Guest Post by Willis Eschenbach
The claim is often made that volcanoes support the theory that forcing rules temperature. The aerosols from the eruptions are injected into the stratosphere. This reflects additional sunlight, and cuts the amount of sunshine that strikes the surface. As a result of this reduction in forcing, the biggest volcanic eruptions are said to depress global temperatures, sometimes for years.
The idea that large volcanoes significantly cool the planet is widely accepted. This effect is built into the climate models, for example. It is a reflection of the dominant climate paradigm, which is that surface temperature is a linear function of forcing. Since it can be measured observationally that the volcanoes greatly reduce the global solar forcing, it follows that they must significantly affect the global temperature.
However, I hold that the climate system is not an inert slave of changes in forcing. I hold that the climate system immediately and actively responds to changes in forcing by adjusting things like albedo, cloud type, cloud formation times and locations, timing of Nino/Nina alterations, and the like, to quickly counteract any forcing changes.
Which means, of course, that according to my hypothesis, even very large volcanoes should a have very small effect on the global temperature. To see which hypothesis is true, mine or the standard AGW hypothesis, I devised a little game I call “Spot the Volcanoes”. Two of the largest volcanoes of the century occurred within a twenty year time span. See if you can tell where they occurred.
Figure 1. First difference (month-to-month change) in global surface air temperature. Timespan shown is twenty years. Two of the largest volcanoes of the 20th century are shown in this record. The volcano in the picture is Mt. Redoubt, Alaska, one of my favorite mountains.
In Figure 1, to make things a bit difficult, I show the month-by-month CHANGE in temperature. This is not the temperature itself, but the month-by-month change in temperature, called “delta T” (∆T). If the temperature is a function of the forcing, the eruptions should be making the temperatures drop for a while. So the game is, where in Figure 1 are the two eruptions? Make your choice before you take the jump …
The answer is shown in Figure 2 below. It contains the record of the atmospheric transmission over Mauna Loa. The two eruptions, of El Chichon and Mt. Pinatubo, are very apparent in the Mauna Loa (MLO) record. I have scaled the Mauna Loa record to the corresponding GISS estimate for the forcing from Pinatubo (in W/m2), in order to show the generally accepted size of the volcanic forcing.
Figure 2. As in Figure 1, plus Mauna Loa atmospheric transmittance observations. These observations are of the total amount of clear-sky sunlight making it through the atmosphere.
Now, I can already hear folks grumbling, that this was not a fair game, that it was rigged because it was the first differences and not the actual temperature itself. And besides, most people don’t spend much time looking at first differences, so it was too hard. And perhaps those folks are 100% correct.
So let’s play a bonus round of “Spot the Volcanoes”, this time using the real temperature data. Figure 3 shows a stretch of the HadCRUT3 global surface air temperature record. This time it includes one smaller and two larger volcanoes. See if you can spot where the big ones erupted:
Figure 3. A stretch of the HadCRUT3 temperature record containing one small and two large eruptions. Don’t bother trying to find the small one.
So once again, the game is to spot two volcanoes.
Now at this time,
.
We’ve got to play the game show music,
.
. dee
. dee
. da dee dee dum
.
So as to hide the answer,
.
Until you make your choice, of the exact location of the two eruptions in Figure 3.
.
So here it is.
Figure 4. As in Figure 2, showing the eruptions of El Chichon (1982) and Pinatubo (1993). The small eruption is Mt. Agung (1963).
I’m sure you understand my point. There is nothing to see. The kinds of temperature excursions we see after the volcanoes are not different from the temperature excursions before the volcanoes.
How big an effect should we have seen, given the IPCC assumptions about climate sensitivity? Well, the average change in forcing over the three years following the Pinatubo eruption is ~ -1.7 W/m2. Now, that’s about half the forcing change expected from a doubling of CO2, maintained for three entire years … and where’s the response? Using the IPCC numbers, we should have seen a temperature drop of 1.4°C at equilibrium, and three years after the step change we should have seen at least a full degree of that …
Instead of a full degree of cooling after Pinatubo, or even half a degree, we see maybe a tenth of a degree of cooling.
But wait, as they say on TV … it’s even worse than that. The drop after Pinatubo may be just by chance, because after the earlier El Chichon eruption we see maybe a tenth of a degree of warming … and the average three year change in forcing for El Chichon is only trivially smaller than Pinatubo, at ~ -1.6 W/m.
So this is a great natural experiment regarding changes in forcing. From these observations, as near as we can tell, half the forcing change expected from a doubling of CO2 was applied for three full years, at two different times, and it resulted in … well, pretty much nothing.
So I’d say that the volcanic eruption data strongly supports my thermostat hypothesis, which says that changes in forcing are almost immediately and nearly completely offset by opposing changes in other aspects of the climate system.
w.
PS—Here’s the double bonus question … the UAH lower temperature record:
Figure 5. UAH MSU satellite based global lower tropospheric temperature record.
This time the game is a bit different. Are there one or two volcanoes in the record, and where is it / are they?.
Now at this time,
.
We’ve got to play the game show music like last time,
.
. dee
. dee
. da dee dee dum
.
So as to hide the answer,
.
Until you make your choice, of the exact location of the two eruptions in Figure 5.
.
So here it is.
Figure 6. As Figure 5 plus transmittance information.
Note that as with the surface temperature record, the globe cooled slightly after Pinatubo … and that as with the surface temperature record, the globe warmed slightly after El Chichon. And since the post-Pinatubo drop is indistinguishable from the post-1983 and the post-1988 drops, there is no reason to assume that the post-1991 drop is due solely to Pinatubo.
Which in my opinion is why all of the analyses focus on Pinatubo, while poor El Chichon is roundly ignored because it didn’t get the memo about causing a temperature drop.
PS—Does this mean volcanoes have no effect on the climate? No, it just means that because of the immediate and basically “equal but opposite” response of the climate system to forcing changes, the effect is much more local, much shorter lived, and much smaller than would be expected if the IPCC estimates of climate sensitivity were correct.
FURTHER READING: Climate forcing by the volcanic eruption of Mount Pinatubo
[UPDATE] People have asked for more information about how the climate responds to counteract the cooling action of the volcano. Figure 7 shows the response of the albedo to the Pinatubo eruption. The albedo immediately began to drop, allowing more and more sunlight to warm the surface.
Figure 7. Anomaly in post-albedo solar isolation for the period 1984-1998. The transmittance change due to the volcano is shown in red. Albedo data from Hatzianastassiou et al.
You can see that it’s not too hard to spot the volcano in this graph … which is exactly the reason why it’s so hard to spot in the other graphs.
w.
Willis,
KR is wiping the floor with you. The argument fails when the best you can say is it’s all just a conspiracy. Try harder.
Willis, you say “because of the immediate and basically “equal but opposite” response of the climate system to forcing changes, the effect is much more local, much shorter lived, and much smaller than would be expected if the IPCC estimates of climate sensitivity were correct.” This is the way the world works, it’s a highly adaptive mechanism which adjusts various balances as required, a very happy pattern from the point of view of development of life-forms. It appears to me, though I can’t quote peer-reviewed chapter and verse, that such adaptation is pervasive.
A very good posting, only marred by the use of the nebulous “forcing”.
There is no such thing as a ‘forcing’ in my physics book. There is a ‘forcing function’ in math, but that’s not physics.
http://en.wikipedia.org/wiki/Forcing_function_(differential_equations)
“In a system of differential equations used to describe a time-dependent process, a forcing function is a function that appears in the equations and is only a function of time, not of any of the other variables. In effect, it is a constant for each value of t.”
Is that really what you meant? A “something” that is “only a function of time”? Really?
Yes, I know, it’s widely used as some kind of shorthand for “something that matters happened”, but IMHO it makes it far too easy to indulge in “hand waving”. Re-read the posting and try to figure out what PHYSICS term belongs where “forcing” is found. Solar radiation? Thermal inertia? Water evaporation? Just what is the “forcing”? It’s a game I like much more than “spot the volcano” as it causes me to realize that there is no “forcing” and trying to figure out what is really meant shows how void the “climate driving event” (an alternative to ‘forcing’) really is in terms of understood physics.
In short: If you can’t put it in physics terms, you are risking self delusion, fuzzy minded muddle, and fog-speak. Oh, and waving your hands madly…
Volcanic Eruptions May Affect El Niño Onset
http://www.nsf.gov/od/lpa/news/03/pr03126.htm
Volcanic and Solar Forcing of the Tropical Pacific over the Past 1000 Years
http://www.meteo.psu.edu/~mann/shared/articles/mczc-jclim05.pdf
It is a reflection of the dominant climate paradigm, which is that surface temperature is a linear function of forcing.
Wow, what a spectacularly wrong statement. It is well known that surface temperatures are a highly non-linear function of forcing. Did you just say it for the sake of putting up a straw man, or did you actually think it was true? Either way you look a bit silly.
“Werner Brozek says:
March 16, 2012 at 10:03 am
Le Chatelier’s Principle initially just basically applied to simple systems, I believe a much more complicated set of Le Chatelier’s types of Principles could be developed for climate, but we are not there yet. Perhaps 50 variables may be changing at any given time.”
Yes, because Le Chatelier’s Principle is if fact the Second Law of thermodynamics.
You might want to reword this sentence:
support the theory that forcing rules temperature.
I think it’s pretty much true by definition that the various forcings rule temperature. It’s a lot more questionable if aerosols, dust, or greenhouse gases dominate, say, solar input.
Quoting Willis above,
“If you think we should not be able to look for the volcanic signature in the record despite the presence of other forcings… ”
Now lets look at Michael Mann’s words, spoken only 2 days ago, where he tries explain away the significance of the MWP,
“Now we can actually explain that period of moderate temperatures 1,000 years ago based on natural factors. A fairly high amount of solar activity, so the sun was a little bit brighter; there were relatively few volcanic eruptions, which are a cooling influence on the climate…”
http://www.abc.net.au/lateline/content/2012/s3454652.htm
He’s trying to say the MWP had the benefit of no volcanic cooling, as compared our recent past which has, it is suggested by Mann, been cooled by volcanic eruptions – hence the CO2 forced climate not trouncing the MWP.
So yes, in light of that kind of hype, Willis is quite right to expect to find evidence of volcanic eruptions in the temperature record.
Bob Tisdale says:
March 16, 2012 at 4:26 pm
Your graph doesn’t show what you claim. I understand Pinatubo, but you get the opposite response from El Chichon. As I mentioned above, nobody looks at El Chichon because it simply doesn’t fit the “volcanoes cause cooling” paradigm. Note that the El Chichon warming starts while the transmittance is still dropping … WUWT?
Same thing only worse. It looks great, cooling for Pinatubo, but is doing the reverse, it’s warming with El Chichon.
You can’t just pick and choose like that, Bob.
w.
PS—Again let me say I object to “removing El Nino”. You are taking the temperature of one tiny part of the earth’s surface, regressing it against the whole surface, and subtracting the regression. Consider that you could do the same with a patch of the North Atlantic … could you justify doing that? I’d have to see at least some theoretical reason for that, not to mention the great increase in the uncertainty of the record, before I’d think that made sense.
Please re-read your reference for Figure 7. The outgoing solar radiation is increased after Pinatubo (their Fig. 6). This agrees with what they say in the text, and also with Lindzen and Choi when they show solar forcing. Are you disagreeing with Lindzen and Choi, and just about everyone else, when you say reflection decreased after Pinatubo? Would a sign error negate your theory?
Anopheles says:
March 16, 2012 at 9:09 am
Tambora was about 5X bigger than Krakatoa, which was about 5X bigger than Mt. St. Helens. (My pet page on the topic is http://wermenh.com/1816.html because I wrote it….)
Krakatoa gets more press because there were more Europeans living in the region and communications were a lot better thanks to telegraph systems. Krakatoa was heard in Europe and people linked them together quickly.
There were other volcanic eruptions in Tambora’s timeframe. It was also during the Dalton Minimum, and the Earth was still working its way out of the Little Ice Age – and may still be. Still, the sulphate haze settled out at a typical settling rate and Tambora’s effect were short lived. There are very few accounts of of cold weather in 1817, but more of the Erie Canal started then as did the westward migration of hard-scrabble farmers to the richer and deeper soil “out west”.
As an example of the silliness that comes from using “forcing”, this “Angles and Pins” argument breaks out:
Now if we had even the smallest clue what Physics Term was meant, we’d have a basis to decide if “ir reflection” or “increased insolation” or “water evaporation” or whatever was linear or non-linear.
As it stands, since “forcing” can be anything, we have idea how it is ‘driven’, what the ‘driver’ might be, or how it might behave mathematically. It can be any function and is anchored in the blue sky of non-physics… A Humpty Dumpty term that means just what the speaker intends it to mean, nothing more, nothing less…
So perhaps the article writer meant “temperatures are directly proportional to insolation” and the reader thinks “temperatures are exponentially proportional to insolation and feedbacks”. Yes, those Angels and Pins…
You may now all resume pin inspection and hand waving…
paddylol says:
March 16, 2012 at 9:51 am
Indonesian volcanoes emit a lot of sulphur dioxide which becomes sulphuric acid and that’s what the long lived aerosols are made of. Mineral dust settles out of the stratosphere pretty quickly, and sulphuric acid droplets settle out during the next couple of years.
For those who wonder why I dislike the practice of “removing the enso variations”, consider the following map:
As you can see, there are other parts of the planet that are better correlated to global surface air temperature. Would you want to regress them against the SAT and subtract the regression? If not, why not?
w.
Francois says:
March 16, 2012 at 4:29 pm
It’s the Mauna Loa atmospheric transmittance data. I thought I had linked to it in the head post, my bad. The link is here, I’ll fix it in the main post.
w.
lgl says:
March 16, 2012 at 4:45 pm
Thanks, lgl, but it’s not. The Nino 3.4 temperature, like all temperatures, jumps all around every month. Yours doesn’t. So it’s some kind of smooth of the temperature. Have you allowed for the uncertainty introduced by the smoothing process?
w.
I never said or even implied that “snow fall amount” was unusual or anomalous, it was the lack of it melting off as it typically did which was unusual, ie persistent cold. One of the coldest winters I can remember had almost no snow here in the Denver area. Snow fall is driven much more by available moisture and local weather patterns here than it is by cold. In the Denver area, it is frequently cold enough for it to snow, but since we are in a border line desert area, about 14-15 inches of precipitation a year (most of which arrives in the spring and early summer) on average it is fairly common for it to be quite cold with little if any snow on the ground.
The year I have in mind there was no snow cover and the ground froze feet deep in many areas around the Denver Metro area. My sewer line froze during several of these cold dry years as it was only buried about 18-24 inches deep. A friend of mine spent the whole winter repairing broken construction equipment torn up while trying to dig the frozen ground. One winter we had a rash of residential natural gas explosions when the spring thaw set in as the gas lines laid in the frozen ground over the winter were broken when the frozen soil settled as it thawed and pulled the lines apart, with leaking natural gas following the poorly consolidated back fill into houses which then exploded as the natural gas collected in the basements.
Your snow plot is another example of asserting proof based on data that is not a valid test of the theory.
Plotting the volcanic eruptions against heating degree days over the core months of the winter by region would be a more relevant test of the assertion that no anomalous cooling took place.
A simple average daily temp will not necessarily show an unusual cold spell, A day could be well within the extremes but the duration of the cold could be highly unusual. Heating degree days could show that persistent cold that simple averages and record lows would not.
Record low temps are often (in this area of the country) caused by a Siberian express (Alberta clipper) cold front sweeping down the front range causing a sharp and extreme cold snap which is preceded the day before by unusually warm weather due to compressional heating as the cold front approaches. As a result there might be a record high temp the day before, and a sharp cold snap the following day. It is the persistence of cold weather that counts when you are talking about the social impacts (and popular perception of a cold winter).
Heating degree days will to some extent integrate daily temps over a period of time. Unfortunately there are several ways that various sources compute heating degree days so it is easy to get an apples to oranges comparison unless these issues are considered.
Unfortunately the NWS does not publish easily accessible data files of heating degree days going back into even recent decades.
A snow less winter that has consistent nightly temps in -10 -15 deg F range can be much harder on society than a warmer winter that has lots of snow that quickly melts off as it typically does in this part of the country.
A brief cold snap and a long term period of persistent cold can have exactly the same average temperature, yet the soaking cold of a week or more of temperatures that never get over freezing will both be remembered as colder but will do more social damage both to people and infrastructure such as frozen pipes, and frost killed crops.
For example in January 1962 we had a cold period where temperatures never exceeded 0 deg F for 9 days but only one record low was set on January 22 at -14 deg F. A record low maximum was also set on the 22nd with a daily high of 11 deg F.
(capitalization is from the original NWS document)
With that brief high spike due to chinook winds to 38 degrees F daily average temperatures would give a totally bogus average that does not accurately represent the temperatures that persisted over this period, and neither do the record lows. It was the prolonged persistent cold that froze water pipes and resulted in deaths and injuries due to exposure.
January 1937 had a similar episode that would be totally misrepresented by cold records.
In 1948 we have a record snow event but temperatures were relatively mild by comparison.
Snow fall and temperature have very little in common, really cold weather seldom is associated with deep snow fall. In bitter cold conditions there is seldom enough moisture present to allow significant snow to develop. In many cases the signature of cold spells people remember are not the low temps that usually happen in the wee hours of the morning when they are snug in their beds, but the low high temps and the failure to warm up during the day. These days will show up in heating degree day numbers, but might be well within the norm when only viewed from the perspective of record low temps or daily average temps.
What is interesting looking at the record weather events in the Colorado NWS weather history is the mid and late 1980’s for January were not marked by record cold events but by several severe wind events some with peak gusts over 100 mph in the Denver Metro area.
Due to a lack of easily accessible weather info, it is very difficult to pull together a snapshot of why that period is remembered as being cooler than normal but one thing is clear by the clips posted above, daily average temps (anomalies from the norm) and record low temps do not accurately reflect the real weather conditions people experience. This is one of the disconnects in the whole process of trying to identify unusual weather periods. The local weather patterns can be highly unusual and persistently colder than usual and not appear at all out of the ordinary when viewed only by looking at low temperature records or daily average temperatures.
When looking for social impacts like freeze damage to infrastructure and crops, cold snaps might be completely invisible to the investigator unless he/she takes the time to drill down into the details of the daily weather patterns and how they compare to typical weather patterns for the area and that time of year.
Larry
HR says:
March 16, 2012 at 5:06 pm
I have not said it is a conspiracy, nor have I implied it is a conspiracy. I have not used the word, nor any synonyms. Finally, other than the Climategate folks, I do not believe that there is a conspiracy. I think there is Noble Cause Corruption run rampant, but not a conspiracy.
So you, sir, are either badly mistaken, or you are a liar. Your choice.
Next time you disagree with something I say, QUOTE MY EXACT WORDS, because obviously you have serious problems with either your comprehension or your honesty.
So as an acquaintance of mine remarked …
Try harder.
w.
E.M.Smith says:
March 16, 2012 at 5:48 pm
Sorry, my friend, but each profession has its jargon, and it doesn’t matter in the slightest if it makes no sense at all, or if you or I don’t like it. Forcing is the term thats used in climate science. I don’t like it either if that’s any consolation.
w.
PS—From the IPCC Glossary:
Bill Yarber March 16, 2012 at 10:25 am
Said :
I’ll listen to Bill! I have the greatest respect for process control engineers!
And it may be all as simple as water vapour/clouds creating a negative feedback rather than the vaguely postulated positive feedback assumed by CAGW proponents. It constitutes around 95% of the volume/quantity of total ‘greenhouse gases’.
It seems inconceivable to me that (eg) a big influx of CO2 capable of raising the earth’s temperature 1 degree C will push more water vapour into the air, compounding the warming, but in complete contrast: a big burst of solar energy capable of raising the earth’s temperature 1 degree C will push more water vapour into the air, which will then condense out cooling the atmosphere and returning it to the previous ‘prewarming’ temperature.
Willis’ volcano data may be telling us the same thing – cooling, less water vapour, less condensation cooling, return to ‘precooling’ temperature.
I went searching this on the Skeptical Science site (it’s OK, don’t panic: I washed, disinfected, changed clothes before coming here!!).
It is actually worth a look, it is by far their weakest argument, and their ‘vaguest’ page:
http://www.skepticalscience.com/water-vapor-greenhouse-gas.htm
And they had to get really desperate with the deny/slice/dice/divert/delete on this one. eg:
Skaal says:
March 16, 2012 at 6:44 pm
My uninformed friend, the dominant paradigm is assuredly that the change in temperature equals the change in forcing times the climate sensitivity … and that’s linear. What do you think the climate sensitivity means?
I agree with you that in fact the forcing and temperature are not linearly related.
But the mainstream view is indeed that temperature is a linear function of forcing, the usual formula is
∆T = λ ∆F
where T is temperature, lambda (λ) is climate sensitivity, F is forcing, and delta (∆) is the “change in” operator.
So on that question I fear that you are the one who is wrong, and spectacularly so.
And because you are wrong, and because most everyone here knows you are wrong, your over-the-top attack on me in your very first post just convinces everyone that in addition to being not that smart, you are also a jerkwagon … let me recommend that the next thread you enter, that your first post be actually pleasant and informative. Otherwise, as just happened, you may just get your okole handed to you on a platter when you make a glaring error and then want to crow about how stupid I am.
Because errors are not a problem. Being wrong is not a problem, I’m wrong as much as the next man.
But being a jerkwagon when you are wrong?
That’s a problem.
w.
Charlie Martin says:
March 16, 2012 at 7:10 pm
No, it’s not “true by definition” that forcing rules temperature. Actually, that’s the great unanswered question in climate—whether when TOA forcing rises temperatures must perforce rise as well, or whether the forcing is offset by one of the many thermostatic mechanisms in the climate system.
So you don’t get to claim it’s “true by definition”. Well, you can claim it, but you just look like a newbie.
w.
Jim D says:
March 16, 2012 at 7:43 pm
Thanks, Jim. We’re measuring the opposite things. I’m measuring the sunlight that’s left after albedo reflections. They’re measuring the sunlight reflected by the albedo. That’s why the signs are reversed.
w.
Willis, so if there is less sunlight left and more reflected, you agree it would get cooler, right?