When Bob Foster posted a note here in April claiming that the sun drives climate and the next little ice age will be in 2030 he was roundly condemned by many AGW believers.
Now there is an article in New Scientist also suggesting “that the sun is about to enter another quiet period”.
The abstract includes comment that:
“It is known as the Little Ice Age. Bitter winters blighted much of the northern hemisphere for decades in the second half of the 17th century. The French army used frozen rivers as thoroughfares to invade the Netherlands. New Yorkers walked from Manhattan to Staten Island across the frozen harbour. Sea ice surrounded Iceland for miles and the island’s population halved. It wasn’t the first time temperatures had plunged: a couple of hundred years earlier, between 1420 and 1570, a climatic downturn claimed the Viking colonies on Greenland, turning them from fertile farmlands into arctic wastelands.
Could the sun have been to blame? We now know that, curiously, both these mini ice ages coincided with prolonged lulls in the sun’s activity – the sunspots and dramatic flares that are driven by its powerful magnetic field.
Now some astronomers are predicting that the sun is about to enter another quiet period.“
You can read the full article ‘Global warming: Will the Sun come to our rescue?’ by Stuart Clark which was published on 18th September by clicking here.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Assuming the next Little Ice Age arrives on schedule and the CO2 theorists stick to their story, will we see them demanding an increase in CO2 emissions 24 years from now?
Probably not.
Schedule ? Theorists – Schills – you don’t like empirical evidence offered previous threads thsi week?
Of course the article isn’t journal published as such and one could argue about some of the science. But for the sake of the argument let’s take the science at face value and indulge the hypothesis.
The point is that it’s not a question of either / or – solar forcing can be as relevant as CO2. CO2 forcing doesn’t go away. The CO2 physics is still OK – as would be volcanism and other radiation blocking influences if impacting.
So the articles concludes with a very interesting sting in the tail for the complacent.
“The coming years could settle the sun’s role on temperatures once and for all. If the expected sunspot crash does takes place, Solanki’s work could receive dramatic confirmation. “Having a crash would certainly allow us to pin down the sun’s true level of influence on the Earth’s climate,” says Weiss.
None of this means that we can stop worrying about global warming caused by emissions into the atmosphere. “The temperature of the Earth in the past few decades does not correlate with solar activity at all,” Solanki says. He estimates that solar activity is responsible for only 30 per cent, at most, of the warming since 1970. The rest must be the result of man-made greenhouse gases, and a crash in solar activity won’t do anything to get rid of them.
What might happen is that the sun gives the planet a welcome respite from the ravages of man-made climate change – though for how long, nobody knows. During the Little Ice Age, the fall in average global temperature is estimated to have been less than 1 °C and lasted 70 years. The one before that persisted for 150 years, but a minor crash at the beginning of the 19th century lasted barely 30. For now, we will have to keep watching for falling sunspot numbers. “The deeper the crash, the longer it will last,” Weiss says.
There is a dangerous flip side to this coin. If global warming does slow down or partially reverse with a sunspot crash, industrial polluters and reluctant nations could use it as a justification for turning their backs on pollution controls altogether, making matters worse in the long run. There is no room for complacency, Svalgaard warns: “If the Earth does cool during the next sunspot crash and we do nothing, when the sun’s magnetic activity returns, global warming will return with a vengeance.””
And therein lies the lesson !
Luke,
It is very hard to get empirical evidence of future events.
I suggested that CO2 AGW theorists would not demand an increase in CO2 emissions as the world plunges into a cold phase for a reason. The reason is that I anticipated your response:
“None of this [about solar-related global cooling] means that we can stop worrying about global warming caused by emissions into the atmosphere.”
The principle of charity requires me to avoid the all too obvious conclusion that CO2 AGW theorists have decided that the best of all possible worlds is the coldest. According to the principle of charity, someone who talks is trying to make sense; accordingly, it is best not to initially conclude that the talker is advocating preposterous idiocy. After all, more CO2 is produced to combat cold weather than hot weather.
Therefore I must conclude that CO2 AGW theorists are more concerned about emissions than about climate. Which leads to preposterous idiocy again, because there’s no point in worrying about emissions without an identified impact on something or other–and CO2 AGW theorists insist the impact is warming. Which leads right back to the first uncharitable interpretation.
Now I’ve run out of charitable interpretations. CO2 AGW theorists merely want to impose a global “planned ecology” and they’ll hang their hat on the nearest, most convenient hook every time.
Might not be a charitable interpretation, but it’s the only one I’ve seen that plausibly explains most of the huffing and puffing over CO2 AGW.
“industrial polluters and reluctant nations could use it as a justification for turning their backs on pollution controls altogether, making matters worse in the long run.”
And therin lies the purpose of promoting this as headline only on a blog!
But if this were to come to pass (hope there were no computer models involved in making this prediction, we don’t trust them compooters), it could indeed be the second chance humanity might end up needing.
There’s a bias inherent in this statement: “industrial polluters and reluctant nations could use it as a justification for turning their backs on pollution controls altogether, making matters worse in the long run.”
Claims of “pollution” merely mean that something someone doesn’t like had been detected. The popular craze for “no detectable levels” has nothing to do with causing environmental damage. The environmentalists would like us to assume that any detectable level is too much, but we must extend charity to ourselves as well.
We are not so wretched that we would believe environmentalists are so stupid as to believe that “any detectable level” is damaging, are we? After all the dose makes the poison, and as everyone knows, the most deadly substance on the planet is water.
Surely better sense can be made of the expostulations of environmentalists, who by their collective designation are obviously concerned with what makes life good for all of us, i.e., the environment.
Schills – mate – pls try to pay attention. Empirical evidence of the CO2 warming we have enjoyed this far. Did I say future? But anyway do you have any reason to suggest that an effect that works now won’t work in the future?
Pls read previous links and consider. It ain’t no theory – it’s physically measured sealed and delivered. What’s wrong with the evidence I have presented this week – are you telling me if you went out into your corn field and measured something you wouldn’t believe it?
And yes Schills you get one debating point for picking on their use of the word “pollution” – I didn’t like it either but doesn’t change the message or intent. Yes CO2 like water isn’t “inherently” toxic as say cyanide. But let’s not chase that time-wasting rabbit. And it was a journalist not necessarily a greenie that wrote the said article.
Until we get a sworn statement from the Sun, all we have is empirical evidence. But the Royal Society was almost certainly wrong in 1892 when its President (The Lord Kelvin) asserted that the correlation between events on Sun and Earth is “mere coincidence”. The Society hasn’t yet changed its view – and is followed to this day by the Great and the Good (and now, by IPCC). A plausible comtrarian hypothesis to the people-driven climate proffered up by the “mainstream”, is that ours is not an autonomous planet travelling in an empty Universe. External climate-drivers operate in (at least) three ways. AYE The best-documented is widely-variable eruptive activity on the Sun (I am not talking here of little-varying total solar irradiance, but of solar wind). Variation in the outflow of charged particles from the Sun is inertially-driven, because the collective motions of the giant planets around the centre-of-mass of the solar system apply enormously-variable torque to the Sun. Thus the Sun has a very irregular orbit – which can be calculated (ie predicted). BEE The inner planets orbit the Sun, and must also be inertially influenced by those giants. Probably, Pacific Decadal Oscillation (PDO) variations – increased upwelling of cold deep water in the equatorial eastern Pacific from the mid-1940s, and reduced upwelling after the Great Pacific Climate Shift of 1976/7 – are driven also by the outer giants. If so, PDO should shift back very soon to its cooler phase – perhaps in 2007. CEE Earth’s magnetic polarity changes infrequently, but that of the Sun reverses at the peak of each 11-year (Schwabe) sunspot cycle. Thus we have a 22-year (Hale) solar-magnetic cycle. A study of South Africa over the last four Hale cycles, shows that Hale dominates rainfall variation there. There is more. But we have enough already to predict future climate change. Despite all the money thrown at IPCC and its fellow-travellers, they can only do uni-directional projections. Planners need predictions.
Luke,
Glad to see you’re on board! Since you believe the global thermostat can be adjusted with CO2, you’ll surely be advocating an increase in greenhouse gases for as long as it takes to keep us cozy during the cold spell.
Schills, schills, .. .. so YOU agree then too that CO2 warms – but think if the cold spell only last 30 years – time to get that mind thinking about things more broadly old son. “Greenhouse will be back with a vengeance !”
Fosbob – yes all fascinating – but you really have a theory or just a few co-incidences? Serious question. There’s other explanations for PDO and 1976/77. And the IPCC and many climatologists reject solar cycles – reason not good enough stats, lack of mechanisms and false skill. Why Inigo Jones stuff doesn’t work etc. Don’t get me wrong – still all very interesting.
But for the scientifically minded why would one not entertain both solar and greenhouse mechanisms. Why – simply because greenhouse gets at our energy systems and that causes a bad case cognitive dissonance with our way of life.
Luke, the theory that inertial influences in the solar system are a far more influential driver of earthly climate (at the global scale – ignore urban heat island effect, land-use changes, etc) than are people, is supported by observations which I call “correlations” and the Royal Society calls “mere coincidence”. Just one example will surfice: Inflection points in the rate-of-change of rotary force (torque), applied by the giant outer planets to the Sun, correlate with inflection points in rate of change of length-of-day on Earth. LOD correlates in turn with PDO, and probaly to an extent with El Nino/La Nina variability. PDO is a dominant influence in world climate at the decadal level. On the other hand, IPCC sees extra-terrestrial influences in climate largely in terms of variation in total solar irradiance (TSI) – and virtually ignores inertia. IPCC says human-caused greenhouse warming has risen to 2.4 Watts/square metre since the industrial revolution. Crowley in 2000 (Science, v.289 pp.270-7) estimated that TSI fell only a picayune 0.3 W/sq.m. between the start of the Maunder Minimum (say, before 1640) to its nadir in about 1690. People died in droves then – with, surely, some other natural cause than TSI change. From about the mid 1980s to the late 1990s Earth brightened (ie less cloud) to give greater solar access to Earth’s surface by about an extra 6-10 W/sq.m.. This whopping change may (we don’t know) have something to do with reversed magnetic polarity on the Sun. The Great and the Good control the disbursement of tax-payer’s money. Why don’t they spend some of it on climate PREDICTIONS, based on the hypothesis of a variable Sun-Earth connection – which can be calculated in advance. Instead, it goes on virtually worthless PROJECTIONS based on the implausible hypothesis of a people-driven climate. Lives could be saved, if planners addressed the next Little Ice Age cold period (Landscheidt Minimum), and the next mega-failure of the Indian monsoon, in timely fashion.
Bob, the fact that the theory of inertial influences on climate leads to predictions, which can be tested against observations, differentiates it strongly from AGW theory.
If I understand what you are saying, there should be an inflexion point in LOD rate of change coming up in 2007. Is this correct? Would these inertial influences be expected to cause an increase in earthquakes, and if so, are we noticing such an increase?
Paul – “AGW theory” “cannot be tested” – that’s not so at all as Philipona’s and Harries papers show. And we have a recent Nature paper that finds no luminosity predictors. Variations in solar luminosity and their
effect on the Earth’s climate
P. Foukal1, C. Frolich2, H. Spruit3 & T. M. L. Wigley4cVol 443|14 September 2006|doi:10.1038/nature05072
“..between 1420 and 1570, a climatic downturn claimed the Viking colonies on Greenland, turning them from fertile farmlands into arctic wastelands”
So how fertile were the farmlands in Greenland?
I have learned from my Nordic sources that it was not possible to grow any crops in Greenland, all grain was imported from Iceland and Norway, you only had the hay for the animals…
Once again regarding the Viking colonies in Greenland, they were established only in the south coast and southwest parts of Greenland, not much difference from today.
The rest of Greenland was only an ice sheet, not much green in sight … makes you wonder if the Greenland warming had something to do with Ocean currents…
The same was the case with the Viking establishments in Canada. Only Newfoundland was suitable to live in for the Viking, more northern parts were too cold , like Baffin Island…
Hi Ann,
Some basic info on the Greenland was Green myth here:
http://illconsidered.blogspot.com/2006/03/greenland-used-to-be-green.html
The Sun’s not to blame:
http://www.eurekalert.org/pub_releases/2006-09/ncfa-cis091106.php
Or the sun is 50% to blame:
http://www.fel.duke.edu/~scafetta/pdf/2006GL027142.pdf
If the trend holds, Solar Cycle 25 in 2022 could be, like the belt itself, “off the bottom of the charts.”
http://science.nasa.gov/headlines/y2006/10may_longrange.htm
I noticed this when looking at archived proxy temperature reconstruction data:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/speleothem/europe/italy/ernesto2003.txt
Frisia, S., A. Borsato, N. Preto, and F. McDermott. 2003.
Late Holocene annual growth in three Alpine stalagmites records the influence of solar activity and the North Atlantic Oscillation on
winter climate.
Earth and Planetary Science Letters, Vol. 216, Issue 3, pp.231-439,
30 November 2003.
ABSTRACT:
Annual growth rates and the ratio of dark to light-colored calcite within
single annual laminae in three contemporaneously deposited Holocene
speleothems from Grotta di Ernesto, an Alpine cave in northern Italy,
respond to changes in surface temperature rather than precipitation.
Based on monitoring of present-day calcite growth, and correlation with
instrumental data for surface climatic conditions, we interpret a higher
ratio of dark to light-colored calcite and the simultaneous thinning of
annual laminae as indicative of colder-than-present winters. Such dark
and thin laminae occur in those parts of the three stalagmites deposited
from AD 1650 to 1713 and from AD 1798 to 1840, as reconstructed through
lamina counting. These periods correspond to the well-known Maunder and
Dalton Minima of solar activity. An 11-yr cyclicity in growth rate,
coupled with reduced calcite deposition during the historic minima of
solar activity, is indicative of a solar influence on lamina thickness.
Spectral analysis of the lamina thickness data also suggests that the
North Atlantic Oscillation variability influenced winter temperatures.
Based on the present-day controls on cave calcite formation, we infer
that high-frequency changes in solar activity modulated the seasonal
duration of soil CO2 production.
Paul Biggs,
I have only had a quick scan of the four references you have made, and couldnt really see that they are in violent conflict with the proposition that, the sun is involved one way or tother,in the long term patterns of climate on earth, and its average temperatures.
Add this to Fosbobs posts as above, then the IPCC would be incompetent not to consider all aspects of the suns influence. But as yet another artifice of the increasingly inept UN it is probably too much to expect from the poor darlings.
I don’t see why anyone in the southern hemisphere is concerned about global warming, even if it is taking place, because it is a purely northern hemispere problem.
The total emissions from southern hemisphere nations are well within the capacities of southern landscapes and oceans to deal with.
It is only the northern hemisphere nations whose emissions are in sufficient volume and concentration as to pose such a problem that their landscapes and oceans are incapable of dealing with.
And, true to form, they seek to export the cost of their problem to everyone else whilst maintaining very tight restrictions on access to the very markets that underpin those emissions.
In political and social terms, they will not share the benefits of their wealth with the rest of the world but want to share the cost of their wealth with everyone.
And the argument that sooner or later their problem will become our problem is fatuous. If they have all sorts of “competitive advantages” that they can go to great lengths to protect then we have every right to protect, maintain and enjoy our own competetive advantages.
And foremost amongst our competetive advantages is the fact that we have a comparatively small population with emissions that are almost entirely absorbed by our landscape alone, let alone absorbed by our oceans.
There is nothing wrong with our oceans providing a service to all humanity by absorbing northern hemisphere emissions. But if there is to be a system of accounting for all emissions and adding a cost to them which is fully tradeable, then it is equally appropriate that the absorbtion function should have a revenue stream for that service funded by the northern hemisphere producers of surplus emissions.
They can’t have it both ways.
Ian have you gone potty?
“even if it is taking place” was that a stress crack.
“small population with emissions that are almost entirely absorbed by our landscape alone”
On the basis of what. You’re now saying Australia is a nett sink?
Yes I know we’re you’re coming from – if you conveniently forget the rest of the world. But perhaps the social contract only extends as far as Woodenbong.
On the southern hemisphere issue – you’ve missed the big joke. It is a southern hemsiphere problem. Pacific turns into a semi-permanent El Nino and who cops it ? Aussie and Southern Africa. God is a WASP North American you know! They’ll have more wrmth for that C3 grass called wheat and the rainfall on better soils geologically fresh from under the last ice sheet. Because you’re indulging yourself in the nicest climatic part of Australia in some boutique permacultural experiment you seem to have forgotten about ongoing droughts that have lingered since the early 1990s.
Malcolm Hill – you may find one of Paul’s Nature papers says it has little modulating influence.
Variations in solar luminosity and their
effect on the Earth’s climate
P. Foukal1, C. Fro¨hlich2, H. Spruit3 & T. M. L. Wigley4
Variations in the Sun’s total energy output (luminosity) are caused by changing dark (sunspot) and bright structures on
the solar disk during the 11-year sunspot cycle. The variations measured from spacecraft since 1978 are too small to have
contributed appreciably to accelerated global warming over the past 30 years. In this Review, we show that detailed
analysis of these small output variations has greatly advanced our understanding of solar luminosity change, and this
new understanding indicates that brightening of the Sun is unlikely to have had a significant influence on global warming
since the seventeenth century. Additional climate forcing by changes in the Sun’s output of ultraviolet light, and of
magnetized plasmas, cannot be ruled out. The suggested mechanisms are, however, too complex to evaluate
meaningfully at present.
Ian: What you say makes perfect sense.It is a regional(european) problem.Most of the southern hemisphere is ocean,ice or non-urban. There is no way there could be a net gain of man-made co2 from this region.
Time for a name change.
Half global warming
In the link to
Phenomenological solar signature in 400 years of reconstructed
Northern Hemisphere temperature record
N. Scafetta1 and B. J. West, 2006
alreadty linked in a pevious comment there is mention of solar mechanisms as yet unknkown which the empirical study suggest s may exist.
It is therefore premature to accept IPCC models that do not fully explore these as yet unknown mechanisms.
As they say, garbage in garbage out when in comes to computer simulatations.
Qute from Discussion Scarfetta and West
In any case, as some authors have already noted
[Douglass and Clader, 2002; Scafetta and West, 2005,
2006], solar change effects are greater than what can be
explained by several climate models [Stevens and North,
1996; Intergovernmental Panel on Climate Change, 2001;
Hansen et al., 2002; Foukal et al., 2004]. For example,
Douglass and Clader [2002] and Scafetta and West [2005]
found that the amplitude of the 11-year solar signature on
the temperature record seems to be 3 times larger than the
theoretical predictions, and similar or larger factors are
likely to persist at lower frequencies as well.
[19] In conclusion, a solar change might significantly
alter climate. It might trigger several climate feedbacks
and alter the GHG (H2O, CO2, CH4, etc.) concentration,
as 420,000 years of Antarctic ice core data would also
suggest [Petit et al., 1999]. Most of the sun-climate coupling
mechanisms are probably still unknown. However,
they should be incorporated into the climate models to
better understand the real impact of the sun on climate
because they might strongly amplify the effects of small
solar activity increases.
It’s important to understand that the bulk of the Sun’s influence on climate is due to eruptivity rather than irradiance – the Sun’s influence is often dismissed as minor when only irradiance is considered.
My Environmental Sciences friend tells me the Sun’s influence is 30% irradiance, and 70% eruptivity.
I can recommend this long exchange between RC and Nir Shaviv, from May this year:
http://www.realclimate.org/index.php/archives/2006/05/thank-you-for-emitting
Nir Shaviv enters the discussion at comment 37, then the debate continues in between other posts: 49, 54, 56, 57, 60, 61, 69, 70, 83, 89, 90, 95, 102, 110, 125, where Rasmus cuts off the discussion.
Enjoy!
Detribe
“It is therefore premature to accept IPCC models that do not fully explore these as yet unknown mechanisms.”
Poor ol’ IPCC can’t win – you want them to make scenarios on unknown mechanisms.
“Poor ol’ IPCC can’t win – you want them to make scenarios on unknown mechanisms.”
That hasnt stopped the with the economic side of things…. in that case they just made it up despite known international best practice standards being in existence.
What is this – tit for tat. And the IPCC have been criticised and encouraged to do better. Although they claim the range of emissions are covered and given modelling runs are expensive and time consuming, they have defended their position not to rerun.
But Malcolm it’s tad difficult to program something if you don’t know what it is?
“Poor ol’ IPCC can’t win – you want them to make scenarios on unknown mechanisms.”
They can’t win on events that have occurred after their current work was done because they couldnt travel in time to the future to find the implications of the work I have just mentioned and just published. In time, say two-five years down the track, they could feasibly test hypotheses based on it, and could then win. By that time the cooling processes could be better identified , possibly confirmed, and the hypotheses about these mechanism, already circulating in the literature and partly mentioned in the paper, as you well know Luke, might well be validated .That’s how science moves forward excited by with new evidence .
In short, Luke, the IPCC can win on this Luke, but they need time to do the new work.
Cosmic rays, magnetic fluxes , cloud albedo coupling, take your choices Luke, for the experiments and measurements. Might have to launch a few new satellites with new instruments though, and wait for more change in the sunspot cycle. All these need something more that a few witty but meaningless remarks though.
PS A lot of Paul Biggs comments are relevant to these hypothetical processes/mechanisms and their putative existence.
Yes I agree but the IPCC review existing science to distill the best available analysis – sometimes imperfectly for you guys and many others. They don’t launch satellites or bankroll major new science activities. Back to various national agencies for that. Meanwhile the possible existence of “celestial or solar eruptive” drivers does not diminish the good evidence we have for a CO@ induced warming. Why do forcings have to be exclusive or single? Could we not live in a world of some complexity?
P.S. 2-5 years nowhere near long enough for any meaningful trends I’d think.
If we recognise that oceans are a carbon sink then surely, the very best place to put an emission intensive industry would be Tuvallu, with vast areas of ocean that ensure that it is most certainly in emission deficit.
And once this takes place they could afford to back-load rock fill to ensure that any sea level rise is off-set by rises in land height.
It would also follow that rural and regional emissions in Australia would be off-set by sinks like veg thickenning and ocean absorbtion to produce a net per capita emission level that could properly drive future investment and settlement patterns.
But that would require reporting methods and standards that actually amount to a “true and fair” view of the sources and sinks. And that would not be in the interests of our urban bulk emitters and their northern hemisphere fellow travellers.
so what you’re recommending Motty is additional investment for better science and more comprehensive data?
” Meanwhile the possible existence of “celestial or solar eruptive” drivers does not diminish the good evidence we have for a CO@ induced warming.”
True it does not mean that CO2 induced warming DOES NOT EXIST, but the 50% contribution implied by the paper http://www.fel.duke.edu/~scafetta/pdf/2006GL027142.pdf
is not part of the IPCC model so that it implies a major model revision needs for to be examined, and that the quantitive contribution of CO2 forcing MAY BE SIGNIFICANTLY OVERESTIMATED in the IPCC model.
“Why do forcings have to be exclusive or single? Could we not live in a world of some complexity?”
Why yes that’s the point Luke, that the IPCC model dismissed the importance , indeed existence, of these additional sun spot cyle implied forcings. You have indeed grasped the point now, which I though was obvious but not followed through in realing the implications.
On the later thread about scepticism there’s all sorts of demands for a new model by the IPCC defenders, and its staring you in the eye if you think a while about the 50% value and continued sun spot cycles.
“P.S. 2-5 years nowhere near long enough for any meaningful trends I’d think.”
Youve missed the point here Luke yet again. The 2-5 years is the experimental time needed to adequately test a radical model revision of the IPCC. Complete testing of the cooling events expected from further sunsot cycle would take about 10- 20 years to see them play out in terms of climate change.
The general prediction is a decreased slope to the gobal temperature curve in spite of continued CO2 levels rising, or even global cooling!
Well it’s up the IPCC reviewers who know more about this stuff than you and I to see if there is enough in the science. To date they’ve been singularly unconvinced. They’re not going to waste their time chasing something that hasn’t got any legs. On what basis do you assert that there’s anything in it?
Much better using scant resources chasing decadal variability and the Southern Annular Mode IMHO.
Another paper claiming increased 20th century solar activity:
Ilya Usoskin (Sodankylä Geophysical Observatory, University of Oulu, Finland) and his colleagues have investigated the solar activity over the past centuries. Their study is to be published this week in Astronomy & Astrophysics Letters. They compare the amount of Titanium 44 in nineteen meteorites that have fallen to the Earth over the past 240 years. Their work confirms that the solar activity has increased strongly during the 20th century. They also find that the Sun has been particularly active in the past few decades.
I. Usoksin and his colleagues have used meteorites to reconstruct past solar activity. Studying the earlier activity of our Sun is one of the oldest astrophysical projects, as astronomers began recording the number of sunspots to trace the Sun’s magnetic activity four hundred years ago.
The international team examined a set of nineteen meteorites whose dates of fall are precisely known, and measured the amount of radioactive isotope Titanium 44 in these meteorites. Titanium 44 is produced by the cosmic rays in the meteorites while they are outside the Earth’s atmosphere. After the meteorite has fallen, it stops producing this isotope. By measuring the Titanium 44 in these meteorites, they are able to determine the level of solar activity at the time the meteorite fell.
Past solar activity is reconstructed with this technique in an independent way, that is, one not affected by terrestrial effects. How high the solar activity was at a given epoch was previously known from measuring the concentration of cosmogenic isotopes produced at that time. But most of the isotopes found on the Earth – in Greenland and Antarctic ice sheets or in tree rings, for instance – are also affected by terrestrial processes, in these examples related to the Earth’s magnetic field and climate. Until now, reconstructing past solar activity was thus very uncertain. This is shown by how various reconstructions that were previously published differ from one other. In the new study to be published this week in Astronomy & Astrophysics Letters, the team shows that the Sun is currently particularly active compared to earlier centuries.
——————————————————————————–
[1] The team includes N. Bhandary (Basic Sciences Research Institute, Ahmedabad, India), G.A. Kovaltsov (Ioffe Physical-technical Institute, St. Petersburg, Russia), S.K. Solanki (Max-Planck Institute for Solar System Research, Katlenburg-Lindau, Germany), C. Taricco (Istituto Nazionale di Fisica Nucleare, Torino, Italy) and I.G. Usoskin (University of Oulu, Finland).
pdf:
http://www.aanda.org/index.php?option=com_base_ora&access=standard&Itemid=39&url=articles/aa/pdf/2006/39/aa5803-06.pdf
OK Paul – clearing my mind. Opening receptors to new information. What would be the climate interaction mechanism with your paper above. How would it work.