General Climate Change Discussion Continued:

[jethro]

But regarding the data for past solar activity, do we have much in the way of reliable proxies going back well before the 1600s?

Can't remember.

Try looking for Carbon 14 data (used for carbon dating so must be a decent record somewhere) also Berylium 10 - both fluctuate in tune with Solar activity.

[Admiral_Bobski]

The fact that heat gets harder to gain with increases in temp and harder to lose with decreases in temp holds true at any scale, though having not done the maths I can't say for certain how much of an effect it would have.

As for proxies, Be10 is one of the most commonly used proxies for solar activity. As can be seen from the graph below, while Be10 concentration gives a broad idea of the waxing and waning of solar cycles it is by no means a bang-on accurate proxy, so it can only really be used as a general indicator.

(source: http://en.wikipedia.org/wiki/File:Solar_Activity_Proxies.png)

:lol:

[Thundery wintry showers]

Looking at those graphs, they raise the possibility that solar activity could have contributed to some of the twentieth century warming, but probably not coming close to explaining all of it. For example if we quote the 0.3C that has been suggested as the middle bound for the Maunder Minimum, the increase in solar activity since 1900 might account for about 0.2-0.3C of the 0.7C or so of warming over the twentieth century- most likely the 1910-1940 warming but not the subsequent 1970-2000 warming. (It is interesting to note that if we took the absolute upper bound for the MM- 0.5 to 0.6C- it could come close to explaining the whole twentieth century warming, if I'm reading the graphs correctly, but of course upper bounds are very low likelihood).

[sunny starry skies]

Looking at those graphs, they raise the possibility that solar activity could have contributed to some of the twentieth century warming, but probably not coming close to explaining all of it. For example if we quote the 0.3C that has been suggested as the middle bound for the Maunder Minimum, the increase in solar activity since 1900 might account for about 0.2-0.3C of the 0.7C or so of warming over the twentieth century- most likely the 1910-1940 warming but not the subsequent 1970-2000 warming. (It is interesting to note that if we took the absolute upper bound for the MM- 0.5 to 0.6C- it could come close to explaining the whole twentieth century warming, if I'm reading the graphs correctly, but of course upper bounds are very low likelihood).

Palaeo-reconstructions of the Sun appear to be a bone of some contention in the scientific literature so far as I can see. The last 1000 years is quite well constrained, and radiocarbon/beryllium-10 reconstructions are in reasonable (though not perfect, as C-Bob's graph shows) agreement with the sunspots. It's beyond this that things get more tricky. Solanki et al (2004) proposed that he could reconstruct solar activity back 11,000 years, and found the Sun's recent activity remarkably high through that time period.

http://www.nature.com/nature/journal/v431/n7012/abs/nature02995.html

But they conclude in their abstract: "Although the rarity of the current episode of high average sunspot numbers may indicate that the Sun has contributed to the unusual climate change during the twentieth century, we point out that solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades"

However, a brief search provides this article by Ogurtsov (2007) which casts some doubt on Solanki's claim, suggesting that you cannot successfully reconstruct solar activity all that far back using those palaeoclimatic records.

http://www.springerlink.com/content/mg547654r7523746/

This link (Muscheler et al, 2005), which should hopefully work for everyone, discusses solar activity and climate as a response to Solanki et al:

http://www.cgd.ucar.edu/ccr/raimund/publications/Muscheler_et_al_Nature2005.pdf

"The comparison between the physical quantities, the 14C-production rate and the solarmodulation parameter, and the visually based sunspot record reveals similarities and striking differences (Fig. 2). The 11-year solar cycle is distinct in all records. On the other hand, solar magnetic modulation was higher or comparable to today during the late eighteenth (and twelfth) century and around AD 1600, whereas sunspot numbers were highest over the recent decades. Sunspot numbers fell to zero during the Maunder Minimum (AD 1650–1700), whereas 14C production and solar modulation continued to vary."

This highlights the nonlinear connection between SN and solar activity directly influencing Earth.

Muscheler's take on the 'unusually high solar activity' question at RealClimate is here:

http://www.realclimate.org/index.php/archives/2005/08/did-the-sun-hit-record-highs-over-the-last-few-decades/

But, this is threatening to be a longer-than-planned post, as it's an interesting topic! To go back to TWS' question about reliable proxies, I think the answer is a frustratingly vague, yes there are proxies, but not entirely, as the proxies don't vary exactly with sunspot number. But of course, as the proxies are recording changes in energy transfer from the Sun (as opposed to changes on the surface of the Sun), they may be even better than sunspot number for measuring energy received at Earth! But as they don't all agree, it's hard to tell which one to use!

But as far as how this affects the temperature indices - both Solanki and Muscheler say that solar activity variations can have only a small impact on recent climate change, so would put them in the brackets of the small variations discussed above. My take on the rate of heating/cooling discussion is that, in my opinion, you have to consider the heating of 1C to be 1K out of 287K heat of the Earth's surface, and therefore it is a very small proportion. Hence the rate of heating or cooling will not change significantly whether the surface temperature is 287K or 286K, so I'm not sure that C-Bob's argument will work. Certainly I don't think the effect would be dramatic in that I think the effect of cooling from 286K (13C) to 285.7K (Maunder Min) would be pretty much the same as cooling from 287K to 286.7K (14C to 13.7C). Unless anyone can say why the effect would be substantially nonlinear?

sss

[Iceberg]

Using the 14C to plot solar activity you get the below graph, I've also added the proxy graph, which as alot of different proxies on it and very roughly plotted boxes the 3 main minium's.

Maunder, Sporer and wolf.

Also the MWP.

According to quite a few skeptics the MWP was similar in temperature to so the early part of the past century (1910-1940).

I would also like to state that CB might well have a good point, what had gone on before the maunder minimum certaintly would effect it's negative effect IMO and the Maunder followed hot off the heels of the other two minimums.

Anyway during the wolf minimum it looked like temps dropped by .3C,

According to Huang et al the Sporer minimum (longer but not as deep as the Maunder) had a temp reduction of 0.6C.

I chose Huang as it had the biggest temp drop, however according to Crowley et al attached Volcanic forcing was considerably negative around this time so I would be tempted to reduce this to 0.4C

The Maunder min didn't really see much of a drop in temps and the assumption might be made that it probably prolonged the 0.4 to 0.8 drop.

Taking all of this into consideration I am still struggling to give more than 0.5C to a maunder like minimum.

Given that the above is for northern hemi temps and given that according to Spencer's global temp record which has been going for 30 years now averging a decadal increase in n.Hemi temps of 0.20 the warming of the last 3 decades has been more than you would expect from cooling of a maunder type minimum, so even with a maunder type min we would be stretching things to say temps would return to even the 70's globally.

The above isn't very scientific, mainly as I don't have 2 weeks to work on it, but it's a stab, worth noting that I am trying to use the figures to give the biggest temp drop, the mean probably supports the 0.3C.

http://www.geos.ed.ac.uk/homes/tcrowley/crowley_science2000.pdf?

[BLAST FROM THE PAST]

The Met Office has over stated the trend of the last ten years. I produced a chart on these threads somewhere last year that gave such evidence. It over cooked individual annual warming as was depicted on that chart.

Wrt to the bolded part,

Right, let me get this straight - you admit that we do not have 'anything like the same handle of forecasting the activity of the sun' and by dint of that you are saying in essence therefore there is little clue as to how upcoming negative solar feedback (minima)might potentially interact and in turn affect the climate trends but at the same time you are stating that because we allegedly have such a good handle on earth climate forcings then the 'other part' (ie solar uncertainty) can be forgotten and taken out of the equation. I find that truly astonishing.

Surely any future revison in terms of solar behaviour that is, as you admit so uncertain, is absolutely crucial!!

I think I just might rather trust a qualified solar scientist in terms of, er, solar behaviour (like Landscheidt) than a scientist, qualified or otherwise, who is making a judgement through AGW assumptive tinted glasses and admits to not knowing much about how the sun might behave!

Quite, don't get embroiled Tamara........time will tell and not that much time either and of importance cycle 25 is the one where Dalton proportions are forecast, 24 is leading us into that. However, sunspots are just part of the solar effect as we know, so whether 0.3c is correct or not is not too much an issue [looking at Icebergs summation, thst seems reasonable]. The solar driven ocean cycles [Perturbation, PDO, AMO etc] may well account for the rest, the longterm southerly movement of the jetstream [had been recorded as moving north over recent decades], the shrinking back of the ITCZ [has been spreading polewards over last 150 years but has now stopped since 2001 and for me both have added to the overall warming] will also have COOLING effect. GWO theory [PFM] two years ago, suggested temps of the 40-70s will be felt through 2008/9 onwards due to the cyclical shift southward of the jetstream...well interestingly are we seeing that? Well 40-60 deg north populated areas have experienced 40-70esque winters 08/09 and 09/10...but not globally.

With a record -ve AO [relative warm arctic] and hefty El Nino [global] warmth is the Jan and Feb talk....interesting to see how the year develops as the El Nino quickly wanes over coming couple of months.

BFTP

Edited March 4, 2010 by BLAST FROM THE PAST

[Guest North Sea Snow Convection]

Quite, don't get embroiled Tamara........time will tell and not that much time either and of importance cycle 25 is the one where Dalton proportions are forecast, 24 is leading us into that. However, sunspots are just part of the solar effect as we know, so whether 0.3c is correct or not is not too much an issue [looking at Icebergs summation, thst seems reasonable]. The solar driven ocean cycles [Perturbation, PDO, AMO etc] may well account for the rest, the longterm southerly movement of the jetstream [had been recorded as moving north over recent decades], the shrinking back of the ITCZ [has been spreading polewards over last 150 years but has now stopped since 2001 and for me both have added to the overall warming] will also have COOLING effect. GWO theory [PFM] two years ago, suggested temps of the 40-70s will be felt through 2008/9 onwards due to the cyclical shift southward of the jetstream...well interestingly are we seeing that? Well 40-60 deg north populated areas have experienced 40-70esque winters 08/09 and 09/10...but not globally.

With a record -ve AO [relative warm arctic] and hefty El Nino [global] warmth is the Jan and Feb talk....interesting to see how the year develops as the El Nino quickly wanes over coming couple of months.

BFTP

Hi Fred, hope you are well

You have just put my own thoughts on paper pretty much better than I ever could - nice summary.

I'm looking forward to the coming decade and more - there are going to be some interesting developments methinks. All the more reason to stick to my 'wait and see' policy - as I am sure you are too.

[Methuselah]

Wait and see?

I think that that's pretty much how science works - one collects data, analyses data, produces a theory, and then uses that theory to make predictions...

It's just that, the theories pertaining to the Sun's output variation over time are even more riddled with uncertainty than is our knowledge of GHGs...So, yes:

Wait and see...

[BLAST FROM THE PAST]

Wait and see?

I think that that's pretty much how science works - one collects data, analyses data, produces a theory, and then uses that theory to make predictions...

It's just that, the theories pertaining to the Sun's output variation over time are even more riddled with uncertainty than is our knowledge of GHGs...So, yes:

Wait and see...

On that, I think it is interesting to note that some quarters placed CO2 AGW forcing as the reason behind the ever mild UK winters and the northward movement of the jet. That is failing currently and with regards to waiting and seeing...well i believe that cycles regards to solar forcing are appearing before our very eyes...what we haven't got yet is the [theory] of cooling...then again we don't have the full forcing upon us yet but we have seen the warming brakes being put on...and I really don't think we have too long to see if that cooling theory is reality [sub 10 years]

BFTP

[Hi Tamara]

Edited March 4, 2010 by BLAST FROM THE PAST

[Iceberg]

On that, I think it is interesting to note that some quarters placed CO2 AGW forcing as the reason behind the ever mild UK winters and the northward movement of the jet. That is failing currently and with regards to waiting and seeing...well i believe that cycles regards to solar forcing are appearing before our very eyes...what we haven't got yet is the [theory] of cooling...then again we don't have the full forcing upon us yet but we have seen the warming brakes being put on...and I really don't think we have too long to see if that cooling theory is reality [sub 10 years]

BFTP

[Hi Tamara]

Ow and the thread was doing so well for at least a little bit.

and what breaks would they be...the ones that give the Spencer data set the warmest months on record recently. !

I've also yet to hear how the position of the Jet stream causes temps to go down(even in the n.Hemisphere), again according to Spencer n.hemisphere land in his last update was the 2nd warmest anomaly recorded over the past 30 years.

[VillagePlank]

Ow and the thread was doing so well for at least a little bit.

and what breaks would they be...the ones that give the Spencer data set the warmest months on record recently. !

I've also yet to hear how the position of the Jet stream causes temps to go down(even in the n.Hemisphere), again according to Spencer n.hemisphere land in his last update was the 2nd warmest anomaly recorded over the past 30 years.

Whoa, slow down soldier.

It does not hold that there might be no study, and such that there is no study, the topic (or even conclusion) of such a study is therefore invalid. I find it at least a little bit disingenuous, that you suggest because you haven't seen it, or no-one has proffered you any evidence, that there is some sort of implication that it is invalid.

Perhaps, a subject matter for a PhD - how the JS affects temps in NW Europe. Certainly a worthwhile study no matter what the outcome. Of course, glib observations shows that if the JS is south, NW Europe is colder, overall, in winter.

But that's not evidence.

[sunny starry skies]

Whoa, slow down soldier.

It does not hold that there might be no study, and such that there is no study, the topic (or even conclusion) of such a study is therefore invalid. I find it at least a little bit disingenuous, that you suggest because you haven't seen it, or no-one has proffered you any evidence, that there is some sort of implication that it is invalid.

Perhaps, a subject matter for a PhD - how the JS affects temps in NW Europe. Certainly a worthwhile study no matter what the outcome. Of course, glib observations shows that if the JS is south, NW Europe is colder, overall, in winter.

But that's not evidence.

I'm quite happy to have as evidence the jetsteam moving south giving NW Europe colder winters - the last couple of winters support that hypothesis nicely (not enough of a sample to prove the case of course as VP says). But the crucial point I think Iceberg was making is that he fails to see how that would make the N Hemisphere as a whole cool down. Yes, NW Europe and parts of the USA have been cold this winter, but the Northern Hemisphere as a whole has been unusually (record-breakingly) warm. Hence there is no evidence there to support a southward shift in the jetstream producing a cooler hemisphere. The evidence to me suggests that whatever perturbation, PDO, solar forcing, whatever, that has moved the jetstream south, has forced a redistribution of temperatures within the hemisphere, but not a cooling of the whole hemisphere.

BFTP, there's no evidence for a slowing in the warming trend. Tamino's riddle-me-this post which I have linked to too many times shows this beyond reasonable doubt. Any trend in the temperature data shorter than 15 years was shown statistically to be within the noise, rather than the trend itself. And recent month plots solidly on average or above average in relation to that rising trend of the last 30+ years.

http://tamino.wordpress.com/2009/12/07/riddle-me-this/

http://tamino.wordpress.com/2009/12/15/how-long/

And more interesting work from Tamino, which it seems he's planning to publish too - Watts' claim that station dropout or adjustments in the GISS dataset introdices biases, already shown to be incorrect by others, has been proven to be totally wrong. I wonder if we'll see a retraction from Watts??

http://tamino.wordpress.com/2010/02/25/false-claims-proven-false/

This has been replicated, in true scientific style:

http://clearclimatecode.org/the-1990s-station-dropout-does-not-have-a-warming-effect/

http://rankexploits.com/musings/2010/a-simple-model-for-spatially-weighted-temp-analysis/

sss

[Iceberg]

Whoa, slow down soldier.

It does not hold that there might be no study, and such that there is no study, the topic (or even conclusion) of such a study is therefore invalid. I find it at least a little bit disingenuous, that you suggest because you haven't seen it, or no-one has proffered you any evidence, that there is some sort of implication that it is invalid.

Perhaps, a subject matter for a PhD - how the JS affects temps in NW Europe. Certainly a worthwhile study no matter what the outcome. Of course, glib observations shows that if the JS is south, NW Europe is colder, overall, in winter.

But that's not evidence.

Oh I quite agree it effects temps on a regional basis, but on a global basis or hemispheric basis, as I say I've seen nothing that suggests this and plenty to suggest otherwise.

[Cycles]

NW Europe and parts of the USA have been cold this winter, but the Northern Hemisphere as a whole has been unusually (record-breakingly) warm. Hence there is no evidence there to support a southward shift in the jetstream producing a cooler hemisphere. The evidence to me suggests that whatever perturbation, PDO, solar forcing, whatever, that has moved the jetstream south, has forced a redistribution of temperatures within the hemisphere, but not a cooling of the whole hemisphere.

BFTP, there's no evidence for a slowing in the warming trend.

Your statements seem to indicate your unawareness of a strong El Nino in place, with this causing a strong redistribution of temperatures, usually happens during an El Nino.

Yes this El Nino is a little different than other's, but it did act normally in causing cooler than norm winter over the southern United States, troughing in the Eastern pacific and Atlantic.

Because earth is in a transition between global warming and cooling, more cold air has been available in mid to high latitudes to produce cooler weather south of the arctic jet. Meanwhile El Nino forced warm air has penetrated north across the eastern Pacific into high latitudes of Alaska and Canada.

Regards

David

[Thundery wintry showers]

But the important point that SSS was making is that it hasn't resulted in a net cooling across the Northern Hemisphere (when if anything I would expect it to do so in the short term, because of the resulting default to cold over Eurasia and warmth over the oceans). With a weaker El Nino than in 1998 but similar global temperatures I think it's entirely consistent with a continued underlying warming trend- it may not be accelerating as yet (as it will need to in the future in order to reach the mid to high part of the IPCC's range) but it is still there, I reckon somewhere around 0.15C/decade.

[Cycles]

But the important point that SSS was making is that it hasn't resulted in a net cooling across the Northern Hemisphere (when if anything I would expect it to do so in the short term, because of the resulting default to cold over Eurasia and warmth over the oceans). With a weaker El Nino than in 1998 but similar global temperatures I think it's entirely consistent with a continued underlying warming trend- it may not be accelerating as yet (as it will need to in the future in order to reach the mid to high part of the IPCC's range) but it is still there, I reckon somewhere around 0.15C/decade.

I agree we have not had net cooling this winter, with the primary reason being the El Nino. But there is more cold air available this winter and the past 2 winters than any time during the period 1997 to 2007. Difference this winter is the El Nino influencing high latitudes on either side of the strong upper level ridges.

[sunny starry skies]

But the important point that SSS was making is that it hasn't resulted in a net cooling across the Northern Hemisphere (when if anything I would expect it to do so in the short term, because of the resulting default to cold over Eurasia and warmth over the oceans). With a weaker El Nino than in 1998 but similar global temperatures I think it's entirely consistent with a continued underlying warming trend- it may not be accelerating as yet (as it will need to in the future in order to reach the mid to high part of the IPCC's range) but it is still there, I reckon somewhere around 0.15C/decade.

Indeed, well put TWS. So far as this year's El Nino goes, looks like it's in line with projections, being a central Pacific Modoki event, of a kind expected to occur more and more frequently in a warming world.

Yeh et al (2009): El Nino in a changing climate. Nature.

http://www.nature.com/nature/journal/v461/n7263/full/nature08316.html (sorry if it's not freely available)

Here's a description, showing that observations of Modoki events have increased in recent years:

http://www.aviso.oceanobs.com/en/news/idm/2009/nov-2009-if-it-s-not-el-nino-then-it-must-be-his-brother/index.html

AVISO has maps of ocean height and temp anomalies since 1992, good for visualising the differences:

http://bulletin.aviso.oceanobs.com/html/produits/indic/enso/welcome_uk.php3

So you can see how different in spatial pattern this year was to events such as 1998. You can also see just how much weaker this year's El Nino has been compared to 1998, yet global temperatures are similar or even higher. Other possible forcings have either not changed or are weaker (volcanic = no change; solar = same or weaker). This is in line with AGW theory raising the baseline, and flattening the thermocline in the Pacific, exactly as predicted.

sss

[Iceberg]

I agree we have not had net cooling this winter, with the primary reason being the El Nino. But there is more cold air available this winter and the past 2 winters than any time during the period 1997 to 2007. Difference this winter is the El Nino influencing high latitudes on either side of the strong upper level ridges.

You'll have to run that one past me again David, sorry, The land masses have been very warm, the seas have been very warm, the Arctic has been very warm, so how can there be more cold available ?

Cold has certaintly been displaced into large chuncks of the populated developed countries, for a few areas more cold is available, but for most areas less cold is available surely. ?

[Cycles]

You'll have to run that one past me again David, sorry, The land masses have been very warm, the seas have been very warm, the Arctic has been very warm, so how can there be more cold available ?

Cold has certaintly been displaced into large chuncks of the populated developed countries, for a few areas more cold is available, but for most areas less cold is available surely. ?

You kind of double talked in your two paragraphs. Yes, some areas are quite warm, but some areas are seeing snow and cold not seen for 100 years.

So here is a question. The cold and snow areas are seeing 100 year records tied or broken. Are the warm areas seeing the opposite...100 year records?

The ocean areas we do not know about, records do not go back far enough, using satellite data versus sparse shipping reports is the same as comparing apples to oranges.

Regards

David

[Thundery wintry showers]

But if we're talking global warming, surely the distribution of records are irrelevant if global temperatures are still high?

[Cycles]

But if we're talking global warming, surely the distribution of records are irrelevant if global temperatures are still high?

Absolutely not. If 100 year cold and snow records are being set and high temperature records are not...then we must have more cold air than usual under these circumstances (El Nino).

Regards

David

[VillagePlank]

Absolutely not. If 100 year cold and snow records are being set and high temperature records are not...then we must have more cold air than usual under these circumstances (El Nino).

Regards

David

If we are posting record cold temperatures in some parts of the world, and the global temperature average is still warm and high - both true, I think - then that posits curious questions.

If we have seen such record breaking low temperatures, then it must either be warmer in a lot more places, or the warm places must be excessively warm to offset such low temperatures such that the average can be higher.

The problem about talking about distribution of temperatures and their frequency is that the corrolary is almost always true for somewhere else. So whilst you point to record low temperatures in some parts of the world, this is a tacit admission that, my god, it's so much warmer everywhere else.

Of course, if the global average was low, then you'd have a point.

Edited March 5, 2010 by VillagePlank

[VillagePlank]

Anyway, so the case is stronger with respect to climate change, then? (here)

Don't get me wrong, but I thought (especially according to the UK's encumbent government) that the case was already settled? If it is settled, then how can such a case get stronger? It's like being convicted of a crime, and then being taken to court, from your prison cell, to be told, that, actually, you are not only guilty, you are more guilty.

By implication, is this an admission that the statements of yesteryear leading up to this announcement were not quite as strong as they were made out to be?

Edited March 5, 2010 by VillagePlank

[Gray-Wolf]

But ,VP, the IPCC only gave us 90% surity when they released in 07' maybe we are now 94% sure? I can never remember any paper I have read say anything other that it 'strengthens the belief' or further our understanding or some such.

And folk do get hauled out of prison to be told their sentence is going up (or down) as new evidence is presented/assesed?

[VillagePlank]

But ,VP, the IPCC only gave us 90% surity when they released in 07' maybe we are now 94% sure? I can never remember any paper I have read say anything other that it 'strengthens the belief' or further our understanding or some such.

And folk do get hauled out of prison to be told their sentence is going up (or down) as new evidence is presented/assesed?

95% (stdv*1.96) is tantamount to scientific certainty, GW.

And, no, "guilty" is a boolean entity. It is either true or false, you can't be more guilty or less guilty, in the same way you can't be more true, or less false. These are oxymorons, and they do not make any sense.

Anyway, it is clear that those who suggested, either intentionally, or otherwise, that the case is (more or less) closed, hence everyone else must necessarily be a denier - ie Gordon Brown amongst others - have shown themselves to have a very clear lack of understanding of both the scientific method, and the complexities of this youthful science we call climate.

(for reference, nothing in science is 'right' or proven. It's all about our current best guess)

Edited March 5, 2010 by VillagePlank