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:
Figure 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:
Figure 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.
Figure 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:
Now, that looks kind of impressive … until you compare it to the larger volcanoes (source):
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.
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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.
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!
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.
High latitude lower VEI eruptions can reach above the tropopause simply because its lower. About 15-17km in the tropics, about 10 km in high latitudes.
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.
…and if so, why were their assertions unchallenged during review?
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!
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.
disregard above. I misread Willis’s inverse.
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.
+ something
“Climate” is to “scientist” as “witch” is to “doctor”.
flydlbee
+1000!
That is the best breakdown I have seen yet… take a respectable profession put another word in front and bingo it immediately is associated with insane ideas. A hundred years from now, hopefully less, people will look at Climate Scientists they same way we look at Witch Doctors today.
First they came for the LIA, then the MWP.
Now they make up excuses to come for the RSS and UAHbdata sets since 1979.
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).
And again sadly, I can only agree. Ben Santer’s name is another huge red flag for me.
w.
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?
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.
http://climategrog.files.wordpress.com/2014/04/uah_tls_365d.png
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.
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
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 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
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.
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
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:
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
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.
Did the burning of the Kuwait Oil fields ,which as a big event and went on from months, have any climate impact?
No, except locally, smoke from fires stay in the troposphere and are quickly washed out by rain.
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.
Volcanoes are given bad name; overall they were and are beneficial for the evolution of life on this planet.
Not when they are really large. Read up on the Siberian Traps and their effect on the biosphere. Or even Laki in 1783.
https://en.wikipedia.org/wiki/Rockdust
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.
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.
Willis, don’t you get bored with volcanos. I note our good friend from Duke has said exactly the same while mentioning your name.
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.
Stephen Ricahrds wrote, “You would think that Santer would have had enough of being made to look the nincumpoop and bete du village.”
But it pays well …
LLNL climate scientist Benjamin Santer wins DOE Distinguished Scientist Fellowship … Santer will receive $1.25 million over five years contingent on his continued employment at Lawrence Livermore.
https://www.llnl.gov/news/llnl-climate-scientist-benjamin-santer-wins-doe-distinguished-scientist-fellowship
And of course there was that MacArthur Fellowship.
” Banging your head against a wall begin to hurt…”
But it all pays the same..
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.
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.
The scientific answer? “Climate change deniers are upsetting the Fire Gods and making them erupt. Small volcanoes did not exist before 1998.”
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.
“”The AGW Titanic is hitting the iceberg.””
At the moment the iceberg appears to be made of soft fluffy absorbent lint.
Or rotten ice.
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.
Willis
Thank you for once again showing the importance of volcanoes.
http://virakkraft.com/VEI-Hadcrut4-1970.png
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
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.
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.
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.
Upside down tiljander…..nice mannian mosh-up…
Mosh-up, that’s funny…
Fascinating. A different version of inversion corruption. First Tiljana upside down now volcano in the mirror. Whatever next ? Upside down -mirror image, perhaps?
Upside down and backwards! How is this even done? And why…
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..)
lgl,
Why did you post your chart upside down and backward?
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.
Regarding Stratospheric eruptions, Spaceweather.com had a story (backend of 2010)
“ALL-CLEAR IN THE STRATOSPHERE”
http://www.spaceweather.com/swpod2010/18dec10/twostratospheres_strip.gif
“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
. 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:
http://en.wikipedia.org/wiki/Mount_Hudson#mediaviewer/File:TOMS_SO2_time_nov03.png
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
Thanks for clarifying & for mentioning Hudson, which I´ve seen.
Sent from Chile.