Prófessor Henrik Svensmark: »Vi anbefaler vores venner at nyde den globale opvarmning, mens den varer«...

 

 

 

Mens Solen Sover nefnist splunkuný blaðagrein í Jyllandsposten eftir Dr. Henrik Svensmark prófessor, höfund hinnar nýstárlegu kenningar um samspil sólar, geimgeisla, skýjafars og hitastigs lofthjúps jarðar, en bloggarinn hefur fjallað um þessi mál í rúman áratug.

(Sjá pistla bloggarans hér, hér, hér, hér, hér, hér, hér,  hér, hér...)

(Myndin hér að ofan er frá Thames við London um 1677. Smella þrisvar á mynd til að stækka.
Fleiri myndir eftir Abraham Hondius hér).

 

»Vi anbefaler vores venner at nyde den globale opvarmning,
mens den varer«.

Hvers vegna segir þú það Hinrik? Reyndar er þetta alveg mögnuð grein hjá þér. Þar kemur margt fram sem við Íslendingar þekkjum svo vel...   Kærar þakkir fyrir að skrifa svona grein "á mannamáli" sem almenningur skilur, því þetta kemur okkur öllum við, ekki síst okkur sem búum á jaðri heimskautasvæðanna.

 

 "Meðan sólin sefur"

 

Dustið nú rykið af dönskunni!

(Þýðing yfir á ensku eftir Nigel Calder er  hér neðar á síðunni ef eihver skyldi gefast upp á dönskunni).

 

 

 Jyllands Posten 9. september 2009:

 

http://jp.dk/opinion/kronik/article1809681.ece

 (Leturberytingar eru að mestu eftir bloggarann til að reyna að gera textann læsilegri af skjá).

Mens Solen sover

HENRIK SVENSMARK, professor, DTU, København

Offentliggjort 09.09.09 kl. 03:00

Faktisk er den globale opvarmning standset, og en afkøling er så småt begyndt. Ingen klimamodel har forudsagt en afkøling af Jorden, tværtimod. Det betyder, at prognoser for fremtidens klima er utilregnelige, skriver Henrik Svensmark.

Den stjerne, der holder os i live, har gennem det seneste par år været næsten uden solpletter, som er det normale tegn på Solens magnetisk aktivitet.

I sidste uge rapporterede det videnskabelige hold bag Sohosatellitten (Solar and Heliospheric Observatory) at »antallet af solplet-frie dage antyder, at Solens aktivitet er på vej mod det laveste niveau i omkring 100 år«. Alt tyder på, at Solen er på vej i en dvalelignende tilstand, og det åbenlyse spørgsmål er, om det har nogen betydning for os på Jorden.

Spørger man det Internationale Klimapanel IPCC, som repræsenterer den gældende konsensus på klimaområdet, så er svaret et betryggende »ingenting«. Men historien og den seneste forskning tyder på, at det sandsynligvis er helt forkert. Lad os se lidt nærmere på hvorfor.

Solens aktivitet har til alle tider varieret. Omkring år 1000 havde vi en periode med meget høj solaktivitet, som faldt sammen med middelaldervarmen. Det var en periode, hvor frost i maj var et næsten ukendt fænomen og af stor betydning for en god høst. Vikinger bosatte sig i Grønland og udforskede Nordamerikas kyst. I det hele taget var det en opgangstid. For eksempel fordobles Kinas befolkning gennem denne periode. Men efter omkring 1300 faldt solaktiviteten, Jorden begyndte at blive koldere, og det blev begyndelsen på den periode vi nu kalder den Lille Istid. I denne kolde periode forsvandt alle vikingernes bosættelser i Grønland. Svenskerne overraskede Danmark med at gå over isen, og i London frøs Themsen gentagne gange. Men mere alvorligt var de lange perioder med fejlslagen høst, som resulterede i en dårligt ernæret befolkning der på grund af sygdom og sult blev reduceret med omkring 30 pct. i Europa.

Det er vigtigt at fastslå, at den Lille Istid var en global hændelse. Den endte i slutningen af det 19. århundrede og efterfulgtes af en stigende solaktivitet. Gennem de seneste 50 år har solaktiviteten været det højeste siden middelaldervarmen for 1.000 år siden. Og nu ser det ud til at Solen skifter igen og er på vej mod det, som solforskere kalder »et grand minimum« som vi så i den Lille Istid.

Sammenfaldet mellem Solens aktivitet og klimaet gennem tiderne er forsøgt bortforklaret som tilfældigt. Men det viser sig, at næsten ligegyldigt hvilken periode man undersøger, altså ikke kun de sidste 1.000 år, så findes en overensstemmelse. Solens aktivitet har gentagne gange gennem de seneste 10.000 år svinget mellem høj og lav. Faktisk har Solen gennem de seneste 10.000 år befundet sig i en dvaletilstand ca. 17 pct. af tiden med en afkøling af Jorden til følge.

Man kan undres over, at det internationale klimapanel IPCC ikke mener at Solens forandrede aktivitet har nogen betydning for klimaet, men grunden er, at man kun medtager forandringer i Solens udstråling.



Netop udstrålingen ville være den simpleste måde, hvormed Solen kunne ændre på klimaet. Lidt som at skrue op og ned for lysstyrken af en elektrisk pære.

Satellitmålinger af Solens udstråling har vist, at variationerne er for små til at forårsage klimaændringer, men dermed har man lukket øjnene for en anden meget mere effektiv måde, hvorpå Solen er i stand til at påvirke Jordens klima. I 1996 opdagede vi en overraskende påvirkning fra Solen - dens betydning for Jordens skydække. Højenergitiske partikler accelereret af eksploderede stjerner, den kosmiske stråling, hjælper til at danne skyer.

Når Solen er aktiv, skærmer dens magnetfelt bedre mod de kosmiske stråler fra verdensrummet, før de når vores planet, og ved at regulere på Jordens skydække kan Solen skrue op og ned for temperaturen. Med høj solaktivitet fås færre skyer, og jorden bliver varmere. Lav solaktivitet skærmer dårligere mod den kosmiske stråling, og det resulterer i øget skydække, og dermed en afkøling. Da Solens magnetisme har fordoblet sin styrke i løbet af det 20. århundrede, kan denne naturlige mekanisme være ansvarlig for en stor del af den globale opvarmning i denne periode.



Dette er også forklaringen på, at de fleste klimaforskere prøver at ignorere denne mulighed. Den griber nemlig ind i forestillingen om, at det 20. århundredes temperaturstigning hovedsagelig skyldes menneskelig udledning af CO2. Hvis Solen nemlig har haft betydning for en anselig del af opvarmningen i det 20 århundrede, så betyder det, at CO2's andel nødvendigvis må være mindre.

Lige siden vores teori blev fremsat i 1996, har den været gennem meget skarp kritik, hvilket er normalt i videnskaben.

Først sagde man, at en sammenhæng mellem skyer og Solens aktivitet ikke kunne være rigtig, fordi ingen fysisk mekanisme var kendt. Men i 2006 efter mange års arbejde lykkedes det os at gennemføre eksperimenter ved DTU Space, hvor vi demonstrerede eksistensen af en fysisk mekanisme. Den kosmiske stråling hjælper med at danne aerosoler, som er kimen til skydannelsen.

Derefter gik kritikken på, at den mekanisme, vi have fundet i laboratoriet, ikke ville kunne overleve i den virkelig atmosfære og derfor var uden praktisk betydning. Men den kritik har vi netop eftertrykkeligt afvist. Det viser sig, at Solen selv laver, hvad vi kan kalde naturlige eksperimenter. Kæmpemæssige soludbrud kan få den kosmiske stråling på Jorden til at dykke pludseligt over nogle få dage. I dagene efter disse udbrud falder skydækket med omkring 4 pct., og indholdet af flydende vand i skyerne (dråber) formindskes med næsten 7 pct. Her er tale om en meget stor effekt. Faktisk så stor, at man populært kan sige, at skyerne på Jorden har deres oprindelse i verdensrummet.

Derfor har vi set på Solens magnetiske aktivitet med voksende bekymring, siden den begyndte at aftage i midten af 1990'erne.

At Solen kunne falde i søvn i et dybt minimum, blev antydet af solforskere på et møde i Kiruna i Sverige for to år siden. Da Nigel Calder og jeg opdaterede vores bog ”The Chilling Stars” skrev vi derfor lidt provokerende »vi anbefaler vores venner at nyde den globale opvarmning, mens den varer«.

Faktisk er den globale opvarmning standset, og en afkøling er så småt begyndt. I sidste uge blev det fremført af Mojib Latif fra universitet i Kiel på FN's World Climate Conference i Geneve, at afkølingen muligvis fortsætter gennem de næste 10 til 20 år.

Hans forklaring var naturlige forandringer i Nordatlantens cirkulation og ikke i Solens aktivitet. Men ligegyldigt hvordan det fortolkes, så trænger de naturlige variationer i klimaet sig mere og mere på.

En konsekvens må være,at Solen selv vil vise sin betydning for klimaet og dermed teste teorierne for den globale opvarmning. Ingen klimamodel har forudsagt en afkøling af Jorden, tværtimod.

Det betyder, at prognoser for fremtidens klima er utilregnelige. En prognose, der siger, at det muligvis er varmere eller koldere om 50 år, er ikke meget bevendt, for videnskaben er heller ikke i stand til at forudsige Solens aktivitet.

Så på mange måder står vi ved en skillevej. Den nærmeste fremtid vil blive overordentlig interessant, og jeg tror, at det er vigtigt at erkende, at naturen er fuldkommen uafhængig af, hvad vi mennesker tror om den. Vil drivhusteorien overleve en betydelig afkøling af Jorden? Ikke i dens nuværende dominerende form. Desværre kan fremtidens klimaudfordringer blive nogle helt andre end drivhusteoriens forudsigelser, og måske bliver det igen populært at forske i Solens betydning for klimaet.

Professor Henrik Svensmark er leder af Center for Sun-Climate Research på DTU Space. Hans bog ”The Chilling Stars” er også udgivet på dansk som ”Klima og Kosmos” (Gads Forlag, DK ISBN 9788712043508)

--- --- ---

 

Uppfært 12. sept. klukkan 21:55;   Nigel Calder þýddi greinina úr dönsku yfir á ensku með samþykki Henriks Svensmark. Þetta er mun betra en Google þýðingin sem var hér áður.

 

 

Published 9 September 2009 in Jyllands-Posten, Denmark’s best-selling newspaper.
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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Sjá: March across the Belts á Wikipedia.  Þar er fjallað um atvikið þegar Svíar komu Dönum á óvart 1658 með því að ganga yfir til Danmerkur, eins og fram kemur í grein Henriks. Þá var kaldasta tímabil Litlu Ísaldarinnar sem féll saman við Maunder lágmarkið í virkni sólar. Margir óttast að álíka kuldaskeið eigi eftir að koma einhverntíman aftur, vonandi þó ekki á næstu áratugum:

Wikipedia síðan byrjar svona:

"The March across the Belts was a campaign between January 30 and February 8, 1658 during the Northern Wars where Swedish king Karl X Gustav led the Swedish army from Jutland across the ice of the Little Belt and the Great Belt to reach Zealand (Danish: Sjælland). The risky but vastly successful crossing was a crushing blow to Denmark, and led to the Treaty of Roskilde later that year...."

  
Að prófessorinn skuli leyfa sér að tala svona...
Ég á bara ekki orð., eða þannig...
Fara ekki margir hreinlega úr límingunum við lestur svona greinar?

En, hvað ætla menn að gera ef í ljós kemur að þetta var bara náttúruleg hitabóla?
Hvernig ætla menn að bregðast við ef ástandið verður eins og á miðöldum þegar Evrópubúum fækkaði um 30%?
Hvernig ætla menn að bregðast við kali í túnum, haustfrostum með ónýtri uppskeru og hafís?
Hvernig...?

Athugasemdir

[Magnús Óskar Ingvarsson, 11.9.2009 kl. 23:11]

Meiriháttar grein. Hvenær skyldu ofsatrúarmenn á koldíoxíðhitun jarðar fara að draga í land? Eru þeir kannski byrjaðir að hægja á sér? Það verður samt erfitt fyrir IPCC að bakka eftir allan samsöng síðasta áratugar.

[Ómar Bjarki Smárason, 11.9.2009 kl. 23:29]

Gott hjá þér að halda þessu til haga, Ágúst. Og svo er þetta ágæt upprifjun í dönsku.....

[Rafn Haraldur Sigurðsson (IP-tala skráð) 12.9.2009 kl. 06:43]

Tek unir með honum Ómari. Mjög áhugavert efni.

kveðja Rafn.

[Ágúst H Bjarnason, 12.9.2009 kl. 09:29]

UCLA News, 9 September 2009

Scientists discover surprise in Earth's upper atmosphere

By

Stuart Wolpert

| 9/9/2009 3:00:00 PM

Heejeong Kim and Larry Lyons

UCLA atmospheric scientists have discovered a previously unknown basic mode of energy transfer from the solar wind to the Earth's magnetosphere. The research, federally funded by the National Science Foundation, could improve the safety and reliability of spacecraft that operate in the upper atmosphere.

 

"It's like something else is heating the atmosphere besides the sun. This discovery is like finding it got hotter when the sun went down," said Larry Lyons, UCLA professor of atmospheric and oceanic sciences and a co-author of the research, which is in press in two companion papers in the Journal of Geophysical Research.

 

The sun, in addition to emitting radiation, emits a stream of ionized particles called the solar wind that affects the Earth and other planets in the solar system. The solar wind, which carries the particles from the sun's magnetic field, known as the interplanetary magnetic field, takes about three or four days to reach the Earth. When the charged electrical particles approach the Earth, they carve out a highly magnetized region — the magnetosphere — which surrounds and protects the Earth.

 

Charged particles carry currents, which cause significant modifications in the Earth's magnetosphere. This region is where communications spacecraft operate and where the energy releases in space known as substorms wreak havoc on satellites, power grids and communications systems.

 

The rate at which the solar wind transfers energy to the magnetosphere can vary widely, but what determines the rate of energy transfer is unclear.

 

"We thought it was known, but we came up with a major surprise," said Lyons, who conducted the research with Heejeong Kim, an assistant researcher in the UCLA Department of Atmospheric and Oceanic Sciences, and other colleagues.

 

"This is where everything gets started," Lyons said. "Any important variations in the magnetosphere occur because there is a transfer of energy from the solar wind to the particles in the magnetosphere. The first critical step is to understand how the energy gets transferred from the solar wind to the magnetosphere."

 

The interplanetary magnetic field fluctuates greatly in magnitude and direction.

 

"We all have thought for our entire careers — I learned it as a graduate student — that this energy transfer rate is primarily controlled by the direction of the interplanetary magnetic field," Lyons said. "The closer to southward-pointing the magnetic field is, the stronger the energy transfer rate is, and the stronger the magnetic field is in that direction. If it is both southward and big, the energy transfer rate is even bigger."

However, Lyons, Kim and their colleagues analyzed radar data that measure the strength of the interaction by measuring flows in the ionosphere, the part of Earth's upper atmosphere ionized by solar radiation. The results surprised them.

 

"Any space physicist, including me, would have said a year ago there could not be substorms when the interplanetary magnetic field was staying northward, but that's wrong," Lyons said. "Generally, it's correct, but when you have a fluctuating interplanetary magnetic field, you can have substorms going off once per hour.

"Heejeong used detailed statistical analysis to prove this phenomenon is real. Convection in the magnetosphere and ionosphere can be strongly driven by these fluctuations, independent of the direction of the interplanetary magnetic field."

Convection describes the transfer of heat, or thermal energy, from one location to another through the movement of fluids such as liquids, gases or slow-flowing solids.

 

"The energy of the particles and the fields in the magnetosphere can vary by large amounts. It can be 10 times higher or 10 times lower from day to day, even from half-hour to half-hour. These are huge variations in particle intensities, magnetic field strength and electric field strength," Lyons said.

 

The magnetosphere was discovered in 1957. By the late 1960s, it had become accepted among scientists that the energy transfer rate was controlled predominantly by the interplanetary magnetic field.

 

Lyons and Kim were planning to study something unrelated when they made the discovery.

 

"We were looking to do something else, when we saw life is not the way we expected it to be," Lyons said. "The most exciting discoveries in science sometimes just drop in your lap. In our field, this finding is pretty earth-shaking. It's an entire new mode of energy transfer, which is step one. The next step is to understand how it works. It must be a completely different process."

 

The National Science Foundation has funded ground-based radars which send off radio waves that reflect off the ionosphere, allowing scientists to measure the speed at which the ions in the ionosphere are moving.

 

The radar stations are based in Greenland and Alaska. The NSF recently built the Poker Flat Research Range north of Fairbanks.

 

"The National Science Foundation's radars have enabled us to make this discovery," Lyons said. "We could not have done this without them."

 

The direction of the interplanetary magnetic field is important, Lyons said. Is it going in the same direction as the magnetic field going through the Earth? Does the interplanetary magnetic field connect with the Earth's magnetic field?

 

"We thought there could not be strong convection and that the energy necessary for a substorm could not develop unless the interplanetary magnetic field is southward," Lyons said. "I've said it and taught it. Now I have to say, 'But when you have these fluctuations, which is not a rare occurrence, you can have substorms going off once an hour.'"

 

Lyons and Kim used the radar measurements to study the strength of the interaction between the solar wind and the Earth's magnetosphere.

 

One of their papers addresses convection and its affect on substorms to show it is a global phenomenon.

 

"When the interplanetary magnetic field is pointing northward, there is not much happening, but when the interplanetary magnetic field is southward, the flow speeds in the polar regions of the ionosphere are strong. You see much stronger convection. That is what we expect," Lyons said. "We looked carefully at the data, and said, 'Wait a minute! There are times when the field is northward and there are strong flows in the dayside polar ionosphere.'"

The dayside has the most direct contact with the solar wind.

"It's not supposed to happen that way," Lyons said. "We want to understand why that is."

 

"Heejeong separated the data into when the solar wind was fluctuating a lot and when it was fluctuating a little," he added. "When the interplanetary magnetic field fluctuations are low, she saw the pattern everyone knows, but when she analyzed the pattern when the interplanetary magnetic field was fluctuating strongly, that pattern completely disappeared. Instead, the strength of the flows depended on the strength of the fluctuations.

 

"So rather than the picture of the connection between the magnetic field of the sun and the Earth controlling the transfer of energy by the solar wind to the Earth's magnetosphere, something else is happening that is equally interesting. The next question is discovering what that is. We have some ideas of what that may be, which we will test."

 

Co-authors on the papers include colleagues at Chungbuk National University in South Korea and SRI International in Menlo Park, Calif.

 

For more about the National Science Foundation and the research it supports, visit www.nsf.gov.

 

UCLA is California's largest university, with an enrollment of nearly 38,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university's 11 professional schools feature renowned faculty and offer more than 323 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Four alumni and five faculty have been awarded the Nobel Prize.

 

For more news, visit the UCLA Newsroom or follow us on Twitte

[Ágúst H Bjarnason, 12.9.2009 kl. 09:33]

 The Resilient Earth, 11 September 2009
<http://theresilientearth.com/?q=content/atmospheric-solar-heat-amplifier-discovered>

Atmospheric Solar Heat Amplifier Discovered

Submitted by Doug L. Hoffman on Fri, 09/11/2009 - 15:18

For decades, the supporters of CO2 driven global warming have discounted changes in solar irradiance as far too small to cause significant climate change. Though the Sun&#39;s output varies by less than a tenth of a percent in magnitude during its 11-year sunspot cycle, that small variation produces changes in sea surface temperatures two or three times as large as it should. A new study in Science demonstrates how two previously known mechanisms acting together amplify the Sun&#39;s impact in an unsuspected way. Not surprisingly, the new discovery is getting a cool reception from the CO2 climate change clique.

Scientists have long suspected that changes in solar output may have triggered the Little Ice Age that gripped Europe several centuries ago, as well as droughts that brought down Chinese dynasties. Now, in a report in the August 28 issue of the journal Science entitled &#147;Amplifying the Pacific Climate System Response to a Small 11-Year Solar Cycle Forcing,&#148; Gerald A. Meehl et al. have demonstrated a possible mechanism that could explain how seemingly small changes in solar output can have a big impact on Earth&#39;s climate. The researchers claim that two different parts of the atmosphere act in concert to amplify the effects of even minuscule solar fluctuations.

Solar irradiance variation during 11-year cycles.

Global sea surface temperature (SST) has been observed to vary by about 0.1°C over the course of the 11-year solar cycle. This should require a change in solar irradiance by more than 0.5 W m^&#150;2, but the globally averaged amplitude change from solar maximum to solar minimum is only about 0.2 W m^&#150;2. There has long been a question regarding how this small solar signal could be amplified to produce a measurable response. In fact, the lack of a plausible mechanism has been used to discount the Sun&#39;s effect on climate by those who support carbon dioxide as the primary driver of global warming. That line of argument may no longer be persuasive. As the report&#39;s authors state in the paper&#39;s abstract:

Two mechanisms, the top-down stratospheric response of ozone to fluctuations of shortwave solar forcing and the bottom-up coupled ocean-atmosphere surface response, are included in versions of three global climate models, with either mechanism acting alone or both acting together. We show that the two mechanisms act together to enhance the climatological off-equatorial tropical precipitation maxima in the Pacific, lower the eastern equatorial Pacific sea surface temperatures during peaks in the 11-year solar cycle, and reduce low-latitude clouds to amplify the solar forcing at the surface.

The two mechanisms mentioned have been modeled individually in the past, and neither alone proved sufficient. Prior to this new report both mechanisms had not been included in the same model. Some models operate from the top down, beginning with the small changes in the sun&#39;s ultraviolet radiation that occur during the solar cycle. The enhanced UV radiation, which promotes stratospheric ozone production and UV absorption, warm that layer of the atmosphere differently at different latitudes. The temperature gradients this creates provide a positive feedback amplifying the original solar forcing while affecting the climate in the lower atmosphere.

Other models work from the bottom up, using a mechanism that centers around the equatorial Pacific Ocean. Solar energy added during the peak of a solar cycle causes more water to evaporate from the ocean&#39;s surface. Through a long chain of changes in atmospheric and oceanic circulation, this results in fewer clouds forming in the subtropics. Fewer clouds mean more solar energy reaches the ocean, resulting in a positive feedback loop that amplifies the Sun&#39;s climate impact.

The problem to date has been that neither mechanism had a large enough impact to account for observed temperature changes. Suspecting that the two might reinforce each other if modeled together, Meehl et al. decided to modify some existing climate models: &#147;Here we use several related climate model versions wherein we can include both mechanisms separately (an atmospheric model with no stratospheric dynamics or chemistry coupled to ocean, land, and sea ice; an atmospheric model with stratospheric dynamics and ozone chemistry driven by specified SSTs and sea ice) and then combine them (the atmospheric model with stratospheric dynamics and ozone chemistry coupled to the ocean, land, and sea ice) to test if they can, indeed, amplify the climate system response to solar forcing to produce responses of the magnitude seen in the observations.&#148;

Two existing models were chosen, one each for the two distinct mechanisms identified above. These were a global coupled climate model,the Community Climate System Model version 3 (CCSM3), and a version of the Whole Atmosphere Community Climate Model (WACCM). The first model, CCSM3, has coupled components of atmosphere, ocean, land, and sea ice. It does not have a resolved stratosphere and no interactive ozone chemistry, so the CCSM3 includes only the bottom-up coupled air-sea mechanism. The second model, WACCM, is a global atmospheric model run with climatological SSTs and changes in solar variability with other external forcings are held constant. It has no dynamically coupled air-sea interaction, but does include a resolved stratosphere and fully interactive ozone chemistry that can respond to the UV part of the solar forcing. Given this configuration it should include the top-down UV stratospheric ozone mechanism.

Composite averages for December-January-February (DJF) of peak solar years: Observed SSTs for 11 peak solar years in the left column; Precipitation for three available peak solar years in right column. Credit: G. Meehl, Science.

After confirming that neither model on its own faithfully reproduced the observed changes in temperature over a solar cycle&#151;both predicted changes about a third the size of those observed&#151;a new model was constructed using the atmospheric component from WACCM coupled to the dynamical ocean, land, and sea ice modules in CCSM3. This hybrid model produced negative SST anomalies in the equatorial eastern Pacific of greater than &#150;0.6°C, much closer to the observed values of &#150;0.8°C. In the researchers&#39; words: &#147;Thus, these models indicate that each mechanism acting alone can produce a weak signature of the observed enhancement of the tropical precipitation maxima, but when both act in concert, the two mechanisms work together to produce climate anomalies much closer to the observed values, thus amplifying the relatively small solar forcing to produce significant SST and precipitation anomalies in the tropical Indo-Pacific region.&#148; Results for both SST and precipitation can be seen in the figure above, taken from the report.

Instead of being off by a factor of three as the conventional models were, their new model was within 25% of the actual observed SST variation, a huge improvement indicating that the combination of mechanisms is much more than the sum of their individual effects (see the plot below). This combination of effects enhances precipitation maxima, reduces low-latitude cloud cover, and lowers the temperature of surface waters in the tropical Pacific Ocean, resulting in the larger warm-to-cold variation. &#147;This highlights the importance of stratospheric processes working in conjunction with coupled processes at the surface,&#148; they concluded.

DJF precipitation as observed and from the models. Credit: G. Meehl, Science.

While this result is from modeling, not empirical evidence, it is an important one. As I have often said on this blog, modeling is what you do when your intuition fails you and you need new insights. This combination of mechanisms, building a new hybrid model that simulates conditions not captured by previous models, is a great example of how models should be used. Note that this new model still did not reproduce the observed data, but it did get much closer to reality&#151;an indication that the coupled atmospheric mechanism approach could be on the right track. &#147;The atmosphere and oceans are a big coupled system,&#148; says Joanna Haigh of Imperial College London, who developed the top-down mechanism, &#147;but it&#39;s incredibly complicated.&#148; Of course more physical observations will be necessary to lend credence to this hypothesis, but finding evidence is much easier once the cause is know (or at least suspected).

Why then, should this report be getting the cold shoulder from the climate change community? Writing in the same issue of Science, Richard A. Kerr reported, &#147;like much work in the long-controversial field of sun-climate relations, the new modeling is getting a cool reception.&#148; This is because of what the existence of a coupled atmospheric solar amplifier could mean to climate change theory overall. Though Meehl et al. include the obligatory &#147;this response also cannot be used to explain recent global warming&#148; statement at the end of their report, what remains unsaid is that if this effect is present for decadal solar variations it would also be present for longer term changes in the Sun&#39;s output.

Historical solar irradiance variation.

As I have previously reported, scientific evidence from NASA points to changes in the type of solar radiation arriving at the top of Earth&#39;s atmosphere as a possible trigger for other powerful climate regulating mechanisms. Scientists have discovered, that while total solar irradiance changes by only 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts. According to Judith Lean, a solar physicist at the U.S. Naval Research Laboratory in Washington, D.C., its possible that long-term patterns&#151;operating over hundreds or thousands of years&#151;could cause even more pronounced swings in solar irradiance (see &#147;Scientists Discover The Sun Does Affect Earth&#39;s Climate&#148;). The discovery of the solar heat amplifying effect provides the causal link between historical changes in solar activity and climate change.

Previously, the direct impact of increased irradiance on global avarage temperature has been estimated at around 0.25°C last century&#151;a three fold amplifying effect would raise that to 0.75°C. This leaves practically no warming effect for CO2 to account for and renders the whole anthropogenic global warming argument moot. In other words, if the atmospheric solar amplifier theory is correct anthropogenic global warming is wrong, a useless theory describing a nonexistent phenomenon. It seems like poetic justice that a modeling experiment may point the way to discrediting global warming once and for all.

Be safe, enjoy the interglacial and stay skeptical.

 The Resilient Earth, 11 September 2009
<http://theresilientearth.com/?q=content/atmospheric-solar-heat-amplifier-discovered>

[Ágúst H Bjarnason, 12.9.2009 kl. 09:35]

National Post

http://network.nationalpost.com/np/blogs/fullcomment/archive/2009/09/11/lorne-gunter-global-warming-takes-a-break.aspx

Lorne Gunter: Global warming takes a break

Posted: September 11, 2009, 8:07 AM by NP Editor

Lorne Gunter, climate change

Imagine if Pope Benedict gave a speech saying the Catholic Church has had it wrong all these centuries; there is no reason priests shouldn&#39;t marry. That might generate the odd headline, no?

Or if Don Cherry claimed suddenly to like European hockey players who wear visors and float around the ice never body-checking opponents.

Or Jack Layton insisted out of the blue that unions are ruining the economy by distorting wages and protecting unproductive workers.

Or Stephen Harper began arguing that it makes good economic sense for Ottawa to own a car company. (Oh, wait, that one happened.)

But at least, the Tories-buy-GM aberration made all the papers and newscasts.

When a leading proponent for one point of view suddenly starts batting for the other side, it&#39;s usually newsworthy.

So why was a speech last week by Mojib Latif of Germany&#39;s Leibniz Institute not give more prominence?

Prof. Latif is one of the leading climate modellers in the world. He is the recipient of several international climate-study prizes and a lead author for the United Nations&#39; Intergovernmental Panel on Climate Change (IPCC). He has contributed significantly to the IPCC&#39;s last two five-year reports that have stated unequivocally that man-made greenhouse emissions are causing the planet to warm dangerously.

Yet last week in Geneva, at the UN&#39;s World Climate Conference -- an annual gathering of the so-called "scientific consensus" on man-made climate change -- Prof. Latif conceded the Earth has not warmed for nearly a decade and that we are likely entering "one or even two decades during which temperatures cool."

The global warming theory has been based all along on the idea that the Atlantic and Pacific Oceans would absorb much of the greenhouse warming caused by a rise in man-made carbon dioxide, then they would let off that heat and warm the atmosphere and the land.

But as Prof. Latif pointed out, the Atlantic, and particularly the North Atlantic, has been cooling instead. And it looks set to continue a cooling phase for 10 to 20 more years. "How much?" he wondered before the assembled delegates. "The jury is still out."

But it is increasingly clear that global warming is on hiatus for the time being. And that is not what the UN, the alarmist scientists or environmentalists predicted. For the past dozen years, since the Kyoto accords were signed in 1997, it has been beaten into our heads with the force and repetition of the rowing drum on a slave galley that the Earth is warming and will continue to warm rapidly through this century until we reach deadly temperatures around 2100.

While they deny it now, the facts to the contrary are staring them in the face: None of the alarmist drummers every predicted anything like a 30-year pause in their apocalyptic scenario.

Prof. Latif says he expects warming to resume in 2020 or 2030. "People will say this is global warming disappearing," he added. According to him, that is not the case. "I am not one of the skeptics," he insisted. "However, we have to ask the nasty questions ourselves or other people will do it."

In the past year, two other groups of scientists -- one, like Prof. Latif, in Germany, the second in the United States -- have come to the same conclusion: Warming is on hold, likely because of a cooling of the Earth&#39;s upper oceans. It will resume, though, some day.

But how is that knowable? How can Prof. Latif and the others state with certainty that after this long and unforeseen cooling, dangerous man-made heating will resume? They failed to observe the current cooling for years after it had begun, how then can their predictions for the resumption of dangerous warming be trusted?

My point is they cannot.

It&#39;s true the supercomputer models Prof. Latif and other modellers rely on for their dire predictions are becoming more accurate. A major breakthrough last year in the modelling of past ocean currents finally enabled the computers to recreate the climate history of the 20th century (mostly) correctly.

But getting the future equally correct is far trickier. Chances are some unforeseen future changes to real-world climate or further modifications to the UN&#39;s climate computers will throw the current predictions out of whack long before the forecast resumption of warming.

National Post
[e-mail]

 http://network.nationalpost.com/np/blogs/fullcomment/archive/2009/09/11/lorne-gunter-global-warming-takes-a-break.aspx

[Ágúst H Bjarnason, 12.9.2009 kl. 09:38]

 WASHINGTON POST: A SKEPTICAL TAKE ON GLOBAL WARMING

The Washington Post, 10 September 2009
<http://voices.washingtonpost.com/capitalweathergang/2009/09/a_skeptical_perspective_on_glo.html>

Matt Rogers

This Capital Weather Gang blog entry is written with considerable trepidation given the politically-charged atmosphere surrounding human-induced global warming.

I am a meteorologist with a life-long weather fascination. As I&#39;m sure you know, meteorology is an inexact science due to the large number of variables involved in predicting and understanding the weather. I frequently say that weather forecasting is a humbling endeavor, and I have learned to respect its challenges. From this perspective, you might be able to better understand why I wince when hearing pronouncements such as "the science is settled", "the debate is over", or even the "the temperature in the 2050s is projected to be..." I realize that forecasting climate and weather are different, but both involve a large number of moving parts.

There are numerous reasons why I question the consensus view on human-induced climate change covered extensively on this blog by Andrew Freedman. But for this entry, I scaled them down to ten:

(10) Hurricanes: One of the strongest value propositions presented for fighting global warming is to slow tropical cyclone intensity increases. Katrina was cited as a prime example. But the storm only made landfall as a category three (five being strongest) and affected a city built below sea level. Stronger storms have hit North America before, but the Katrina route and the weak levees made this situation much worse. I follow global hurricane activity closely and earlier this summer, we reached a record low. Florida State has a site that tracks global hurricane activity here. Since the 1990s, this activity has been decreasing, which goes against what we were told to expect on a warming planet.

(9) Ice Caps: In 2007, the Northern Hemisphere reached a record low in ice coverage and the Northwest Passage was opened. At that point, we were told melting was occurring faster than expected, and we needed to accelerate our efforts. What you were not told was that the data that triggered this record is only available back to the late 1970s. Prior to that, we did not have the satellite technology to measure areal ice extent. We know the Northwest Passage had been open before. In Antarctica, we had been told that a cooling of the continent was consistent with global climate models until a recent study announced the opposite was true. The lack of information and the inconsistencies do not offer confidence.

(8) El Niño: This feature in the Tropical Pacific Ocean occurs when water temperatures are abnormally warm. Some climate change researchers predicted that global warming would create more and stronger El Niño events like the powerhouse of 1997-98. Indeed in 2006, esteemed climate scientist James Hansen, predicted this. But we are now about to complete an entire decade without a strong El Niño event (three occurred in the 1980s-1990s). So the more recent 2007 IPCC report backtracked from Hansen&#39;s prediction, noting that there were too many uncertainties to understand how El Niño will behave with climate change. Recent research speaks to how important El Niño is to climate. In the past two decades, these warm El Niño and opposite cold La Niña events have accentuated the global temperature peaks and valleys highlighting the importance of natural variability and the limitations of the science.

(7) Climate Models: To be blunt, the computer models that policy-makers are using to make key decisions failed to collectively inform us of the flat global land-sea temperatures seen in the 2000s (see more on this in item 5 below). The UN IPCC did offer fair warning of model inadequacies in their 2007 assessment. They mentioned a number of challenges, which is wholly reasonable since countless factors contribute to our global climate system--many of them not fully understood. My belief is that they are over-estimating anthropogenic (human) forcing influences and under-estimating natural variability (like the current cold-phase Pacific Decadal Oscillation and solar cycles). The chaos theory describes why it is far more difficult to project the future than climate scientists may realize (I give them a break here since climate modeling is in its relative infancy). We poor hapless meteorologists learned the chaos theory lesson long ago.

(6) CO2 (Carbon Dioxide): The argument that the air we currently exhale is a bona fide pollutant due to potential impacts on climate change flummoxes me. CO2 is also plant food. Plants release oxygen for us, and we release CO2 for them. Over the summer, CO2 reached almost .04% of our total atmosphere as reported here. Because CO2 is but a sliver of our atmosphere, it is known as a "trace gas." We all agree that it is increasing, but is there a chance that our estimate of its influence on the Greenhouse Effect is overblown given its small atmospheric ratio?

(5) Global Temperatures: As a meteorologist, verification is very important for guiding my work and improving future forecasts. The verification for global warming is struggling. Three of four major datasets that track global estimates show 1998 as the warmest year on record with temperatures flat or falling since then. Even climate change researchers now admit that global temperature has been flat since that peak. As shown above, the CO2 chart continues upwards unabated. If the relationship is as solid as we are told, then why isn&#39;t global temperature responding? I&#39;m told by climate change researchers that the current situation is within the bounds of model expectations. However, when I look at the IPCC 2007 AR4 WG1 report, I can see that without major warming in the next 1-2 years, we will fall outside those bounds. This is why I believe James Hansen is predicting a global temperature record in the next two years.

(4) Solar Issue: Look for this issue to get bigger. Our sun is currently becoming very quiet. Not only is the number of sunspots falling dramatically, but the intensity of the sunspots is weakening. The coincident timing of major solar minimums with cooler global temperatures (such as during the Little Ice Age) suggests that maybe the sun is underestimated as a component for influencing climate. The second half of the twentieth century (when we saw lots of warming) was during a major solar maximum period- which is now ending. Total solar irradiance has been steady or sinking similar to our global temperatures over much of this past decade. Indeed, recent research has suggested the solar factor is underestimated (here and here). Perhaps one day, we&#39;ll have a different version of James Carville&#39;s famous political quote...something like "It&#39;s the sun, stupid!"

(3) But what about...? Ultimately after I explain my viewpoint on climate change, I get this question: "But what about all this crazy weather we&#39;ve been having lately?" As a student of meteorology, we learned about amazing weather events in the past that have not been rivaled in the present. Whether it was the 1900 Galveston Hurricane, the 1889 Johnstown Flood, or even the worst tornado outbreak in history (1974), we have and will continue to see crazy weather. Very few statistics are available that correctly show an increase in these "crazy" events.

(2) Silencing Dissent: I believe the climate is always changing. But what percentage of that change is human-induced? Like most, I believe that a more balanced energy supply benefits us politically due to the reduced reliance on foreign sources and benefits us locally due to improved air quality. But several times during debates individuals have told me I should not question the "settled science" due to the moral imperative of "saving the planet". As with a religious debate, I&#39;m told that my disagreement means I do not "care enough" and even if correct, I should not question the science. This frightens me.

(1) Pullback: Does climate change hysteria represent another bubble waiting to burst? From the perspective of the alarmism and the saturation of the message, the answer could be yes. I believe that when our science or economic experts tend to be incorrect, it usually involves predictions that have underperformed expectations (Y2K, SARS, oil supply, etc). Can we think of any other expert-given, consensus-based, long-term predictions that have verified correctly? Not one comes to mind. I believe that predictions of human-caused climate change will continue to be overdone, and we&#39;ll discover that natural factors are equally and sometimes even more important.

Copyright 2009, WP

http://voices.washingtonpost.com/capitalweathergang/2009/09/a_skeptical_perspective_on_glo.html

[Ágúst H Bjarnason, 12.9.2009 kl. 09:42]

Daily Express

BRITS &#39;LOSING FAITH&#39; IN CLIMATE CHANGE SCIENTISTS

Daily Express, 11 September 2009
<http://www.express.co.uk/posts/view/126606/Sceptical-Britons-losing-faith-in-climate-change-scientists>

By Emily Garnham

BRITONS are becoming less trusting of scientists who say climate change is caused by humans, according to new research.

Almost a third of people questioned (29 per cent) believed evidence linking human activity and global warming had been exaggerated - a figure which has doubled since 2003.

A quarter of those surveyed thought the evidence was &#147;unreliable&#148;, while a third said there was too many &#147;conflicting&#148; views on the environment.

One in five people thought climate change was caused by natural temperature fluctuations and half blamed the media for being too alarmist.

The research, led by Dr Lorraine Whitmarsh from Cardiff University, polled 551 people of ranging ages and backgrounds last year.

Four in ten believe leading experts still question the causes of climate change

Their attitudes to climate change were compared with another survey carried out six years ago.

The findings were unveiled by Dr Whitmarsh at the British Science Festival in Guildford.

She said: &#147;What was really striking was a doubling of the proportion of people saying claims that humans are changing the climate are exaggerated.

&#147;More people now seem to have some degree of scepticism or doubt.

&#147;It might be to do with the fact that some aspects of climate change involve uncomfortable truths.

&#147;People are understandably reluctant to change their lifestyles, and there may be some residual uncertainty that they latch onto.

&#147;They might be prepared to recycle, or unplug appliances when they&#146;re not in use, but there&#146;s a lot of unwillingness to make major changes to things like transport and food.&#148;

Today, as before, there was a &#147;hard-line&#148; group of about 20 per cent who firmly refused to believe human activity had any impact on global warming, Dr Whitmarsh said.

Copyright 2009, Express

[Sveinn Atli Gunnarsson, 12.9.2009 kl. 09:52]

Sæll Ágúst

Það er aldeilis það eru komnar margar og langar athugasemdir hjá þér :)

Hér er tengill á mýtu um áhrif sólar á hitastig sem tekin er fyrir á síðunni Loftslag.is.  Kenningar Svensmark eru einmitt umtalaðar þarna á síðunni. Gæti verið semmtilegt mótvægi við þessa færslu. Kannski ágætis mótvægi við þessa færsluna þína...fyrir þá sem vilja skoða þetta nánar...

[Albert Albertsson (IP-tala skráð) 12.9.2009 kl. 12:27]

Kæri Ágúst,

í upphafi verð ég að biðja þig afsökunar á því að hafa í síðustu athugasemd minni rangnefnt þig Ásbjörn, sem stafar af því, að þegar ég ritaði athugasemdina hafði ég nýlokið við að lesa greinargerð um málmtæringu eftir Ásbjörn okkar Einarsson. Athugasemdir þínar og tilvitnanir eru áhugaverðar fyrir margra hluta sakir. Það hvernig athugasemdir almennings og tiltrú hans á kenningum og spám sjálfskipaðrar "vísinda-elitu" hafa breyttst er merkilegt. Síbylju áróður, sem gerir m.a. ráð fyrir illa upplýstum almenningi virðist nú á undanhaldi. Það sem mér fannst áhugaverðast var frásögnin af líkanreikningunum, sem spiluðu saman "top down" og "bottom up" áhrifunum á SST.  Kenning Henriks Svensmark virðast mér a.m.k. að hluta styðja og skýra líkanniðurstöðurnar enn frekar. Nú virðist vera að kristallast heildstæð kenning/skýring á flóknum veðrabrigðum og er það vel. Punktarnir 10 hans Matt Rogers eru greinargóðar og auðskildar "macro" skýringar. Matt hittir ef til vill naglann á höfuðuð þegar hann segir að reiknilíkönin og þær hugmyndir og aðgengileg "skammtíma" gögn, sem byggt er á hafi ekki enn slitið barnskónum. Til að ljúka þessu vil ég minnast á þá furðulegu frétt, að aukinn styrkur kolsýru í andrúmsloftinu geti átt drjúgan þátt í því að koma af stað eldgosum. Hefur þú rekist á einhver skrif um þetta? Sé lítil ísöld í uppsiglingu þá er gott að eiga jarðhitann því ég á erfitt með að trúa að aukin kolsýra geti haft áhrif á það sem gerist í miðju jarðar eða hvað. Um áratuga skeið hef ég haldið því fram að jarðhitakolsýran sé auðlind, sem beri að nýta en ekki mengunarstraumur. Það sem ég hef lesið og sem að verulegu leiti er komið frá þér gerir það að verkum að ég mun halda mig við þessa skoðun þar til annað kemur í ljós. Kærar kveðjur og einlægar þakkir fyrir ánægjulegt og fræðandi efni.

[Ágúst H Bjarnason, 12.9.2009 kl. 14:13]

Sæll Svatli.

Vissulega eru kenningar Henriks Svensmark mjög umdeildar. Sem betur fer vil ég meina, því ekkert er eins hættulegt vísindum og að telja að menn séu samdóma um að eitthvað sé rétt, og að óþarfi sé að ræða málið frekar. Scienific consensus kallast það víst stundum. Sem betur fer komast vísindin þó yfirleitt yfir slíka þröskulda, þó þeir tefji fyrir. Ég fjallaði eitthvað um það í athugasemdunum á síðu þinni um daginn.

Ég þakka þér fyrir að birta á síðu þinni umfjöllun um Svensmark. Menn eiga auðvitað ekki að gleypa allt gagnrýnislaust, og eru kenningar Henriks ekki undanskildar.

Ég skellti inn í morgun nokkrum greinum sem birtust flestar í gær. Tilgangurinn var að benda á hve þessi mál eru mikið í umræðunni erlendis.

[Ágúst H Bjarnason, 12.9.2009 kl. 15:49]

Sæll Albert.

Auðvitað skildi ég það vel þegar þú ávarpaðir mig Ásbjörn, og sá þig jafnvel fyrir mér vera að pæla í flóknum jarðvarmavandamálum með vin okkar Ásbjörn í huga. Stundum skrifa puttarnir annað en maður hugsar, það þekki ég vel. Auðvitað er bara mikill heiður að því að vera ruglað saman, þó aðeins sé eitt augnablik, við svo færan vísindamann sem Dr. Ásbjörn. 

Ég reyndi að skilja samhengi hnatthlýnunar (ekki endilega af mannavöldum) og eldgosa. Fyrst kom mér til hugar kenning Trausta Einarssonar, er kenndi mér í gamla daga við HÍ, um það hvernig úrkoma sem treður sér niður í glufur í jarðskorpunni, geti valdið spennu sem losar upp bergið í glufunum, þannig að vatnið kemst enn neðar, o.s.frv. Bergið brotnar upp langt niður í jörðina. Þannig var hugsanlega hægt að ímynda sér auknar líkur á eldgosum eftir rigningasumur, ef ég man rétt. (Hvers vegna ekki þá einnig eftir vatn frá bráðnuðum jöklum?). Gott ef það var ekki ítarleg fræðigrein um þetta í Tímariti VFÍ fyrir svo sem þrem til fjórum áratugum. Síðan kom mér til hugar að mönnum hefði hugkvæmst að þegar farg jöklanna minnkar, að þá séu meiri líkur á að kvikan brjóti sér leið upp. Það gerist auðvitað aðeins á eldvirkum svæðum undir eða við jökla. Annars skil ég ekki almennilega þetta samhengi og tel varla að það geti verið mikið.

[Sveinn Atli Gunnarsson, 12.9.2009 kl. 17:57]

Það er enginn að segja að ekki eigi að ræða málin frekar. Mjög fíint að benda á veikar hliðar í öllum málflutningi varðandi þessi mál ;)

Frá mínu sjónarhorni, þá lítur þetta þannig út að kenningar Svensmark (eins áhugaverðar og þær nú eru) eru almennt ekki taldar geta afsannað neitt í kenningunum um loftslagsbreytingar af mannavöldum. Þetta er svolítið spurningin um hvað er drífandi þáttur í þessu tilliti. Ég get ekki séð að kenningar hans útskýri hvað hefur valdið þeirri hækkun hitastigs sem orðið hefur á síðustu áratugum, þar liggur kannski hundurinn grafinn. En það er almenn sátt (það er aldrei hægt að fá alla til að vera sammála) um að loftslagsbreytingar þær sem nú eru yfirstandandi séu vegna aukningar gróðurhúsalofttegunda í andrúmsloftinu. Að sjálfsögðu verða svo sveiflur og er það hluti af hinum náttúrulegu sveiflum. Þessar náttúrulegu sveiflur geta t.d. sólargeislun, Enso-fyrirbærin og öðru í þeim dúr, sem m.a. veldur því að hitastigið stígur ekki í beinni línu, heldur koma fram sveiflur og jafnvel getur hitastig lækkað um tíma.

[Ágúst H Bjarnason, 12.9.2009 kl. 18:40]

Við erum örugglega sammála um margt Svatli, en kannski ekki allt, Sjálfur hef ég mikinn áhuga á því sviði rannsóknanna sem tengjast nábýli okkar við breytistjörnuna sól, svipað og kemur fram í umfjöllunum í athugasemdum 4 og 5, og svo auðvitað Svensmark...

Ég yrði manna ánægðastur ef Svensmark og fleiri sem hafa spáð kuldakasti næstu áratugina í tengslum við lægð í virkni sólar reyndust hafa rangt fyrir sér og ef við gætum notið hlýindanna hér áfram.

[Ágúst H Bjarnason, 12.9.2009 kl. 19:31]

Það er vel fylgst með sólinni og segulhvolfi jarðar í dag. Fjöldi gervihnatta tekur þátt í rannsóknunum.

Stærri mynd hér. 

++

[Sveinn Atli Gunnarsson, 12.9.2009 kl. 19:54]

Já, ætli við séum ekki sammála um margt, enda margt áhugavert undir sólinni ;)

Ég hugsa að ég yrði ánægðari ef Svensmark hefði rétt fyrir sér, þá væri vandamálið af öðrum toga en annars. Ég tel bara ekki að þeir þættir sem hann nefnir geti verið drífandi þættir varðandi þá hitastigshækkun sem verið hefur á undanförnum áratugum, eftir að hafa kynnt mér þessi mál. Hugsanlega eru þetta hlutir sem geta haft áhrif á hina náttúrulegu sveiflu, en að þetta sé drífandi þáttur það held ég ekki að geti verið.

[Ágúst H Bjarnason, 12.9.2009 kl. 22:09]

Ég uppfærði ensku þýðinguna í pistlinum. Þar var illa gerð Google þýðing, en nú er komin þar þýðing úr dönsku yfir á ensku eftir Nigel Calder, þýðing sem Henrik Svensmark hefur samþykkt.

[Höskuldur Búi Jónsson, 13.9.2009 kl. 10:28]

Það eru töluverðar rangfærslur í þessu hjá Svensmark.

Hann segir að það sé að kólna en ekki hlýna: Það er rangt, reyndar miðað við niðursveifluna sem er í sólinni þá ættu efasemdarmenn loks að vera búnir að átta sig á því að hlýnunin er ekki af völdum sólarinnar - því annars væri skítakuldi á jörðinni.

Hann talar um hlýindaskeið á miðöldum (sem reyndar var staðbundin við Norður Evrópu) og gefur í skyn að sveiflur í sólinni hafi ráðið þar - er ekki líklegt að sveiflur í t.d. NAO ráði þar mun meira, þar sem þetta var bara staðbundið frávik - sólin skýn á alla jörðina ekki satt.

Litla ísöldin hefur almennt séð verið talin af völdum niðursveiflu í sólinni, auk annarra þátta - t.d. eldvirkni og fjarlægð jarðar á sporbaug um sólu - nýleg rannsókn bendir reyndar til þess að hiti jarðar hafi verið á hægri niðursveiflu vegna aukinnar fjarlægðar jarðar á sporbaug um sólu og að það hafi ráðið hvað mestu um hitastig jarðar - þar til iðnbyltingin hófst með þeirri losun á CO2 sem er af völdum manna.

Af ofangreindu að ráða þá getur niðurstaða Svensmarks varla verið rétt - vissulega hafa sveiflur í sólinni áhrif, en þessar sveiflur eru mun minni en svo að þær hafi ráðandi áhrif á loftslag.

[Ágúst H Bjarnason, 13.9.2009 kl. 11:12]

Höski Búi:

1) Henrik Svensmark á vafalítið við hlýnunina síðastliðin 7 ár, en hún hefur greinilega stöðvast. Hitastig lofthjúps jarðar hefur staðið í stað á þessum tíma þrátt fyrir að ekkert lát hafi veið á aukningu CO2. Það er samt rétt að hitastigið hefur haldist hátt.  (Ég tek ekki mið af niðursveiflunni síðustu mánuði og læt hana liggja á milli hluta, enda að öllum líkindum um að ræða áhrif frá La-Nina). NOAA gerir ráð fyrir í síðustu spá sinni El-Nino næstu mánuði, þannig að við ættum að öðru jöfnu að sjá hækkun hitastigs í einhvern tíma.

2) Hlýindaskeiðið á miðöldum var hnattrænt fyrirbæri. Ekki takmarkað við Norður Evrópu. Það benda rannsóknir víða um heim til.

3) Vissulega horfa menn til niðursveiflunnar í virkni sólar og þeirrar staðreyndar að virkni sólar og hitafar fylgdist þá að þegar menn hafa áhyggjur af hitafarinu næstu áratugina. 

4) Við þurfum væntanlega ekki að bíða í mörg ár til að komast að raun um hvort Svensmark og fleiri hafa rétt fyrir sér.

Muni kólna verulega í takt við verulega minnkun í virkni sólar, þá er ekki ólíklegt að hann hafi haft rétt fyrir sér.

Haldi aftur áfram að hlýna með svipuðum hraða og í lok síðustu aldar og ef sólin stefnir í lægð. þá hefur hann haft rangt fyrir sér. 

Það er víst best að fullyrða sem minnst núna, heldur bíða bara í áratug eða svo