Volcanoes Once Again, Again

Guest Post by Willis Eschenbach [also, see update at the end of the post]

Anthony recently highlighted a couple of new papers claiming to explain the current plateau in global warming. This time, it’s volcanoes, but the claim this time is that it’s not the big volcanoes. It’s the small volcanoes. The studies both seem to follow what I call “Willis’s Rule of Author Count”. The first study is Total volcanic stratospheric aerosol optical depths and implications for global climate change, by D. A. Ridley, S. Solomon, J. E. Barnes, V. D. Burlakov, T. Deshler, S. I. Dolgii, A. B. Herber, T. Nagai, R. R. Neely III, A. V. Nevzorov, C. Ritter, T. Sakai, B. D. Santer, M. Sato, A. Schmidt, O. Uchino andJ. P. Vernier. The second study is Observed multi-variable signals of late 20th and early 21st century volcanic activity, by Benjamin D. Santer, Susan Solomon, Céline Bonfils, Mark D. Zelinka, Jeffrey F. Painter, Francisco Beltran, John C. Fyfe, Gardar Johannesson, Carl Mears, David A. Ridley, Jean-Paul Vernier, Frank J. Wentz.

Now, Willis’s Rule of Author Count says that the quality of any study is inversely proportional to the square of the number of listed authors. And these two studies have seventeen and twelve authors respectively … not a good sign.

The abstract of the first paper says:

Understanding the cooling effect of recent volcanoes is of particular interest in the context of the post-2000 slowing of the rate of global warming. Satellite observations of aerosol optical depth above 15 km have demonstrated that small-magnitude volcanic eruptions substantially perturb incoming solar radiation. Here we use lidar, Aerosol Robotic Network, and balloon-borne observations to provide evidence that currently available satellite databases neglect substantial amounts of volcanic aerosol between the tropopause and 15 km at middle to high latitudes and therefore underestimate total radiative forcing resulting from the recent eruptions.

The abstract of the second paper, in turn, says:

The relatively muted warming of the surface and lower troposphere since 1998 has attracted considerable attention. One contributory factor to this “warming hiatus” is an increase in volcanically-induced cooling over the early 21st century. Here, we identify the signals of late 20th and early 21st century volcanic activity in multiple observed climate variables. Volcanic signals are statistically discernible in spatial averages of tropical and near-global SST, tropospheric temperature, net clear-sky short-wave radiation, and atmospheric water vapor.

Now, it is certainly possible that “small-magnitude volcanic eruptions substantially perturb incoming solar radiation”. There are lots of things that perturb incoming solar radiation, with clouds heading the list. Whether small volcano emissions in turn perturb the global surface temperature is a separate question.

But for eruptions to be an explanation for the current plateau in global warming, the authors would have to show a significant increase in volcanic eruptions in the 21st century. And unfortunately (but predictably) I see no sign in either paper that they have even tried to do that.

So let’s do their job for them by taking a look at the actual records of eruptions, both large and small. The data on all known eruptions is available from the Smithsonian Volcanism Project.

Now, we have some choices in how to display this data. Let me show three of these different ways.

First, we can show the total numbers of eruptions by year, without regard to the size of the eruption. Figure 1 shows that information:

annual count of recent eruptionsFigure 1. Count of all volcanic eruptions, regardless of their strength, during the end of the 20th and the start of the 21st centuries.

As you can see, there is very little difference between the post-2000 (or post 1998, depending on the study) eruption count and the number of eruptions during the end of the 20th century. After 2000 (or 1998), it went up a bit, then it went down a bit … overall, little change.

But wait, I can hear you saying, the eruptions are not all of the same strength … what is the average strength of the eruptions? And reasonably so, since strong eruptions would have a bigger effect than small eruptions. So let’s look at that data.

The strength of an eruption is measured by the volcanic explosivity index, or VEI. This is a logarithmic scale. This means that an eruption with a VEI of 5 is ten times stronger than an eruption with a VEI of 4, and so on.

In order to properly average these, it’s necessary to use a “logarithmic mean” To do this, you first convert the VEIs to actual values (by taking ten to the power of the VEI). Then you average the actual values, and then take the logarithm of the resulting average to convert it back into the logarithmic VEI scale. Figure 2 shows that result:

annual logmean of recent eruptionsFigure 2. Annual logarithmic mean of the volcanic explosivity index, all volcanoes.

In 1991, there were two strong eruptions, Pinatubo (VEI of 6) and Cerro Hudson (VEI of 5). Other than that, there’s not a lot of variation.

Once again, you can see that the post 2000 (or post 1998) average strength of the volcanic eruptions are little different from the strength of the eruptions prior to the turn of the century. So that cannot be the cause of 21st century plateau in global surface temperatures.

Finally, we could read the implicit claim as being that there is some kind of increase in the number of small volcanic eruptions. After all, the authors say that these are the overlooked eruptions. So let’s take a look at the small pre- and post-2000 eruptions.

annual count of recent eruptions vei less than 3Figure 3. Annual count of the smaller eruptions, those with a volcanic explosivity index of less than 3.

Once again, we see little change in the number of small volcanoes. After 2000, it goes above the average, and then it goes about the same amount below the average.

Conclusions? Well, the papers may be correct in their claim that the effect of eruptions on the clarity of the atmosphere may have been underestimated.

But they are absolutely not correct in the claim that this underestimation reveals the cause of the recent 18+ year plateau in temperatures as being eruptions. There is almost no post-2000 change in either the number of eruptions, the strength of eruptions, or the number of small eruptions.

Overall? I’d say that Willis’s Rule of Author Count, that the quality of any study goes down inversely proportional to the square of the number of listed authors, is validated once again …

[UPDATE: The underlying claim of these two papers is that although there have been no large eruptions in the 21st century, it is the weaker eruptions that are causing the plateau in temperature. These are eruptions with a volcanic explosivity index (VEI) of four. Some commenters below still think that the eruptions of VEI four are significant. The Santer document shows the effect of some of the VEI 4 eruptions on the stratospheric aerosol optical depth (SAOD), which is their main indication of volcanic change. The study says:

We use stratospheric aerosol optical depth (SAOD) data from Vernier et al. [2011] to study changes in stratospheric loadings of volcanic aerosol.

The eruptions  make a change of about .002 in the SAOD, viz:

near global saod and ceres sw

mean monthly saod legendNow, that looks kind of impressive … until you compare it to the larger volcanoes (source):

mean monthly saod

You can see the sizes of Krakatoa in the 1880s, Pinatubo in 1991, El Chichon in 1982, and Mt. Agung in 1963, along with some smaller volcanoes … and then you can see the part that Santer et al. are discussing. This is the almost-flat line in the post-2000 era. Sorry, but given the short-term, weak, local effects of even the largest volcanoes, I’m not buying the idea that those tiny post-2000 wiggles have any discernible effect at all.

My best regards to you all,

w.

ONCE AGAIN: If you disagree with someone, please do everyone the favor of QUOTING THE EXACT WORDS THAT YOU DISAGREE WITH. This prevents all kinds of misunderstandings and misrepresentations.

FURTHER READING: I note that this is not the first time that Susan Solomon has made the claim that volcanoes are the cause of the current pause in temperatures. In addition, she was the main mover behind one of the IPCC reports, from memory the Fourth, and is fully and completely invested in the meme of “CO2 Roolz Everything, OK” … whenever I see her name on a study, I’m sad to report that I just wince. See here for my discussion of her previous work.

246 thoughts on “Volcanoes Once Again, Again

  1. My understanding is that conventional wisdom says that “small” volcanic eruptions have less than proportional effect because their ejections don’t get that high in the atmosphere and are quickly rained out. Is this being challenged?

    • Dunno, but carbonyl sulfide (COS) could be a way for the less energetic eruptions to have a way of getting sulfur to the stratosphere. COS is not very reactive in the troposphere, but if it gets hit with short wavelength UV, it dissociates and can become part of the sulfate formation mechanism. UV that short of a wavelength is only plentiful in the stratosphere. The big caveat is going to be how quickly or efficiently, COS can diffuse across the tropopause. From what I understand, COS tends to stay in the troposphere for up to nine years.

    • We can barely find a temperature signal from the very largest stratospheric eruptions. Willis has posted on this several times.

      The large ones do clearly show up in the lower stratosphere temperatures but for the surface, it is only the largest ones that go high into the stratosphere that seem to have a (barely detectable) signal. Some of the largest ones leave nothing in the temperature series.

      If we can only barely detect the largest ones, how can several small ones that leave no stratospheric or aerosol optical depth signal, have an impact.

      • Right. The graph of optical transmission plainly shows significant but brief excursions from large volcanoes, then a quick return to a remarkably smooth & consistent plateau (while “little” volcanoes are constantly occurring). That graph says all we need to know.

        More warmy attempts to explain the lack of predicted CO2 warming — just like exaggerated human-aerosol effects.

      • First of all, I am not a “warmy” I think the whole idea of Globular Warming is a giant festering crock of [insert disgusting material here].

        I do, however, think that the background level of the Junge layer is affected by this mechanism, but the guys that track the Tau line seem to have given up interest since about 2012. I was thinking that maybe a signal from the Tolbachik flood basalt or the Holurhaun eruption in Iceland may show some effect. I guess it’s sort of my fault for expecting Nasa to keep a data set updated.

        http://data.giss.nasa.gov/modelforce/strataer/

        An oddity though… Mobile Bay actually started forming Ice recently. Not a lot of ice, mostly a “hey, check that out” sort of thing for the locals. Not totally uncommon, but it is quite rare.

        http://fox10tv.com/2015/01/08/mobile-bay-spectacular-as-frozen-wonderland/

      • Please see this Aerosol Optical Depth Animation from January 2005 to November 2014 – press the Play button
        http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MODAL2_M_AER_OD

        Can anyone spot any volcanoes? I cannot.

        You can clearly see the significant effects of agricultural burning in South and Central America and Africa, and Southeast Asia.

        Here is the commentary that accompanies the Aerosol animation:

        High aerosol amounts are linked to different process in different places and times of year. High aerosol amounts occur over South America from July through September. This pattern is due to land clearing and agricultural fires that are widespread across the Amazon Basin and Cerrado regions during the dry season. Aerosols have a similar seasonal pattern in Central America (March-May), central and southern Africa (June-September, and Southeast Asia (January-April).

        In other cases, however, aerosol concentrations are not related to fires. For example, from May through August each year, aerosol amounts rise dramatically around the Arabian Peninsula and nearby oceans due to dust storms. Elevated aerosol amounts nestle at the foothills of the Himalaya Mountains in northern India in some months, and linger over eastern China for much of the year. These elevated aerosol amounts are due to human-produced air pollution.
        _____________

        Please see this Fires Animation from March 2000 to November 2014 – press the Play button
        http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MOD14A1_M_FIRE

        Here is the commentary that accompanies the Fires animation:

        The fire maps show the locations of actively burning fires around the world on a monthly basis, based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The colors are based on a count of the number (not size) of fires observed within a 1,000-square-kilometer area. White pixels show the high end of the count —as many as 100 fires in a 1,000-square-kilometer area per day. Yellow pixels show as many as 10 fires, orange shows as many as 5 fires, and red areas as few as 1 fire per day.

        Some of the global patterns that appear in the fire maps over time are the result of natural cycles of rainfall, dryness, and lightning. For example, naturally occurring fires are common in the boreal forests of Canada in the summer. In other parts of the world, the patterns are the result of human activity. For example, the intense burning in the heart of South America from August-October is a result of human-triggered fires, both intentional and accidental, in the Amazon Rainforest and the Cerrado (a grassland/savanna ecosystem) to the south. Across Africa, a band of widespread agricultural burning sweeps north to south over the continent as the dry season progresses each year. Agricultural burning occurs in late winter and early spring each year across Southeast Asia.
        _______________

        Please see this Carbon Monoxide Animation from March 2000 to November 2014 – press the Play button
        http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MOP_CO_M

        Here is the commentary that accompanies the Carbon Monoxide animation:

        These maps show monthly averages of global concentrations of tropospheric carbon monoxide at an altitude of about 12,000 feet. The data were collected by the MOPITT (Measurements Of Pollution In The Troposphere) sensor on NASA’s Terra satellite. Concentrations of carbon monoxide are expressed in parts per billion by volume (ppbv). A concentration of 1 ppbv means that for every billion molecules of gas in the measured volume, one of them is a carbon monoxide molecule. Yellow areas have little or no carbon monoxide, while progressively higher concentrations are shown in orange and red. Places where the sensor didn’t collect data, perhaps due to clouds, are gray.

        In different parts of the world and in different seasons, the amounts and sources of atmospheric carbon monoxide change. In Africa, for example, the seasonal shifts in carbon monoxide are tied to the widespread agricultural burning that shifts north and south of the equator with the seasons. Fires are an important source of carbon monoxide pollution in other regions of the Southern Hemisphere, such as the Amazon and Southeast Asia.

        In the United States, Europe, and eastern China, on the other hand, the highest carbon monoxide concentrations occur around urban areas as a result of vehicle and industrial emissions. Fires burning over large areas in North America and Russia in some years can be an important source. The MOPITT observations often show that pollution emitted on one continent can travel across oceans to have a big impact on air quality on other continents.
        ________________

        What about CO2? There is not similar CO2 animation from this NASA site, but here is a CO2 animation from September 2002 to July 2008 (give it a minute to load):
        [video src="http://svs.gsfc.nasa.gov/vis/a000000/a003500/a003562/carbonDioxideSequence2002_2008_at15fps.mp4" /]

        Try to find the impact of fossil fuel combustion in this CO2 data – I cannot.

        No sign of volcanoes either…

    • Maybe they refer to volcanoes hidden in the oceans or in their imagination? International socialism need the predictive power of progressive enlightenment liberalism(policy based science/propaganda) to get a climate treaty in Paris later this year?

    • Some of the people behind these 2 studies are the same. Why do they participate in 2 different studies to tell the same story? Maybe if the same people tell the same story in 2 different studies then the 2 studies verify each other?

    • Climate change| that is real and that you can measure.
      The ghost of climate change: climate change that is imaginary and needed to promote policy.
      The trinity of climate change: the result of climate science being politicized.

  2. *sigh* Most of the warmista’s won’t even admit there is a pause *at all* when you try to discuss the pause with them. I do see that articles like this have their place (getting them to admit there is a pause at all). How much can people have their heads shoved up their asses?

    • Why do we even consider these frauds. They are political scientist working at the bid of their controllers and contemptible

    • They don’t have their heads up their “asses”, or horses for that matter.

      They do have their hands in the till, though.

    • They know they can adjust the data to make the pause disappear, they just have to wait a few years. In fact you can already see the front end of the pause changing in some data sets.

    • At least Thomas Stocker, a leading head of the IPCC, admits the pause by declaring it is finished now by the “heat record” of 2014. See here:
      http://www.schweizamsonntag.ch/ressort/meinung/kann_die_menschheit_die_erderwaermung_stoppen/

      It’s a rather unscientific conclusion of course, but Stocker is more an activist than a true scientist, according to this very fitting quote by Matt Ridley about the “heat record” of 2014:

      “True scientists would have said: this year is unlikely to be significantly warmer than 2010 or 2005” and left it at that.

  3. But wait! These two papers were peer reviewed, were they not. You must have overlooked something, Willis. Peer review is sacrosanct.

    • If they get 97% of all scientists to contribute to the article, then peer review is a shoo-in.

      • Good point. I was about to object to Willis’ rule, but, as you suggest, more authors-more friends, and more peer friends.

      • I believe that every peer reviewed paper that purports to have more than one author, should specifically disclose exactly what part of the paper was written by which author.

        I know for example, that in the US Patent Office peer reviewed literature (AKA US patents), Every named “inventor” must be able to claim SOLE responsibility for at least ONE element of at least ONE claim in the patent, that eventually gets by the examiner to become a part of the claimed invention. I have never been a “co-inventor” of any element of any patent claim, but I have added my share of novel features to gizmos, that also included individual contributions from other inventors.

        I have never stumbled across their ideas at the same time, nor have they mine.

        But collectively we have improved on each others work.

        But of course this is the age when 4 yr. olds are taught in kiddiegarden, and subsequently, to sit quietly at a table with a bunch of other restless brats, and let the smart kid solve the problem, then all get the same grade. This eventually becomes a focus group.

        Just how many “scientists” have their names on the paper that discovered the Higgs boson, or whatever it really is that they think they have found ??

        It often works in reverse; for example, when Steven Chu gets the Nobel Physics prize for inventing “optical tweezers”, but the Swedes ignore the Bell Labs chap who really invented them, and then hired, and taught Chu, how to do it many years later.

        And of course in 2014, they ignored Dr. Nick Holonyak who invented the visible (red) LED, but gave the Nobel Physics prize to Shuji Nakamura, who of course invented the blue LED.

        Nakamura was an admirable and deserving choice for the prize, but they should have included Holonyak, who started the whole thing rolling, decades earlier.

        I think the real authors of scientific advances should be recognized by name, not by the focus group they were in.

    • First disclaimer: I have not yet opted to pay to view the full articles for these two papers.

      Second disclaimer: regarding authors showing a significant increase in their chosen volcanic eruptions in the 21st century, I am going to assume to be correct Mr Eschenbach’s assertion that “unfortunately (but predictably) I see no sign in either paper that they have even tried to do that.”

      I also would expect to read somewhere in each of these papers that the volcanic activity being claimed as the mechanism for reduced 21st century global warming would be clearly shown to be statistically or significantly increased as compared to periods of previous higher warming rates. As a result, I have a couple of open questions for any of the more vocal AGW proponents that regularly post here (e.g. Mr Stokes, Mr Mosher, Mr Socrates, Mr Gates, etc.)

      First question: Can we agree that if this major oversight/omission of the subject articles identified and separately analyzed by W.Eschenbach does exist, that the peer review process at Geophysical Research Letters is flawed?

      Second question (possibly N/A depending on answer #1): If you do not agree that the GRL peer review is flawed, can you explain why the omission as identified by W. Eschenbach would be acceptable for the conclusion drawn?

      Thanks in advance.

      Bruce

      • It would be interesting if we knew about small volcanic activity between 1910 to 1950. We had a warming then cooling trend.

        Abstract
        …..Preliminary application of the eruption chronology to global and hemispheric temperature trends for the period 1880–1969 demonstrates that episodes of frequent and intense ash-producing eruptions tend to be associated with periods of cooler hemispheric temperatures, while volcanically quiescent episodes tend to correspond with periods of hemispheric warming.
        http://www.sciencedirect.com/science/article/pii/003101827990083X

    • They, Santer, Salomon and Ridley from the first study first per viwed the other study. Then Santer, Solomon and Ridley from the other study per viewed the first study?

  4. Willis, Excellent. Thanks for your effort. My gut feeling was that the studies were nonsense, but your finding and analyzing the relevant data took all of the guesswork right out of it. Thanks, much appreciated!

  5. Willis and others please do look at the dates of acceptance for the second article also the first. X-mas eve for the second? thats peer review?

    michael

    • oops 29th not 24th of dec but then isn’t this vacation time? Why would people be be rushing out a paper it this time of year?

  6. Willis,

    At this point, when the overwhelmingly majority of authors on papers, such as these, are little more than rubber stamps of consensus “communication”, one wonders if some of these people are “authors” of mutually contradicting papers. With 50 plus reasons and counting as well as pause denial, some of these authors are likely to truly be typing out of both sides of their keyboard.

  7. The logarithmic nature of CO2 and temperature is driving them nuts! What is the saturation point of CO2 for IR anyhow?

  8. Good job, Willis. You brought out the obvious, and as I sometimes say, the best way to refute the climate change extremists is through actual data. They seem allergic to it. Actual data drives them to their models to receive comfort.

  9. CTM:

    “… truly be typing out of both sides of their keyboard.”

    Thank you for a very amusing mental image regarding the two-faced CAGW climateer profiteers using their keyboards in perverse ways… :->

  10. “Now, Willis’s Rule of Author Count says that the quality of any study is inversely proportional to the square of the number of listed authors. And these two studies have seventeen and twelve authors respectively … not a good sign.”

    =======================================

    Excellent rule Willis, which deserves a suitable name.

    May I suggest “Widdecombe Fair Science”

    • Willis’s Rule of Author Count has an immediate, intuitive, appeal. I would like to see it backed up by something more than intuition, and gain at least the status of Parkinson’s Law and the Peter Principle.

  11. Now Showing: The Little Volcano That Could!
    Sound Track by Ben Santer: I think I can….I think I can….I think I can…..

  12. If I understand correctly, volcanoes produce cooling effects via aerosols and the effects of aerosols were taken into account by NASA authors and their colleagues when they estimated +0.6 W/m2 as the recent net global warming.

    James Hansen et al. (2011) Earth’s energy imbalance and implications, Atmos. Chem. Phys., 11, 13421-13449, 2011). URL:
    http://www.atmos-chem-phys.net/11/13421/2011/acp-11-13421-2011.pdf

    Based on the result obtained by Hansen et al., Graeme Stevens had this to say:

    The net energy balance is the sum of individual fluxes. The current uncertainty in this net surface energy balance is large, and amounts to approximately 17 Wm–2. This uncertainty is an order of magnitude larger than the changes to the net surface fluxes associated with increasing greenhouse gases in the atmosphere (Fig. 2b). The uncertainty is also approximately an order of magnitude larger than the current estimates of the net surface energy imbalance of 0.6 ±0.4 Wm–2 inferred from the rise in OHC. The uncertainty in the TOA net energy fluxes, although smaller, is also much larger than the imbalance inferred from OHC.

    Graeme L. Stephens et al, An update on Earth’s energy balance in light of the latest global observations. Nature Geoscience Vol. 5 October 2012
    URL: http://www.aos.wisc.edu/~tristan/publications/2012_EBupdate_stephens_ngeo1580.pdf

    The estimate of 0.6 Wm-2 was updated by Loeb and others in 2012 to 0.5 Wm-2.

    Reference: Norman G. Loeb, John M. Lyman, Gregory C. Johnson, Richard P. Allan, David R. Doelling,Takmeng Wong, Brian J. Soden and Graeme L. Stephens. Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty. (Nature Geoscience Vol 5 February 2012)
    URL: http://www.met.reading.ac.uk/~sgs02rpa/PAPERS/Loeb12NG.pdf

    This revised estimate leads to the conclusion that the energy imbalance is 0.15% of incoming solar radiation. Since the uncertainty is in both downward and upward flux, the energy imbalance is 0.075% of total energy flux. This estimate of energy imbalance is so small that little confidence can be placed on its accuracy. We ought to regard the current estimate of global warming as arising from spurious precision.

    The metric for net warming is +0.5Wm-2 compared with 17Wm-2 uncertainty. The uncertainty is 34 times as big as the measured net warming.

    What the authors of these two volcano papers purport to do is to show that the net energy imbalance would be higher than +0.5Wm-2 if small-scale vulcanism were taken into account. However, adjusting a metric that is spuriously precise would get us nowhere at all. Even if they double the net warming to +1.0 Wm-2, the uncertainty would still be 17 times bigger than the measured warming.

    • Frederick,

      Fantastic post, Frederick. If you look further in Hansen’s paper, it gets worse:

      “We also must quantify the causes of changes of Earth’s energy imbalance. The two dominant causes are changes of greenhouse gases, which are measured very precisely, and changes of atmospheric aerosols. It is remarkable and untenable that the second largest forcing that drives global climate
      change remains unmeasured. We refer to the direct and indirect effects of human-made aerosols”

      I see nowhere where they measure volcanic aerosols.

      Now as to this alleged energy imbalance caused by humans, Hansen makes some startling observations:

      “The precision achieved by the most advanced generation of radiation budget satellites is indicated by the planetary energy imbalance measured by the ongoing CERES (Clouds and the Earth’s Radiant Energy System) instrument (Loeb et al., 2009), which finds a measured 5-yr-mean imbalance of 6.5 W m−2 (Loeb et al., 2009). Because this result is implausible, instrumentation calibration factors were introduced to reduce the imbalance to the imbalance suggested by climate models, 0.85 W m-2″</b

      So they introduce a phony calibration factor because the measurement error is something like 600%. Bottom line, the alleged energy imbalance cannot even be measured by satellites. The other method of measuring energy imbalance is indirectly through "measurements of changes in the heat content of the ocean and the smaller heat reservoirs on Earth" (per Hansen) Call me completely skeptical if this method can measure to the accuracy of 0.5 W/m-2.. Hansen had this to say about the ocean heat content approach:

      "An alternative potentially accurate approach to measure Earth’s energy imbalance is via changes in the ocean heat content, as has been argued for decades (Hansen et al.1997) and as is now feasible with Argo data (Roemmich and Gilson, 2009; Von Schuckmann and Le Traon, 2011). This approach also has sampling and instrument calibration problems, but it has a fundamental advantage: it is based on absolute
      measurements of ocean temperature. As a result, the accuracy improves as the record length increases, and it is the average energy imbalance over years and decades that is of greatest interest.”

      “Potentially accurate”?? So further bottom line. The ALLEGED energy imbalance simply CANNOT even be measured. When one has a hypothesis, the scientific method requires confirmation by testing. If the testing, or measurement cannot be performed, the hypothesis remains unconfirmed. QED.

      • Because this result is implausible, instrumentation calibration factors were introduced to reduce the imbalance to the imbalance suggested by climate models, 0.85 W m-2

        Holy donuts Batman! What is the purpose of putting a satellite into orbit if you are simply going to adjust it to give the answer you already expected to see? Oh look, the books don’t balance. Lets just adjust the figures so they do. In business that is called go to jail. In climate science it is called business as usual. Standard Operating Procedure.

        If observations don’t match the models, adjust the observations.

      • But…but… we were told the models were tuned to match the data. Now they’re tuning the data to the models? Just

        Wow!

    • ferdberple stated:

      ” What is the purpose of putting a satellite into orbit if you are simply going to adjust it to give the answer you already expected to see?

      Exactly. This is how they do science. It’s pure insanity. Their whole AGW hypothesis is a ruse. The alleged energy imbalance can’t even be scientifically measured, so they fake the measurements by adjusting the data to comply with what was expected.

  13. Excellent critique. The effluvium (love that word – describes the content of the paper well, don’t you think?) from small volcanoes clears from the atmosphere quickly because it doesn’t reach so high and there isn’t much of it. And, of course, it rains. The dust from big volcanoes can be seen at sunset/sunrise for up to 3 years, so even this is not enough to explain a 19 year hiatus. I was near Volcan Hudson when it went off – an immense amount of material was introduced into the atmosphere, but the skies cleared quickly. Incidentally, much of the effluvium was large particulate pumice – it had near zero residence time in the atmosphere.
    Can I help them out in their salary aspirations by suggesting grants may be awarded for studies on increased dust concentration in the atmosphere from drying deserts? Particulate pollution from nano- plastic particles and nano-technology by-products? Anti-matter coronal effects from the top of thunderstorms? Increased eructation from processed foods. What ever takes take their fancy – they don’t seem shy of suggesting all sorts of mechanisms – other than water vapour/ice which really is important and which could easily provide the negative feedback loop that is holding the temperature constant in spite of increasing CO2 levels.

  14. Beautiful data Willis – I love it when alarmist arguments can be quickly dismissed with a little basic research & data. Exposes them for the political agenda driven bunch they are versus the science driven bunch skeptics are.

    Well done!

  15. Ok, it took awhile but I’ll now have to agree, grudgingly, that volcanoes ain’t got much pull.
    Which only gives more weight to the other drivers.

      • And excepting that volcanism is by far mostly submarine, and eruptions are punctuated (and still possibly cyclic) and exhale a great deal of heat into ocean basins, which will modify currents. So volcanism is far from sidelined, it is very much a player in that regard, and also in regard to known optical effects of big eruptions.

        It’s CO2 rise that’s better and better explained by volcanism, and that what’s being sidelined here, not volcanoes, when ocean cyclicity is deeply implicated in climate variability, and altered by bottom water thermal regime (which is the open question).

      • Unmentionable,

        The same problem of CO2 from volcanoes as for aerosols: if they are responsible for the increase over the past 160 years, there should be an enormous increase in activity (a 4-5 fold since 1959, when accurate measurements started), which isn’t seen anywhere.
        Further most CO2 from undersea volcanoes is absorbed in the deep oceans and distributed in the enormous amount of (bi)carbonates there.
        Last but not least, volcanic CO2 has a higher δ13C level than CO2 in the atmosphere. The atmosphere and the ocean surface shows a sharp decline in δ13C level, completely in parallel with human emissions…

      • Ferdinand Engelbeen
        January 10, 2015 at 3:39 am
        “Last but not least, volcanic CO2 has a higher δ13C level than CO2 in the atmosphere. ”

        Yes, it looks unlikely (I regretted the sentence the moment I posted). As with all oceanic data sample coverage is low or very low and data surprisingly diverse with geography, and with deposition context. But a small δ13C depletion is the overall. So it’s an overstatement to say rising atmospheric CO2 is adequately explained by underwater volcanism that simultaneously imparts a thermal rise, inducing any actual warming cycle.

  16. “But for eruptions to be an explanation for the current plateau in global warming, the authors would have to show a significant increase in volcanic eruptions in the 21st century. ”

    No. they would not have to show this.

    Showing it would help, but its not necessary.

    What’s important is total forcing.

    • Except that CO2, the putative major forcing has risen during this period at about the same rate as before it. For the temperature to flatline, there must have been a drop in total forcing–something else must have changed. If not rising volcanic SO2, what?

    • Steven Mosher January 9, 2015 at 9:16 pm

      “But for eruptions to be an explanation for the current plateau in global warming, the authors would have to show a significant increase in volcanic eruptions in the 21st century. ”

      No. they would not have to show this.

      Showing it would help, but its not necessary.

      What’s important is total forcing.

      Say what? Given that as I have shown, there is no difference in the volcanic eruptions during the time of increasing temperatures and the time of the plateau in warming, then how on earth can the eruptions be the reason for the pause?

      You’ll have to explain that claim a whole lot better than you’ve done so far, Mosh.

      w.

      • I think Mosh must be thinking that it is the total force of the accumulated Volcanic Emissions over the last 2 Centuries has reached the Tipping Point at the end of 1997. Obviously you proved that there was no change in average volcanic activity, however they may wish to measure it.

      • Every volcanic eruption is chemically different. How many or how intense these eruptions are means nothing. Aerosol forcing has been measured by the paper “Total volcanic stratospheric aerosol optical depths and implications for global climate change” which states “we determine the global volcanic aerosol forcing since 2000 to be −0.19 ± 0.09 Wm−2 [which] translates into an estimated global cooling of 0.05 to 0.12°C.”

      • mosh is correct… with “climate science” the formula is come to desired conclusion, “adjust” data to fit conclusion…. deny any contrary indicators… make wild guesses with lots of maybe and possibly… and publish, publish, publish! It does not matter if right or wrong just publish what supports the predetermined desired conclusion, ignore all else and call lots of unsavory names those that disagree…. “climate science” at its best. not sure where to put the “sarc” tag but there might need to be one somewhere…

        Cheers!

        Joe

    • In total, it is the analyses being forced, as are the dubious data ‘adjustments’.
      Unaffected, the climate continues to change, ‘pause’, and cycle, naturally.
      The null hypothesis stands….and that’s what’s important.

    • What they would have to show is that the volcanic aerosols have increased and they have not shown this.

      What they have shown is that there is more, between 15k and the tropopause, than they originally thought. They then use this and the “pause” to infer that there was less earlier in the 20th century and then blame the pause on this.

      They have no data, from AERONET, pre 98 with which they can determine the aerosol levels.

      • Another beautiful example of the logic of ‘Climate Science’. ‘Y’ is happening now, since everyone knows ‘X’ causes ‘Y’, then ‘X’ must have been the case in the past… Which proves ‘Y’ = k’X’.

    • Steven Mosher: ” What’s important is total forcing”
      ####
      Actually no , Steven. What’s important is the _change_ in total forcing. There seems to have been no attempt to demonstrate such a change from the period previous to the study.
      That is the reason for comparing volcanic activity, Steven.
      Without showing that the study era (post 2000) was an era of increased volcanic aerosols, then their conclusion is simply a bald assertion.
      And Steven, I advise that you avoid bald assertions if you have any regard for your reputation as a scientist.

    • Mosher writes “What’s important is total forcing.”

      What’s important is the possibility of an “internal” forcing.

  17. Willis, all correct. Nicely and newly displayed this post. Well done. You reached the same conclusion as essay Blowing Smoke in ebook of same name published last year. Or my posts based on same on the previous thread. Nice to have further visual validation from a data hound such as yourself.
    BTW, your rule of author count is something new (well, to me) but sure seems empirically validated here. Worth a larger statistical test.

  18. Willis. Is the VEI the correct parameter to estimate the quantity of fine partic and sulphate/SO2. Im no vulcanologist, but I cant intuitively see the relationship. Surely it is the mass of those two (mostly) that is important not the VEI. Your thoughts ?

    • Your question was adressed to Willis, whom I am not. But an answer.
      VEI takea no account of the composition of ejecta. Only the maximum altitude attainable.

      • But VEI is correlated with the type of volcanism as is particulate ejections, which occur most heavily in volcanoes above subduction zones.

    • Terry January 9, 2015 at 9:32 pm Edit

      Willis. Is the VEI the correct parameter to estimate the quantity of fine partic and sulphate/SO2. Im no vulcanologist, but I cant intuitively see the relationship. Surely it is the mass of those two (mostly) that is important not the VEI. Your thoughts ?

      Good question, Terry. The answer is, the VEI is not really the correct parameter, but it’s the nearest and best we have. Charles Lamb had something he called the “DVI”, the Dust Veil Index, but it stops in (from memory) about 1988 or thereabouts, so it’s of no use to us for modern data.

      Also, what Rud said.The VEI is a measure of power in the eruption, not the makeup of what is being ejected.

      w.

      • Willis: I’m with Terry and Rud on this: If the ‘pause’ can be explained by volcanic activity it must surely be based on the sheer amount of ejecta that remains (stratospherically?) airborne after ejection.

        But then, we surely must take into account that there is a possible delay between the eruptions and the effect they have on climate – if any. It seems inconclusive to me that the effects of any eruptions have an immediate and long-term effect on climate – which is supposed to be the aggregation of weather over a period of thirty years, or so I was told by people like Nick Stokes et al.

      • I should have read the comments further before posting. I see that Rud has made a similar observation further down the thread. Sheer cooincidence.

  19. So does that mean the heat is still hiding in the oceans? Skeptics are not the intended audience for the “it’s the volcanoes” line. Why would they think someone wouldn’t look at the number and size? Oh.. I know, the truly faithful. It has to be co2!!! It’s a villain just lurking around the shadows, just waiting. That tipping point must be around here somewhere.

  20. Willis writes “Well, the papers may be correct in their claim that the effect of eruptions on the clarity of the atmosphere may have been underestimated.”

    Only with the assumption of a very high sensitivity…and there’s not a lot of evidence for that.

    Its another case of “making stuff up” to suit their message.

  21. Willis, with regard to your FURTHER READING comment, you do know that she’s in the National Academy of Sciences, but then so is Peter Gleick. I’d like to think it’s actually an alarmist computer model for the NAS but, sadly, no.

  22. Some scientific journals report details of what was contributed by each listed author. Presumably this allows for a more open and honest apportioning of credit for ideas or work done. Or blame, should that later prove necessary.

  23. This reply is not from Willis. But the general response is, wrong question.
    Ejecta comprises many things. Example, Basaltic lava is not a major aerosol plume (Iceland at present).
    VEI does not consider the nature of the ejecta, only the force ejected.That is why St. Helens ( VEI 5) had zero impact on atmospheric opacity measured at MLO. See essay Blowing Smoke in book of same name for details.
    It is a combination of the force (will the plume reach the tropopause) and its constituents (lava, ash, aerosols) that determines whether and for how long an eruption might impact weather.

    Since ‘climate’ is defined as the weather ‘envelope’ over at least 30 years, the whole Santer/Solomon volcano thingy is just nonsense. Unless you believe in supervolcanoes erupting for decades, nonstop. Well, the MSM does not report any of same!

  24. Another points is where the volcanic eruptions actually are.

    Volcanoes close to the tropics are able to disperse their ejecta further afield than volcanoes close to the poles, and also into the other hemisphere, which affects world temperatures more significantly.

    Volcanos with more sulphur dioxide also apparently have a more significant effect than those with less. Eruptions vary significantly in the level of S02.

    Let me guess, the papers don’t even bother with any of these things, let alone whether eruptions have changed in frequency and output pre and post ~2000.

    • Thanks, thingadonta, an interesting issue about tropic vs polar. I’ll take a look if I have time … so many clowns, so few circuses, and above all, so little time.

      w.

  25. Seems to me that the various authors may well have looked at the volcano activity data much as Willis has. It is very likely that they went no further because that data did not support their hypothesis. I wonder what they didn’t report.

  26. Knowing your sense of humor, I could not help but notice Figure two giving an all-too-appropriate ‘finger’ to the results… what a wonderfully wicked display!

  27. the value of a climate published study l should be the the inverse of the square of the numbers of listedcathors. I.e. (n authors) ^-2.

  28. I disagree with Willis’ Rule of Author Count – what are you gonna do with the LHC folks that found the Higgs? There are 4000 of them, and to make it proper, all of them would have to be named… this is actually being discussed as a real problem for publishing the results ;)

    • There is a difference. LHC folks are scientists. “Climate Scientists” don’t do science and know little about climate. See, that was easy.

  29. First they came for the LIA, then the MWP.
    Now they make up excuses to come for the RSS and UAHbdata sets since 1979.

  30. whenever I see her name on a study, I’m sad to report that I just wince.

    I have to say, me too. And hers wasn’t the only name on those studies that made me wince. So did Benjamin D. Santer (B. D. Santer).

  31. I seem to remember a panic attack from the warmists a year or two ago about global warming causing increased volcanic eruptions.

    So now: assume the truth of both that and this thesis that increased vulcanism is responsible for the pause.

    We have a lovely balancing act.

    Ain’t nature wonderful?

  32. Nice simple analysis Willis. In fact they may be onto something if they were not so blinded by propping up their failed hypothesis.

    Volcanoes are key IMO. But not the little ones. The problem is that they are ( in some cases wilfully ) ignoring long term WARMING effect of volcanoes.
    The first clue is the cooling of the stratosphere that occured after both El Chichon and Mt Pinatubo. The smaller eruptions have no visible effect on this scale and the stratosphere is where they say they matter.

    Having identified the timing of effect in the stratosphere, we can see the complementary warming of the surface record bears a striking resemblance.
    http://climategrog.wordpress.com/?attachment_id=902

    The bottom line is that it is the lack of volcanoes that explains the lack of warming compared to the previous 30 years.

    • PS , I say wilfully because Soloman who is a co-author on both papers has done extensive work on changes in ozone in relation to volcanoes. The drop in ozone after major stratospheric eruptions allows more shortwave energy into the lower climate and represents global warming “forcing”. There’s a link to one of her papers in the above linked article where they examine ozone and lower stratosphere temps.

      Also both NCAR and IPCC recognise the step nature of the changes and hence their link to two major eruptions.

      If they have not yet made the connection with “global warming”, one wonders why not.

  33. Willis: The total number of eruptions is not important. Neither is the log mean annual VEI or the number of volcanoes with VEI <3. These are all straw men. The important factor is the number eruptions capable of transferring a significant amount of aerosol above the tropopause (where it will persist). The authors claim to have measured an increase in total aerosol since 2000 and claim it comes from volcanos weaker than the VEI 5 and 6 volcanoes that have traditionally been associated with cooling. That means you should have concentrated your analysis on volcanoes with VEI = 4. There were 14 volcanos with VEI = 4 between 2002 and 2011 and one with VEI = 5. Between 1900 and 1999, there were only 52 volcanoes with VEI = 4, 10 with VEI = 5 and three with VEI = 6. There clearly have been an unusually large number of VEI = 4 volcanoes during the hiatus than in earlier decades.

    The key question is whether these previously ignored volcanoes resulted in higher levels of stratospheric aerosol than during earlier decades when VEI = 4 volcanoes were ignored. Most of the measurement techniques used during the hiatus were not available in earlier years. When the first paper was not behind a pay-wall, I thought that the methods that were used both before and during the hiatus gave contradictory results before the hiatus and therefore an ambiguous increase during the hiatus. The uncertainty in increase in aerosol forcing was about 50% of the total increase and this may have been a 25%-75% confidence interval.

    A on-paywalled paper on this subject is available here: http://onlinelibrary.wiley.com/store/10.1029/2011GL047563/asset/grl28118.pdf

    • Comparing VEI 4 eruptions in the early 1900’s with 2000-2010 is very doubtful. It is vary unlikely that we have a complete record of such small eruptions that far back. How good is the record of small volcanic eruptions for e. g. Ethiopia, the Subantarctic Islands or Kamchatka in 1900-1910?

    • Frank January 10, 2015 at 12:33 am Edit

      Willis: The total number of eruptions is not important. Neither is the log mean annual VEI or the number of volcanoes with VEI <3. These are all straw men. The important factor is the number eruptions capable of transferring a significant amount of aerosol above the tropopause (where it will persist). The authors claim to have measured an increase in total aerosol since 2000 and claim it comes from volcanos weaker than the VEI 5 and 6 volcanoes that have traditionally been associated with cooling. That means you should have concentrated your analysis on volcanoes with VEI = 4.

      Thanks, Frank, but the papers made no such claim. In fact, they didn’t mention VEI once, neither in the papers nor in the three Supplementary Online Information PDFs. So I fear it’s unclear where you got your claim about VEI = 4.

      There were 14 volcanos with VEI = 4 between 2002 and 2011 and one with VEI = 5. Between 1900 and 1999, there were only 52 volcanoes with VEI = 4, 10 with VEI = 5 and three with VEI = 6. There clearly have been an unusually large number of VEI = 4 volcanoes during the hiatus than in earlier decades.

      There were 16 volcanoes of VEI = 4 and above from 1995 to 2014 (most recent 20 years).

      There were 17 volcanoes of VEI = 4 and above from 1975 to 1994 (previous 20 years)

      Sorry, not seeing the “unusually large” difference.

      In any case, the underlying problem is that even the largest volcanoes make so little difference in the global surface air temperature that they cannot be identified in the record unless you know what year they occurred in. You can’t find them by just looking at the record. See my previous posts in this regard, viz:

      Overshoot and Undershoot
      Prediction is hard, especially of the future.
      Volcanic Disruptions
      Dronning Maud Meets the Little Ice Age
      Missing the Missing Summer
      New Data, Old Claims About Volcanoes
      BEST, Volcanoes and Climate Sensitivity
      Volcanic Corroboration
      Volcanoes: Active, Inactive, and Retroactive
      Stacked Volcanoes Falsify Models
      The Eruption Over the IPCC AR5
      Volcanoes Erupt Again
      Eruptions and Ocean Heat Content

      As a result, I fear that the idea that small eruptions are the “cause of the pause” doesn’t pass the smell test.

      w.

      • Shouldn’t we give credit where credit is due? After all, they did state:”One contributory factor”. /sarc

      • Willis: You say that the two decades from 1995-2014 had a normal number (16) of large volcanos (VEI 4 and greater), but that is irrelevant. There were ZERO large volcanos from 1995 through 1998 (when temperature was rising rapidly) and an unusual concentration of 13 large volcanos from 2002-2011 (most of the hiatus). The aerosols from the three large volcanos in 2011 persisted through at least 2012.

        Why did I focus on VEI = 4 or greater volcanos? All but one of the eleven volcanos shown in Figure 1 of Rindley were VEI = 4. (I don’t know why the authors didn’t list all 13 large volcanos VEI 4 and 5 volcanos that occurred between 2002 and 2001, or why they included one with VEI = 3.)

        During the period without large volcanos, measured levels of aerosols were low, near the detection limit. This period is the baseline from which the increase in aerosol forcing was determined, but the baseline is highly uncertain. New instruments provided more accurate measurement of the modestly higher aerosol present during the period of higher volcanic activity, but those new instruments can’t tell us how much forcing has changed (they weren’t available in 1995-1998) or what “normal” levels of volcanic aerosols were during the 20th century. So all estimates of how much cooling those 13 large volcanos produced from 2002-2012 are highly uncertain. A 95% confidence interval would probably include no cooling and therefore normally not form the central conclusion of a scientific paper.

        To demonstrate that the number of VEI = 4 and VEI = 5 volcanos was unusual between 2002 and the end of 2011, I looked at the total number of such volcanos for the entire twentieth century: 53 VEI = 4 and 9 VEI = 5 (and 3 VEI = 6). VEI = 4 volcanos have not been detected more frequently in recent years, there were 32 in the first half of the century and only 21 in the second. So normal volcanic activity appears to consist of about one VEI=5 volcano per decade and 4-5 VEI=4 volcanos per decade, not the 13 from 2002-2011.

      • Willis: I’ve read your earlier posts on volcanos and clearly remember trying to “spot the volcano”. Unfortunately, monthly GMT is too noisy for the modest cooling expected from even the largest volcanos to be readily apparent. According to Paul_K’s summary at The Blackboard, Pinatubo supposedly reduced temperature by about 0.6 degC about six months after the eruption. About year earlier, the monthly CRUTEMP anomaly rose 0.6 degC between Feb and Mar 1990 and varied by 1.0 degC during the whole year. One needs to do a more sophisticated analysis than inspection by eye to see the transient effects of even powerful volcanos in noisy data. If you plot average annual temperature anomalies, you run into the problem that there was no volcanic cooling in the first half of the 1991 and less cooling in the second half of 1992. The climate plotter at Nick Stock’s blog formerly (but not currently) allowed you to plot monthly data with Gaussian smoothing over a selectable number of months. If you plotted monthly data with a Gaussian smooth over 13 months, the effects of Pinatubo and El Chichon were clearly visible. So if you really want to “spot the volcano”, I suggest you try that approach.

        http://rankexploits.com/musings/2012/pinatubo-climate-sensitivity-and-two-dogs-that-didnt-bark-in-the-night/

        The other thing you need to remember is that it takes time for volcanic aerosols to cool the earth and they dissipate long before equilibrium (ECS) is reached. In theory, the -3 W/m2 Pinatubo aerosol forcing would cool an Earth with a 25 m mixed layer at an initial rate of -0.1 degC/month. The Pinatubo forcing began to drop after about 6 months. As the planet cooled, Planck feedback diminished the effectiveness of the aerosol forcing.

        Given that the 13 VEI 4&5 volcanos between 2002 and 2011 barely produced -0.1 W/m2 of aerosol forcing, I’m skeptical that they played an important role in the hiatus. However, a -0.1 W/m2 forcing for a decade is as important as a -1 W/m2 forcing for one year. I think it makes far more sense to question scientists ability to accurately quantify CHANGES in aerosol forcing that are less than 0.1 W/m2. IMO, it doesn’t makes sense to question whether there were unusual number of large volcanos during most of the hiatus.

      • Frank January 10, 2015 at 4:06 pm

        Willis: You say that the two decades from 1995-2014 had a normal number (16) of large volcanos (VEI 4 and greater), but that is irrelevant. There were ZERO large volcanos from 1995 through 1998 (when temperature was rising rapidly) and an unusual concentration of 13 large volcanos from 2002-2011 (most of the hiatus). The aerosols from the three large volcanos in 2011 persisted through at least 2012.

        I’m sorry, but your simple unsupported claim that it is “irrelevant” that the recent two decades have the same number of VEI 4+ eruptions as the previous two decades tells us nothing. The previous two decades were the time of rapid warming, and the recent two decades were almost no warming … but both periods had the same number of VEI 4+ eruptions. That’s very relevant to the claim that eruptions are the reason for the lack of recent wraming.

        And your succeeding claim, that what is really relevant is the number of eruptions over a four year period, shows that your idea of “relevance” is … well … peculiar.

        To demonstrate that the number of VEI = 4 and VEI = 5 volcanos was unusual between 2002 and the end of 2011, I looked at the total number of such volcanos for the entire twentieth century: 53 VEI = 4 and 9 VEI = 5 (and 3 VEI = 6). VEI = 4 volcanos have not been detected more frequently in recent years, there were 32 in the first half of the century and only 21 in the second. So normal volcanic activity appears to consist of about one VEI=5 volcano per decade and 4-5 VEI=4 volcanos per decade, not the 13 from 2002-2011.

        What you are not taking into account is that in the earlier part of the 20th century, we didn’t have airplanes and satellites to detect every volcano, in particular the smaller eruptions. You can see this clearly by looking at the last two centuries of records of eruptions of VEI 4 or less, viz:

        Note that the number of small eruptions doesn’t level off until 1950 … when airplanes became common and communications became rapid and detailed.

        Now, we have two choices. Either the number of small eruptions of VEI 4 or less has been steadily increasing for 200 years … or we’re looking at a huge observational bias based on the fact that the further back we go, the fewer small volcanoes we noticed.

        w.

        [“number of small earthquakes of VEI 4 or less” or “number of small volcanoes of VEI 4 or less”? .mod]

        [Fixed, thanks. -w]

      • Willis: When there are doubts that a cluster of VEI = 4 volcanos can cause a slight cooling, it makes no sense to include VEI 1-3 volcanos in the discussion. With current technology, we can watch a localized plume of aerosols enter the stratosphere at one latitude, gradually spread out over several months, and then fade away. All but one of the volcanos cited in this paper were large volcanos (VEI 4 and higher). The other, Soufriere
        Hills (2006), is listed at VEI “4?” in one reference, but as 3 in the current Smithsonian table.

        Out of the 52 VEI = 4 volcanoes in the 20th century, there were 11 MORE volcanos with VEI = 4 in the first half of the 20th century (32) than the second half (21). Therefore, there is no reason to believe that improved observations are responsible for the cluster of VEI = 4 volcanos from 2002-2011. This is especially true given the fact that there were ZERO VEI = 4 volcanos for five years in the late 1990’s. (Willis’s data shows that our ability to detect weaker volcanos has increased with time, but those weaker volcanos they don’t appear to be major contributors to stratospheric aerosol levels.)

        Chance has presented us with an opportunity to compare a five-year period with no large volcanos (VEI 4-6) to a decade with an unusual concentration of large volcanos (12, VEI 4; 1, VEI 5). We have poor measurements that show that more aerosol was present when more large volcanos were occurring, but the forcing associated with enhanced volcanic activity was uncertain. The estimated cooling produced (0.05-0.12 degC, possibly a 25-75% confidence interval) doesn’t explain the pause.

        It turns out that chance also produced a second cluster of large volcanos between 1980 and 1986: 2 with VEI = 5 (including El Chichon) and 7 with VEI = 4. Was there a suppression of warming warming during this period?

      • Frank January 11, 2015 at 2:17 am Edit

        Willis: When there are doubts that a cluster of VEI = 4 volcanos can cause a slight cooling, it makes no sense to include VEI 1-3 volcanos in the discussion.

        Frank: When there are doubts that VEI = 5 volcanos can cause a slight cooling, it makes no sense to include VEI 4 volcanos in the discussion.

        All that they have shown is that SOME VEI 4 volcanoes may have a detectable (although very small) effect on the optical depth of the atmosphere … but we knew that already. They claim that there is also an effect on the clear-sky upwelling shortwave, but I find the evidence for this to be extremely weak. They disguise their lack of evidence in two ways. First, they don’t include all of the VEI 4 eruptions in their results. Here are the actual VEI=4 volcanoes, of which they’ve used six, plus one VEI 3 volcano for unknown reasons:

               Volcano.Name Start.Year Start.Month VEI
        1            Ulawun       2000           9   4
        2             Ruang       2002           9   4
        3        Reventador       2002          11   4
        4             Manam       2004          10   4
        5            Rabaul       2006           8   4
        6           Chaiten       2008           5   4
        7             Okmok       2008           7   4
        8         Kasatochi       2008           8   4
        9     Sarychev Peak       2009           6   4
        10 Eyjafjallajokull       2010           3   4
        11           Merapi       2010          10   4
        12        Grimsvotn       2011           5   4
        13            Nabro       2011           6   4

        Second, they smooth the CERES dataset that they are using with a centered smooth. And third, they don’t ever look at the global effect, only what they call “Near-Global (50°N-50°S)”. Their results show that only two out of their seven volcanoes had any detectable effect … not impressed.

        If you think that such a change in two of the seven VEI 4 eruptions is significant, well, I guess we’re out of things to discuss.

        w.

      • Willis: From reading Venier, I gather we can now track whether a concentrated plume of aerosols any volcano reaches the stratosphere, how it spreads first east-west and then globally, and then dissipates. Since only some VEI = 4 volcanos are listed, I conclude that not all of the inject material into the stratosphere. A table in Venier lists the Soufreier Hills volcano (VEI 3 in the Smithsonian table) as a “4?”. Whichever rating is correct, the paper has data showing that the concentrated plume of aerosol did reach the stratosphere.

        So, not all VEI = 4 volcanos are the same and counting the numbers of such volcanos is a crude way to measure their potential impact on climate.

      • Frank January 12, 2015 at 1:04 pm

        So, not all VEI = 4 volcanos are the same and counting the numbers of such volcanos is a crude way to measure their potential impact on climate.

        Thanks for the comment, Frank, but their “potential impact on climate”? Seriously? Did you not read the update to the head post? Big volcanoes change the SAOD by something like 0.15, and their “impact on climate” is very small.

        According to Santer, some VEI 4 volcanoes, the strong ones, change the SAOD by 0.002. This is about a thousandth of the change from a big volcano … and you are seriously claiming that this minuscule change may have some impact on climate?

        Is this some form of climate homeopathy, where the tiniest dosage still has the power to create large changes?

        In mystery,

        w.

    • Of all the VEI 4 you note since 2000, only one affected optical depth measured by LIDAR at MLO. That was Surychev on the Kamchatka peninsula. It did so because a high latitude eruption where the tropopause is lower. Its aerosol plume was extensively studied; 95% washed out in 3 months. Details and references in essay Blowing Smoke.

      • Rud: MLO LIDAR data can be seen at the link below. Comment on the same page say:

        “The changes to Versions C do not significantly alter previously published conclusions concerning this dataset by NOAA/ESRL authors, and strengthen the case for a general DECLINE in transmission (or transmittance) between 2000 and 2009.”

        http://www.esrl.noaa.gov/gmd/grad/mloapt.html

        Figures 1-3 in Vernier (2011) indicate that we have a very good idea of which VEI 4 volcanos (and one VEI 5) are contributing aerosols to the stratosphere, at what latitudes, and for how long.

        http://onlinelibrary.wiley.com/doi/10.1029/2011GL047563/abstract

        What we don’t have a good idea of is how much aerosol in present – the data is very noisy. Even worse, we don’t know how much aerosols have changed, because many measurements are being made with systems that became available after 2000. In other words, we can’t tell if the low level of aerosols that we are able to measure in the 2000’s is different from normal background levels of aerosol that is usually present.

      • And that is why Carl Sagan pulled back a bit from his nuclear winter claims. He expected a huge effect from the fires, but it was much less than he expected. But thanks to Red Adair and human ingenuity the fires didn’t burn nearly as long as the doomsayers said they would.

    • Not when they are really large. Read up on the Siberian Traps and their effect on the biosphere. Or even Laki in 1783.

      • Both Siberian and Deccan Traps are part and parcel of what the world is today; it is the major disasters that move evolution one step at the time.
        Darwin thought that evolution is a smooth progression. It is not it is a saw-tooth escalator; each disaster is a temporary setback forcing surviving ‘inhabitants’ to adapt and move forward.
        Vesuvius AD 79, Laki in 1783, Krakatoa 1883 and many others have done fair share of human life destruction, but then Genghis Khan or more recently Adolph H, Stalin etc. did even more so,.. I’ve gone off at a tangent there.

  34. As always, great post, Willis!

    Facts are such stubborn things….

    CAGW advocates seem to believe peer-review has magical properties that somehow turn hypothetical assumptions and presumptions into reality… Not so much…

    My take on all the sudden interest in volcanoes is that large eruptions occur quite frequently (six major eruptions since 1750, for an average of around 2 or 3 per century), so by promoting the idea that large volcanic events have long-term and profound cooling effects on Earth’s climate, once the next one occurs, CAGW advocates can more easily blame the large eruption for CAGW’s complete inability to accurately predict global temps.

    Ironically, Earth’s ability to quickly recover from the cooling effects of large eruptions is irrefutable proof that Earth’s climate is not as sensitive as CAGW advocates assert it to be…. This whole idea of climatic “runaway feedback loops” just doesn’t exist, because if they if they did, we wouldn’t be around to debate about it; a paradox.

  35. Willis, don’t you get bored with volcanos. I note our good friend from Duke has said exactly the same while mentioning your name.

  36. You would think that Santer would have had enough of being made to look the nincumpoop and bete du village. Banging your head against a wall begin to hurt after the first blow.

  37. Do you get a feeling there is going to be a new ‘revised temperatures’ moment? They will be claiming that without the volcanoes, the temperatures would be so much higher higher and would fit in exatly along the centre line of the models.

    • This is already being done for sea level measurements. University of Colorado Sea Level Research group provides satellite sea level data. However. the actual data is not a real measurement of sea level. They add a “glacial isostatic adjustment” because they say the ocean basins are getting slightly larger. What a crock of you know what. Imagine if you had a diving pool and filled it full, and the depth was 10 feet, Now let’s say you enlarged the pool by a factor of 2, with the same amount of water. Well, the new depth is now 5 feet. But NO. Not according to the University of Colorado. No, it’s still 10 feet deep. Dive right in! Oh the stupidity.

  38. The fact the authors are looking for a “reason” to explain “the Pause” IMHO is a remarkable feat on it’s own.

    At least they no longer deny the warming has stopped.

    So here we have this scientific conference in India claiming that AGW fears have been greatly exaggerated.
    http://economictimes.indiatimes.com/news/environment/global-warming/fears-of-man-made-global-warming-exaggerated/articleshow/45786412.cms

    The AGW Titanic is hitting the iceberg.

  39. The scientific answer? “Climate change deniers are upsetting the Fire Gods and making them erupt. Small volcanoes did not exist before 1998.”

  40. Most volcanoes are on the sea floor and erupt underwater. Many of these are not even discovered let alone documented when they are active. Gas from submarine volcanoes is either dissolved in seawater or bubbles to the surface unnoticed.
    Another issue is that volcanoes vary considerably in type. Some can be very gaseous and others much less so. A relatively small volcano may release considerably more gas than a larger complex. For example many of the volcanoes along Africa’s Rift Valley are very high in dissolved CO2. These can produce huge quantities of gas during relatively small eruptions, many of which go unreported or not studied by vulcanologists.
    There is too little known to make any useful estimates and I suspect that many more active volcanoes will be discovered before any meaningful estimates for gaseous emissions.

  41. “”The AGW Titanic is hitting the iceberg.””

    At the moment the iceberg appears to be made of soft fluffy absorbent lint.

  42. It occurs to me that any global warming has apparently ceased. You surely can’t say it has “paused” until, at some time in the near or distant future, it restarts. Expectation is not really good enough.

    The fact that everyone and his brother are postulating reasons from the sublime to the ridiculous for this cessation, is laughable. Nobody really knows, other than with the benefit of history.

    The climate does what it does, does what it always has done, and always will do – change, we can never stop it, accidentally or deliberately.

    Whilst it is in amiable mood, and we are comfortable, why worry? We could do with it getting a bit warmer, but the portents appear to suggest the opposite. Instead of “preparing” for a warmer world, wasting time and money on stupid efforts to alter the future (we can’t, with climate), maybe we should be more concerned with the fact that the planet isn’t warming significally, hasn’t for some considerable time, and with the hindsight that we possess, consider what we should be doing in an effort to protect ourselves from the likely coming cold. We know that the globe cyclically warms and cools, we also know that the latest Holocene interglacial is cooler than the previous Eemian. Why are we involved in so much expenditure in going in the wrong direction, inevitably to shoot ourselves in both feet?

    I’m not a scientist, or an expert – merely an interested layman, who makes his own observations.

    I don’t often post here, but I am concerned.

  43. Willis
    Thank you for once again showing the importance of volcanoes.

    Using your fig.2 it’s around 0.2 degC/LogMeanVEI, so Santer is probably right.
    (note high VEI gives longer delay, ~3yrs, the eruptions late 2000 were weak, short delay)

    • Sorry, lgl, but that graph is totally unintelligible. What is the upper line, and where did it come from?

      Also, the curious part is that your upper line starts to go down well before there is any increase in VEI. Take a look at about 1987, where it starts to drop … if the upper line is temperature, is the drop starting in 1987 causing volcanoes in 1990 and 1991?

      w.

      • Surely you aren’t going to insist on a silly little thing like temporal ordering or an actual correlation between the events and top-of-troposphere measurements of total broadband insoolation, Willis…;-)

        I do have one comment to make on your graph, though. When you plot average VEI per year, the year 1990 has an average VEI under 5. Yet Pinatubo was 6. I have a hard time seeing how the cumulative average for the year can be less than the peak contributor — you aren’t finding the average VEI per volcano, you are finding the average VEI of the year. Are you dividing this out by months or something? That would drop VEI by a factor of 10, agreed, but I’d argue that when presenting annualized data there is little point in plotting the annual average of the VEI per month. Just do total VEI per year, which would make Pinatubo-Hood 2 units higher, over 6 and not over 4. This is actually perfectly sensible, given that VEI is associated with total volume of ejecta and the lifetime of this ejecta is order of a year and not order of a single month. Maybe one would do better with a six month or three month average (which would reveal the decay structure and hence provide a better match to ML transmittivity data) but in an annual presentation, why not use annualized data? You seriously misrepresent the VEI of the year’s events and to be honest, even the factor of 10 is not enough — Pinatubo/Hood is two orders of magnitude low, not one. So I don’t quite see how you arrive at the numbers in the plot. I think the signal should be much larger than the noise.

        Finally, what’s the spike in 2010? All I see in my major eruptions data is four VEI 4s in 2010 and 2011 combined, and sadly, on a log scale even all four 4’s do not even a 5 make (let alone only two per year in a single year peak) and yet this single year peak is commensurate with El Chichon or Mt St Helens. So exactly how, again, did you get the average VEI result? Am I missing something?

        rgb

      • rgbatduke January 10, 2015 at 10:44 am

        I do have one comment to make on your graph, though. When you plot average VEI per year, the year 1990 has an average VEI under 5. Yet Pinatubo was 6. I have a hard time seeing how the cumulative average for the year can be less than the peak contributor — you aren’t finding the average VEI per volcano, you are finding the average VEI of the year.

        If this is intended for me, I don’t understand it at all. The average of a series of numbers is ALWAYS less than the peak contributor. And I am finding the average VEI for the year.

        Finally, what’s the spike in 2010? All I see in my major eruptions data is four VEI 4s in 2010 and 2011 combined, and sadly, on a log scale even all four 4’s do not even a 5 make (let alone only two per year in a single year peak) and yet this single year peak is commensurate with El Chichon or Mt St Helens. So exactly how, again, did you get the average VEI result? Am I missing something?

        The spike is in 2011. During that year there two VEI 4s and a VEI 5. Because the average is logarithmic, the larger values dominate the average, giving an annual average of just under four.

        So I don’t quite see how you arrive at the numbers in the plot.

        For each year, because the VEI is a logarithmic scale, I took a logarithmic average. I took 10 ^ VEIs, took the average of those numbers, and then took the log of the average.

        w.

    • Fascinating. A different version of inversion corruption. First Tiljana upside down now volcano in the mirror. Whatever next ? Upside down -mirror image, perhaps?

    • I think you forgot the /sarc tag…

      If that ridiculous overlay that you mocked up were true, why does the temp anomaly start dropping in ~2004 when there hadn’t been a change in volcanic activity since 1993? Or did the Earth anticipate the coming increase in 2008? /sarc (<—- see how that's done..)

      • There is a negative correlation between VEI and temperature and then it is better to flip one of the charts to show the correlation, standard procedure. But it isn’t backward.

  44. Regarding Stratospheric eruptions, Spaceweather.com had a story (backend of 2010)

    “ALL-CLEAR IN THE STRATOSPHERE”

    “Since 1996, lunar eclipses have been bright, which means the stratosphere is relatively clear of volcanic aerosols. This is the longest period with a clear stratosphere since before 1960.”

    http://spaceweather.com/archive.php?view=1&day=19&month=12&year=2010

    “The lunar eclipse record indicates a clear stratosphere over the past decade, and that this has contributed about 0.2 degrees to recent warming.”

    • Which fairly precisely matches the Mauna Loa data, BTW. Since 1996 and the full decay of Pinatubo/Hood ejecta, Mauna Loa has measured a nearly constant broadband atmospheric transmittivity of 0.93 \pm 0.01. I disagree with the conclusion that this has contributed to “global warming” as this is obviously the dynamical equilibrium transmittivity of the atmosphere and is a remarkably stable constant except for perturbations from major volcanoes. However, even the major volcanoes have almost no resolvable effect on global temperature given the much larger variations due to things like ENSO, CO_2, and unknown dynamical factors.

      At best you should say “0.2 degrees of presumed recent warming in recovery from presumed Pinatubo cooling”, but the data does not really support this assertion — Pinatubo cooling was at most 2-3 years and was already “done” by 1996 and obviously was completely swamped by Super-ENSO warming in 1997-1998 which reset the global climate state to make any ceteris paribus argument moot by warming up PAST any imagined new equilibrium and then falling back. But one cannot really see any climate effect of the mild drop of transmittivity in the early 1960s — the 60’s cooling started almost 20 years earlier after the peak in the 1940s and there is no correlation in the local transient or systematic trend. There is no response at all to the 1980’s majors. Only the Pinatubo/Hood double whammy MAYBE influenced temperature for a couple of years. Maybe.

      So first, one has to establish that top of troposphere insolation has any appreciable impact on global average temperature even when it drops by as much as 5% for periods as long or longer than a full year.

      I think what this is all leading to is that a mix of dynamic feedback from clouds and the enormous buffering capacity of the oceanic heat bath are going to end up cancelling almost any effect from things happening above the mid-troposphere up to and including variations in the integrated top of troposphere insolation, and will turn out to have dynamic response times on the order of decades plural — maybe even a century. Response to CO_2 is better supported by the data, although in a multivariate nonlinear chaotic dynamic system it is difficult to be certain in one’s attribution of effect to cause. Personally I think a nonzero, positive total climate sensitivity is very well supported by the data (with some considerable range of argument still as to what the specific number might be) but I freely admit that I can’t solve the coupled Navier-Stokes equation in MY head, either, and all the variation we observe could be pure nonlinear dynamics that laughs at CO_2 as much as the climate apparently laughs at 5% variations in TOA insolation.

      rgb

      • By Hood, do you mean St. Helens, the nearly perfectly Fuji-like conical volcano which spectacularly committed seppuku in 1980, tragically taking my brave friend & former student Reid Blackburn with it? The one named by CPT Vancouver for his diplomat pal rather than by LT Broughton for ADM Hood.

      • Oops, no, I mean Mount Hudson, in Chile, which also erupted in 1991 — sorry, Hood, Hudson, Helens, I get confused.

        http://en.wikipedia.org/wiki/Mount_Hudson

        It was largely ignored because of the more spectacular Pinatubo, but it was a VEI 5 eruption (which is “significant”) and was characterized by a high sulfur dioxide emission — lots of aerosols.

        That is one of the catches in all of this analysis, BTW. VEI is not terribly well correlated with aerosol emission — note the complete difference between Mt. St. Helens (VEI 5, not much aerosol) and El Chichon (also VEI 5, but with a huge aerosol contribution, almost comparable to Pinatubo and Hudson combined. There is a nice graphic here:

        illustrating part of the problem. Note well the log scale — even though there are some clusterings, only the peaks matter because the integrated aerosol contribution on a LINEAR scale is going to be utterly dominated by the few peaks in this graph. So don’t be misled by the apparent clustering of low intensity events on the right — add them all up they don’t equal a single addtional bar in the 100-1000 range, let alone the very few bars that reach the 1000-10000 range that seems to actually show up on Mauna Loa. Of the events on this graph, only El Chichon and Pinatubo/Hudson show up on Mauna Loa. The entire 1996 to the present stretch is flat, suggesting that whatever the integrated aerosol emissions of the volcanoes in the right hand part of this graph (and beyond) they have no observable impact on stratospheric reflection and are quite irrelevant to the apparent near-cessation of warming.

        It is also clear that there is more than “just” aerosol emissions that matters. The lack of any signal from the 1979-1980 cluster, with a highly emissive VEI 3 (Sierra Negra) and a comparatively non-emissive VEI 5 (Mt St Helens) suggests that one probably needs a lot of SO_2 AND a major blast to get it up into the stratosphere to have much impact. This of course means that we can even MORE strongly ignore the collective emissions of the VEI 3 or less volcanoes, and probably can ignore most 4’s and about half of the 5’s. The SO_2 from wussy little volcanoes probably never reaches the stratosphere — it is turned into acid rain long before it gets that high (remember, it is heavier than even CO_2 which is already heavier than O_2 and N_2, so it experiences if anything a slightly negative net atmospheric buoyancy, and is highly water soluble. In fact one way in which it (and other aerosols) cool is by nucleating clouds in the lower atmosphere. Which is plausible and can occur even from comparatively weak volcanoes over large regions where the concentration is NOT well-mixed. So I don’t quite understand why anyone would hypothesize a nonexistent connection to stratospheric tranmission.

        It also provides us with a plausible reason for the warming of the 1980s. There are a reasonable number of LARGE emissions across the fifteen years from 1987 to 1999, but there was actually a dearth of smaller high SO_2 contributors. This could have combined with high solar activity (and hence low radiation AND slightly higher solar constant) to cause some fraction of the warming over this exact stretch. In that sense, weak vulcanism COULD be a cause for cooling or neutralization of warming or whatever, not from the integrated VEI but from the NONlinear effect of the SPATIALLY DISTRIBUTED collection of small emitters.

        To put it another way — a 20 kiloton nuclear device exploded at one place does far, far less damage than 20,000 one ton conventional devices spread out over a much larger area, which does still less than 40,000,000 pounds of TNT with e.g each building in a city containing just one pound. This process cannot continue indefinitely because one has to exceed the threshold where the shock front can knock stuff down but it illustrates the point. 10 VEI 5 eruptions happening at 10 different places on the planet very likely have a larger impact than 1 VEI 6 at one place IF one isn’t assuming “well mixed” impact but instead are looking at the localized area that is strongly impacted.

        rgb

  45. Willy, how do they get around the atmospheric transmission measurements at Mauna Loa? They are very steady around 0.93:

    http://www.esrl.noaa.gov/gmd/grad/mloapt.html

    They would seem to show that there has been no measurable change in atmospheric transmission, at least in the Northern Hemisphere, during the “pause” unless there was been som major change in measuremet procedures at exactly the right point in time.
    Of course they may still be right that aerosols have been underestimated, but in that case they have been underestimated before 2000 as well.

    • It’s worse than that, tty. Even when the Mauna Loa data shows a drop in atmospheric clarity there is no corresponding drop in temperature. See my post called Volcanoes Erupt Again for a full discussion.

      w.

    • PS As a matter of fact Figure 2 above matches the Mauna Loa record remarkably well, suggesting that the normal atmospheric transmission with “background volcanism” is 0.92-0.94.

      • This is exactly right, see actual data and an actual fit with a tiny slope to the whole data set including volcanism and a hand-drawn zero-slope line fit to split the equilibrium to which the system returns at 0.93. The other line is basically 0.92, so 0.93 \pm 0.01 is very, very close to being right.

        And as Willis says, there is at most a weak drop in temperature in association with major changes in stratospheric clarity — too weak to take seriously. Willis thinks (I think, he can correct me as I do not mean to put words in his mouth and I’m trying to repeat the outcome of our earlier discussions of this issue) it isn’t there at all. I think it is there, but with a transient effect so short as to be ignorable and so small as to be easily overwhelmed by natural dynamics and hence erased. But we completely agree that whatever the response, it can be completely ignored in climate models without doing any real harm, at least out to Tambora scale events (where we lack good global temperature data to work with but anecdotally VEI 7 had an effect on weather for more like 5-7 years — “almost” at the level of climate impact — and had an immediate and profound effect on the weather for 1-2 years).

        In other words, the actual historical data almost certainly completely refutes an assertion of a weak 0.3 C reduction in observed warming over almost 20 years due to any sort of alteration of stratospheric transmittivity from any or all causes, mostly because Mauna Loa is a direct observation that no such alteration of stratospheric transmittivity in fact has occurred.

        I don’t know how anyone can correlate a flat line plus or minus a relative 1% of pure annual timescale noise with a supposed cancellation of warming due to something that is changing substantially over the same time frame, e.g. CO_2 concentration. But hey, some people will try anything to hang onto a broken hypothesis.

        rgb

      • rgbatduke January 10, 2015 at 11:32 am

        And as Willis says, there is at most a weak drop in temperature in association with major changes in stratospheric clarity — too weak to take seriously. Willis thinks (I think, he can correct me as I do not mean to put words in his mouth and I’m trying to repeat the outcome of our earlier discussions of this issue) it isn’t there at all. I think it is there, but with a transient effect so short as to be ignorable and so small as to be easily overwhelmed by natural dynamics and hence erased. But

        Actually, I agree with you, Robert, and have said so before. Very large volcanic eruptions have a minor transient effect on surface temperatures, which is local rather than global, and which is so small as to be overwhelmed by other fluctuations.

        w.

      • My bad, Willis. Sorry, I do get confused about where we agree and were we disagree — I think I was remembering our also comparatively weak disagreement over whether or not one can model a smooth CO_2 rise from 1850 to the present to extrapolate over the region where we have at best inconsistent and slightly dubious ice core data. In the end, I only trust Mauna Loa data, and even that only somewhat provisionally, and ML data is very, very smooth and systematic even with just annualized averaging. Not perfectly smooth, but it shows none of the bumps that the ice core data do (and which I seriously doubt as being globally representative, even if they do represent the local not necessarily well or correctly mixed conditions that ice cores supposedly capture).

        But in that case — YEAH, so we BOTH agree that really big volcanoes (or smaller big SO_2 emitters, sometimes) may have a really small impact on temperature that lasts a really short time, more or less indistinguishable from other sources of natural variation e.g. ENSO. In fact, often much smaller than ENSO events, even for very large volcanoes indeed.

        Volcanoes can probably simply be ignored, although I wouldn’t rule out lower troposphere effects like modulation of albedo through cloud nucleation from enough even small VEI SO_2 emitters — all we can really rule out via Mauna Loa transmittivity is any stratospheric connection. But that’s a very different story and even that story is less compelling than the probable temperature CO_2 concentration correlation as far as the data only is concerned. I just don’t think that we have a particularly good handle on the science yet, especially not if we have people that should know better than asserting a stratospheric connection that is actively contradicted by prior direct observations doing it anyway while ignoring the much simpler albedo connection.

        I need to get the TOMS data from the source, though — I don’t want to screen scrape it out of a log plot. It does open up more possibilities for a volcanic connection than just VEI, even though I’m sure that we almost completely lack a knowledge of it even by proxy before 1979. Sadly, the Global Sulfur Dioxide page has data that is so raw as to be useless, graphically encoded. I have no good idea how to get a simple table of annualized SO_2 emissions per volcano or per planet, with or without including human contributions from high sulfur coal. It does look like NASA has very good instrumentation for detecting it, though, even in eruptions that humans would find unimpressive.

        rgb

  46. Yep, total rubbish by people who know zero about volcanoes.
    Every volcano erupts slightly differently from each other and each different volcano can erupt differently at each eruption.
    There are an estimayed 3million volvsnoes on the planet, most of them under the ocean surface. One thing ALL volcanoes emit is CO2.

    • There are an estimayed 3million volvsnoes on the planet

      Really? And you know/estimate this how? There are 1500 “active” volcanoes on the land surface, around 500 of which are actually active at any given time. A naive estimate would extrapolate this by a factor of (say) 4 since the ocean is 70% of the surface to get 2000 active volcanoes worldwide, where by active I mean actually erupting. Allowing for this to be wrong by a full order of magnitude would give you 15,000 (the 500 on land don’t change as we’re pretty certain about that, only the 1500 in the sea). Two orders of magnitude would be 150,000. Three orders of magnitude would be 1,500,000. And you’re asserting another factor of two, to end up with 3,000,000 (where the 500 on land are then pretty much irrelevant).

      So you’re basically saying that for every actually erupting volcano on the land surface, there are 2000 hidden, erupting volcanoes on the sea floor. Sure, why not? Or why not 10,000! Or 200. Or 10.

      Do you have any actual data to back up that “estimate”?

      rgb

      • There are a lot more volcanoes under the oceans than there are on land. But they are largely an unknown. I hate to link to NewScientist, but here it is:

        The true extent to which the ocean bed is dotted with volcanoes has been revealed by researchers who have counted 201,055 underwater cones. This is over 10 times more than have been found before. The team estimates that in total there could be about 3 million submarine volcanoes, 39,000 of which rise more than 1000 metres over the sea bed.

        For a more technical explanation, see here.

        Dr. Brown is correct. We just don’t know the extent of underwater volcanoes, or for that matter, how much CO2 they add to the atmosphere.

      • Note well that finding underwater cones is irrelevant compared to land, as well. On land, rain and wind produce an ongoing process of weathering so that “cones” simply don’t last. The 1500 active volcanoes is the count of the “cones” that they think have erupted in the last 15,000 years, and of these, only around 500 are ACTUALLY active as in emitting magma, ash, gases etc. There are plenty of much more ancient cones that aren’t included in this count, and in all probability many that one would count if there were no weathering have simply vanished, or been tipped sideways and turned into something else.

        On the ocean bottom, there is no wind and no rain. There is almost no current, and what current there is moves at a snail’s pace. It is cold. There is little chemistry to cause weathering. Cones last a long, long time.

        So the big question is not how many humps are there in the bottom that could conceivably be identified as being leftovers from volcanoes. It is how many of these lumps are active by either of the related definitions on land — an eruption in the last 15,000 years, or actively erupting now.

        I would think that mere seismology could rule out 200,000 significantly erupting sea bottom volcanoes. There are whole books describing the signal of volcanic eruptions from VEI 1 and 2 on up. I would expect that we could hear 200,000 active sea bottom eruptions with an absolutely unmistakable signal, picked up by the navy sound detector grid that is sensitive enough to locate submarine screws and whale calls at tens to hundreds of miles.

        At subduction zones or spreading rifts, I’m perfectly happy to think that volcanoes might be more common than on the plate boundaries on land, if only because one expects the crust to be somewhat thinner there (especially at rifts). I’m equally certain that all sorts of interesting stuff happens down there (some of which we are slowly sorting out). But three million, active volcanoes is a bit difficult to swallow with only 500 or so on the 30% of the surface that is visible.

        Finally, it is important to differentiate cones from volcanoes per se. Mauna Kea has over 100 cinder cones on its flanks, but is really only one big volcano. Many cinder cones are monogenetic, which means that if you find them you can be reasonably sure they WON’T erupt again, they don’t count as active in any useful sense of the word now or in the future. The United states is covered with weathered, ancient volcanoes. New Mexico is rife with them (I’ve climbed a number). Texas too. Even Maine has its share. So when the land count of actively erupting volcanoes is held to be around 500, they are not counting cones or things that at one time were volcanoes, weathered or unweathered. They are counting things that are actually spewing magma and/or ash.

        How many of THESE are there on the sea floor? I have to say that I find 3,000,000, or even 300,000, really really unlikely. Even 30,000 seems a bit of a stretch, but perhaps there are some very active rift or subduction zones. But geological time and frequency are not the same as human time, and even “active” zones are probably marked by comparatively few actually active cones. The active cones actually take the pressure off of the surrounding area and make violent eruptions there somewhat less likely, at least one would expect.

        rgb

      • You forget that the oceanic ridge system is 53000 miles of volcanoes. two places on land show the extent of volcanisity, Iceland and Ethiopia. These two places are quiet compared to the ridges. Every sea mount is an extinct volcano which still emit CO2 a so called pollutant.
        The estimate of 3million is not mine but appears on the excellent website
        http://www.geologist-1011.org
        The estimate is based on sea floor surveys not wishful thinking.
        I go back to the basis of the blog that the claim is not based on data of current eruptions but wishful thinking and straw clutching.

  47. “The relatively muted warming of the surface and lower troposphere since 1998” I cringe every time I read statements like this. It states that there has been warming since 1998. But for there to be warming the temperature must have risen since 1998. If the temperature in my living room has stayed the same since 5PM, do I say my living room has been warming since 5PM? NO! I say my living room is still warm or has not changed or has not been warming since 5PM! It may be warmer then before 5PM but it is not “warming”. The abstract has a flat out demonstrable lie in it!
    “in the context of the post-2000 slowing of the rate of global warming” Ok post 2000 you may be able to draw a statistically significant warming trend, maybe, if not it too is wrong. My house warmed by 2C/hr from noon to 5PM, from 5PM to present the rate is 0. Do I say from 5PM to present the rate is slowing? Slowing as in slower but still moving up. Or in common English, from 5PM to present the rate has stopped?
    These are educated people who most likely put a lot of thought into the wording of the abstract. How can one believe anything that follows when they are not honest enough to admit the warming has stopped?

    • The worst thing, for me, is that I’m not even mildly surprised anymore. I know I should be angry, but it’s more like watching the baddies in an old movie: The plot may be ridiculous, but I only really notice how bad the acting is.

      I’m glad that other people can still get riled by it.

  48. Couldn’t stay up late enough to catch this early on but,

    How can these perturbed homo sapiens justify or even explain what they do to their parents? We went into major hock to ship you off to a no longer ivory tower – tusk pollution maybe, virtual poaching it is – but I could be wrong. This could be totally on-line peering and it is cheap because we don’t even need that lab anymore.

    I am only relieved that Bernie Sanders and Peter Shumlin would be completely incapable of reading this, not Willis, bs, not even capitalized, baffling brains.

    The state of education is gravely sad. Free community college for gpa=2.5!!! Baring grade inflation, let’s have some standards or launch a major distributed denial of service to academe.

    • A quote from your link Johanus ,

      ” Her work connecting volcanic chlorofluorocarbons to increased damage to the ozone layer formed the basis of the Montreal Protocol, an international agreement to protect the ozone layer by regulating damaging chemicals”
      Soooooo, chlorofluorocarbons are formed naturally from volcanoes and now the same volcanoes are causing global cooling……so is the ozone hole getting bigger? Hmmmm….I guess we better start capping those volcanoes or do we need more of them to cool the planet?!?! Mah!!!!

  49. Isn’t it obvious? With more than 50 factors shown to be contributing to the ‘pause’ the effect of each is tiny when considered in isolation – that’s why we can’t see it in the graphs – like all the best climate theories it can’t be measured.

  50. My biggest problem with all of these “explanations” of the missing warming is the question of coincidence.

    Given that CO2 has been rising on pretty well a “business as usual” basis for the time in question, any of these explanations – or any combination of them – must have acted to more-or-less exactly offset the additional CO2 forcing without having any physical basis for doing so. That’s a coincidence and a half over nearly a 1/5th of a century.

    Of course, I’m at risk of falling foul of the warning about correlation not showing causation here, which is really another way of saying that coincidences can, and do, happen.

    But since virtually the whole of the AGW position is based on correlation (with the one physical exception that CO2 does absorb IR) , they should NOT be satisfied with any explanations that rely on coincidence to explain such exact correlation in the deviation from warming! ,

    • Joe, correlation does not prove causation, true.
      But absence of correlation disproves causation. Also true.
      And that is the problem that a temperature pause despite rising CO2 gives the warmunists. Hence the increasingly laughable desperation to find alternative explations nicely diced up by Willis here.

      • Agreed, Rud, which is sort of an extension of my point.

        What they’re essentially saying is that there would be correlation between CO2 and temperature over the pause if it wasn’t for this huge coincidence of unrelated factors that just happen to be exactly offsetting it.

        Now, to my simple mind, if coincidence can explain the magnitude of that unrelated offsetting then it can just as likely explain any of the (far less exact) correlation they’ve “found” in the earlier data.

  51. Nice post Willis!
    We have listened to them telling us that the heat has disappeared into the oceans (an explanation that defies common sense!) and that now the warming has stopped due to the activity of vertically challenged volcanoes!
    The warming stopped around the time when satellites were able to produce data that was accurate and could not be cherry picked, so to me the simple explanation is that the computer models are wrong!

  52. Errr yes maybe

    The possible volcanic contribution to atmospheric C02 levels was discounted by “warmists” but now they want to blame the aerosols from the same [previously non-existent] volcanoes for perturbing their models.

    And where is the evidence for a late 20th /early21st century increase in volcanic activity ??

    Dear me

    • Yes. You nailed it, Steve.
      Meanwhile, back at the ranch, the rate of earthquake occurrences in the US southern central plains seems to be increasing, with 10 quakes in Oklahoma of mag 2.5+ in the past 24 hrs, so maybe there really is an uptick in gas release from all geo- tectonic sources.

  53. “Willis’s Rule of Author Count ” sounds like it is related to the new consensus approach to science.

    The idea seems to be that there is strength in numbers. So instead of relying on the quality of the research and conclusions, you go with the largest number of authors you can get to sign it. This happens in Congress quite often and we all know well Congress works..

  54. There is a plausible mechanism to explain “Willis’s Rule of Author Count, that the quality of any study goes down inversely proportional to the square of the number of listed authors.” The larger the number of authors, the smaller the number of outside experts remaining in the particular field of study who are (a) competent to review and (b) free of conflicts/close associations with one or more authors.

    On a related note, would a freedom of information act request be applicable to Livermore personnel to be able to see the peer reviewers’ comments, questions and suggestions for improvement? If so, that would certainly reveal something about the strength of the review process itself.

  55. When I look at the data I see the exact opposite of what is claimed in this paper. keep in mind that the pause is really more like the top of a sine wave. The warming continued to around 2005 and then cooling began.

    http://www.woodfortrees.org/plot/rss/from:1996.75/plot/rss/from:1996.75/to:2005/trend/plot/rss/from:2005/to/trend

    Looking at the data, it was right after 2005 that the number of small volcanoes was generally reduced. Hence, one might argue the hiatus is being caused by a lack of volcanoes, not more of them.

    Of course, that would also mean that the warming itself was the result of more small and large volcanoes and not CO2.

    Just sayin …

    • Or, one could look at the data clearly and use R and conclude that it is a waste of time to even be distracted by volcanoes when considering the climate. We have good data on top of troposphere insolation for over 60 years! We don’t need to build complex theoretical GCM models involving aerosols — we can directly measure their effect on the transmittivity of the stratosphere, and look for the sensitivity of the actual climate to the major boluses of aerosols in model fits. And there is none.

      Basically, the 60 year average top of troposphere insolation is totally flat, with the mean transmittivity of the stratosphere being around 0.92, assuming (as always) that the stratosphere is on average well-mixed so that Mauna Loa is a reasonable representation of the rest of the stratosphere, allowing for geometry. The equilibriuminsolation is around 0.93 and again, flat to well within our ability to resolve a slope over all 60 years. Major volcanoes — VEI 5 and up — can have a large (5%!) transient effect on top of troposphere insolation but even this large a variation in the Earth’s annual incoming energy budget, sustained for at least a year, has almost no statistically resolvable effect on the temperature and what effect it might have has a lifetime of less than 3 years and is hence arguably an impact on the weather, not the climate. Even major volcanoes are completely negligible in terms of climate impact compared to, say, El Nino events.

      So let’s not argue that they are causing warming OR cooling, because at the top of the troposphere insolation simply isn’t varying at all so trying to attribute climate change to changes in broadband radiation due to reflection off of the stratopheric mix of gases is a rather waste of time. See the actual figure below.

      Which, incidentally, does a pretty darned good job of invalidating all of the world’s GCMs, BTW, as they rely on substantial cancellations between aerosol-driven cooling and CO_2 driven warming to fit the reference period, which is odd given that Mauna Loa shows that — outside of two volcanic events that had almost no impact on temperatures (certainly an impact far smaller than natural variation) there is basically no change in equilibrium aerosol-driven cooling or warming, or anything at all over the last 60 years completely embracing the reference period used by the CMIP5 models displayed in AR5.

      One can do a rather excellent job of fitting global temperature in a model that ignores aerosols altogether. For good reason — whatever effect they might have appears to be cancelled by negative feedbacks and/or swamped by the enormous buffering potential of the ocean, and the stratospheric reflectivity seems to be rather amazingly stable. I look for things reported by satellites regarding e.g. major spikes in its water vapor content that supposedly affect global temperature and see nothing of it in Mauna Loa data.

      rgb

      • RGB wrote: “The equilibrium insolation is around 0.93 and again, flat to well within our ability to resolve a slope over all 60 years.”

        As best I can tell, newer instruments and technology are showing it isn’t perfectly flat in the 2000s. Unfortunately, we don’t know how much change (forcing) has occurred. The insidious part is that an ambiguous change has lasted for more than a decade and transient temperature change is the product of forcing (W/m2) and time. At its peak, Pinatubo produced at least 30-fold more stratospheric aerosol than the weaker volcanos in the 2000’s, but Pinatubo’s were mostly gone in a few years. The advocates of some volcanic cooling during the hiatus assert a fairly constant, but weak forcing for more than a decade.

      • Frank January 11, 2015 at 2:49 pm

        RGB wrote: “The equilibrium insolation is around 0.93 and again, flat to well within our ability to resolve a slope over all 60 years.”

        As best I can tell, newer instruments and technology are showing it isn’t perfectly flat in the 2000s.

        Frank, while you may well be correct, what you are missing is a sense of scale. Here is an overview of the measurement used in the Santer study, the stratospheric aerosol optical depth (SAOD):

        Yes, the newer instruments can show us trivially small variations in the post-2000 data … but so freakin’ what? The variations that Santer et al claim are significant are on the order of .002 … look at the graph above to see how ludicrously small that is. Below are the Santer results. You can see that they are just an extreme closeup of the right side of the graph above.

        w.

      • Willis wrote: “The variations that Santer et al claim are significant are on the order of .002 … look at the graph above to see how ludicrously small that is.”

        Frank replies: Finally something we CAN agree upon. [There has been an unusual cluster of VEI = 4 volcanos since 2002.] Those volcanos may have caused a barely detectable increase in stratospheric aerosols compared with 1995-1999. We certainly don’t know if that is an increase over normal levels of aerosols. To define a forcing, one needs to know the amount of the agent during the 2000’s AND before (usually pre-industrial for anthropogenic forcing). Unfortunately, integration of this weak, perhaps nonexistence, forcing over a decade produces a partial “explanation” for the pause. (Forcing is power, temperature change is proportional to energy or power * time.)

        What happened to the confidence intervals for this forcing/temperature change? They aren’t being shown because the 90% or 95? ci almost certainly includes ZERO! The sensible thing to criticize about this work is the possibility it is derived from changing our changing ability to measure stratospheric aerosols and/or noise in the data.

  56. Boy, looking at your graph 1 and graph 3 (graph 2 doesn’t matter, they were looking at small volcanos), it looks like volcanic activity is higher in the naughts than in the 90s. Why don’t you put a 60 month average on your charts, or is that why you didn’t?

  57. A surgical takedown and dismantling of yet another excuse for the “global warming hiatus.” Thank you and well-done Willis.

  58. They are investigating the wrong metric. The relationship between cooling and volcanic loading has less to do with the overall VEI metric and more to do with the amount of volcanic sourced sulfur compounds that enter the stratosphere. Local cooling related to ash is exactly that, local cooling, and is rather short lived. Sulfur compounds injected into the stratosphere circulates on a global scale and can indeed induce global cooling and is best measured by the amount of these compounds found in polar deposits. But even that metric alone is short lived. Of more importance is the juxtaposition of volcanic stratospheric events with ENSO conditions, specifically related to conditions that allow equatorial recharge of oceanic heat stores. This incoming solar heating, or lack thereof due to veiling in the stratosphere, most definitely affects global temperatures past the point in time that veiling clears up.

    So why do I say this? Because I know that clouds also affect solar heating in the equatorial band and can be modeled. Stratospheric veiling can also be modeled in much the same way. These less heated pools of water then ride oceanic currents, leading to changes in weather patterns on a global scale.

    Changes in ocean heat is the main source of weather pattern variations. Therefore any changes in ocean heat will change weather patterns. Sulfur loading will indeed change incoming solar insulation thus will decrease oceanic uptake. This is the proper logical way to understand volcanic forcing on a global, and longer term scale.

    The present studies are at too fine a scale and focus on events that hardly rise above background noise in the stratosphere related to sulfur compounds.

  59. Basaltic (chemically “basic”) eruptions, as in Hawaii less explosive making mainly coarse ejecta from sand-like lappili tuff, to spindle shaped bombs often of many kilograms in mass (molten blobs shaped by spinning in the air). These are typically benign as far as residence time in the atmosphere. Not so benign if hit on the head with even a small one, but if it happens, you can rest assured that it didn’t occlude the sunshine for more than a minute or so!

    The acid volcanics and intermediate types are high in silica, are viscous and very gassy with the usual suite of noxious gases, SO2, CO2 and lots of water. The force of the explosions disintegrates the brittle silicious foamy rock and blasts it often up into the upper atmosphere. Because even the -50 micron pieces are riddled with gas bubbles, they are very light and can be born along in the upper atmosphere for long distances and even easily re lofted by thermal updrafts when they begin to settle.

    http://imgarcade.com/1/volcanic-ash-microscope/

    WILLIS, the acid volcanics are continental crustal types. It would be good if it were possible to sort the volcanoes by type Acid vs Basaltic to see if we have had more acid volc. If not, then its Q.E.D. for your investigation results.

  60. It’s very simple.

    There are volcanoes hiding where we can’t find them. Probably underground…

  61. Willis here is something you should think about and the term solar activity can be replaced with any climatic force one may want to use.

    Yes solar activity is always influencing the climate but at times of no solar extremes (solar flux 90-150 range) the solar contribution is going to be lost to noise in the climate system.

    Also the mean state of the climate/earth dynamics at the times of solar forcing are going to cause given solar conditions to result in different climate outcomes. This statement applying to all items that may exert a force on the climate.

    In summary I think climate sensitivity to various forcings is EXPONENTIALLY dependent upon the mean state of the climate/earth dynamics at the time the forcing is taken place which is why correlations are hard to come by and so many different climate outcomes (although a similar trend in a general sense) is always the result.

    The climatic outcomes all different over the past 20000 years while the same essential forces have been in play throughout this time frame I think proves my point. This is why no climatic theory no mater how could fails to stand the test of time.
    .

  62. One last thought due to the no reaction or hostile reaction I got from various places.

    It is amazing that when I put out something like I did yesterday about how climate sensitivity to given forces depends upon the mean state of the climate and earth dynamics and changes exponentially due to those factors that I was either ignored or treated as if it just is not so, when it is so in my opinion.

    The reason why I think I am getting this reaction is it destroys all of the various theories in trying to explain why the climate changes in the way it does due to some force because it takes away the notion that one can come up with a climate prediction based on that premise.

    I think strongly that all the various climatic outcomes going back just 20000 years never mind further with essentially the same forces present then as now no matter what the choice of the forcing goes a long way in proving the point I am trying to make.

    So I say to all the climatologist out there knock yourself out in trying to prove your theory is correct because it is not going to result in the result you may want and all one has to do is go back a sufficient amount of time to show how every climate theory no matter how good does not stand the test of time.

    At best maybe general climatic trends can be forecasted and that is what I am going for.

  63. And here is yet another bit of evidence to support Willis argument:

    This is a direct graph of the atmospheric transmittivity as measured at the top of Mauna Loa (which means very close to the top of the troposphere). This is a direct measure of “just” the effect of volcanic aerosols and water vapor and other optically coupled gases on total stratospheric transmission, with 1 – transmission being effective reflection. One is above most of the water vapor, clouds, soot, and other human-induced stuff.

    There are two things worth drawing your attention to in this graph. The first is that the major volcanoes — VEI 5 and up — have a clearly discernible effect on TOA transmission. I have a variation of this graph where I label the three substantial divots in transmission in the 60’s, the 80’s and the 90’s with the major eruptions that produced them. VEI 4 and under eruptions have almost no discernible effect, even a transient one. There are a couple of spikes observable in the late 90’s and close to 2010 — but there are no specific eruptions one can attribute these two as all of the significan eruptions in the 2000’s are 4’s, and 4’s produce almost no spike at all unless they are incidentally sulphur-rich eruptions (which happens, BTW, and is a variable almost independent of VEI). To illustrate the problem, Mt. St Helens, a 5, produced no visible spike at all in transmission, but sulphur-rich El Chichon at 5 produced a spike almost as noteworthy as the double whammy of Pinatubo and Mt Hudson at or close to 6. If you look for correlations between these spikes and global temperature dips, if you squint and look a bit cross-eyed then one can convince oneself (and R) that there is a weak, transient correlation between VEI 5 and up eruptions and temperature, but it is more difficult than seeing the 3-D unicorn in a dot stereogram because the effect is comparable to the natural noise and trend and is often confounded by (cancelled by) that noise.

    I think that both Willis and I are in agreement that the effect of volcanoes of VEI less than 6 is almost completely irrelevant to the climate, and one could argue that even 6’s have a pretty ignorable, highly transient effect on long term trends, with any effect they produce completely disappearing within 1-3 years. That is, volcanoes by definition have no effect whatsoever on the “climate” if we define climate in terms of decadal or longer trends, but they can have an effect on global weather. Obviously this would not be true if e.g. Yellowstone or the Siberian Traps erupted as a supervolcano — a major sulphur-rich eruption that basically never stops on a century time scale — but Pinatubo? Krakatoa? Fooey. I spit on your Krakatoa as having more than a transient effect on the weather, not the climate.

    The second thing is that I’ve fit a linear trend to the mlo data over the entire interval (to avoid cherrypicking) with R. Note that with the big divots, this makes R sad — R-squared is basically 0 because the data is not, not, not linear with those huge nonlinear holes. But aside from this, R finds that the data has no linear trend — the best fit slope is, well statistically indistinguishable from zero, weighing in at -3. \times 10^{-5} change in transmittivity per year. Yes, this is negative, but the uncertainty is larger than the value. The only effect of the eruptions is to pull the best fit line well down from what is obviously a dynamic equilibrium line that describes the atmospheric transmittivity in the almost perfectly constant background forcing from all sources — those small-to-medium volcanoes, human emissions, changes due to solar activity, and the effect of space alien rays being beamed down from cloaked transmitters as they try to terraform the earth to better match their needs before invading us (Look, I can do conspiracy SF theories too, Ma!).

    Indeed, it is perfectly obvious that on average, the broadband transmittivity of the stratosphere has basically not varied over the entire time frame of the Mauna Loa data. That makes looking for a correlation between volcanism and the change in this transmittivity rather moot, because it has not changed in any statistically resolvable way for almost 60 years. To put it bluntly, it is like looking for the effect of stock market prices on the mass of a brick. The mass of the brick doesn’t change much, right? In fact, some would say that it doesn’t change at all. You know that even before you look at the stock market data. So why would one publish a paper suggesting that the generally rising stock prices represented by the Dow Jones are causing the mass of the brick to decrease, which is why you should worry about your house floating away if the market ever really takes off?

    Well, OK, there are three things in this graph that are worthy of note. The third thing is this. The mean transmittivity of the stratosphere is (according to R, again) — around 0.92, INCLUDING the fortunately balanced spikes from major volcanoes. Obviously, the equilibrium to which transmittivity regresses is a bit higher than this, so I drew a dashed line by hand at 0.93 that does a pretty good job of splitting the noise on what appears to be the nearly completely insensitive equilibrium transmittivity — the data isn’t worthy of an better treatment as it is pretty obviously flat outside of the major divots and their sort-of exponential return.

    Now look. Both El Chichon and the Pinatubo-Hood double drove top-of-troposphere insolation down well below 0.9 — arguably down to maybe 0.88 — for at least one full year. Let’s put that in perspective. TOA insolation is roughly 1300-something watts/m^2 — it varies by 91 watts/m^2 over a year so there is little point in doing much better than that in this argument. Mauna Loa measured a drop in insolation at the top of the troposphere of five percent that lasted for a full year. That is, top of troposphere insolation was reduced by a staggering 68 watts/m^2 (transiently, much more!) for at least one full year.

    Let’s consider what effect this should have had on the Earth’s temperature if any of the naive high-sensitivity models were correct. Over all of the Earth’s land surface area, temperatures are dominated by short-timescale relaxation processes. It warms up right now when the sun shines. It cools down quickly at night, often by as much as 20 to 40 C. If you drop insolation by 5%, you should see profound, immediate cooling, worldwide, in the entire land surface area. After all, the total change in forcing expected from doubling CO_2 is around 5 watts/m^2 — this is an order of magnitude greater (although still smaller than the annual variation with its anticorrelation with global surface temperture).

    Yet the actual observed effect is almost invisible against the noise. Here’s my own solution to Willis’ “Spot the volcano” game, played with R and an ad-hoc model based on fitting the Mauna Loa transmittivity divots to converted average VEI (using the same method he describes above, but including only 4’s or higher as 3’s and below are truly just noise when even 5’s have almost no effect on temperature). First the recent time spanned by the actual ML transmittivity data:

    Can you spot the volcanoes? Note well that I really do try to help you by providing a best-fit prediction of their effect, and in the thick black line you can see the early 60’s volcanoes (the Tsar Bomba, which was effectively a 5, Mt Agung 5, and Shiveluch 4.5 but included as honorable mention), Mt St Helens/El Chicon, and Pinatubo/Hood. Can you resolve the signal from the noise? I sure can’t. As I said, if you squint a bit you can maybe convince yourself that Pinatubo caused the small, slightly lagged blip in temperature immediately following, but I count at least 9 other downward fluctuations in temperature with almost exactly the same appearance, magnitude, and duration and none of them are correlated with, well, anything. That’s the point of Willis’ game — if you were given the data and told that there were two events that dropped top of troposphere insolation by 5% for over a year and you were to make your best guess as to what years they were, there are at least 4 years you would guess before getting around to Pinatubo. Basically 100% of all people, armed with the entire statistical panoply of R or just their own eyes, would get it wrong. You’d have a better chance of getting it right if you labelled the divots in temperature with numbers and rolled dice to guess.

    This is precisely how our minds and biases trick us in to thinking that there is a causal correlation between events. We somehow focus on the local correlation and deselect all events that don’t fit the pattern with our brains and then unsurprisingly find a good correlation within the selected subset! It is why the gods of statistical reasoning get angry when you pick cherries to make cherry pie, as you are likely to conclude that your pet hypothesis that all red berries are good to eat because cherries are is true, and poison a whole lot of people when they try to eat any of the numerous poisonous red berries available in the wild.

    Let’s play Spot the Volcano one last time, this time for the entire range of arguably good data represented by HadCRUT4, using this same model (built with 60 years of Mauna Loa data, and now hindcast into the past for validation):

    I’m not going to list the minor events, but the volcano data contains four clearly discernible VEI 6’s: Krakatoa, Santa Maria, Novarupta and Pinatubo (in temporal order). Each of these “should” have produced a substantial divot in global temperature that one would expect is resolvable from the noise and natural variation. Again, if you let your brain only look at the local correlation between the predicted divots and the events, you can convince yourself that there was a sudden cooling in 3 out of the four cases. But now invert the question. If you were told that there were 4 VEI 6 eruptions that occurred during the timespan of this data and asked to make your best guess as to when they happened and how long afterwards they affected temperatures, 100% of all rational guessers would guess wrong. I doubt that given all four chances independently that people would get even one guess right, although a few might hit Krakatoa or Santa Maria. But Novarupta? Temperatures rose strongly all the way through Novarupta, which is the kind of thing that gives cherrypickers migraines as they try to resolve the cognitive dissonance between their pet hypothesis and something that more or less directly refutes it. Pinatubo? Don’t make me laugh — people wouldn’t even guess a single event from the 1980s on given the wealth of sharp drops in the 50’s and 60’s and elsewhere in the record. And even Krakatoa and Santa Maria are far from the most rapid or disruptive of coolings in the record.

    To conclude, it will be very difficult for me to be convinced by Santer et. al.’s paper, because no matter how hard you try, you aren’t going to succeed in convincing me that there is a strong causal relationship between leaving a brick out in the sun and its mass, even with a perfectly good physical basis for that belief. I even believe the truth of the assertion — a sun-warmed brick will almost certainly have slightly more mass than the same brick, cold. The problem is measuring that difference in a 1 kilogram brick, because hey, come on, the mass of the brick doesn’t change on any measuring apparatus you are likely to be able to afford to build or apply and even if you do a really careful job and confirm (again) relativity theory, the variation is so small compared to the total mass of the brick that nobody cares.

    That’s what the graphs above ever so clearly show. Sure, why not, maybe it is true that volcanoes weakly affect weather (but not climate). They certainly “should”. R can — with a bit of help — manage to fit a model that explains a tiny part of the total variation in global T slightly better than one that omits volcanoes altogether. But what we learn from this is that in the end we do not care if it is technically true, because it is a nearly irrelevant effect compared to the other, much much larger factors driving the climate.

    We learn one last thing. The Earth’s climate is awesomely stable. Every year it manages to countervary average global temperature and a 7% annual variation in top of atmosphere insolation. It manages to shrug off 5% sustained variations in top of troposphere insolation with anywhere from a response the opposite of what one expects (Novarupta) where any cooling is swamped by natural warming driven by things we Do Not Understand to no effect at all (El Chichon, and actually many other VEI 5’s in the climate record) a mere 1-3 year response, at best, to the three VEI 6 events in the climate record that one can squint hard and convince one’s self are relevant to transient changes in global weather (but that have no effect at all on the trajectory of the climate.

    rgb

  64. Willis’ author rule has a software analog. The more developers working on a software project, the worse the quality. The is partly due to the more challenging communications, and the difficulty of making more and more separately written pieces work well together. It is also because poor and incompetent programmers can only be found in large groups because they cannot survive elsewhere, which also causes good programmers to avoid large groups when they can choose to do so. Finally, the group dynamics of peer acceptance and attempts at group harmony mean that stupidity is not challenged in larger groups.
    I believe these forces are also at play in science groups.

    • The quote from the Tao of Programming:

      3.4

      A manager went to the master programmer and showed him the requirements document for a new application. The manager asked the master: “How long will it take to design this system if I assign five programmers to it?”

      “It will take one year,” said the master promptly.

      “But we need this system immediately or even sooner! How long will it take if I assign ten programmers to it?”

      The master programmer frowned. “In that case, it will take two years.”

      “And what if I assign a hundred programmers to it?”

      The master programmer shrugged. “Then the design will never be completed,” he said.

  65. Oops, sorry mod — could you remove the spurious spaces in the last two web links to graphs on my website? My mouse was apparently greedy by one space when I grabbed the text and they hence failed to expand inline.

    rgb

    • Robert, as always your comments move the discussion forwards. As you point out, the MLO data is a clear refutation of their claims.

      I’ve removed the spaces in your links, so the graphs are now part of your most interesting exposition.

      Finally, I’ve never read “The Tao of Programming”, but if that is any example, the guy definitely understands both programming and the dynamics of large groups …

      w.

      • It’s on my personal website, under “general”. I didn’t write it, but I wish that I did. It’s pretty funny and oh, so very true (and I say this as a professional coder, among my many and various hats).

        rgb

  66. Even in 105 F Phoenix you have to heat your pool from within to compensate for the heat lost to evaporation. Same with the oceans, the heat comes from inside, not from the LWIR/CO2 heated air. It’s water vapor, the most powerful GHG, precipitation, clouds, albedo, winds that power the climate. CO2 is a bee fart in that hurricane.

    IPCC AR5 TS.6 Key Uncertainties is where climate science “experts” admit what they don’t know about some really important stuff. They are uncertain about the connection between climate change and extreme weather especially drought. Like the 3” drought that hit Phoenix. They are uncertain about how the ice caps and sheets behave. Instead of gone missing they are bigger than ever. They are uncertain about heating in the ocean below 2,000 meters which is 50% of it, but they “wag” that’s where the missing heat of the AGW hiatus went, maybe. They are uncertain about the magnitude of the CO2 feedback loop, which is not surprising since after 17 plus years of rising CO2 and no rising temperatures it’s pretty clear whatever the magnitude, CO2 makes no difference.

    http://www.writerbeat.com/articles/3713-CO2-Feedback-Loop

    Barring some serious flaw in science or method, Miatello’s paper should serve as the death certificate for AGW/CCC.

    http://principia-scientific.org/publications/PSI_Miatello_Refutation_GHE.pdf

    http://www.climatism.net/facts-about-global-warming/http://www.seipub.org/des/paperInfo.aspx?ID=21810

    The summary states:
    “In our view the greenhouse phenomenon, as it was postulated by J. Fourier (1824), estimated by S. Arrhenius (1906), first quantified by S. Manabe and R. Wetherald (1967), explained by R. Lindzen (2007), and endorsed by the National Academy of Science and the Royal Society (2014), SIMPLY (sic) DOES NOT EXIST” (bold highlighting by others).

  67. Below(LAST PARAGRAPH) from rgtbatduke which is correct to a degree but which assumes the earth dynamic /mean state of the climate is constant which it is not which means the same outcome is not going to come about from a particular forcing at a particular point in time.

    I present this argument s

    In summary I think climate SENSITIVITY to various forcing is EXPONENTIALLY dependent upon the mean state of the climate/earth dynamics at the time the forcing is taken place which is why correlations are hard to come by and so many different climate outcomes (although a similar trend in a general sense) is always the result.

    The climatic outcomes all different over the past 20000 years while the same essential forces have been in play throughout this time frame I think proves my point. This is why no climatic theory no mater how could fails to stand the test of time.
    .

    I think that both Willis and I are in agreement that the effect of volcanoes of VEI less than 6 is almost completely irrelevant to the climate, and one could argue that even 6’s have a pretty ignorable, highly transient effect on long term trends, with any effect they produce completely disappearing within 1-3 years. That is, volcanoes by definition have no effect whatsoever on the “climate” if we define climate in terms of decadal or longer trends, but they can have an effect on global weather. Obviously this would not be true if e.g. Yellowstone or the Siberian Traps erupted as a supervolcano — a major sulphur-rich eruption that basically never stops on a century time scale — but Pinatubo? Krakatoa? Fooey. I spit on your Krakatoa as having more than a transient effect on the weather, not the climate.

    • Well, sure, depending on the time scale. But still, total temperature variation of maybe 20 C over all inferrable time in the last billion or so years, over a period where the atmospheric chemistry and power output of the sun and radius of the moon’s orbit and configuration of the continents themselves all varied substantially? I call that pretty stable, even when it is currently bi- or multistable with a ~10 C oscillation.

      Un stable to current conditions would be a kick into snowball Earth, permanently, or hothouse Earth, equally permanently (that is, on 100 million to billion year timescales — eventually the Sun itself isn’t “stable”).

      rgb

      • Totally agree! Eventually, our star will consume us and the planet will die! Unless humans can travel to another distant planet, we are on a path to extinction, just like all other life on this rock!

    • Salvatore, you’ve shown data which claims that in Greenland the temperature swung by about ± 6°K. Generally this is taken as being around twice the swing of the globe as a whole, since the polar regions swing much more than the tropics. This gives a global swing of about ± 3°K.

      Now, the temperature of the planet is about 290K. This means that the “extreme” swing that you’re talking about is a ± 1% swing in the temperature …

      To me, far from refuting the idea that the earth’s climate is stable, the fact that the largest temperature swing you can find in a million years is a trivially small ± 1% swing is clear evidence that the earth’s climate is amazingly stable. There is no inherent reason that a system ruled only by clouds and wind should be anywhere near that stable, .

      If you had any experience trying to govern an engine to a given speed, you’d recognize that holding even a modern engine with a modern governor to ± 1% is a very difficult task. I fear that you’re talking about things that you don’t really understand. A 1% swing is trivially small, and is evidence of a stable system.

      w.

      • Depends on what you mean by stable, Willis.
        The Holocene began with a precipitous rise in temperature of an estimated 4-6° C in a few decades. The whole of the Pleistocene has seen such precipitous temperature excursions either as interstadials or interglacial.
        The advance and retreat of continental glaciation, although involving time frames in millennia, is not what I would count as stable. In fact, I view the Pleistocene as a period of climate instability.

      • I´ve had fun myself showing climate change in kelvins, but to be fair, the baseline for our planet isn´t absolute zero.

        The fact is that earth´s climate has ranged between its surface covered with oceans of molten rock & of frozen water ice. If it ever were entirely frozen over during the Cryogenian (Snowball Earth v. Slushball), its average T was probably around -50 C. Its maximum T since the Hadean is unclear, but during the Phanerozoic Eon has rarely exceeded about 25 C.

        But during our Eon (past 543 million years), it hasn´t gotten as cold as during the long Cryogenian Period, so climate has indeed been more stable. However even during the Phanerozoic, climate has varied from vast ice sheets at both poles to lush vegetation & crocodilians there.

        Hard to compare the stability of earth´s climate with those of its sister planets. Mercury & Venus don´t vary much, due to having almost no atmosphere & too much (although the composition of Mercury´s tenuous atmosphere does vary greatly, but being tidally locked to the sun, its surface ¨climate¨ is reminiscent of our moon´s). Mars was probably more earth-like early in its history, but its climate is fairly stable now, although swept by dust storms & having experienced global warming along with earth (but then so has dwarf planet Pluto). The storm on Jupiter marked by its Great Red Spot has lasted at least hundreds of years.

      • I think some NASCAR engineers might beg to differ, but then again they are looking for speed over varying track conditions, not necessarily keeping the engine within 1% of any given rpm :)
        Just say’n.

      • At least one study suggests peak warmth during the melting of a Snowball Earth interval of 40 degrees C, for a temperature swing of about 90 degrees in the Cryogenian (-50 to +40). Present mean global T is around 14 degrees C.

  68. And yet with this very stable climate the earth has had glacial and inter-glacial periods not just one or twice but many times over. Ice sheets covering vast expanses of the earth at times.

    I do not define that as evidence of a stable climate.

  69. My definition of a stable climate would be one in which the mode of the climate would either stay in either a glacial state or inter-glacial state permanently.

    The fact that the climate of the earth is so close to a glacial/inter glacial threshold makes a definition of a stable climate in the sense of overall temperature changes for the globe valid but not in the fact that the resultant climate change for much of the globe from glacial versus inter-glacial conditions is drastic.

    I guess it is how one wants to define stable.

    • But RGB was talking of stable temperature.not stable climate. A 1 – 2% variation in temperature over the history of the planet is extraordinarily stable.

      Imagine for a moment that you have an ice cube tray of pure water, which you place in a freezer set for 0 degrees C, with a variation of +/- 0.5 degrees. That’s a pretty good thermostat but you’ll find that your ice cubes keep freezing and thawing – very stable temperature but apparently unstable conditions.

      The fact that the Earth’s temperature is so stable despite being so close to a point where climate conditions can change quite drastically, and in ways that should have a large effect on one of the known feedbacks, is almost enough to make the scientist in me go to church next Sunday!

  70. Again stable is in the eyes of the beholder. I define stable as a global temperature variation of 1C or less over a 100 year period, anything more I would say is not stable.

    Well, sure, depending on the time scale. But still, total temperature variation of maybe 20 C over all inferrable time in the last billion or so years, over a period where the atmospheric chemistry and power output of the sun and radius of the moon’s orbit and configuration of the continents themselves all varied substantially? I call that pretty stable, even when it is currently bi- or multistable with a ~10 C oscillation.

  71. One last item.

    I think the delicate balance between the earth being in an inter-glacial state versus a glacial state makes the word stable in regards to climate take on a whole different meaning.

  72. Stable – not stable. Tomayto – tomahto. The only pertinent question is what causes that stability/instability and it’s rather obvious that it is not CO2, anthropo or not, or the other non-water GHGs.

  73. Matt said:

    I disagree with Willis’ Rule of Author Count – what are you gonna do with the LHC folks that found the Higgs? There are 4000 of them, and to make it proper, all of them would have to be named… this is actually being discussed as a real problem for publishing the results ;)

    Willis is right, this whole damned authorship thing has been bastardized to support the publish-or-perish meme. I doubt if all 4,000 of the LHC folks will have had anything to do with actually ‘writing’ the paper. The two or three or four (depending on complexity) actual authors that write the paper should be listed and a way found to credit the others with work done. It’s down right stupid to conflate research with authorship, they are two entirely different functions and capabilities.

    In engineering development we had tech writers that, if they were good at their jobs, could tell a five year old how to program an iPhone to drive the family car around the block… and explain all the potential errors encountered. This (i.e., use of tech writers) limits what I call specialized language development where each new area of science (or engineering) tries to define its own (new) vocabulary (i.e., language) in order to appear important and fool the masses into thinking they know what they are talking about (and increase funding).

    In other words “It’s the research stupid, not who writes it up.”

  74. Here we go agin. I demonstrated that large volcanoes do not cause volcanic cooling but now these guys claim that it is the small ones that behind our backs do the coolimg. Have I said that stupidity annoys me? If not, make a note of it. The problem seems to be that they lack a basic understanding of what they are looking at when they see a global temperature graph. Specifically, they have no idea that a global temperature graph consists of a concatenation of ENSO phases, El Nino and LaNina, that alternate throughout the length of the graph. Unless they are specifically repressed to get a nice, smooth ciurve, the normal global temperature graph looks like a bandsaw, with saw teeth represented by El Nino peaks and the slots in between them by La Nina valleys. The actual graphs distributed also show a smattering of temperature lows that are said to be volcanic cooling. These “cooling” valleys are nothing more than normal La Nina valleys, attributed, by mistake, to some volcano that preceded them. Volcanic cooling does exist, but not down here, in the troposphere. All they had to do to know this was to read my book but apparently they are non-readers, in need of a course in remedial reading. The hot volcanic gases from an eruption go straight up into the stratosphere which gets hot. That happens aproximately at 22 kilometer height. Cooling follows a year or two later but it cannot descend down past the tropopause and just hangs up there. As to the blockage of sun’s rays, it appears to be no worse than that from a medium-sized cloud that keeps happening all the time. We would be completely unaware of all this if it wasn’t for those “experts” who have invented volcanic cooling. It is just another failed hypothesis, in a class with that of greenhouse warming. They have had plenty of clues that they are mistaken but they simply haven’t got the stuff to pick them up and use them. They have noticed, for instance, that some volcanoes are followed by volcanic “cooling” while others are not. Occasionally they will draw in an imaginary cooling that does not exist to correct for “errors” of measurement. This is particularly likely to happen with climate models where all the volcanic coolings are built into the code. The myth of volcanic cooling probably originated when someone noticed that a nice deep valley followed a strong volcanic eruption and appropriated it for the volcano. Later someone discovered that another volcano was not at all followed by any such valley. They admit now that both cases happen but they have no idea why. Here is the explanation. If the eruption coincides with an El Nino peak there will be a La Nina valley right next to it that looks like the work of a volcano and quickly gets appropriated for it. This is what happened with Pinatubo. But if an eruption coincides with the bottom of a La Nina valley it will be followed by an El Nino peak and there is no valley you can appropriate for it. This is what happened with El Chichon. Self et al. who discovered and named the Pinatubo “cooling” event remarked about the strange absence of cooling after the El Chichon eruption. As to their stealing that La Niina for Pinatubo, they opined that “…Pinatubo climate forcing was stronger than the opposite, warming effects of either the El Nino event or the anthropogenic greenhouse gases in the period 1991-93.” That shows you the quality of “experts” we are stuck with. Just remember that there is no such thing as volcanic cooling. All volcanic coolings on record are misidentified La Nina valleys. The presence, absence, or size of the observed “cooling” depends entirely on the exact time of eruption in relation to the position of the ENSO wave train into which it gets interpolated. To learn more, read my book (What Warming?), pp. 17-21. The quote is from “Fire and Mud” p. 1109`.

  75. Mosher says:

    No. they would not have to show this.

    Showing it would help, but its not necessary.

    What’s important is total forcing.

    Well, did they show that? i.e. that total forcing was different compared to prior time periods.

  76. ” Here we use lidar, Aerosol Robotic Network, and balloon-borne observations to provide evidence that currently available satellite databases neglect substantial amounts of volcanic aerosol between the tropopause and 15 km at middle to high latitudes and therefore underestimate total radiative forcing resulting from the recent eruptions.”

    Lucky we have Willis!

  77. “Steven Mosher

    January 9, 2015 at 9:16 pm

    What’s important is total forcing.”

    What “forcing”? Or are you talking crap again…

  78. Neither the strength nor the numbers of eruptions are important, it is their cooling effect that matters.
    This effect can be measured through the global temperatures which, according to models, should have risen more than they did.
    This fits perfectly well with data!

  79. I would suggest the earth’s temperature is ‘stable’.

    A controlled system is classed as stable if: After a transient input change, the system returns to its ‘required’ value without sustained oscillations.

    And that is what happens, in the geological time scale, something happens to perturb the temperature and after a few decaying oscillations, the temperature returns to a baseline of sorts.

    In control speak, this is stable.

  80. Large volcanic eruptions have and will always cause cooling that is a 100% certainty which is rare in the climate arena.

    Small eruptions however will not have much of an impact on the climate because the SO2 particles do not reach high enough into the stratosphere.

    The stability of the climate here is my response to that

    The bottom line is the delicate balance of the earth’s climate from a glacial state versus an inter- glacial state NEGATES the notion that the climate of the earth is stable.

    By the way I think a stable climate is one in which the temperatures varies by no more then plus or minus 1C over a period of a 1000 years. I had said a 100 years I meant a 1000 years.

    Willis I am curious as to how you view my statement below.

    I think climate sensitivity to various forcing is EXPONENTIALLY dependent upon the mean state of the climate/earth dynamics at the time the forcing is taken place which is why correlations are hard to come by and so many different climate outcomes (although a similar trend in a general sense) is always the result.

  81. johnmarshall January 10, 2015 at 3:17 am

    Every volcano erupts slightly differently from each other and each different volcano can erupt differently at each eruption.
    There are an estimayed 3million volvsnoes on the planet, most of them under the ocean surface. One thing ALL volcanoes emit is CO2.

    johnmarshall January 11, 2015 at 3:20 am

    You forget that the oceanic ridge system is 53000 miles of volcanoes. two places on land show the extent of volcanisity, Iceland and Ethiopia. These two places are quiet compared to the ridges. Every sea mount is an extinct volcano which still emit CO2 a so called pollutant.
    The estimate of 3million is not mine but appears on the excellent website
    http://www.geologist-1011.org
    The estimate is based on sea floor surveys not wishful thinking.
    I go back to the basis of the blog that the claim is not based on data of current eruptions but wishful thinking and straw clutching.

    John, I took a look at your “excellent website”. His claimed source for the figure of 3 million undersea volcanoes is as follows:

    Given the more than 3 million volcanoes worldwide indicated by the work of Hillier & Watts (2007) …

    Unfortunately, the work of Hillier and Watts is paywalled. However, that’s not the big problem. H&W’s abstract says:

    Globally (±60° latitude), we use bathymetry data acquired along 39.5 × 106 km of ship tracks to find 201,055 probable seamounts, an order of magnitude more than previous counts across a wider height-range (0.1 < h < 6.7 km).

    So the source for the site you refer to says NOTHING about the 3 million active volcanoes that you refer to. Instead, it says that there are about 200,000 seamounts (extinct volcanoes).

    In addition, that’s seamounts of all sizes, tiny to large. Note that they have included seamounts that are 100 metres high … 330 feet tall? That’s a pimple, not a seamount …

    H&W also says:

    Nevertheless, we predict 39 ± 1 × 10^3 large seamounts (h > 1 km), implying that ∼24,000 (60%) remain to be discovered.

    So there are ~ 40,000 large seamounts. But again, that says nothing about volcanoes, just seamounts. Well, it does say something about volcanoes, because for every active volcano, there are lots of seamounts. Seamounts are extinct volcanoes, but unlike on the land, they don’t get worn away to nothing. Instead, up near the surface the unceasing waves grind off the top, giving them their distinctive flat-topped shape … but the rest of the seamount persists for millions of years because there are no erosive forces down deep.

    So that means that there are probably a few thousand active undersea volcanoes.

    Finally, I can’t find anything about seamounts degassing any significant amounts of CO2. Active volcanoes, sure, they give out CO2. But as far as I can see, extinct volcanoes (whether on land or in the sea) are a trivially small source of CO2. If you have information otherwise, then you should bring it forward.

    In any case, your claim of three million submarine volcanoes is simply not true. Heck, according to your own citation there are less than a tenth of that number of seamounts even if you count pimples, and a tenth of those seamounts are large seamounts, and active volcanoes are perhaps a tenth of that number.

    In other words, Robert Brown’s back-of-the-envelope calculation is about right … no surprise there.

    w.

    • Quick calc:

      Assume 53,000 miles of undersea mountain ranges (spreading or split crustal zone)
      Assume 53,000 miles of trenches on the other side of each plate
      Total =106,000 miles of splits or trenches, but the trenches will likely have volcanoes also, right?

      If 106,000 miles of active seismic zones, then at 1 volcano per 20 miles (far, far more than up the western US coast, right?)
      then you’d still only have 5000 volcanoes. And about half of those 5000 would be on land or right near island subduction zones.

      3 million “lava seeps” or vents? No.

  82. Leaving the volcano number argument the orriginal paper was about aerosols. Whilst volcanoes on land do preduce aerosols far more come from the oceans. These come from coastal surf zones, storm wave tops etc and include salt. Tropical aerosols are lifted high into the troposphere by convection and will affect weather.

  83. Let me get this straight: CO2 absorbs light energy and *warms* the atmosphere; volcanic dust absorbs light energy and *cools* the atmosphere?

    • tadchem, if by “light energy” you mean “visible light”, the usual meaning, then no. CO2 doesn’t absorb visible light. Volcanic aerosols, on the other hand, both absorb and reflect visible light, both of which tend to cool the surface. The net effect of eruptions on the atmosphere itself, however, is warming from the additional absorption of solar energy.

      Regards,

      w.

  84. I’ve put an update at the end of the head post showing how trivially small the recent variations in stratospheric aerosol optical depth are when compared to volcanoes like Pinatubo.

    w.

    • More support for Willis (I think) re Mount Tambora

      https://wattsupwiththat.com/2014/09/19/laki-caused-1783-could-icelands-bardarbunga-volcano-trigger-another-year-without-a-summer/#comment-1742472

      Mount Tambora

      [Excerpt from wiki]

      With an estimated ejecta volume of 160 km3 (38 cu mi), Tambora’s 1815 outburst was the largest volcanic eruption in recorded history. The explosion was heard on Sumatra island more than 2,000 km (1,200 mi) away. Heavy volcanic ash falls were observed as far away as Borneo, Sulawesi, Java, and Maluku Islands. Most deaths from the eruption were from starvation and disease, as the eruptive fallout ruined agricultural productivity in the local region. The death toll was at least 71,000 people, of whom 11,000–12,000 were killed directly by the eruption;[6] the often-cited figure of 92,000 people killed is believed to be overestimated.[7]

      The eruption caused global climate anomalies that included the phenomenon known as “volcanic winter”: 1816 became known as the “Year Without a Summer” because of the effect on North American and European weather. Crops failed and livestock died in much of the Northern Hemisphere, resulting in the worst famine of the 19th century.[6]

      [end of excerpt]

      [Excerpt from my above post]

      The Dalton Minimum had 2 back-to-back low SC’s with SSNmax of 48 in 1804 and 46 in 1816. Tambora erupted in 1815.

      Two of the coldest recorded years in the Dalton were 1814 (7.75C year avg CET) and 1816 (7.87C year avg CET).

      [end of excerpt]

      Commentary:

      So, for CET’s, it appears that the 1815 eruption of Tambora had minimal effect, since CET’s in 1814 were slightly lower than CET’s for 1816.

      However, the anecdotal evidence suggests that 1816 was a much harder year for humanity than 1814.

      What to believe?

      Best to all, Allan

      • There is a fact that orbital stresses coincide with solar activity. When there is a change around a gravitational mass stresses increase, and when it balances out the stress decreases.

  85. Ah Yess… I agree with Susan Solomon’s expert research, every time I light a match in a warm room it cools. You see, the sulfur dioxide from the match reflects the ambient heat away from its source increasing the amount of empty space where the evil carbon pollution cant exist. See it causes cooling! Ah Ha!

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