Corrected Sunspot History: Climate Change Not Due to Natural Solar Trends

[donsutherland1]

From the International Astronomical Union (IAU):

 

The Sunspot Number, the longest scientific experiment still ongoing, is a crucial tool used to study the solar dynamo, space weather and climate change. It has now been recalibrated and shows a consistent history of solar activity over the past few centuries. The new record has no significant long-term upward trend in solar activity since 1700, as was previously indicated. This suggests that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity. The analysis, its results and its implications for climate research were made public today at a press briefing at the International Astronomical Union (IAU) XXIX General Assembly, currently taking place in Honolulu, Hawai`i, USA.

 

http://www.iau.org/news/pressreleases/detail/iau1508/

[LithiaWx]

Thank you for posting this. Hopefully this will help temper some of the CC deniers who use solar in their rants.

[donsutherland1]

Thank you for posting this. Hopefully this will help temper some of the CC deniers who use solar in their rants.

 

IMO, that probably won't happen. Just as is the case with the surface temperature data sets, those arguing against AGW will very likely suggest that the data is being 'fudged,' 'manipulated,' or worse.

[StudentOfClimatology]

Seems there are two things being debated here..the sunspot record itself, and the potential solar influence on climate change.

First, regarding this new sunspot dataset. It's one of many interpretations of the sunspot record (which is tweaked for factors like clustering, telescope resolution/spot size, etc, as measurement techniques and subsequent homogenizations change over time). There's no consensus as to which one is correct, so that alone is an Achilles heel of the solar/climate theory.

Second, even if the Sun were responsible for climate change, you'd never find a linear correlation between solar forcing and temperature change due to the thermal inertia of the system. It'd take 50+ years for the upper oceans to statistically equilibrate to any sustained change in external radiative forcing, maybe longer depending on the depth and prolificacy of the upper mixing layer(s).

So basically this entire topic of discussion should be relegated to the hypothetical realm. Most of this is speculatory.

[donsutherland1]

Seems there are two things being debated here..the sunspot record itself, and the potential solar influence on climate change.

First, regarding this new sunspot dataset. It's one of many interpretations of the sunspot record (which is tweaked for factors like clustering, telescope resolution/spot size, etc, as measurement techniques and subsequent homogenizations change over time). There's no consensus as to which one is correct, so that alone is an Achilles heel of the solar/climate theory.

Second, even if the Sun were responsible for climate change, you'd never find a linear correlation between solar forcing and temperature change due to the thermal inertia of the system. It'd take 50+ years for the upper oceans to statistically equilibrate to any sustained change in external radiative forcing, maybe longer depending on the depth and prolificacy of the upper mixing layer(s).

So basically this entire topic of discussion should be relegated to the hypothetical realm. Most of this is speculatory.

 

If the corrected data is accurate, solar activity has been remarkably stable for centuries. Hence, even considering inertia from stored oceanic heat, the solar argument for the observed and ongoing rise in surface temperatures is weaker than it had been.

[StudentOfClimatology]

If the corrected data is accurate, solar activity has been remarkably stable for centuries. Hence, even considering inertia from stored oceanic heat, the solar argument for the observed and ongoing rise in surface temperatures is weaker than it had been.

I'm personally skeptical. Not only are there now four separate mainstream interpretations of the sunspot record, but the BE^10/C^15 isotope record on both poles suggests significant variability in solar activity w/ an exceptional modern maximum relative to ~ 85% of the Holocene.

If this interpretation is correct (questionable), then solar theories involving direct radiative forcing will be relegated to the trash heap. Theories involving GCRs/aerosol nucleation are another story, though I don't really follow that stuff to begin with.

[Isotherm]

I'm very skeptical of this information. Most of the literature I've come across supports the existence of a modern maximum, and certainly, a significant increase in solar activity since the Maunder Minimum. The burden of proof is on those who believe solar activity has been stable over the past few centuries.

[donsutherland1]

I'm very skeptical of this information. Most of the literature I've come across supports the existence of a modern maximum, and certainly, a significant increase in solar activity since the Maunder Minimum. The burden of proof is on those who believe solar activity has been stable over the past few centuries.

The revised yearly data doesn't completely do away with the Maunder Minimum or Modern Maximum. Using the data, one finds the following average number of sunspots:

 

1700-99: 76.2

1800-99: 72.7

1900-99: 90.0

2000-14: 77.5

 

The data can be found at:

http://www.sidc.be/silso/datafiles

[stadiumwave]

IMO, that probably won't happen. Just as is the case with the surface temperature data sets, those arguing against AGW will very likely suggest that the data is being 'fudged,' 'manipulated,' or worse.

 

I don't think everyone that questions timely adjustments, studies released etc...all in one year, right ahead of Paris climate talks...are people who argue against AGW at all. I can only speak for myself, I know AGW is absolutely true but that doesn't mean that I don't question some things being done. 

 

Fudged data etc...if there is any...DID NOT create AGW, but I'm very skeptical of the integrity climate science in this age.  I'm not skeptical of AGW at all...just skeptical of certain things going on.

 

Don...I have tremendous respect for you but I can't understand why you think it's beyond the realm of possibilities that there is any corruption in climate science.  And then if anyone does question anything about climate science you label them a denier.  If I question the latest adjustments of the past year by NOAA that eliminated the hiatus why does that make me a denier? The hiatus didn't change the fact that AGW is real...nor do any adjustments change that fact.  But you cannot convince me that there hasn't been a desire to eliminate the hiatus because of stupid deniers using it to argue that AGW isn't real. The hiatus has been a PR nightmare; however, it's totally wrong to see some things that have taken place over the last year to eliminate that achillies heal.  The end does not justify the means in the end.

[donsutherland1]

I don't think everyone that questions timely adjustments, studies released etc...all in one year, right ahead of Paris climate talks...are people who argue against AGW at all. I can only speak for myself, I know AGW is absolutely true but that doesn't mean that I don't question some things being done. 

 

Fudged data etc...if there is any...DID NOT create AGW, but I'm very skeptical of the integrity climate science in this age.  I'm not skeptical of AGW at all...just skeptical of certain things going on.

 

Don...I have tremendous respect for you but I can't understand why you think it's beyond the realm of possibilities that there is any corruption in climate science.  And then if anyone does question anything about climate science you label them a denier.  If I question the latest adjustments of the past year by NOAA that eliminated the hiatus why does that make me a denier? The hiatus didn't change the fact that AGW is real...nor do any adjustments change that fact.  But you cannot convince me that there hasn't been a desire to eliminate the hiatus because of stupid deniers using it to argue that AGW isn't real. The hiatus has been a PR nightmare; however, it's totally wrong to see some things that have taken place over the last year to eliminate that achillies heal.  The end does not justify the means in the end.

A few quick points:

 

First, I don't ever recall having referred to any members here as "deniers." Labeling does nothing to deal with the subject matter or arguments.

 

Second, I'm looking forward to seeing what the other major science centers e.g., Hadley, have to say regarding the ERSSTv4, which essentially eliminated the pause or hiatus. Such review is helpful and can only advance scientific understanding. Peer review is a healthy and constructive process. Hence, I don't have any issues with your position of being skeptical regarding this revised SST data set.

 

Third, on the issue of scientific integrity, I don't have the necessary information to make judgments. I do know that various fields have had numerous retractions in papers, so such a possibility in the climate science field wouldn't be all too surprising.

[stadiumwave]

A few quick points:

 

First, I don't ever recall having referred to any members here as "deniers." Labeling does nothing to deal with the subject matter or arguments.

 

Second, I'm looking forward to seeing what the other major science centers e.g., Hadley, have to say regarding the ERSSTv4, which essentially eliminated the pause or hiatus. Such review is helpful and can only advance scientific understanding. Peer review is a healthy and constructive process. Hence, I don't have any issues with your position of being skeptical regarding this revised SST data set.

 

Third, on the issue of scientific integrity, I don't have the necessary information to make judgments. I do know that various fields have had numerous retractions in papers, so such a possibility in the climate science field wouldn't be all too surprising.

 

 

Thanks for you kind response.  I hope I'm wrong.  Maybe the peer reviewed process will be telling either way regarding ERSSTv4.  However, the adjustments are within the margin of error so I don't expect any backlash either way.

[StudentOfClimatology]

The revised yearly data doesn't completely do away with the Maunder Minimum or Modern Maximum. Using the data, one finds the following average number of sunspots:

1700-99: 76.2

1800-99: 72.7

1900-99: 90.0

2000-14: 77.5

The data can be found at:

http://www.sidc.be/silso/datafiles

The more I look at this data, the more skeptical I'm getting. There is fantastic agreement between the BE^10 & C14 isotope ratios from the mid-Holocene into the modern era, and the other sunspot records largely confirmed these proxies to be correct. This new dataset flies in the face of all the physically sound proxy data in existence.

I'm calling BS on this one.

[donsutherland1]

For comparison:

 

Corrected data:

1700-99: 76.2
1800-99: 72.7 Change from prior century: -3.5
1900-99: 90.0 Change from prior century: +17.3
2000-14: 77.5 Change from prior century: -12.5

 

Earlier data:

1700-99: 45.7
1800-99: 42.5 Change from prior century: -3.2
1900-99: 60.5 Change from prior century: +18.0
2000-14: 51.4 Change from prior century: -9.1

 

The century-scale changes between the two versions are largely the same. The only major difference is that the new version shows approximately 26-30 more sunspots than the prior one.
 

[nflwxman]

For comparison:

Corrected data:

1700-99: 76.2

1800-99: 72.7 Change from prior century: -3.5

1900-99: 90.0 Change from prior century: +17.3

2000-14: 77.5 Change from prior century: -12.5

Earlier data:

1700-99: 45.7

1800-99: 42.5 Change from prior century: -3.2

1900-99: 60.5 Change from prior century: +18.0

2000-14: 51.4 Change from prior century: -9.1

The century-scale changes between the two versions are largely the same. The only major difference is that the new version shows approximately 26-30 more sunspots than the prior one.

Thanks Don. The relative is more important than the absolute in regards to climate change over the past few decades.

[donsutherland1]

Thanks Don. The relative is more important than the absolute in regards to climate change over the past few decades.

 

Absolutely.

[chubbs]

My only quibble is that the press release implies that there was some scientific evidence for a solar influence on recent climate before this update.

[LakeEffectKing]

My only quibble is that the press release implies that there was some scientific evidence for a solar influence on recent climate before this update.

Which should make the objective reader pause....if all along, we have been told that the solar impact was negligible anyways, even before any revisions, why all of a sudden is there the entertainment that, with the revision, we are to believe: "This suggests that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity."...this statement sounds like a very shoddy/politically motivated attempt at disproving an alternate hypothesis (recent warming having a larger solar component), even though the notion of such a line of thinking, was "debunked" previously, without the revisions......smells of confirmation bias type science....IOW...doesn't sound like the authors were too confident in the notion that the degree of solar attribution (prior to said revision) was low....

[chubbs]

Which should make the objective reader pause....if all along, we have been told that the solar impact was negligible anyways, even before any revisions, why all of a sudden is there the entertainment that, with the revision, we are to believe: "This suggests that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity."...this statement sounds like a very shoddy/politically motivated attempt at disproving an alternate hypothesis (recent warming having a larger solar component), even though the notion of such a line of thinking, was "debunked" previously, without the revisions......smells of confirmation bias type science....IOW...doesn't sound like the authors were too confident in the notion that the degree of solar attribution (prior to said revision) was low....

 

I wouldn't read too much into it - just typical PR overstatement. The work wouldn't sound as significant it the presser said more accurately that it was another line of evidence that confirms current scientific understanding of solar impact on climate.

[Mallow]

Thread re-opened. Cool it with the personal attacks. There will be more consequences in the future.

[skierinvermont]

For those interested in the peer-reviewed paper that made these changes necessary to the outdated sunspot data here it is:

 

http://arxiv.org/ftp/arxiv/papers/1407/1407.3231.pdf

 

I'd suggest reading this before reading any of the posts above by people who don't like the paper's findings.

 

By the way, to anybody that follows solar stuff closely, these revisions were a long-time coming and seem to be pretty unanimously agreed upon by experts in the field...

[nzucker]

Solar activity was relatively high around 1700 (which was a spike after the Maunder Minimum and before the smaller Dalton Minimum), so you're not going to find a big rise in solar activity if you create a trend line from 1700-2015. Also, solar activity has been relatively stable since the rapid uptick around 1950, so any warming in the past 50 years must be attributable to anthropogenic causes and not the sun's doing. However, some of the warming from the cold Maunder Minimum/Dalton Minimum until 1950 is probably related to the rapid rise in sunspots and associated solar activity. 

 

Also, we did see a bottoming out of global temperatures in the 2008-2009 period, which was the bottom of Solar Cycle 24. IPCC literature tells us that any given cycle has a variation in TSI that can provoke a global temperature response of about 0.1C, which may explain why the warming has accelerated since 2013. However, that figure is within one cycle; there may be a larger change in global temperatures when multiple cycles have low/no sunspots, as happened during the Maunder and Dalton Minimum.

 

Overall, this doesn't seem to change much regarding what we know about climate change and solar activity. Solar activity was relatively high 1900-1999, but has stabilized since 1950, and was relatively low 1800-1899, but not as low as the 1600s. Solar activity is not a primary cause of observed warming, especially not since 1950.

[Isotherm]

The following paper demonstrates that solar activity in the most recent period was at the highest levels in 9,400 years.

 

http://www.aanda.org/index.php?option=com_article&access=doi&doi=10.1051/0004-6361/201219997&Itemid=129

 

 

 

Furthermore, Usoskin et al. (2014), "A 3000 year record of solar activity" found that solar activity in the past century was a unique event compared to the previous three millennia.

 

 

Another peer reviewed journal, "Living Reviews of Solar Physics", published a paper which demonstrated that the past century's solar activity was the highest in the last 1200 years. The study: "A history of solar activity over millennia."

 

 

 

 

 

There are countless peer reviewed papers supporting the notion that the solar activity since 1900 was significantly elevated compared to previous decades, and millennia. As StudentofClimatology noted earlier, proxy data is largely in agreement with that position.

[Isotherm]

Solar activity was relatively high around 1700 (which was a spike after the Maunder Minimum and before the smaller Dalton Minimum), so you're not going to find a big rise in solar activity if you create a trend line from 1700-2015. Also, solar activity has been relatively stable since the rapid uptick around 1950, so any warming in the past 50 years must be attributable to anthropogenic causes and not the sun's doing. However, some of the warming from the cold Maunder Minimum/Dalton Minimum until 1950 is probably related to the rapid rise in sunspots and associated solar activity. 

 

Also, we did see a bottoming out of global temperatures in the 2008-2009 period, which was the bottom of Solar Cycle 24. IPCC literature tells us that any given cycle has a variation in TSI that can provoke a global temperature response of about 0.1C, which may explain why the warming has accelerated since 2013. However, that figure is within one cycle; there may be a larger change in global temperatures when multiple cycles have low/no sunspots, as happened during the Maunder and Dalton Minimum.

 

Overall, this doesn't seem to change much regarding what we know about climate change and solar activity. Solar activity was relatively high 1900-1999, but has stabilized since 1950, and was relatively low 1800-1899, but not as low as the 1600s. Solar activity is not a primary cause of observed warming, especially not since 1950.

 

 

You're selling the Sun short by only focusing on TSI. There are solar amplification mechanisms beyond TSI, and accumulated solar energy has a much higher correlation to global temperature than sunspot cycling. Due to the Earth's thermal inertia, it takes awhile for the full effects of heightened solar activity to manifest. And thus, multiple similar strong solar cycles, while not increasing in magnitude, will certainly aid in enhancing the warming over time. This is why many are incorrect in expecting a quick and sudden drop in global temperatures in the past decade, immediately during/following one less active cycle.

 

The attribution of solar activity on climate continues to be debated in the literature, and there are innumerable peer reviewed papers demonstrating a strong solar component. The percent attribution of anthropogenic vs. solar post 1950 is still quite debatable.

[chubbs]

The following paper demonstrates that solar activity in the most recent period was at the highest levels in 9,400 years.

 

http://www.aanda.org/index.php?option=com_article&access=doi&doi=10.1051/0004-6361/201219997&Itemid=129

 

When I went to the above paper link, the journal identified a related paper, abstract copied below, which calls into question the findings in the paper linked above.

 

No evidence for planetary influence on solar activity

R. H. Cameron and M. Schüssler

 

Abstract

 

Context. Recently, Abreu et al. (2012, A&A. 548, A88) proposed a long-term modulation of solar activity through tidal effects exerted by the planets. This claim is based upon a comparison of  (pseudo-)periodicities derived from records of cosmogenic isotopes with those arising from planetary torques on an ellipsoidally deformed Sun.

 

Aims. We examined the statistical significance of the reported similarity of the periods.

 

Methods. The tests carried out by Abreu et al. were repeated with artificial records of solar activity in the form of white or red noise. The tests were corrected for errors in the noise definition as well as in the apodisation and filtering of the random series.

 

Results. The corrected tests provide probabilities for chance coincidence that are higher than those claimed by Abreu et al. by about 3 and 8 orders of magnitude for white and red noise, respectively. For an unbiased choice of the width of the frequency bins used for the test (a constant multiple of the frequency resolution) the probabilities increase by another two orders of magnitude to 7.5% for red noise and 22% for white noise.

 

Conclusions. The apparent agreement between the periodicities in records of cosmogenic isotopes as proxies for solar activity and planetary torques is statistically insignificant. There is no evidence for a planetary influence on solar activity.

[StudentOfClimatology]

When I went to the above paper link, the journal identified a related paper, abstract copied below, which calls into question the findings in the paper linked above.

I'm pretty sure that paper is rebutting the proposed idea that planetary tidal forcings govern solar activity. It's not calling the BE^10/C^14 record into question.

The beautiful thing about the proxy record is you don't need to worry about changes in telescope resolution, or in the way sunspots are counted, etc.

[Isotherm]

When I went to the above paper link, the journal identified a related paper, abstract copied below, which calls into question the findings in the paper linked above.

 

No evidence for planetary influence on solar activity

R. H. Cameron and M. Schüssler

 

Abstract

 

Context. Recently, Abreu et al. (2012, A&A. 548, A88) proposed a long-term modulation of solar activity through tidal effects exerted by the planets. This claim is based upon a comparison of  (pseudo-)periodicities derived from records of cosmogenic isotopes with those arising from planetary torques on an ellipsoidally deformed Sun.

 

Aims. We examined the statistical significance of the reported similarity of the periods.

 

Methods. The tests carried out by Abreu et al. were repeated with artificial records of solar activity in the form of white or red noise. The tests were corrected for errors in the noise definition as well as in the apodisation and filtering of the random series.

 

Results. The corrected tests provide probabilities for chance coincidence that are higher than those claimed by Abreu et al. by about 3 and 8 orders of magnitude for white and red noise, respectively. For an unbiased choice of the width of the frequency bins used for the test (a constant multiple of the frequency resolution) the probabilities increase by another two orders of magnitude to 7.5% for red noise and 22% for white noise.

 

Conclusions. The apparent agreement between the periodicities in records of cosmogenic isotopes as proxies for solar activity and planetary torques is statistically insignificant. There is no evidence for a planetary influence on solar activity.

 

 

 

The isotope proxy record was the relevant piece of information pertaining to this thread's topic, and the paper you posted does not refute it, as SOC noted. That paper is responding to the notion of modulation of long term solar activity via tidal effects exerted by planets.

[CAD_Wedge_NC]

You're selling the Sun short by only focusing on TSI. There are solar amplification mechanisms beyond TSI, and accumulated solar energy has a much higher correlation to global temperature than sunspot cycling. Due to the Earth's thermal inertia, it takes awhile for the full effects of heightened solar activity to manifest. And thus, multiple similar strong solar cycles, while not increasing in magnitude, will certainly aid in enhancing the warming over time. This is why many are incorrect in expecting a quick and sudden drop in global temperatures in the past decade, immediately during/following one less active cycle.

 

The attribution of solar activity on climate continues to be debated in the literature, and there are innumerable peer reviewed papers demonstrating a strong solar component. The percent attribution of anthropogenic vs. solar post 1950 is still quite debatable.

Strongly agree. This is my stance as well. The debate, in my mind, comes down to the amount of weight each component has on climate change.

[nflwxman]

First class tin foil hat stuff here guys.  The solar component is very small and it has been declining since 1950 and yet temperatures still go up?  Can it have a small affect on global temperatures?  Sure.  But the overall difference in forcing from a modern solar max and min is like 0.2 W/m^2.  Solar certainly had some contribution to the early 20th century warming, but that impact is long gone and the temperatures remain elevated.

[FallsLake]

First class tin foil hat stuff here guys.  The solar component is very small and it has been declining since 1950 and yet temperatures still go up?  Can it have a small affect on global temperatures?  Sure.  But the overall difference in forcing from a modern solar max and min is like 0.2 W/m^2.  Solar certainly had some contribution to the early 20th century warming, but that impact is long gone and the temperatures remain elevated.

I agree if your only looking at the heat output differences. There have been studies focused on the changes in cosmic rays (between min & max solar cycles) and their effects on cloud cover. (so)I don't think this topic is so black and white...    

[Mallow]

I agree if your only looking at the heat output differences. There have been studies focused on the changes in cosmic rays (between min & max solar cycles) and their effects on cloud cover. (so)I don't think this topic is so black and white...    

 

I thought the cosmic ray theories were shown to be a negligible contribution (if at all) by the peer reviewed science quite a while ago.