UPDATED: This opinion piece from Professor Henrik Svensmark was published September 9th in the Danish newspaper Jyllands-Posten. Originally the translation was from Google translation with some post translation cleanup of jumbled words or phrases by myself. Now as of Sept 12, the translation is by Nigel Calder. Hat tip to Carsten Arnholm of Norway for bringing this to my attention and especially for translation facilitation by Ágúst H Bjarnason – Anthony
Translation approved by Henrik Svensmark
While the Sun sleeps
Henrik Svensmark, Professor, Technical University of Denmark, Copenhagen
“In fact global warming has stopped and a cooling is beginning. No climate model has predicted a cooling of the Earth – quite the contrary. And this means that the projections of future climate are unreliable,” writes Henrik Svensmark.
The star that keeps us alive has, over the last few years, been almost free of sunspots, which are the usual signs of the Sun’s magnetic activity. Last week [4 September 2009] the scientific team behind the satellite SOHO (Solar and Heliospheric Observatory) reported, “It is likely that the current year’s number of blank days will be the longest in about 100 years.” Everything indicates that the Sun is going into some kind of hibernation, and the obvious question is what significance that has for us on Earth.
If you ask the Intergovernmental Panel on Climate Change (IPCC) which represents the current consensus on climate change, the answer is a reassuring “nothing”. But history and recent research suggest that is probably completely wrong. Why? Let’s take a closer look.
Solar activity has always varied. Around the year 1000, we had a period of very high solar activity, which coincided with the Medieval Warm Period. It was a time when frosts in May were almost unknown – a matter of great importance for a good harvest. Vikings settled in Greenland and explored the coast of North America. On the whole it was a good time. For example, China’s population doubled in this period.
But after about 1300 solar activity declined and the world began to get colder. It was the beginning of the episode we now call the Little Ice Age. In this cold time, all the Viking settlements in Greenland disappeared. Sweden surprised Denmark by marching across the ice, and in London the Thames froze repeatedly. But more serious were the long periods of crop failures, which resulted in poorly nourished populations, reduced in Europe by about 30 per cent because of disease and hunger.
It’s important to realise that the Little Ice Age was a global event. It ended in the late 19th Century and was followed by increasing solar activity. Over the past 50 years solar activity has been at its highest since the medieval warmth of 1000 years ago. But now it appears that the Sun has changed again, and is returning towards what solar scientists call a “grand minimum” such as we saw in the Little Ice Age.
The match between solar activity and climate through the ages is sometimes explained away as coincidence. Yet it turns out that, almost no matter when you look and not just in the last 1000 years, there is a link. Solar activity has repeatedly fluctuated between high and low during the past 10,000 years. In fact the Sun spent about 17 per cent of those 10,000 years in a sleeping mode, with a cooling Earth the result.
You may wonder why the international climate panel IPCC does not believe that the Sun’s changing activity affects the climate. The reason is that it considers only changes in solar radiation. That would be the simplest way for the Sun to change the climate – a bit like turning up and down the brightness of a light bulb.
Satellite measurements have shown that the variations of solar radiation are too small to explain climate change. But the panel has closed its eyes to another, much more powerful way for the Sun to affect Earth’s climate. In 1996 we discovered a surprising influence of the Sun – its impact on Earth’s cloud cover. High-energy accelerated particles coming from exploded stars, the cosmic rays, help to form clouds.
When the Sun is active, its magnetic field is better at shielding us against the cosmic rays coming from outer space, before they reach our planet. By regulating the Earth’s cloud cover, the Sun can turn the temperature up and down. High solar activity means fewer clouds and and a warmer world. Low solar activity and poorer shielding against cosmic rays result in increased cloud cover and hence a cooling. As the Sun’s magnetism doubled in strength during the 20th century, this natural mechanism may be responsible for a large part of global warming seen then.
That also explains why most climate scientists try to ignore this possibility. It does not favour their idea that the 20th century temperature rise was mainly due to human emissions of CO2. If the Sun provoked a significant part of warming in the 20th Century, then the contribution by CO2 must necessarily be smaller.
Ever since we put forward our theory in 1996, it has been subjected to very sharp criticism, which is normal in science.
First it was said that a link between clouds and solar activity could not be correct, because no physical mechanism was known. But in 2006, after many years of work, we completed experiments at DTU Space that demonstrated the existence of a physical mechanism. The cosmic rays help to form aerosols, which are the seeds for cloud formation.
Then came the criticism that the mechanism we found in the laboratory could not work in the real atmosphere, and therefore had no practical significance. We have just rejected that criticism emphatically.
It turns out that the Sun itself performs what might be called natural experiments. Giant solar eruptions can cause the cosmic ray intensity on earth to dive suddenly over a few days. In the days following an eruption, cloud cover can fall by about 4 per cent. And the amount of liquid water in cloud droplets is reduced by almost 7 per cent. Here is a very large effect – indeed so great that in popular terms the Earth’s clouds originate in space.
So we have watched the Sun’s magnetic activity with increasing concern, since it began to wane in the mid-1990s.
That the Sun might now fall asleep in a deep minimum was suggested by solar scientists at a meeting in Kiruna in Sweden two years ago. So when Nigel Calder and I updated our book The Chilling Stars, we wrote a little provocatively that “we are advising our friends to enjoy global warming while it lasts.”
In fact global warming has stopped and a cooling is beginning. Mojib Latif from the University of Kiel argued at the recent UN World Climate Conference in Geneva that the cooling may continue through the next 10 to 20 years. His explanation was a natural change in the North Atlantic circulation, not in solar activity. But no matter how you interpret them, natural variations in climate are making a comeback.
The outcome may be that the Sun itself will demonstrate its importance for climate and so challenge the theories of global warming. No climate model has predicted a cooling of the Earth – quite the contrary. And this means that the projections of future climate are unreliable. A forecast saying it may be either warmer or colder for 50 years is not very useful, and science is not yet able to predict solar activity.
So in many ways we stand at a crossroads. The near future will be extremely interesting. I think it is important to accept that Nature pays no heed to what we humans think about it. Will the greenhouse theory survive a significant cooling of the Earth? Not in its current dominant form. Unfortunately, tomorrow’s climate challenges will be quite different from the greenhouse theory’s predictions. Perhaps it will become fashionable again to investigate the Sun’s impact on our climate.
–
Professor Henrik Svensmark is director of the Center for Sun-Climate Research at DTU Space. His book The Chilling Stars has also been published in Danish as Klima og Kosmos Gads Forlag, DK ISBN 9788712043508)
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So, basically, it is a big massive conspiracy and you can’t trust scientists and scientific organizations specifically charged with providing the U.S. government sound scientific advice like NAS.
I think it’s more like Little Mac’s Pinkerton operatives during the American Civil War. There was no “conspiracy” whatever. Yet somehow they always managed to “count” three to six times as many rebs as were actually there. (That’s what happens when you get paid by the reb.)
I doubt the “Limits to Growth” gaggle was actually “conspiring” either. They just happened to be going with the same (wildly ridiculous) flow. Being sheep, they had to go in a flock. Great minds think alike. And sometimes not-so-great minds.
In the history biz we see this sort of thing all the time. We like to think of it as “class action behavior” (we have less polite descriptives).
Our oceans, volcano’s and our sun drive our climate.
In what way, we still have to find out.
CO2 is not in the list.
What’s interesting to research is how the changes (drop and rise) in temperatures can happen in such small time frames (10 years).
http://news.scotsman.com/scitech/Last-Ice-Age-happened-in.4351045.jp
http://anhonestclimatedebate.wordpress.com/2009/03/23/canadian-prairie-winter-temperature-anomalies-drop-by-66-71-degrees-c-in-just-three-years/
http://discovermagazine.com/2002/sep/cover
Stephen Wilde (11:18:51) :
Additionally, if the sun has increased it’s power by 30% yet the system has retained stability then I would venture that nowadays the speed of the hydrological cycle is proportionately faster than it was when the sun was cooler.
Leif Svalgaard:
Perhaps the 50 times as much CO2 also had something to do with it. Speculating about billions of years is premature”
Reply:
Now, Leif, I thought you didn’t accept CO2 as a climate forcing agent ?
In theory the increase in the power of the sun could now be being offset by the reduction in CO2 but over those billions of years the CO2 level has varied a great deal so if the presence or absence of CO2 were capable of destabilising the system there were plenty of past opportunities for our liquid oceans to disappear.
No, the truth is that as Richard says there is a powerful mechanism that has preserved our liquid oceans despite everything that sun and CO2 variations
(and every other type of variation including severe volcanicity and sizeable meteorite strikes) could throw at us over billions of years.
It is the speed of the hydrological cycle, stupid !
We see it now on a daily basis and nothing that humanity does by way of CO2 emissions will make one jot of difference.
Everything about billions of years past is speculation not just what I say.
However I am pointing out a current observable phenomenon that has the power to explain why that 30% increase in solar output has failed to boil our oceans away.
Look at a pot of boiling water and ensure that all the steam condenses and returns to the pot.
It doesn’t matter how much energy you apply the water will never go away and the maximum temperature of the water will never exceed 100C.
All that happens is that the more energy you put in the faster the water circulates from liquid to steam and back again.
So it is with the Earth.
The hydrological cycle pumps energy to space as fast as is necessary to maintain stability.
Since the air cannot warm the oceans the equilibrium temperature is set by the oceans and now in light of these new (to me) thoughts I don’t think it is the sun that sets the temperature at all.
What really sets the equilibrium temperature is the density and pressure differential between water and space. The air in between has an effect but due to it’s very low density as compared to water it has no significant influence (CO2 even less and human CO2 even less than that).
Apply more energy from whatever source (even the sun) and the density and pressure differentials drive the speed of the hydrological cycle instead of raising the equilibrium temperature.
Look again at that pot of boiling water. The water boils at 100C simply because of the density and pressure differential prevailing on Earth. Change the density or the pressure and the boiling point changes. The water still can get no hotter than the boiling point whatever it might then be.
Likewise at the surface of the oceans it is the density and pressure differentials that dictate the temperature at which the evaporative change of state occurs. Change the energy input whether from Sun or GHGs or whatever and all you do is change the speed of evaporation for no change in overall equilibium temperature.
The oceans are a pot of water. The air always returns the water to the pot. The temperature of the water is set by the temperature at which evaporation occurs. The temperature at which evaporation occurs is set by density and pressure differentials.
However much energy is added (30% increase in solar power or a vast increase in GHGs) all that happens is that the rate of the hydrological cycle increases for no change in the temperature at which evaporation occurs.
To change the temperature at whch evaporation occurs one has to change the density of the entire body of air around the planet. few ppm (or even a lot) of extra CO2 would have no significant effect.
Tyndall observed a real feature of the composition of the air but it cannot affect the equilibrium temperature of the planet.
The properties of water do it all.
Why do you think that all life is bags of mostly water ?
It is the only compound that can maintain stability long enough for life to develop as it has done on Earth in the face of natural disruptions both astronomic and geological.
Is there an error here so simple that it should shut me up or is there not ?
Invariant (08:59:49) “I have not said that “the sun is surprisingly insensitive due to increases in greenhouse gases”.”
You expose the usual painting of everyone at WUWT (a diverse bunch) with the same broad-brush assumptions.
Stephen Wilde (12:37:24) :
Leif Svalgaard:
Perhaps the 50 times as much CO2 also had something to do with it. Speculating about billions of years is premature”
Reply:
Now, Leif, I thought you didn’t accept CO2 as a climate forcing agent ?
If there is enough of it, I give it a good chance. E.g. on Venus. Although in the Venus case one has to be a bit careful. Just a very thick atmosphere in itself might have most of the effect, but there is the question of how it got that way.
Then there is the carbonyl sulphide possibility: http://www.astrobio.net/pressrelease/3222/a-carbonyl-sulphide-blanket
So, some greenhouse effect was probably at work. I think there may be others as well. The bottom line is that the atmosphere was so different that most of we say is just speculation and not helpful in the current situation.
Stephen Wilde: One obvious problem with your hypothesis is that it proves too much. In fact, we know that there have been significant variations in climate over the eons. Your hypothesis seems to suggest there shouldn’t have been.
[Besides which, I don’t think it makes sense to say, “the hydrological cycle pumps energy to space as fast as is necessary to maintain stability.” While that cycle can affect how heat is moved around in the atmosphere (and hydrosphere), ultimately the heat must be lost to space via radiation and the rate at which it is lost is set by the Stefan–Boltzmann Law applied using the temperature of the effective radiating level.]
A more reasonable hypothesis as to why the temperatures have remained within certain bounds would involve these points:
(1) The amount of radiation emitted by an object is proportional to T^4, so the temperature doesn’t have to change as dramatically as would be the case if it were not proportional to such a high power of T in order to maintain balance. (And, of course, these basic equations of radiative equilibrium are included in climate models.)
(2) On geological timescales, there are negative feedbacks in the carbon cycle. For example, when we had the periods of snowball or slushball earth ( http://en.wikipedia.org/wiki/Snowball_earth ), weathering of rocks no longer removed CO2 from the atmosphere and it eventually built up to a level sufficient to melt the ice. Likewise, during warmer periods, the weather rate would increase eventually drawing the CO2 level down and causing cooling. Unfortunately, these feedbacks operate over geological timescales and thus won’t come into play in our current “experiment”.
Leif says:
I lost you there, Leif. How would a thick atmosphere matter if it were not IR-active? In that case, the radiation from the surface would escape directly into space and the Stefan-Boltzmann Equation would limit what this temperature could be.
Stephen Wilde and Leif Svalgaard:
Leif quotes Stephen as saying:
“Stephen Wilde (11:18:51) :
Additionally, if the sun has increased it’s power by 30% yet the system has retained stability then I would venture that nowadays the speed of the hydrological cycle is proportionately faster than it was when the sun was cooler.”
And replies with:
”Perhaps the 50 times as much CO2 also had something to do with it. Speculating about billions of years is premature.”
Perhaps the extra CO2 did have “something to do with it” but the available evidence does not support such a contention. As I said, “the Earth is constrained within close limits of global temperature in each of two stable states; viz. glacial and interglacial. And its temperature has been the same within narrow bounds in each of those stable states throughout the ~2.5 billion years since the Earth gained an oxygen-rich atmosphere.” But the CO2 went up and down like a fiddler’s elbow over that time. So, it seems improbable that the extra CO2 did have “much to do with it”.
Stephen asks my opinion on variation to the speed of the hydrological cycle, but I am certainly not willing to speculate on that over the ~2.5 billion years because the geography of the continents varied greatly and that must have had an effect on the hydrological cycle.
Indeed, I strongly agree with Leif when he says:
“Speculating about billions of years is premature.”
We can observe that the robust bi-stability has existed over that long time-scale, but nobody knows the cause of that bi-stability.
However, the work by Dick Thoenes using salt pans (not published because of commercial confidentiality) does suggest that evapourative cooling is a severe brake on surface temperature rise when additional surface heating is applied. Therefore, the reaction of the hydrological cycle is to act as a control on surface temperature. Indeed, sea surface temperature has a maximum value of 305K and this is achieved in the tropics (this was first determined by Ramanathan & Collins, Nature (1990) and has been confirmed by several other studies since then). Also, most land surface is moist so it also cannot rise above that limit: there are a few dry desert places that can and do get above it but their area is too small to be significant.
So, the important question is:
Why does the climate cycle exhibit such a robust bi-stability that global temperature has not been discernibly affected by ~30 per cent increase to solar variation, major changes to the distributions of land masses, and very fluctuating atmospheric CO2 concentrations over the last ~2.5 billion years?
I do’nt know the answer to that question, nobody does. It needs investigation, and study of the hydrological cycle is an obvious place to start that investigation.
I add that I would like to know why some people think that robust bi-stability could be disturbed by the relatively trivial effect of doubling modern atmospheric CO2 concentration when nobody knows the cause of the bi-stability.
I hope the above is a clear exposition of my views that Leif commented and Stephen questioned.
Joel Shore:
In response to my post to you that said and asked:
“Firstly, as you admit, the figure is from IPCC AR4 but with added annotation. Please explain why you think the IPCC included the figure if, as you assert, it is meaningless because “the presumed structure [of other mechanisms] is too small”.
In reality, IPCC WG1 included that figure because it explains the model-predicted patterns of warming from the various forcing mechanisms. ”
You have replied:
“It is not the IPCC’s fault that their figure has been used by you to try to illustrate things that it was not designed to illustrate.”
That reply is surreal. I used the illustration to show what the IPCC says it shows. And you have not answered my question that was:
“Please explain why you think the IPCC included the figure if, as you assert, it is meaningless”.
I have answered (in this case “answered” is a polite euphemism for “demolished) every point you have made on this matter. And I will address your responses to me if and when they address my points. Until then, I think it best that I ignore your repetitions of your assertions because I have already refuted them with facts.
Richard
The first paper of Session 4 in the upcoming SOHO23 conference (http://www.soho23.org/) looks especially relevant to Dr. Svensmark’s findings:
Session 4
How does the Solar Wind transmit the Unique Properties of Solar Minimum out to the Heliosphere?
Nathan Schwadron (Chair)
Title: Review of unusual in-situ conditions during the present solar minimum.
Edward J. Smith (INVITED)
Affiliation: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA, 91001, USA
Abstract: Ulysses observations are witness to the present unusual solar minimum. Compared to the previous four minima that took place since continuous measurements by spacecraft began, the heliospheric magnetic field (HMF) strength and solar wind pressure have decreased to new lows. The field is about 20 % weaker than in the previous minimum and the solar wind pressure is correspondingly low principally as a result of a decrease in density. The combined Ulysses observations obtained over the last 18 years have revealed that the solar wind pressure, nmv2 (where n, m and v are number density, mass and speed), and magnetic flux, r2 Br (where r and Br are solar radial distance and the radial component of the HMF), are correlated not only in the heliosphere but at the coronal source. The decreases observed and implied at the source are clearly associated with a decrease in the Suns polar cap field strength by a factor of about two. Ulysses has also shown that r2 Br is independent of solar latitude throughout the solar cycle so that the longer record of magnetic field measurements by in-ecliptic spacecraft can be used to study variations in total heliospheric magnetic flux over the four solar cycles since 1967 and their relation to sunspot numbers and the solar magnetic field. In addition to the changes in Br, the field strength, B, and solar wind pressure, systematic variations in the inclination of the current sheet separating fields from the north and south solar hemispheres, i.e., the heliospheric magnetic equator, provide important information about the orientation of the Suns magnetic dipole. Estimates of the dipole strength and inclination obtained by these heliospheric measurements are complementary to those of the more complex photospheric magnetic fields recorded by magnetographs and to modeling of the solar heliospheric field. The accumulated information should assist in attempts to answer questions relevant to this workshop such as why this minimum is so different and what that may imply for the new cycle just beginning.
“Joel Shore (14:29:43) :
Stephen Wilde: One obvious problem with your hypothesis is that it proves too much. In fact, we know that there have been significant variations in climate over the eons. Your hypothesis seems to suggest there shouldn’t have been.”
Reply:
It’s nice to have the problem of a hypothesis that proves too much.
To answer your point I see no reason why the modulating effect of a variable speed for the hydrological cycle should not nevertheless leave room for significant climate variation.
You seem to have missed my observation that the oceans release energy to the air at variable rates over a number of timescales. ENSO on an interannual basis, Phase changes at 25 to 30 year intervals and possibly the 900 year cycle mentioned by Richard S. Courtney which may be internal to the system or solar induced (I’ve not made my mind up on that).
Anyway the oceanic variability in the supply of energy to the air on whatever timescales introduces quite enough variability to explain observed climate changes and over time the speed of the hydrological cycle changes to neutralise the effect every time.
Joel Shore:
“[Besides which, I don’t think it makes sense to say, “the hydrological cycle pumps energy to space as fast as is necessary to maintain stability.” While that cycle can affect how heat is moved around in the atmosphere (and hydrosphere), ultimately the heat must be lost to space via radiation and the rate at which it is lost is set by the Stefan–Boltzmann Law applied using the temperature of the effective radiating level.]”
Reply:
You have to remember that we are dealing with 4 dimensions here. The usual 3 plus time.
The hydrological cycle doesn’t just move energy up and down, forward and back and from side to side it also accelerates and decelerates the flow of energy through the air between surface and space. Ultimately there is another layer of variability at the air/space interface which is governed by the varying interaction between the flow of energy from sun to sea to air to space as it comes up against the portion of solar energy that reacts exclusively with the top of the atmosphere.
Just the same 4 dimensional process is going on within the oceans. Energy is moved up and down, forward and back, side to side and the rate of release to the air is accelerated and decelerated.
That affects the operation of the Stefan-Boltzmann Law and causes it to have differing effects over time.
The air circulations have to do two things:
1) Arrange for the sea surface temperature to match surface air temperature over time.
2) Arrange for the energy radiated out to space to match energy received from the sun over time.
Both processes have to work in balance otherwise we say goodbye to liquid oceans. We have had liquid oceans for billions of years so it must work out.
Everything we observe in the air from sea level to top of atmosphere is a consequence of those competing and mutually contradictory requirements.
It is hardly surprising that betweeen sea surface and top of atrmosphere we see a lot of phenomena that are hard to explain individually but I suggest you slot everything into my overarching scenario and I think it must then make sense.
Richard S. Courtney:
Stephen asks my opinion on variation to the speed of the hydrological cycle, but I am certainly not willing to speculate on that over the ~2.5 billion years because the geography of the continents varied greatly and that must have had an effect on the hydrological cycle.
Reply:
Of course that must be so but the fact that we still have liquid oceans after billions of years suggests that it was those very changes in the speed of the hydrological cycle which prevented the varying geography of the continents from upsetting the basic equilibium set by the temperature (taking a global average of course) at which evaporation from the ocean surface occurs.
No need to speculate. We have liquid oceans. They can only be maintained if changes in the speed of the hydrological cycle can neutralise everything thrown at the system by astronomic and geological events over billions of years.
What else could possibly do it ?
Joel Shore (14:33:07) :
I lost you there, Leif. How would a thick atmosphere matter if it were not IR-active?
PV=RT
Gerry (14:48:35) :
The first paper of Session 4 in the upcoming SOHO23 conference (http://www.soho23.org/) looks especially relevant to Dr. Svensmark’s findings
I don’t think so, as the cosmic ray intensity is not markedly different this minimum from all previous minima where we have data [back to 1952]. When comparing cosmic ray stations, remember that different stations show slightly different variations and one must look at many to see the correct pattern. It is like measuring temperature, you cannot just look at one place and say that is representative of the whole globe.
Leif: I understand that the ideal gas law will control the temperature structure of the atmosphere but I don’t think that gets you around also having to satisfy the First Law of Thermodynamics. If the surface temperature were as hot as Venus’s is and the atmosphere were not IR-active, Venus would be radiating heat away like crazy! (There were some original proposals that Venus could be generating lots of heat by processes like nuclear reactions but a paper way back in the 60s of thereabouts showed that there was no way to conduct heat to the surface fast enough to keep Venus as warm as it is, even if there were some mechanism producing the heat within the planet.
Richard S. Courtney says:
Perhaps in the strange world that you inhibit, you really think that you have! I suppose you can continue to fool yourself and some people for a while. But fortunately, science will win out despite the best efforts of people like you to obfuscate it and spin it.
Joel Shore (17:27:50) :
Leif: I understand that the ideal gas law will control the temperature structure of the atmosphere but I don’t think that gets you around also having to satisfy the First Law of Thermodynamics. If the surface temperature were as hot as Venus’s is and the atmosphere were not IR-active, Venus would be radiating heat away like crazy!
The CO2 in such a large amount would help to keep in the heat. The high pressure also helps to make the number of atoms higher, so a combination of the two. There is also a perpetual cloud cover to prevent some of the heat from escaping. But why get bogged down with Venus? It is different from Earth that it is hard to transfer from one atmosphere to the other.
It seems the real human tragedy will come with the end of the interglacial period, which has been historically quite short. Are we about half way through a normally 20K year interglacial period? It seems like distant generations will be grateful if we could postpone the end of the interglacial by even a few thousand years. Global warming adaption seems feasible. Why are we trying to keep the end of the interglacial period on schedule? I am truly asking since I’m not a scientist. As a layman it seems odd that so many are worried about global warming even if it turns out to be true.
John Phillips: The latest thinking concerning the interglacial is this one would, left to its own devices, likely last about another 50,000 years: http://www.sciencemag.org/cgi/content/short/297/5585/1287 It is also generally understood that we have already pumped enough greenhouse gases into the atmosphere to stop another glacial period from occurring at least in the near term.
You should also understand that a slide into a glacial period generally happens rather slowly. The rate is less than 0.1 C/century. By contrast, the warming is currently running about 0.16 C/decade…or more than 10 times as fast. Future generations will have lots of time to worry about coming glacial periods. In the meantime, we have to worry about what is going to happen on the scale of decades to centuries!
Joel Shore to Richard S. Courtney:
“in the strange world that you inhibit” – dont you mean “inhabit”? Interesting Freudian slip.
Richard S. Courtney:
“Firstly, the Earth is constrained within close limits of global temperature in each of two stable states; viz. glacial and interglacial. And its temperature has been the same within narrow bounds in each of those stable states throughout the ~2.5 billion years since the Earth gained an oxygen-rich atmosphere.”
Richard went on to discuss equilibrium, oscillation and harmonics and I believe this is the right way to approach this issue. We are dealing with non-linear or non-equilibrium pattern formation. “Seeking equilibrium but never finding it” is exactly right.
One common feature of non-linear systems at the boundary of linearity and chaos is the STRANGE ATTRACTOR. For an explanation of this look at:
http://en.wikipedia.org/wiki/Attractor
Strange attractors are valleys in a landscape of possible states in a non-equilibrium system (where the vertical scale is inverse probability). Such systems frequently pop between stable states. Glacial and interglacial are strange attractors.
The robustness and stability of the system to peturbation, such as the change in sun output, that Richard mentioned, are classic and expected features of the non-equilibrium / non-linear system.
We need to snap out of this linear catholic logic and understand that this is a non-equilibrium / non-linear quasi chaotic system. No single factor – least of all CO2 – will drive the whole system – except for something large enough like a flood-basalt event of the Indian or Siberian type.
Biologists are beginning to understand this with the development of “systems biology” which breaks the trend for championing a single hero gene or homone or causative signalling pathway, but instead recognises a multiply interlinked spider-web of factors and instead probes the system for sensitivity to individual factors or agents.
This systems approach is needed for climate study, recognising non-equilibrium dynamics.
Finally about the length of interglacials. John Phillips – why 20k years? If you look at the Vostok core, the recent interglacials (around -128, 238 and 323 kyrs) are spikes with complex shapes and no obvious duration can be concluded. The one at -238 kyrs is a spike with < 5 kyrs duration. The ones at -128 and -323 kyrs are a spike followed by a slightly lower plateau – then another fall. Do you define length as FWHM? THis would involve a baseline global temperature much colder than the present.
In view of it being a non-equilibrium system there is no way of telling when we will plop back to glacial or semi-glacial except by looking at the pattern. For the current interglacial to continue for 50k yrs as Joel Shore suggests would completely break the pattern of the last 400k yrs and would thus seem improbable.
Joel: "we have already pumped enough greenhouse gases into the atmosphere to stop another glacial period from occurring at least in the near term."
How do you reconcile that assertion with this fact: During start of the rapid descents to colder temperature immediately after each of the recent interglacial spikes (-128, 238, 323 kyrs) the CO2 level in the atmosphere was in each case as high or higher than today. It did not stop the slide then. It wont now.
Oh poor Joel, you take such a pasting and yet keep bouncing back up like one of those round bottomed clowns in a bird cage. Yes of course AGW is a conspiracy and one in which you have to ignore present and history and believe models which are programmed to show catastrophic warming. You of course haven’t read Plimer’s exceptional book yet I’ve read all of the so called rebuttals and they have no real substance or credibility especially being written by known AGW extremists like Monbiot from the Guardian and his stooges so please be serious about “screamer” rebuttals which are predominantly ad hominem. Monbiot refused to debate the issues with Plimer (as all AGW proponents refuse debate with knowledgeable skeptics) and I, who know nothing, would gladly debate Climate change with Monbiot. He wouldn’t even get to be next to the sink with my wife. You haven’t answered any of my questions neither just the same old AGW mantras which have only one basis, yes you can’t see it now, no you have never been able to see it, yes it is falsified daily, no it has little provable scientific basis but believe me it will happen because the models say it will.
Of course those quotes are from the UN/IPCC and were linked in a post on a newer thread. What’s the problem Joel, you don’t read any books which challenge the AGW weak hypothesis and you don’t read posts on here. Do I have to say that you have credibility at the same level of eco-loonies like Monbiot.
Read Plimer and we’ll discuss the issues but until then please don’t comment on what is in it especially its spelling mistakes and rhetorical statements taken at face value. Even better, discuss them with Plimer, my bet is that he’d eat you for breakfast.
Joel Shore (19:00:53) :
John Phillips: The latest thinking concerning the interglacial is this one would, left to its own devices, likely last about another 50,000 years: http://www.sciencemag.org/cgi/content/short/297/5585/1287 It is also generally understood that we have already pumped enough greenhouse gases into the atmosphere to stop another glacial period from occurring at least in the near term.
Proof is in the pudding: the existing CO2 ,though growing ,has not managed to stop a cooling PDO and it will stop the ice age?,
masonmart (23:49:30) :
re Joel
…”You of course haven’t read Plimer’s exceptional book yet I’ve read all of the so called rebuttals and they have no real substance or credibility especially being…”
I have read Plimers book cover to cover. Twice. It is a good read.
I havnt read all the rebuttals, but I myself found Plimer’s take on CO2
from volcanoes a bit out of line. He says that there is vast output
of CO2 from volcanoes. This isnt supported by references in his book,
even though he has plenty of references backing most other assertions.
Somebody suggested that he may have confused CO2 with SO2.
A Professor of Geology confused on something so basic?
Anyway I’d like to see more on this specific item from Plimer.
Phlogiston:
Sincere and grateful thanks for your comments. It pleases me that your comments demonstrate that at least one person has chosen to evaluate my contribution and not to be deflected from that consideration by Joel Shore’s smokescreen of bluster, untruths and evasions.
Science is about acknowledging we have no certainty and merely have a best understanding in the light of present knowledge. But political activity is about asserting certainty where none exists.
In my opinion we need to oppose the perversion of science by political activity, and we need to oppose it with every tool at our disposal.
Importantly, we need effective tools for the defence of science against political activity, and I would like to find some.
Therefore, those of us who are concerned to stop political objectives distorting scientific investigation need to find effective responses to Joel Shore and his fellows. Clearly, my presentation of logic, facts and reason were not effective: they rolled off him like water from a duck’s back.
So, I hope you and others will note whether Joel Shore responds to your question and attempts to answer it. Addressing whatever answer he provides to you – or noting his failure to provide an answer – is important because his behaviour here is typical of AGW-advocates. If we cannot convince him of the enquiring nature of science then it is not likely we can convince others like him.
We need to find effective tools to defend science against political activity.
Richard
Stephen Wilde:
You ask me:
“the fact that we still have liquid oceans after billions of years suggests that it was those very changes in the speed of the hydrological cycle which prevented the varying geography of the continents from upsetting the basic equilibium set by the temperature (taking a global average of course) at which evaporation from the ocean surface occurs.
No need to speculate. We have liquid oceans. They can only be maintained if changes in the speed of the hydrological cycle can neutralise everything thrown at the system by astronomic and geological events over billions of years.
What else could possibly do it ?”
I answer that I do not know, and I remind that I stated good reasons why the hydrological cycle is a probable explanation. I then said:
“So, the important question is:
Why does the climate cycle exhibit such a robust bi-stability that global temperature has not been discernibly affected by ~30 per cent increase to solar variation, major changes to the distributions of land masses, and very fluctuating atmospheric CO2 concentrations over the last ~2.5 billion years?
I do’nt know the answer to that question, nobody does. It needs investigation, and study of the hydrological cycle is an obvious place to start that investigation.”
However, the fact that we cannot think of another cause is not evidence that the postulated cause is the true cause. That is the logical fallacy of ‘argument from ignorance’, and it is the mistake made by AGW-advocates.
In the Middle Ages experts said, “We don’t know what causes crops to fail: it must be witches: we must eliminate them.” Now, experts say, “We don’t know what causes global climate change: it must be emissions from human activity: we must eliminate them.” Of course, they phrase it differently saying they can’t match historical climate change with known climate mechanisms unless an anthropogenic effect is included. But evidence for this “anthropogenic effect” is no more than the evidence for witches.
Similarly, at this stage, the dominance of the hydrological cycle over the entire climate system has no more evidence than the evidence for AGW.
I think the dominance of the hydrological cycle is probably right, but that is merely an opinion and not a fact. In a post that is awaiting moderation I have pointed out that it is a denial of the scientific method to adopt certainty where none exists.
So to answer your specific question; i.e.
“What else could possibly do it ?”
I reply
I do not know but I want to know.
I hope that answer is acceptable.
Richard
Just started reading The Black Swan and in the opening pages the author makes some interesting statements about the future and the past.
When we look at things in retrospect, it always looks like we understand what happened. When we write history books, it is always easy to leave out whatever appears in hindsight to have been irrelevant. When we evaluate the results of our predictions, it is always easy to reevaluate what was inconsequential about our predictions and what was important, to the extent that the prediction is portrayed as having been essentially correct. If the reevaluation is being done by experts, they have more tools for reevaluating the results in a way that makes the expert opinion continue to be correct.
Somehow, the climate has continued to confirm the models, the climate continues to be consistent with the models, as experts can identify the specific events that caused the particular variations in weather and short term climate, and once we take those into account, we can still see the long term consistency with the models.
So I have two questions. How do we tell the difference between a rational truth and a post-rationalised fiction? (See, CO2 could be a Black Swan to the Resilient Earth, after all, and the models might, unlikely as it seems, turn out to be right, after all). How would we know, when both sides can explain so much to their own satisfaction?
Second, doesn’t the inherent unpredictability of the future not mean that we need a different way of thinking about things? One which can work in sync with our natural inability to predict, rather than constantly trying to predict, believing we just need to be smarter and more expert when predicting? Like, calling them scenarios instead of predictions, and adding error bars and averages of model ensembles, and adding more model runs on bigger computers at finer resolution, and adding probability estimates to quantify the uncertainty, as if all this expertise was somehow compensating for our essential myopia? Like, working on developing upper body strength so that I can flap my arms hard enough to fly like a bird?
Remind me, Heisenberg Compensators, they’re just a Star Trek thing, right, they don’t actually exist?