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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rbateman (09:38:23) :
So, if someone took two or 3 signals out of a choice of a dozen, superimposed them by addition, the training of scientists does not allow them to unravel.
Is this true?
You lost me again. If you think you have something to show, get on with it. Say what it is you are on to [or whatever] or suggest. Guessing games are not my strong side.
Joel Shore (20:28:41) :
Oh, here http://www.cdc.noaa.gov/csi/images/GRL2009_ClimateWarming.pdf is a peer-reviewed paper that has now appeared in Geophysical Research Letters that has shown again what that RealClimate post showed, which is that periods of a decade or so of negative trend are in fact not uncommon in climate models forced with greenhouse gases.
So expect that this new evidence will now greatly increase your faith in climate models?.
It is not new evidence. It is going back and adding a few more parameters to fiddle with the data, in a very complicated way, true, dragging in fluid dynamics etc, but the end result is: like fitting a Fourier series to a function, it fits a complicated convoluted program to a known function.
This navel gazing only happened because the data did not behave as they were predicting.
The thing is that the IPCC published growing curves for the future correlated with growing CO2, and that cannot be undone.
In any case, the basic problem with all these GCM is that they have no handle on error propagation, as is admitted in the IPCC report and I have given a reference in a previous thread here. No error band accompanies an individual model projection, because it is unknown. This means that the future temperatures shown are at best a guess, at worst a Tarot output. Instead of error propagation IPCC has the spaghetti of models and commits the hubris of averaging the spaghetti and calling them projections and, in parallel, confusing cursory readers of the IPCC reports who think the color bands are real errors.
I would expect that the neural net model of Tsonis et al ( there was a thread here some time ago )would be a better direction to follow for chaotic modeling of climate , rather than trying to make a silk purse ( chaotic approximations) from a sow’s ears ( linear approximations of highly non linear functions).
Harold Ambler (07:03:27) :
With regard to Oulu Neutron Monitor, are you suggesting that it is poorly calibrated?
Some more long-term series:
http://www.puk.ac.za/fakulteite/natuur/nm_data/data/nmd_e.html
RR Kampen
What figures are you quoting? Are you from Holland?
In the CET record back to 1660 our warmest winter remains 1869 followed by 1834
Other than 2006 the four warmest autumns are 1730 1731 1818 1729
Our two warmest summers are 1976 and 1826.
Many of the ‘warm’ records are still held by dates prior to the 1980’s.
Bearing in mind the Hadley record covers the LIA it is remarkable that average and individual temperatures show a limited difference between then and now.
tonyb
Tiles (01:11:09) :
…ever heard of thermal inertia? That could well explain continued warming in the face of a fading sun.
There is no such thing as “thermal inertia” so it most certainly could not.
Sonicfrog says:
Paranoid much, are we? Do you actually believe that the climate modelers have nothing better to do than spend lots of their effort and energy worrying about what “skeptics” will think when they create their models? (And, by the way, the models were not created around 2005…although that is likely around when the last updates that could appear in AR4 could have possibly been made.)
Anyway, even if you look at Hansen’s original model runs that he showed in 1988 (which are no doubt very crude by today’s standards…particular in handling of the oceans), you can see periods of cooling or little warming for several years at a time: http://www.realclimate.org/images/Hansen06_fig2.jpg (Note that Scenario’s B and C include a volcanic eruption in 1996 and Scenario C supposes a leveling off in emissions after ~2000 but Scenario A is an extremely aggressive scenario with continued growth in emissions and no negative volcanic forcing…and it still shows periods like 2002-2008 or 2014-2018 that are about flat, and even the whole period from 1996-2008 looks like it shows pretty minimal warming.)
What may be confusing you is that the IPCC projections of future warming, which are based on averages over model runs look nice and smooth, just as a plot of say the average temperature here in Rochester over the course of a year using all the data for the 100+ years we have would be nice and smooth showing a fairly sinuosoidal seasonal cycle. However, an actual individual year’s temperature data would have much more ups-and-downs and would include periods of at least a week or so where the temperature trend is the opposite of what one would predict from the seasonal cycle (e.g., you would see some periods with negative temperature trends in the spring and some periods with positive temperature trends in the fall). Likewise, an individual run of a climate model (and the actual climate trajectory that we follow) shows a lot of variability superimposed on the general warming trend.
I don’t see that at all. It looks to me like you could identify decent length periods after 2030 with cooling or essentially flat behavior (for example, periods starting in ~2034). They do become less likely in these later years because that is a run for the A2 scenario, which is a quite aggressive one in terms of future emissions growth, hence the general acceleration of the warming over time.
Leif Svalgaard (12:17:45) :
I was hoping you would see the L&P might be at work in there.
Mick (01:46:48) :
“One can’t defeat a paranoid religion with logic and common sense. Or argument.”
One can not defeat ANY religion with facts and logic. They are all constructed to be immune to such criticism. ALL religions are wrong. It is cliché to say that religion and science are not in conflict but it is untrue. Science is in conflict with all error and untruth.
anna v:
I agree it is not new evidence. It is just going back and looking at the individual realizations in the climate modeling archive. And, there is no “adding a few more parameters to fiddle with the data”. They simply looked at the model runs that were already available.
That is just silliness. The reason they went back and looked at it is because they discovered that on the web and in the blogosphere, people apparently had no clue about how a function that consists of a slow steady rise with superimposed random fluctuations would look like.
That is just nonsense. The IPCC curves represent the longterm trendlines. Nobody ever expected the actual global temperature increase would be steady! It hasn’t happened in the past for the real global temperature data and it hasn’t happened in individual runs of climate models dating back at least to Hansen’s crude models from the 1980s. The IPCC explicitly discusses how they average ensembles of runs in order to get a better handle on the forced component by averaging over the climate noise.
Hi Joel
What do you make of the Met offices admittance that it has cooled over the last decade-contrary to their models?
Tonyb
rbateman (13:36:33) :
I was hoping you would see the L&P might be at work in there.
I don’t think L&P has anything to do with the cosmic ray count, and in any event, the time interval is too short for any conclusions.
TonyB (12:55:33) :
“What figures are you quoting? Are you from Holland?”
—
These figures are from Holland. Should’ve mentioned although that was a reply wherein the context was clear.
tallbloke says:
I think you are misinterpetting what I said a bit. My sentence was not really addressing the issue of “realism” in general but the issue of initialization of the models with realistic initial conditions and whether that could improve short-term predictability. And, I think the jury is still out on that one.
And, actually, I don’t think it really takes long-term ocean cycles to get negative trends over about a decade. My guess is that a simple model that has a linear trend of, say, ~0.17 C / decade (which I believe is roughly the value over the last 30 years or so) and superimposed yearly random noise of about the magnitude as is seen in the real climate system would show this behavior. (This is probably true even if you assume noise uncorrelated from year-to-year although a more realistic model would have some correlations. I think Tamino had a post a while back where he demonstrated this with some computer-generated data that assumed some sort of simple year-to-year correlation.)
And, by the way, it is important to note that if you look at the global temperature data, you can also find 10-year periods when the trend was a lot greater than the 0.17 C / decade, again because of the noise.
As for whether some of the late 20th century warming could be attributed to PDO or other such long term oceanic cycle, I remain quite skeptical although I suppose further time will tell.
TonyB says:
Could you give my a link to what you are referring to?
acementhead (13:25:20): There is no such thing as “thermal inertia” so it most certainly could not.
Usually thermal masses with thermal time constants are more useful concepts than thermal inertia. Please read these equations from Wikipedia:
http://en.wikipedia.org/wiki/Time_constant#Thermal_time_constant
Thus, the transient solution to the heat balance for our planet,
m•cp•dT/dt = Qin – Qout
will always involve the thermal time constant tau that is proportional to the thermal mass m•cp. For example, changing the temperature of our planet from T0 to T1, may involve the thermal time constant tau in the following manner:
T(t) = T1 + [T0 – T1] exp(-t/tau)
In words, the thermal time constant says that larger thermal masses lead to slower changes in temperature. The thermal mass for the oceans is huge, so we have to wait many years to see that the global temperature change when our sun is less active.
[Although the equations are crude approximation any trained physicist with sufficient intuition and imagination understands that the underlying mechanism remains the same – large thermal masses always leads to slow thermal transients.]
Leif Svalgaard (13:45:58) :
Preposterous!
RR Kampen (11:16:34) “Statistical analysis on the record since 1706 ‘proves’ this impossible.”
Are you assuming a random distribution? (untenable)
How are you accounting for shared-variance with natural factors?
[rhetorical questions – no need to answer]
Joel Shore says:
For example, with the HADCRUT3 global temperature (yearly average data), I find that least-squares trendlines for 10 year periods starting in 1970 have a range from a low of +0.002 C/decade for 1987-1996 to a high of +0.430 C/decade for 1974-1983. For 12 year periods, the range is from +0.019 C/decade for 1997-2008 to +0.352 C/decade for 1992-2003. For 8 year periods, the range is from -0.117 C/decade for 2001-2008 to +0.523 C/decade for 1994-1981. For 15 year periods, the range is from +0.076 C/decade for 1979-1993 to +0.280 C/decade from 1991-2005. For 20 year periods, the range is from +0.100 C/decade for 1977-1996 to +0.234 C/decade for 1984-2003.
As you can see, as the period gets shorter, the range in trends that you find gets larger and as the period gets longer the range in trends gets tighter.
“Paul Vaughan (14:38:59) :
Are you assuming a random distribution? (untenable)”
Untenable? Maybe, but you can’t prove it. You can prove the data to be or to seem (equivalent, of course) randomly distributed though – that is, modulo the very significant recent trend. I’m sorry. The data are available, like a try? The whole amateur meteo community in Holland tried to find sines of all sorts or whatever regularity or function in those data and every new generation tries again. Snowball in hell. The data pass all tests for randomness.
(small correction – added closing tag for italics)
RR Kampen (15:11:05) : Your comment is awaiting moderation
“Paul Vaughan (14:38:59) :
Are you assuming a random distribution? (untenable)”
Untenable? Maybe, but you can’t prove it. You can prove the data to be or to seem (equivalent, of course) randomly distributed though – that is, modulo the very significant recent trend. I’m sorry. The data are available, like a try? The whole amateur meteo community in Holland tried to find sines of all sorts or whatever regularity or function in those data and every new generation tries again. Snowball in hell. The data pass all tests for randomness.
I have updated my blog and the English translation is now by Nigel Calder.
Regards, Agust H Bjarnason, Iceland
http://agbjarn.blog.is/blog/agbjarn/entry/946551/
REPLY: Agust, thank you, I have updated the translation here with the one you have kindly facilitated. You have my thanks and the thanks of many readers here. – Anthony
Joel
Here is the reference.
BBC radio 4 at 1.30pm today, Vicky Pope of the Met office reluctantly admits the climate has been cooling against their expectations and models
http://news.bbc.co.uk/1/hi/programmes/more_or_less/8248922.stm#email
This is the BBC’s Tim Harford item (the link is found at the bottom of the box to the right of the item “Blowing cold, then hot”).
transcript
“Tim: If the cooling that the Leibniz Institute predicts actually takes place, are you worried that ’s going to take the wind out of some of the sails of scientists who are warning about the threat of global warming?
Vicky: It’s very important to realise that there will be ten-year periods where the temperatures don’t increase or they even decrease as the Leibniz study is suggesting –
Tim: We’ve just had one.
Vicky: Yes, in fact we have, but that doesn’t mean that global warming has stopped, it’s simply a question of natural variability, giving a temporary decrease in temperature overlaid on top of a long-term warming trend, and in fact I believe that’s what the results of that study suggest –
Tim: Sorry to interrupt but you say that were going to have ten-year periods of cooling. How can we be sure that the rapid warming we saw in the 1980s and 1990s wasn’t the exceptional period?
Vicky: This is the point really, is that 1998 was exceptionally warm because there was an El Nino, because there was a natural variation overlaid on top of climate change. So what you can see very clearly is a long-term trend and then these periods of rapid warming and less rapid warming or even cooling overlaid on top of that because of natural variations.”
This should also be seen in the context of the New Scientist interview. All I am saying is that the models did not predict the (officially) admitted cooling and they are having to take ‘natural variability’ into greater account. I make no predictions as to whether this is the start of a longer cooling trend.
tonyb’
Re: TonyB (15:26:37)
Thanks for that. I see natural variation mentioned 3 times in that brief excerpt. It’s nice to see nature finally being acknowledged.
What we need next: ENSO forecasts that work like tide-tables.
The only difference between the alarming warming of today and the alarming cooling of the 70’s is that today we have the finest alarming computer arrays, cranking out enormous amounts of heat.
That heat must be pumped out of the building, and, wouldn’t you know it, the Stevenson box is the recipient, finding it’s way onto the front page of the news.
This killer computational capability, then, is put to work creating the boogey man hiding under our beds.
Of all the things to be used for.
TonyB (12:55:33) :
After reading RR Kampen’s comments no one can say that opposing views aren’t allowed at WUWT —though I’m not sure of the point he is trying to make.
He could include the Medieval Warming Period in his comments which could serve to make him look unbiased.