosmic rays just happens to be coincident with Jun 60N insolation? (Bard and Frank, EPSL, 2006 is also another good source for why this is rubbish). -gavin]
12 February 2007 at 23:31
I do not understand your response: [Response: ??? Try reading the papers you cite - Palle: “However, there is no clear systematic trend [in the ionization] since the 1960s.” (figure 7 caption). This is exactly what one would expect given the lack of trend in CLIMAX. If there is no trend in the input, you can’t get a trend in the output, whatever the mechanism! - gavin]
The affect is due to an increase in the Global Electric Current, not GCR. What input at Climax are you referring to? The ions are still being produced. The electroscavenging process is removing them.
From Palle’s paper “Another explanation may be other climatic parameters are acting on cloudiness in addition to atmospheric ionization. A clear decreasing trend over approximately the past two decades is seen in both the total cloud amount … and low level cloud data. A simple linear fit to the yearly low cloud data has a slope of -0.065%/yr. If the this trend is subtracted from the low cloud data the correlation coefficient rises from 0.49 to 0.75, significant at the 99.5% level.
[Response: No trends in cloud cover are statistically significant given the uncertainties in the data and systematic issues with the satellite measurements. Why do you think there is an increase in ‘electroscavenging’? And what do you think is driving it? -gavin]
12 February 2007 at 23:40
I don’t know if this 2004 simulation finding climate change correlations with CO2 concentrations and GCR fluxes during the Paleozoic, Mesozic & Cenozoic has been cited yet. Haven’t read the whole article, so don’t know how the author derived inputs, to include cloud cover.
http://www.agu.org/pubs/crossref/2004/2003GC000683.shtml
12 February 2007 at 23:47
It’s all about the muons:
http://www2.slac.stanford.edu/vvc/cosmicrays/cratmos.html
13 February 2007 at 0:13
Are Milankovitch Cycles and other orbital variations of the earth commonly factored in to AGW climate models? Without a better understanding of cosmic radiation, I would imagine these variables are considered statistically insignificant, yes?
13 February 2007 at 0:30
Can anyone answer these questions, simply?
The Little Ice Age - real or not?
The lack of sunspots at the same time - real or not?
Is it a coincidence - yes or no?
13 February 2007 at 0:33
Re: #34 Al Bedo,
Hi, I’m GW-ish.
13 February 2007 at 0:42
Re: Ice Ages
There seems to be some suggestion that galactic cosmic rays are a root cause of ice ages, are modulated by earth’s orbital variations, related to Milankovitch cycles, etc.
The climate effect of orbital cycles has to do with the amount of solar energy intercepted by earth, not the output of the sun, and says nothing at all about variations in the sun.
Understanding the impact of astronomical cycles on paleoclimate is a rapidly advancing field, and our understanding of it is attaining a level of maturity which is very impressive. Those who know the details of the effects of orbital cycles cannot take seriously the suggestion that their impact is through modulation of GCRs. Those who suggest that such a phenomenon is real, cannot possibly have an understanding of the effect of orbital cycles on the distribution of solar energy.
This is yet another example of throwing out an interesting idea, which seems plausible until you actually learn something about the phenomenon. It reminds me of one of the most famous pseudo-science books of all time, Velikovsky’s Worlds in Collision, which attempted to explain world-shaking biblical events (like the plagues Moses brought upon the Egyptians) by astronomical events. It all sounded extremely convincing to those who were ignorant of the topics, but to those in the know it was pure fantasy, and not even very good fantasy. Astronomers would typically say “The biblical archeology was very impressive, but the astronomy is utter nonsense,” while archeologists would typically say, “The astronomy was fascinating, but the archeology is utter nonsense.”
For those who are interested in a few details of the effect of astronomical cycles, I’ve posted about the topic on my blog here and here.
13 February 2007 at 0:44
Re: Global dimming. Does Stanhill’s Forum piece (EOS 88,p 58, 2007) require any response from RC (beyond what I was able to find in previous posts?) He’s claiming a total 20 W/m^2 for 1958-1992. He does not mention the “urban effect” reported by Alpert et al (GRL 32, L17802, 2005); is that the issue?
Thanks
13 February 2007 at 0:45
Re: #44
The fastest orbital (Milankovitch) cycle affecting climate is the precession cycle, with a period never shorter than about 19,000 years. That’s much to slow to affect climate significantly on century-long timescales. Therefore their effect can be safetly ignored in AGW climate models.
13 February 2007 at 0:47
Why no, the people doing this work are totally unaware of such things!
Right?
That’s your basic point, yes? That scientists trying to understand AGW are librel, perhaps even commie, conspiracy people who don’t actually pay attention to stuff that appears in undergrad science textbooks.
Right?
13 February 2007 at 0:59
From the Oct 16, 2006 RC (Gavin’s?) analysis of Svensmark, et al:
“(Missing step #4). Finally, to show that cosmic rays were actually responsible for some part of the recent warming you would need to show that there was actually a decreasing trend in cosmic rays over recent decades - which is tricky, because there hasn’t been (see the figure)”
The figure comparing CR flux vs. temperature cuts a fine figure, but the CR measurement displayed is for neutrons. Muons are the relevant form of CR, since they’re implicated in cloud formation. In Svensmark’s 1999 article, it would be possible to draw a statistically justifiable slightly downward sloping line through his muon data, as detected by ionization chambers, 1937-1994 & shown in his Figure 3. I don’t know if it could be extended to 2006 at the same inclination.
http://www.dsri.dk/~hsv/new_sven0606.pdf
Suffice it to say that neutron detectors & muon measuring ionization chambers or telescopes show slightly different GCR fluxes. The muons are relevant, as per my prior probably overly cryptic comment & link to discussion of muons at the SLAC site.
However, it seems to me that Svensmark concentrates more on apparent correlation or coincidence of GCR & solar cycles than on trendlines over shorter time frames, such as 22 year cycle for the reversal of the Sun’s magnetic field, the ~11 year sunspot cycle & peak years within each cycle.
13 February 2007 at 1:00
Re: #45
Little Ice Age — probably real. Paleoclimate reconstructions (hockey sticks) show a cooler period from about 1450 to 1800, but the total cooling, even in the most highly-varying reconstructions (Moberg et al.), amounts to only about 0.5 deg.C, and in other reconstructions is much less. We’ve already seen more warming than that in just the last century.
Lack of sunspots at the same time — not so. Sunspot counts only begin in earnest in the mid-1600s; there have been a number of minima in sunspots counts (most notably the “Maunder minimu”) but the record shows large variations, not only during the “little ice age” but after that as well.
Coincidence — probably not. Solar forcing is known to be an important factor in climate change (contrary to contrarians, it is not ignored or underestimated by climate scientists), and may have been an important player in climate changes over the last few thousand years. But there are other players as well, most notably volcanic eruptions. Also, the changes in temperature in the last few thousand years are considerably smaller than what we’ve seen in the last century, and are vastly smaller than what we expect to see in the next century.
13 February 2007 at 1:25
Reply to Peter’s #45, then I’ll shut up.
The Little Ice Age - real or not?
Real. Period before & after a low in the 1690s was remarkably cold, certainly in a good chunk of the “temperate”, subarctic & arctic NH at the very least, as you must know. Googling produces copious excellent, coherent studies from disparate proxies & actual thermometer readings of various qualities. The early 19th century dip has been associated with Tambora blowing in 1815, of course but the secular trend was in any case cool until ~1850.
The lack of sunspots at the same time - real or not?
Maunder Minimum is well documented, despite imperfection of sunspot record in that period, generally assessed as 1645 to 1715, confirmed by C14 & Be10 data.
Is it a coincidence - yes or no?
It’s definitely a coincidence, but possibly not merely so. It could be a meaningful correlation. How significant, lots of work may soon be funded to determine. Are we at the beginning of a new paradigm shift, replacing 20 years of greenhouse gas AGW consensus building? Possibly. The climate itself in coming decades will help answer that & your questions, along with experimentation & rejiggered computer simulations.
Sunspots aren’t as scary as runaway CO2 feedback scenarios, but there should still be plenty of funding to keep paleoclimatologists, geophysicists & other climate & atmospheric scientists busy, maybe bringing more astrophysicists, statisticians & mathematicians into the fold well into the next 22 year solar magnetic cycle. Maybe by then we’ll be worrying about global cooling again, as in the 1970s, scanning the northern horizon for the advancing ice sheets.
Perhaps unsatisfactory replies.
13 February 2007 at 2:10
#18 Gavin comment : “we get bored too”
Whose fault ?
It appears there’s nothing new in Nigel Calder op-ed. So, does it deserve a discussion? And how could we expect new insights on these over-debated topics?
Before adressing GCR-nebulosity question, I suggest it would be more useful to get correct nebulosity climatologies. An article on what we know and don’t know from current measures (e.g. ISCCP, BSRN, ERBS, HIRS, AVHRR, etc.) would be interesting. IPCC AR4 mentions it as an “important develoment since the TAR”.
13 February 2007 at 2:24
All the contrarian theorists seem to have missed an important point, which is that while climate certainly is affected by solar variations, volcanic activity, and so on (maybe even cosmic rays, though as mentioned it’s hard to see how a lack of variation could produce climate changes), if you want to use any of these as a complete alternative model of current climate trends, you have a twofold problem. First, you have to incorporate your theory and data into some sort of model that gives results that match actual observations. Second, you have to find a way to explain why the measured increase in CO2 is _not_ producing the effects that theory and experiment predict it should.
As far as I can tell, very few have even tried to do the first, and almost nobody the second. Which to my way of thinking puts these theories into the same class as science-fictional “warp drives”: something thought up to get the result the author wants
13 February 2007 at 2:26
“Why no, the people doing this work are totally unaware of such things!
That scientists trying to understand AGW are librel, perhaps even commie, conspiracy people who don’t actually pay attention to stuff that appears in undergrad science textbooks.”
Actually, I’m generally interested in the concept of warming/cooling cycles and the variables which may drive them, as is Nigel Calder. But I’m also interested in whether of not Cognitive Dissonance is having a greater impact on bias in AGW science than hard evidence. It is my firm belief that c.d. is the greatest single psychological factor responsible for unintended bias in scientific experimentation - partially because it is as prevalent in highly educated people as it is in the common man.
And I’d like to thank Tamino for a quick honest answer.
13 February 2007 at 5:31
I thought that the term was GLOBAL WARMING and not LOCAL WARMING as was the MWP or LOCAL COOLING was LIA. Anyway the article is publiched in the daily telegraph (DT) here under one of the most viewed items.
http://www.telegraph.co.uk/news/main.jhtml;jsessionid=MVR0D2TLU54GPQFIQMGSFFWAVCBQWIV0?xml=/news/2007/02/11/warm11.xml
The DT is a well known right wing newspaper that seems to print all things climate skeptical, we remember Mr Monkston and Bob Carter don’t we. However they did print a rebuttal from Al Gore to Mr Monkston so fairs fair I suppose.
One thing that this article does suggest however is the notion of the little knowns in climate science, ice dynamics is one area I believe especially in the area of how fast ice sheets will move but I guess that real data can help here refine the mathematics. Cloud formation is another area as well as others. I mean is the uncertainty in the projected climate temperatures from slightly differing models due to little knowns in current climate science or by chaos theory (sensitivity to initial conditions that project out after a long period of time) perhaps. 1.5 to 4.5 Deg C even after a lot more spending is not that much more accurate than climate models run 20 years ago is it ?
Can we get more accurate climate models and if not then why not ?
I would also like to be told why CO2 levels of 700 or 900 ppm means no greater temperatures than 550 ppm which is what we are currently heading for by around 2090.
13 February 2007 at 6:37
#55
James, nobody thinks a solar contribution to climate change implies a non-contribution of GHGs.
Before creating new models, we may simply hope that present GCMs better cope with all climate forcings and parameters. Model intercomparisons is a good way for that. Is solar correctly implemented (even without the so hyped GCR effect, masked TSI trends, etc.)? A recent contribution of Raschke and al. (link thereafter) suggest a negative answer. I quote them :
“A careful intercomparison of recently released data sets on the radiation climatologies as computed in the projects ISCCP-FD and GEWEX-SRB showed considerable differences of more than 20 to 50 Wm-2 in monthly averages of radiation flux products at the top of the atmosphere (TOA) and at ground for large latitudinal zones covering up to 25% of the Earth’s surface.”
Raschke, E.; Kinne, S.; Gorgietta, M.; Uphoff, M.; Bakan, S.; Okamoto, H.
Inconsistencies of the incoming solar radiation boundary condition in global modeling
Abstracts at EGU General Assembly
CL40 Climate Models Intercomparison: Dynamics and Physical Processes :
http://www.cosis.net/members/meetings/sessions/accepted_contributions.php?p_id=237&s_id=4196&PHPSESSID=f29025fe7d71ae5f96d46ab2b26dfd6a
13 February 2007 at 7:13
Re 5 and 6
Interesting question. I couldn’t find the link but I think I read that this particular die off is disease related.
However it does beg the question if AGW is a stressor that makes individual species such as bees or corals more susceptible to disease in general.
However if you think modeling the complexities of climate is difficult you should talk to some biologists studying interconnected ecosystems, I think they’d tell you that modeling those systems is a couple of orders of magnitude more difficult.
Based on some of the opinions I have read here and elsewhere it seems that gleaning information from such models is probably a useless excersise since the current models are probably not sophisticated enough and there is just too much we don’t know. So let’s roll up our sleeves and get back to chopping and burning down the forests shall we.
13 February 2007 at 7:39
It’s hard to see how to reconcile the sine/cosine style pulse of the cosmic ray record with the steady increase in temps. If there’s any effect at all, it has to be real tiny because it’s getting swamped by the effect of greenhouse gases.
13 February 2007 at 7:46
James (55). A response to your challenges is quite easy. As an experienced computer modeller (albeit not of climate), I know it is easy to produce “some sort of model” to show pretty well anything you want. The climate models (as with most computer models) are highly sensitive to the assumptions made by those who develop them. Models are not proof, although a very useful tool for those who can use them with honesty and integrity. With regard to AGW theory, this predicts an accelerating rise in temperatures. In contrast, the trend has not increased since at least 2002 (some would say 1998). While AGW advocates can come up with explanations why there is currently no rising trend (despite having the highest CO2 emission rates ever), you cannot deny that this is a mismatch to the theory.
[Response: Maybe you’d care to point us to the publication that predicts that temperatures must increase year on year in AGW simulations? Or the model run that says that interannual variability vanishes once CO2 reaches 380ppm? The first step in testing a theory is being clear about what is predicted. -gavin]
13 February 2007 at 7:54
I’ve been arguing this very story on slashdot for a day or so, thanks for tackling it head on.
One minor but I think important point: After posting the “Taking cosmic rays for a spin” story as comment on slashdot several replies said it does not adequately state what is wrong with the CR - climate change link, and I think they have a fair point.
A much stronger (and more civil) argument is made by this RC story. Only a suggestion but you might want to add the link to this article while it’s still fresh.
13 February 2007 at 8:17
#56 Is cognitive dissonance a problem?
The nice thing about science is that it provides a way around cognitive dissonance (the experiment). Dream up any theory you like, if it doesn’t fit the experimental data, CD won’t save you.
If anybody has a CD problem, clearly it’s the contrarians, as they are ignoring tons of evidence. On top of that, they are (in effect) denying the basic mechanism:
1- CO2 traps heat (known since more than a century)
2- We are putting lots of CO2 into the atmosphere (undisputed)
3- The temperature goes up (and lo and behold, that what we see)
That is, warming is to be expected: we should be very surprised if there were NO warming.
13 February 2007 at 8:23
then I don’t see any reason why different energy bands will be trending differently than the ones monitored at CLIMAX.
Well, the lower energy GCRs should be more strongly modulated than the more energetic GCRs (since interplanetary magnetic fields in the solar wind and at the heliopause affect the former more strongly than the latter), but I agree I don’t see why the trends should be qualitatively different. If anything, the signal should be stronger in the lower energy GCRs than in the higher.
Isotope evidence (10Be, 14C) is, I imagine, more of a proxy for the lower energy GCRs than the energetic ones that make muons that can reach low alitudes, since the flux of the former is much greater. I hope none of the contrarians are touting this evidence to support a theory that involves higher energy GCRs while dismissing the recent neutron data.
If there really is a connection between GCRs and cloudiness, it offers the possibility of new geoengineering approaches to mitigating global warming. The total energy in cosmic rays hitting the Earth isn’t all that large (and even less in the more energetic ones), so it’s conceivable it could be artificially enhanced with accelerators in space. A whacky idea, but amusing to consider.
13 February 2007 at 10:24
This is great! If true, it would mean we can expect some cooling when the rays decrease. Of course, until it’s proven to be the only cause of GW (and GHGs have no noticible impact), then we do still have to keep reducing our GHGs….in fact, it just makes economic & (other) environmental sense to reduce our GHGs whatever the situation re GW.
As for funds to conduct research, have they tried Exxon? Or is it that even Exxon has serious doubts about their research.
13 February 2007 at 10:30
Re: Dick V (62)
I trust most readers can see the irony in the following statement by DV:
“If anybody has a CD problem, clearly it’s the contrarians, as they are ignoring tons of evidence. On top of that, they are (in effect) denying the basic mechanism:”
While I respect the right of AGW advocates to have their views (hopefully derived from an assessment of the arguments rather than blind faith, or the naive emotion of seeing photos of polar bears standing on melting ice), there are too many AGW zealots who happen to ignore “tons” of uncertainty, arriving at the nonsensical view that ‘the argument is settled’.
As for ‘denying the mechanism’, I think there are very few who would deny the theory. The issue is whether the mechanism is significant. We emit many pollutants and do many things that impact on our environment, but this does not automatically mean they have a significant or devastating impact. It is my view, having followed and assesed the arguments closely for years, that the case for AGW is far from made - and I am far from alone (even if I may feel in a minority). The debate lives on!
13 February 2007 at 10:58
It might seem an obvious question, but would clearer skies make for warmer weather and visa versa clouds make it cooler as Svensmark asserts?
13 February 2007 at 11:00
Simple question from the back row. If the sun and cosmic radiation have nothing to do with global warming then what exactly caused global warming in prehistory? Please email me with the answer so I can understand why climate change now has to be caused by man and cannot be caused by factors beyond our control. Does this mean that once man controls his excesses there will be no more climate change?
13 February 2007 at 11:18
RE # 66
PHE you said:
[there are too many AGW zealots who happen to ignore “tons” of uncertainty, arriving at the nonsensical view that ‘the argument is settled’.]
That raises several questions and begs clarification.
Do YOU really measure scientific reports and analyses “of uncertainty” in “tons”? How about a pound or two of actual peer-reviewed, published reports on uncertainty so that we can all digest their content and come to the same or similar conclusions as you? Give us links and titles so we can read what you are reading.
As regards zealots, I hope you can differentiate zealots from scientists and well read lay persons who contribute to RealClimate. I agree that photos of stranded polar bears will not cause Texas Utilities to reassess plans to construct 11 coal-burning power plants. But Australian drought is being measured in lost economic growth for 2006 and honest scientists there are projection more of the same and worse.
If you are a parent, you might reconsider your watch and wait attitude. Might be there are more things to take into consideration than your uneasy feeling about the preponderance of evidence that your approach spells hurt for future generations.
Maybe the reason you feel in a minority is you lack the ability to process and act upon information that challenges your comfort level.
13 February 2007 at 11:32
Lets look at it this way……If the earth was the size of a roughly a large house, a supertanker is visible as a miilimeter sized sliver moving along the ocean. Taking into effect all the stored carbon released the past 200 or so years from all the industrial revolution factories, would it impact this large ball? Decidedly, yes. If I smoke a cigar in a large room, will the people coming in an hour later detect this stench? Again, the answer is yes. The anomoly here is not this sphere with all inside it, it is the impact the human inhabitants are making on it.
13 February 2007 at 11:38
There was a book I read as a child, which had an enormous impact on me, and drove me to decide to major in Geophysics. The name of the book was “The Restless Earth.”
13 February 2007 at 11:49
Any veteran inquisitive scientist trying out a new Chinese restaurant can try out the hot and sour soup, and depending on it being to his or her liking or not, can make certain inferences about the rest of the meal. And so it is with the carbon spike in the earth’s atmosphere and what future implications one can infer from this spike. I for one am guilty of being innocent of going with my intuition, but am learning to go with the facts presented before me, and sanely and intelligently putting aside my emotions and innocent intuition and embracing the facts. Two things I know……There is no Santa Claus, and the earth is heating up due to man’s poor stewardship.
13 February 2007 at 11:55
To reply to gavin’s challenge in no. 61:
I don’t suggest that temperatures must increase year-on-year, or that there should be no interannual variability. The theory predicts that temperature will rise as CO2 rises. We know that the rates of CO2 emissions are increasing year-on-year and that atmospheric CO2 concentrations are rising steeply now compared to the first half of 20th century (AR4 Fig SPM-1). It is difficult to reconcile this evidence with (i) the much greater IPCC certainty that AGW is significant and (ii) that the rate of temperature rise has reduced in the last 5 to 10 years (AR4 fig SPM-3) rather than giving any sense of an increasing rate to match the CO2 trend.
13 February 2007 at 12:30
On the doubling (or not) of the Sun’s coronal magnetic field in the past 100 years (Lockwood, et al, 1999, from Nature, cited below), there is now a decent body of research from around the world, both confirming & denying this finding in all or part.
http://www.nature.com/nature/journal/v399/n6735/abs/399437a0.html
For reconstruction of early 20th Century IMF:
http://www.springerlink.com/content/m2667×314012646h/
For some at least partially contrary findings or analysis:
http://adsabs.harvard.edu/abs/2001AGUSM..SH52A02L
http://www.copernicus.org/icrc/papers/ici6227_p.pdf
Other discussion readily Goggleable.
Should a secular increase in IMF be shown, it would of course remain to be demonstrated what observable or plausibly reconstructible effect this had on some parts or all of our planet.
While muon flux as measured far above, just above, at or below the earth’s surface may or may not show a downtrend globally, this could be an experimental artifact, as the record isn’t geographically complete or temporally long enough. There could be regional effects, perhaps related to the solar & terrestrial magnetic fields, like the auroras.
As is usually the case, we need to know more. Or at least I do. Maybe someone else doesn’t.
[Response: So what is the positive evidence that muon flux has changed in recent decades? It’s not sufficient to assert that it might have done and so there might be an unquantified effect on climate. Occam’s razor starts to come into play here…. - gavin]
13 February 2007 at 12:34
RE: #73 - As with all systems, the bugaboo in the stability analysis is the parasitics. Do they result in an asymptotic situation, where, when you approach the “safe operating envelope,” the parasitics result in a “fold back” innately due to their increasing contribution to energy dissipation? Or are they more in the realm of something that adds to the main “control loop” and results in a “runaway” situation? The prevailing theory of the orthodoxy appears to be something like the latter, albeit on a limited scale (for example, the “runaway” in this case would not be at the total system level but only within the behavior of the parasitic terms, resulting in a new “higher equilibrium”). My own experiences with complex systems suggest that as you scale, the sorts of mechanisms that might result in a complete system runaway or even a runaway of some parasitic term across the system, become more and more implausible. That’s because with increasing scale and complexity, the opportunities for loss of efficiency and internally dissipative mechanisms increase. Consider grid lock.
13 February 2007 at 12:49
#63 DV,
What you are saying seems to me to be a big part one of two of why there is a debate:
Part one:
1- CO2 traps heat (known since more than a century)
2- We are putting lots of CO2 into the atmosphere (undisputed)
3- The temperature goes up (and lo and behold, that what we see)
That is, warming is to be expected: we should be very surprised if there were NO warming.
This makes sense, but raises the question - is the AGW consensus based on assigning the observed warming to GHG’s primarily? Do I have this right?
And, if other forcing factors are discovered, wouldn’t we have to remove some of the correlated value assigned to GHG’s? And, if the other forcing factors are cyclical and likely to turn down eventually, doesn’t this mean that some long term projections for AGW effects have to be revised?
As to part two:
I ask these questions because, I’m not a scientist, but I believe the recommendation is to reduce GHG emission by 50% over some period (soon). Given that fossil fuel energy is a huge driver of the global economy, I think it behooves all of us to examine the projections carefully.
From what I can interpret in the SPM Radiative Forcing Chart, there is what looks to me to be a lot of uncertainty regarding cloud cooling and its interaction with aerosols. Does this relate to the debate over GCR or is it a separate issue? Or to rephrase that, can aerosols and GCR both be factors that when better understood will remove the uncertainty depicted in the SPM?
13 February 2007 at 12:54
Those interested in Solar contributions and cosmic rays should review the comments by Nir Shaviv and Gavin at RealClimate: http://www.realclimate.org/index.php/archives/2006/05/thank-you-for-emitting/#comment-13470
13 February 2007 at 13:19
Am I missing something obvious here? How can total cosmic rays be inferred from neutron monitors? A neutron is uncharged so you wouldn’t expect any variation corresponding to changes in the solar magnetic field. The charged particles obviously would be affected.
13 February 2007 at 13:21
A reply to PHE (#73): First, the graph you actually want to compare the temperature trend to is the calculated total forcing (made up of GHG concentrations - CO2, CH4, N2O, etc. - and aerosol forcing). CO2 may be the largest contributor to forcing, but it is not the only one. Methane at least has hit a plateau for the last decade, though it is not obvious if this is a temporary pause or a long term one. But my guess is that the total forcing will follow a roughly linear trend for the past couple decades. (And in fact, even for just CO2, because of the logarithmic relationship of concentration to forcing, you expect a linear forcing trend from an accelerating emission trend)
Second: You are microanalyzing short term trends in what is a long term phenomena. It might be interesting for you to take said forcing graph, assume that temperature scales exactly proportionally, but then add “noise” to the temperature plot. Run this 100 times. For a decent number of cases even if the underlying equation is accelerating you’ll still get a temporary reduced rate of rise in the last few years. One outlier (like 1998) can make a large difference in any short term analysis.
13 February 2007 at 13:40
Re” #68
I presume you’re asking about what caused global warming during the ice ages.
Small changes in the orbit of the earth, and in the tilt of earth’s axis, can cause sizeable changes in the distribution of incoming sunlight. Greater axial tilt, for example, causes more solar energy to reach the polar regions while less reaches the tropics, and this can lead directly to the decay of ice sheets near the poles.
When the ice sheets shrink, this reduces the earth’s overall reflectivity (ice is highly reflective but land and sea are not). This causes more incoming solar energy to be absorbed into the climate system rather than reflected back to space, and this warms the planet as a whole.
When the planet warms, so do the oceans. Warmer oceans will hold less CO2, so that CO2 leaves the oceans and enters the atmosphere. Since CO2 is a greenhouse gas, this warms the planet even more. This causes more reduction in ice sheets, more CO2 released from ocean to atmosphere, which in turn causes more warming, etc… a classic “feedback mechanism.”
For a few more details and some graphs, see the links in my previous post #47.
These astronomically-related factors are very slow; the fastest cycle is precession, changes in the orientation of earth’s axis relative to perihelion (the point of closest approach to the sun), and this cycle is never less than about 19,000 years. So, they’re much to slow to explain modern global warming, which is very rapid — about twenty times faster than the warming rate during a reasonably rapid deglaciation.
If we reverse our climate-changing activities, there will still be natural climate change. But if the past is any indication, it will be slow enough that we’ll have plenty of time to adapt.
13 February 2007 at 13:42
I just read Wong et al. 2006 (thereafter). Between 1980s and 1990s, their best estimate for TOA radiative flux over Tropics (20°N-20°S) is +0,7 W/m2 for LW and -2,1 W/m2 for SW. The later number implies a significant downward trend of albedo (probably nebulosity). More insolation leads to more ocean heat content, I suppose, and more energy to be redistributed from tropics to pole. Could we expect this decadal radiative trend is involved in the 90’s warming?
PS : if the ERBS measure is correct, it doesn’t plead in favour of Lindzen Iris effect, as Wong et al. conclude.
Wong, T., B. A. Wielicki, R. B. Lee, III, G. L. Smith, K. A. Bush, and J. K. Willis, 2006: Re-examination of the Observed Decadal Variability of Earth Radiation Budget using Altitude-corrected ERBE/ERBS Nonscanner WFOV data. J. Climate, 19, 4028-4040.
Downloadable at Wong page :
http://asd-www.larc.nasa.gov/~tak/wong/f-publications.html
13 February 2007 at 13:53
[[It is my view, having followed and assesed the arguments closely for years, that the case for AGW is far from made - and I am far from alone (even if I may feel in a minority). ]]
A distinct minority, especially among climatologists. Rather like those who still hold out hope for Einstein to be wrong about relativity. There are some of them, too, and they’d be quick to tell you the case for AGW is far from made.
13 February 2007 at 13:55
[[Simple question from the back row. If the sun and cosmic radiation have nothing to do with global warming then what exactly caused global warming in prehistory? Please email me with the answer so I can understand why climate change now has to be caused by man and cannot be caused by factors beyond our control. Does this mean that once man controls his excesses there will be no more climate change? ]]
Nobody ever said manmade CO2 was the one and only possible cause of climate change. There are many things that have changed the climate in the past, and there are many things affecting it now. But the main item driving the present warming is manmade CO2. In short, your argument is a straw man.
13 February 2007 at 13:57
Reply to #78:
As has been discussed here previously, neutrons are not the best indicator of total GCR, but more importantly are inappropriate for climatic studies. Muons are implicated in cloud formation, as shown in my SLAC link in comment #43.
The solar coronary magnetic field (IMF) does seem to have increased in the past hundred years. I posted objections to Lockwood’s assessment of doubling, but these researchers present a graph which appears to confirm it:
http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU2004_IAUS223%2FS1743921304006817a.pdf&code=a73460a442553c154786ecfec8f757c2
It might not be possible to download the IAU article from this link. If not, please if interested Google “reconstruction open solar magnetic field 19th 20th centuries ivanov miletsky” or some portion of these keywords. The authors reconstruct the IMF since 1844 & 1915.
13 February 2007 at 13:58
[[I don’t suggest that temperatures must increase year-on-year, or that there should be no interannual variability. The theory predicts that temperature will rise as CO2 rises. We know that the rates of CO2 emissions are increasing year-on-year and that atmospheric CO2 concentrations are rising steeply now compared to the first half of 20th century (AR4 Fig SPM-1). It is difficult to reconcile this evidence with (i) the much greater IPCC certainty that AGW is significant and (ii) that the rate of temperature rise has reduced in the last 5 to 10 years (AR4 fig SPM-3) rather than giving any sense of an increasing rate to match the CO2 trend. ]]
I’d recommend a good course in statistics. You are trying to generalize from a sample of 5-10 years. The warming has been going on for over 100 years, though the most recent phase of it has lasted about 30. Mean global annual surface temperatures are a random walk around a steadily increasing mean.
13 February 2007 at 14:02
#89 Tamino, I agree with your description with just some questions about ocean cooling / warming link to CO2 atmospheric rise during glacial/interglacial transition. As there is no change in total solar forcing (just an orbital/regional one centered on Northern Hemisphere, not on Southern oceans) and as there’s a great thermal inertia for oceans, how do we explain the relatively high and fast increase of CO2? Shouldn’t we expect a millienium rather than secular lag between Milankovitch forcing and CO2 response?
13 February 2007 at 14:04
[[This makes sense, but raises the question - is the AGW consensus based on assigning the observed warming to GHG’s primarily? ]]
The climatologists don’t arbitrarily “assign” the warming to GHGs. They calculate it on physics grounds and then see if the evidence matches the prediction.
13 February 2007 at 14:05
Re 61, 73
These are both pattern-matching arguments: that the temperature curve should mimic the shape of CO2 emissions or concentrations. Even if you neglect noise, which exists on many time scales, such expectations are incorrect. They ignore both the nonlinearities (e.g. forcing is proportional to log(concentration)) and the dynamics of the system (temperature is two integrations removed from emissions: CO2 must accumulate in the atmosphere, and the heat from the resulting forcing must accumulate in the atmosphere and ocean). To make a serious claim that reality and models are diverging, one must at least account for the basic physics and forcings of the system. A suitable model could fit on a napkin - the ball is in your court.
13 February 2007 at 14:19
Concerning New Scientist 10th Feb 2007 edition (Vol 193, No. 2590) and its alarmist out of breath “This Week: Climate Change” article by (probably) Fred Pearce : a figure on page 9 is really the culmination of “immoral” alarmism: a graphical illustration tells about “the sun versus humans” and wants to depict the difference between the “natural solar radiation” (they forget to say: the increase of …) and human caused radiative forcing. According to the SPM this is about 1.6 W/m2 to 0.12 W/m2 (lets not discuss this here), so the relationship is about 13 to 1; the illustration draws a very tiny solar disk and a huge man-made-effects disk suggesting a 269 to 1 relationship (when you draw disks, please do not expect that the visual clue is to compare the diameters! it’s the surface, stupid!). [edit]
13 February 2007 at 14:42
Re #66
PHE,
Apparently I was not clear enough in my post (apologies). What I meant was the following: suppose somebody has a theory in which phenomenon X is the cause of (most of) global warming - then clearly the burden is on him to provide an argument why the expected warming due to GHGs is NOT there, or is far less than we think it is (see post #55). If he doesn’t do that, he is in fact denying the basic greenhouse gas warming mechanism (of which we know it’s there).
As regards to how much different things contribute: personally I am impressed by how well current theory (embodied in models) reproduces measurements quantatively. It seems to me that GHGs (+ aerosols and a few other things) pretty much explain all observed warming.
Does that end all debate? Of course not, I just think that more than enough evidence is in to make an informed decision on mitigating policies now.
13 February 2007 at 14:43
The Svensmark paper was interesting and innovative. However, it ignores the fact that there seems to be no measurable decrease in GCR flux in the 30 years we’ve had measures of it by satellites. I’ve looked at the GOES data myself, and the modulation over solar cycle stands out clearly, but there is no lont-term trend. Conversely, the solar-cycle modulation, which is a factor of 3-5 in GCR flux over 11 years does not seem to influence weather that much.
Look, if someone could come up with a forcing mechanism that could explain the trends other than anthropogenic CO2, nobody would be happier than me. However, no one has proposed a mechanism that is even plausible.
So, on the one hand, we have a mechanism that explains the trends pretty nicely and that we know is present and we have no competing hypothesis that approaches credibility. To reject a perfectly good model simply because you don’t like the implications is simply anti-scientific. If your opposition is to the policies that you think may be implemented, the place to get involved is at the policy level.
13 February 2007 at 15:09
Re #76
JD Will,
[This makes sense, but raises the question - is the AGW consensus based on assigning the observed warming to GHG’s primarily? Do I have this right?] I agree with Barton in #87: my understanding is that scientists don’t “assign” warming to GHGs to make predictions fit observed temperature rise: how much warming some GHG causes is determined in independent experiments.
[Cloud cooling and aerosols] I am really not qualified to answer this one. We’ll have to ask the good folks at RC.
13 February 2007 at 15:19
>78 “… How can total cosmic rays be inferred from neutron …”
Here’s a start:
http://scholar.google.com/scholar?sourceid=Mozilla-search&q=neutron+%2B%22cosmic+ray%22+%2Bmonitor
13 February 2007 at 15:46
This is the wrong topic I know, but was curious about this article: http://www.sciencemag.org/cgi/content/abstract/1138478v1
Since I can’t read Science I’m a bit curious to know what impact this have on the dynamic part of the modelling on glaciers. A step back to around 2001 or is there still evidence that the melting goes faster?
13 February 2007 at 15:51
Calder is also making the argument that there are warming/cooling cycles in increments much smaller than 19,000 years - based on extensive historical evidence he claims is largely ignored by the AGW community. I don’t know that the book will cover such evidence, but want to read it before jumping to conclusions.
13 February 2007 at 16:06
Interesting in the article about the California frost. I remember that thread about the January heatwave.In the NCDC website it said that while last month the eastern USA was a lot warmer than average the West was a lost colder. An average month?
13 February 2007 at 16:17
#90
“I just think that more than enough evidence is in to make an informed decision on mitigating policies now”
Do we know if GHGs count for 50, 70, 90% of the last decades warming? No. Do we know if climate sensitivity is definitely constrained to 2-4,5 K and which value is really the most convincing? No.
Precaution principle probably commits us to take policy decisions, but I don’t think policymakers are better informed in 2007 than in 2001. Just look at low and high extremes of range for 2100 projections : 1,1-2,4 K versus 2,9-6,4 K. In the first case, a not so damaging warming for which adaptation would probably be a better option. In the second case, catastrophic warming against which a drastic and urgent reduction of GHGs emissions is needed.
13 February 2007 at 16:22
Reply to #91:
Ray comments that Svensmark “ignores the fact that there seems to be no measurable decrease in GCR flux in the 30 years we’ve had measures of it by satellites. I’ve looked at the GOES data myself, and the modulation over solar cycle stands out clearly, but there is no long-term trend. Conversely, the solar-cycle modulation, which is a factor of 3-5 in GCR flux over 11 years does not seem to influence weather that much.”
What matters is muon flux in the lower atmosphere, more than overall flux in space. We don’t have a good record of that, but what we do showed an anomalous low in the ’90s followed by a lower than average high, but as Ray points out, in the regular pattern. A downtrend could be drawn through the data points. The muon series probably isn’t long enough, with adequate geographic coverage or even reliable enough upon which to base a firm conclusion.
There does seem to be or at least arguably is a detectable or reconstructible increase in solar IMF since the mid-19th century, so it’s not unreasonable to assume some effect from this on GCR in general & muon flux in particular. We may not have the capability now & surely not in the past to measure whether such modulation actually occurred or is occurring. We may however be able to infer it from future climatic observations, in lieu of other persuasive explanations, should earth not experience the changes forecast in AGW scenarios.
“Look, if someone could come up with a forcing mechanism that could explain the trends other than anthropogenic CO2, nobody would be happier than me. However, no one has proposed a mechanism that is even plausible.”
I feel that GCR forcing via nebulosity is at least a plausible mechanism, more readily subject to testing than AGW.
“So, on the one hand, we have a mechanism that explains the trends pretty nicely and that we know is present and we have no competing hypothesis that approaches credibility. To reject a perfectly good model simply because you don’t like the implications is simply anti-scientific. If your opposition is to the policies that you think may be implemented, the place to get involved is at the policy level.”
You probably know reputable atmospheric scientists who would not agree that AGW is a perfectly good model & that there are credible competing hypotheses, if not personally, then through their work. I do.
Few would doubt that human activity has had no effect on climate change. Ruddiman thinks it has for thousands of years. Life has had profound effect on climate, the land, sea & atmosphere for billions of years. The moot question to me is what part of observed climate change (setting aside the issue of how valid the observations, reconstructions & modeling may be) is anthropogenic & how much attributable to natural causes, which may be unknowable. Someone may be smart enough to know all of them, but I’m not.
I’d feel more comfortable with AGW if the atmosphere had detectably warmed up before & more than the land & sea, & if other causes could not produce the same responses generally cited as proof of AGW via the greenhouse effect. Even with the most extreme adjustments to satellite & balloon data, it appears last I checked that the areas that should have warmed first & most haven’t. Please correct me if wrong.
I am already involved on the policy level. There are good reasons to be concerned about burning fossil fuels, regardless of how much weight you give to AGW computer simulations.
13 February 2007 at 16:32
Re JLMcC (69) ‘Tons’ was taken ironically from the words of Dick Veldkamp. A good reference on AGW uncertainties is IPCC TAR. Look at the sicence rather than the Summary [by] policymakers. As many here will tell you, one year/drought doesn’t make a rule (see gavin’s response to my comments). I have two young children, and what I recognise is that they now have the best prospects in the history of mankind - in life expectancy, healthcare, world peace, prosperity, etc. And we (in the developed world) are doing a pretty good of balancing our prosperity with environmental protection. I am what many Americans would derogatarily call a ‘liberal’. I am an environmentalist, but also a rational scientist who despairs at the distortion and misuse of science as I see in the ‘case’ for AGW.
Re Steve Sadlov (75). I like your satire.
Re Marcus (79) The graph I had in mind on Fig SPM-1 was the inset in the top graph which shows the rise in CO2 since about 1750. Nothing more complicated than that.
Re BPL (82). I suppose if scientific truth was based on a vote, you’d win. [edit - no politics]. The ridiculed minority are not necessarily wrong. That’s why its important to carefully assess the facts and feel the need to be convinced ‘yourself’ rather than to go with your heart, the flow, the popular view, etc.
Re BPL (85) You don’t need to convince me to be wary of short term data. First, direct it at all those who argue the current drought in Australia, Hurricane Katrina, the current mild winter in Europe, etc, are due to AGW. Second, try the AR4 Summary [by] Policymakers which argues the rate of sea level rise is increasing (1993-2003 compared to 1961-2003)when a look at their own Fig SPM-3 shows this is nothing more than selective statisitcs.
Re T. Fiddaman (88) I do not expect the absence of noise. My comments were intended to be ironic. Its the AGW advocates who seem to argue that a simple correlation between CO2 rise and temperature between (just) 1976 and 1998 (just 22 years!) is sufficient to claim impending doom. The only other period of 20th century temperature rise (1910 to 45) was at a time when CO2 emissions and levels were much lower and which IPCC TAR (amongst others) claims was due to natural effects. Individual droughts, hurricanes, mild winters are the natural noise that don’t make the rule. AGW advocates have not convincingly demonstrated that the current global temperature or rising trend is anything more than long period ‘noise’.
Re. D. Veldkamp (90) With regard to who has the burden of proof: whatever the theories, there is no convincing evidence that (i) current temperatures are exceptional in human history (ii) that the rate of rise is exceptional (almost identical to 1st half of 20th Century (iii) that the climate is currently undergoing exceptional change (though it is currently warming) (iv) that predictions of rising trends are anything more than an extrapolation of the present trend combined with the ASSUMPTION that CO2 is the cause, or (v) that rising temperatures will cause the postulated disasters. You will no doubt be convinced that all this is ‘obvious’ and proven. I recommend, however that you rely more on the science of AR4 (when it is published) and of others, than on the ‘medievel-style’ headlines of ‘the end of the world is nigh’ (Nothing new there then. While the climate continually changes, human nature changes little)
I hate long postings. I normally get bored well before the end.
13 February 2007 at 16:47
Re #95: Edward Barkley — Climate changes on many time scales. I suggest you read W.F. Ruddiman’s “Earth’s Climate: Past and Future” which is actually organized via the different time scales.
13 February 2007 at 17:26
Have you seen this [edited]? The part about icebergs can’t be calving and receding is pure bs. How to stamp out that book?
13 February 2007 at 18:00
Re #58: Charles, when I see results of the sort you quoted the first question I ask myself is whether the authors of the study have offered an opinion as to its significance. Since abstracts are often written with other people in the field in mind as the sole audience, often no such opinion is included. Fortunately, in the case you quoted the authors noted: “There is a need to understand and eliminate these solar irradiance inconsistencies in modeling (even though their overall impact is expected to be minor in comparison to impacts from inconsistencies introduced by the representation of clouds).” Bear in mind that there literally hundreds of papers published evey year with regard to needed improvements to the GCMs.
13 February 2007 at 18:05
Magnus, the Howat article is extensively blogged over at the NYT, here:
February 8, 2007 — Greenlandâ��s Glaciers Take a Breather –By John Tierney
http://tierneylab.blogs.nytimes.com/2007/02/08/greenlands-glaciers-take-a-breather/#more-29
I hoped to find a science journalist in the comments; none yet. I added links to a full text related 2005 paper from the same author, and one from Lamont-Doherty from 2006.
13 February 2007 at 18:16
#56, even if there were cognitive dissonance, and somehow the whole AGW thing were overestimated or a farce, at least the error is in the right direction, bec the solutions to GW actually help the economy.
A lethally wrong direction error would be to assume AGW is not happening, when in deed it is happening.
So, if anyone can prove beyond a shadow of a doubt that AGW is not happening, then, well, I’ll still keep on reducing my GHGs, because it’s saving me money to do so & reducing many other harms, and, who knows, we may just need those fossil fuels when the earth starts in on a natural cooling cycle who-knows-when.
13 February 2007 at 18:26
I believe the consensus of this thread is that Svensmark’s cosmic ray/climate correlation is indeed something to take into account.
I declare “the science is settled.”
We must now introduce a new world protocol agreement to mitigate/slow cosmic rays.
13 February 2007 at 18:30
Re:98. So what do you think drives the muon production if it isn’t the GCR–in particularly the moderate to high energy portion above the magnetic cutoff?
As to your list of dissenting atmospheric scientists, shall we start with you naming 10 that regularly publish in relevant, peer-reviewed journals and seriously question the importance of anthropogenic mechanisms?
The UAH group has had to backtrack quite a bit on their satellite/balloon discrepancy. It is still nonzero, but MUCH smaller. I don’t think you can view this as a serious discrepancy at this point. Moreover, why should it surprise you so much that the insulator is at a lower temperature than the source of the IR.
13 February 2007 at 18:40
RE #67 & 76, I know nothing about clouds & GW, but I think I read somewhere that some types of clouds lead to cooling and some to warming (I think the high whispy strat ones, or is it the other way around?).
Of course, that’s during the day when the sun is shining. I imagine at night, none of the clouds would contribute to further cooling, and it seems to me they all (to various degrees) might contribute to warming — the cloud “blanket-effect,” especially the ones that look like goose-down comforters. I guess I should eventually read some books on GW.
13 February 2007 at 18:56
For those, like PHE #99 who state that the recent rise in temperature is almost identical to the first half of the twentieth century, I recommend a look at today’s posting in the Nasa Earth Observatory: http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3
13 February 2007 at 19:23
Edward Barkley wrote
I’d suggest people quit invoking “cognitive dissonance” when they mean something like “ignoring an inconvenient view”. Cognitive dissonance means nothing of the sort. Wikipedia has a decent summary:
When people carelessly use “cognitive dissonance” in discussions like this, they actually mean something like Piagetian assimilation. Assimilation is the process of altering or distorting perceptions of incoming stimuli in order to make the input fit into pre-existing cognitive schemata, while accommodation is the process of altering the schemata to take account of new data. Someone who systematically ignores contrary data illustrates the triumph of assimilation over accommodation, cognitive rigidity over learning.
13 February 2007 at 19:57
Re 105: John, can I recommend a good dictionary for you?
13 February 2007 at 20:02
In reference to 108, that 2006 was the fifth warmest year, I note that the GISS data has diverged considerably from the HadCRUT3 data set in recent years.
And the GISS dataset is VERY different than the raw, unadjusted GISS temperature readings.
http://hadobs.metoffice.com/hadc