Guest Post by Willis Eschenbach
The word “forcing” is what is called a “term of art” in climate science. A term of art means a word that is used in a special or unusual sense in a particular field of science or other activity. This unusual meaning for the word may or may not be logical, but each field has its terms of art, and it’s useless to complain that they don’t make sense. The IPCC defines “radiative forcing” as follows:
Radiative forcing
Radiative forcing is the change in the net, downward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun. Sometimes internal drivers are still treated as forcings even though they result from the alteration in climate, for example aerosol or greenhouse gas changes in paleoclimates.
Now, the current climate science paradigm says that regarding the things that affect temperature, everything averages out in the long run except for any changes in total forcing. The current paradigm further says that the future evolution of the climate can be forecast by the simple linear relationship given as:
Change in temperature equals climate sensitivity times change in total forcing.
Me, I think that’s simplistic nonsense, but let’s set my opinion aside for a bit and compare their forcing claims to the actual observations of the changes in forcing. As an example, let me use the forcings that are the result of volcanic eruptions. The larger eruptions blast aerosols (various molecules and minerals) into the stratosphere, reducing the incoming sunshine. These forcings have been estimated by Sato as being of the following amounts:
Figure 1. Volcanic forcings estimated by Sato et al. http://data.giss.nasa.gov/modelforce/RadF.txt Forcings are negative because they represent a reduction in available solar energy due to volcanic aerosols. The large eruption at the far right is Pinatubo in the Philippines, 1991, and the eruption to its left is El Chichon, Mexico, in 1982.
You can see that some eruptions, like that of El Chichon, produced a much larger aerosol cloud in the northern hemisphere (red) than in the southern (blue), while others like Pinatubo were more equal in the distribution of the aerosols between the hemispheres. In all cases, the hemisphere where the volcano is located shows the greatest effect from the eruption.
As I mentioned above, I think that the idea that the temperature slavishly follows the changes in forcings to be a fundamental misunderstanding of how the climate system operates. Instead, I say that although initially the temperature responds to the forcings, soon the climate system responds to the resulting changes in temperature by changing the forcings themselves, often in very non-linear ways. In particular, I have presented plenty of evidence that the climate system responds to increasing tropical temperatures by varying the timing and strength of the daily emergence of the cumulus cloud field. Part of the climate system response works like this:
On warmer days, the emergence of the tropical cumulus cloud field is both earlier and stronger. This cuts down on the available solar energy by reflecting more of it back to space. The high cloud albedo means that less sunlight reaches the surface, so the surface cools.
And on cooler days, the opposite occurs. The tropical cumulus field emerges later, and is weaker. As a result, the day warms up more than it would otherwise, because there is less cloud albedo and thus more available solar energy.
All that is required to show that this effect exists is to show that tropical albedo is positively correlated with temperature … as I have done here, here, and here.
Now, if we assume for the moment that my theory is correct, what kind of climate response would we expect to find from a volcanic eruption large enough to put aerosols into the stratosphere and cause some global cooling? Well, eruptions reduce available solar energy in two ways—increased reflection from white aerosols, and increased absorption from dark aerosols.
So the first thing to happen after the eruption would be the reduction in incoming sunlight from the increased albedo and increased stratospheric absorption. Then after the decreased sunlight actually starts to cause widespread cooling, the climate system would respond. We’d expect the climate system response following such an eruption to have the following characteristics:
• Right after the eruption, there would be a reduction in available solar energy, due to the volcanic aerosols in the stratosphere.
• This initial eruption-induced reduction in available solar energy would be both deeper and sooner after the eruption in the hemisphere where the eruption occurred than in the opposite hemisphere.
• As a result, the corresponding climate reaction in the eruption hemisphere would also both be deeper and occur sooner than the climate reaction in the opposite hemisphere. In other words there will be a dose-related effect, where a larger reduction is met with a larger climate reaction.
• The form of the climate reaction will be an albedo reduction, which will cause increase in available solar energy. The increase in available energy will be of the same order of magnitude as the corresponding decrease due to volcanic aerosols.
With those predictions derived from my theory about the nature and timing of the climate response, we can compare them to what actually happened when Mount Pinatubo erupted. I’ve taken the albedo records for the globe and for each hemisphere individually, and analyzed what happened after the eruption of Pinatubo in June of 1991. This gave me the anomaly in the amount of solar energy that is actually available to the climate system. Figure 2 shows three variables for the period 1984-1997, which includes the eruption of Mt. Pinatubo on June 15, 1991.
First, in black, is a closer look at the same dataset shown in Figure 1. Black shows the global average of the Sato volcanic forcing data for the period 1984-1997.
Second, in violet, is the aforementioned anomaly in the amount of incoming sunshine, in watts per square metre. This is the “available energy”, meaning the solar energy that remains after the albedo reflections.
Third, in gold, is the amount of incoming solar energy that is absorbed in the stratosphere. Recall that volcanoes affect the sunshine in two ways—changes in reflection (violet line) and changes in absorption (gold line). The gold line shows the reductions from absorption of solar energy by stratospheric aerosols.
Figure 2. Sato estimated volcano forcing (black), available solar energy anomaly after albedo (violet), and stratospheric absorption forcing (gold). The observed values (violet and gold) are expressed as anomalies around the value they had the month before the eruption. See below for methods and data sources.
Now, the first thing I noticed is that immediately after the eruption, all three datasets agree with each other—as we would expect, there is a precipitous drop in downwelling solar radiation. However, after that they go their separate ways, so it’s hard to tell what the overall effect of the absorption and the reflection might be.
For that kind of comparison, I use a running post-eruption average. This is the average forcing over the period from the date of the eruption to the date in question. So for example, the data point for January 1996 represents the average forcing from the date of the eruption until January of 1996. Figure 3 shows that type of post-eruption average applied to Figure 1, with the actual Figure 1 data shown grayed out in the background for reference.
Figure 3. Post-eruption averages. Total observed eruptive forcing [reflection (violet) plus absorption (gold)] is shown in yellow. Other colors as in Figure 1 — black is the Sato estimate of total volcanic forcing; violet is available solar anomaly after albedo reflections; gold is stratospheric absorption anomaly. Each point on the graph represents the average forcing from the eruption until that date.
The important thing to note is that from the eruption to the end of the record (end of 1997) the Sato forcing estimate (black line) has an average forcing of about minus one watt per square metre (W/m2). However, the observed change in total forcing of the period (yellow line, sum of purple (albedo forcing) and gold (absorption forcing) is a bit more than plus one watt per square metre.
Also, the speed of the climate response is visible in Figure 3. The total forcing (yellow line) follows the Sato forcing estimate (black line) for the first four months or so after the eruption. But after that, while the Sato calculated forcing continues to become more and more negative, the observations show that the total observed forcing does not ever become much more negative than it was at four months after the eruption. Instead, it runs level for about a year, and then rapidly increases. By the end of 1993, the observed post-eruption average forcing has returned to pre-eruption values … while the Sato theoretical forcing is still at minus two W/m2.
Now, Figures 2 and 3 show the global situation. We also have data for each hemisphere separately. This will let us observe the difference in the response of the climate in the two hemispheres. Here are the observed forcing and the Sato theoretical forcing for the northern and southern hemisphere.
Figure 4. As in Figure 2 but by individual hemisphere. The two panels show the Sato estimated forcing (black), the solar absorption forcing (gold), and the available solar energy after albedo (upper panel, red, northern hemisphere; lower panel blue, southern hemisphere)
The most notable difference between the hemispheres is the deep drop in available solar energy in the northern hemisphere (red line, upper panel) during the months immediately following the eruption. I note also that following that initial drop, the amount of available energy in the NH steadily increases in both the absorption (gold) and reflection (red) datasets.
To conclude this analysis I looked at the post-eruption averages for the individual hemispheres. Figure 5 shows those results:
Figure 5. As in Figure 3 but by individual hemisphere. These show the running average starting at the time of the eruption and moving forwards.
In the northern hemisphere we can see that the initial drop in forcing was almost as large as the Sato estimate. However, from there, the climate response kicked in, and the amount of available energy started to rise rapidly. In the southern hemisphere, on the other hand, the response was smaller and initially slower.
However, once the SH response began, the available solar energy rose very quickly. Both hemispheres took about the same amount of time, about two years, for the average forcing over the post-eruption interval to return to zero.
And in both hemispheres, the eventual response was nearly identical—the average change in total available sunshine at the end of the record is about plus a watt and a half per square metre, compared to the Sato estimate which has an average change to the end of the record of minus one watt per square metre.
Conclusions: The main conclusion that I draw from this is that the central paradigm of modern climate science is wrong—temperature does not slavishly follow the forcings.
To the contrary, when the tropical temperature changes, the solar forcing subsequently changes in the opposite direction, negating much of the effect of the volcanoes.
And in particular, the observations agree with the theoretical predictions, which were:
• Right after the eruption, there would be a reduction in available solar energy, due to the volcanic aerosols in the stratosphere.
• This initial eruption-induced reduction in available solar energy would be both deeper and sooner after the eruption in the hemisphere where the eruption occurred than in the opposite hemisphere.
• As a result, the corresponding climate reaction in the eruption hemisphere would also both be deeper and occur sooner than the climate reaction in the opposite hemisphere. In other words there will be a dose-related effect, where a larger reduction is met with a larger climate reaction.
• The form of the climate reaction will be an albedo reduction due to the temperature reduction, which will cause an increase in available solar energy. The increase in available energy will be of the same order of magnitude as the corresponding decrease due to volcanic aerosols.
These theoretical predictions are all visible in the graphs above, and they lead back to the title of this piece. The reason volcanoes don’t matter much is that the climate rapidly responds to re-establish the status quo ante. Yes, eruptions do put loads of aerosols into the stratosphere; and yes, these aerosols do cut down available solar energy; and yes, this does have local effects in space and time … but because available solar energy in the tropics goes up as the temperature goes down, the balance is quickly restored. As a result of this and other restorative phenomena, the climate system has proven to be surprisingly insensitive to such variations in forcing.
My best regards to everyone,
w.
The Usual Request: If you disagree with someone, please quote the exact words that you disagree with, so we can all be clear both who and what you are objecting to.
Methods and Data
Sato Theoretical Forcing: The Sato data is from here. Following Sato, I have used the aerosol optical depth (AOD) to estimate the forcing. Sato says that the forcing is estimated as a linear function of the AOD, which seems reasonable. I have used his formula for the “instantaneous” forcing (as opposed to the “equilibrium” or other forcings), since we are discussing the immediate effects of the eruptions.
Available Solar Energy Anomaly After Albedo: For the albedo data, I digitized the albedo shown in Figure 5(b) of the most interesting study, Long-term global distribution of Earth’s shortwave radiation budget at the top of atmosphere, by Hatzianastassiou et al. I multiplied the monthly (1 – albedo) by the monthly TOA solar to get the absolute value of the available solar energy after albedo reflections. Then I subtracted the “climatology”, which means the monthly averages, from that dataset to get the anomaly in available solar energy
Stratospheric Absorption: While researching for this post, I had an interesting insight about the increase in stratospheric absorption of solar energy after an eruption. This was that I could use the change in stratospheric temperature to calculate the amount of additional sunlight being absorbed, using the Stefan-Boltzmann relationship. For the stratospheric temperatures, I used the UAH satellite based estimate of the lower stratosphere, Version 6.0beta2, available here. Yes, I am aware that this is an uncertain estimate, but it’s accurate enough for a first-order analysis such as this one.
Sensitivity to Assumed Emissivity: I used the most conservative assumption, that of a blackbody relationship with emissivity=1. If we assume a graybody, the change in solar absorption corresponding to a given temperature difference goes down in proportion to the change in emissivity. This reduces stratospheric absorption forcing. And this in turn increases the difference between the observed (yellow line) and the Sato theoretical forcings (black line) in the period immediately after the eruption, but makes little difference in the later years because the stratospheric absorption term is small. For an example of the change in the early years, using an emissivity of 0.5 reduced the largest total forcing decrease (reflected plus absorbed) to about minus one W/m2, rather than the approximately minus 1.75 W/m2 as shown after the eruption in Figure 3.
Data: One of the bad things about this is that the dataset is so short. Can’t be helped, because as far as I know there’s no hemispheric estimate of the albedo during the time of the previous eruption, El Chichon in 1982. (If you know of such a dataset, please post a link). But the good side of short data is there’s not much of it, so it’s easy to move around … for example, I’ve been looking at one-minute radiation measurements from Mauna Loa, 31 million data points per year since 1980. That’s hard to download, and too big for me to put up on something like photobucket.
But here we only have 14 years at 12 months per year = 168 records, so it’s small enough to put into an Excel spreadsheet, which I’ve done in .csv format here. The spreadsheet contains the TOA solar values, the albedo values, the Sato forcing values, the stratospheric temperature values, and as a special bonus, the hadCRUT4 records for the period both globally and for individual hemispheres. Enjoy.
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For clarity: Willis is the ‘reaction of the system’ to the eruption solely the the cloud mechanism OR are you saying ‘I know the system reacts’ and I am looking for how my hypothesis: ‘that there is a reaction’ versus the Sato’s model and demonstrate my hypothesis ‘fits the data’ better than Sato’s?
The reason I ask, is I am not a big fan of the ‘my model fits the data better than yours’ but I am a big fan of the data imply some underlying concept that is evident in the analysis.
It seems to me that you are arguing that ‘the data supports a reactive self-adjusting system’ rather than the Sato model. Hence, we should investigate the fundmentals of what they ,say cumulus reaction to cooling in the tropics, are really doing what the set of reactions are.
ToA is 340 W/m2 +/- maybe 10. According to IPCC AR5 the additional RF due to the 120 ppm of CO2 added between 1750 and 2011 is about 2 W/m^2. The four models use 2.6, 4.5, 6.0 and 8.5 W/m^2 as the RF due to corresponding ppm of CO2. Trivial in comparison to 340.
The notion is that this additional RF is trapped in the atmosphere under a blanket, another half baked analogy as incomplete as the GHE. Both ignore the role of water/water vapor as master thermostat.
The RF of CO2 is lost in the ebb and flow, uncertainty and rounding errors of the total global power (watt is power, not energy) balance.
Geothermal heat flux through the ocean floor is a huge uncertainty.
TOA is 1362 Wm^-2 give or take maybe 4 Well that is average for the whole solar orbit period, and it has that value pretty much 24 hours a day. But it only illuminates a bit more than half te planet ata time.
At 340 Wm^-2, even continuously, even a perfect black body cannot reach a Temperature of 288 K, which is earth average, let alone reach 333K or more which some tropical desert surfaces reach or exceed every day in northern summers.
Earth is not a perfectly thermally conducting isothermal black, or even gray body, which it would have to be to be 59 deg. F everywhere at all times, in the Kevin Trenberth et al climate model .
The interesting aspect and semi-proof of Willis’ point is that Pinatubo, for example, had “forcing” of -4.0 W/m2 while the most temperature dropped was about -0.35C.
That forcing is almost as large as doubled CO2/GHGs yet the surface temperature barely moved. It is, in fact, hard to pick out from the normal internal variability.
So why does doubled CO2 produce 3.0C yet an equivalent change from a volcano produce -0.35C. It could be magic although I’m sure the climate change prophesy has an excuse/explanation.
As nearly as I can divine from the incantations of Warmunistas, they might murmur something about water vapor feedback. But even without that supposition, the assumed effect of CO2 alone is around one degree C, which still looks too high. This suggests net negative feedbacks, as in fact observed with volcanoes.
.35c is significant, no matter what time period it covers and that is just from one isolated volcanic eruption.
In addition it only had an explosive index level 6. Much less significant then say a 7 or 8.
What would happen if Yellowstone erupted for example?
According to Willis ,and his line of reasoning hardly anything.
the central paradigm of modern climate science is wrong—temperature does not slavishly follow the forcings.
================
Climate science ignores the most fundamental of principles. When subjected to a change, systems react to counter the change.
Volcanoes are important for replenishing atmospheric CO2 via subducted limestone (mostly) and fossil fuels. The current CO2 crash would have lasted for millions of years without Man burning fossil fuels. We would have had to wait for a period of massive volcanism and an end to the current ice age with the melting of Greenland and Antarctica (releasing CO2 from the oceans). That’s how the Carboniferous CO2 collapse ended, the only other time in earth’s history when CO2 levels have been so low.
‘The word
“forcing”“farcing” is what is called a “term of art” in climate science.’AKA as “jargon”.
g
Years ago I had a long-running debate with a colleague in Ecology who insisted that interactions in ecosystems were linear. He liked linear equations because then complex analyses of the whole system could be done, such as tracing dependencies and impacts. He wanted analytical expressions and because he wanted this he insisted that the real world had to match what he needed. I never made any headway even though we remained friendly. This situation is the same, the assumption that responses to forcings are a simple multiplicative relationship is to deny that negative feedbacks can exist. In science such an important thing should be determined empirically and rigorously and not just because it is a convenient simplification. Kudos to Willis for keeping on pushing his (correct IMO) theory.
Willis Eschenbach: “The increase in available energy will be of the same order of magnitude as the corresponding decrease due to volcanic aerosols.”
Nice work, Willis. That is precisely what explains the absence of volcanic cooling. They are all imaginary but are shown on various temperature curves. I demonstrated (“What Warmomhg?” pages 17-21) that all these so-called “volcanic cooling” incidents are nothing more than misidentified La Nina valleys. ENSO and the occurrence of volcanoes are not in phase. If by chance an eruption coincides with an El Nino peak it will be followed by a La Nina valley which invariably is named as this volcano’s cooling. An example is Pinatubo. You find it marked even on monthly satellite temperature charts. On the other hand, if the eruption coincides with a La Nina valley it will be followed by an El Nino peak and that volcano will not get any cooling to call its own. An example is El Chichon. Intermediate cases of various degrees of reduced cooling also exist because of the various possible mismatches between eruptions and ENSO phases. I have had it out for five years now but the climate “scientists” who control temperature records are still ignorant of this.
How about large eruptions cause El Nino conditions/episodes,
feed·back ˈfēdˌbak/ noun
1. information about reactions to a product, a person’s performance of a task, etc., used as a basis for improvement.
synonyms: response, reaction, comments, criticism; More
2. the modification or control of a process or system by its results or effects, e.g., in a biochemical pathway or behavioral response.
Therein lies the problem. Most folks confuse reactionary forces as feedback. It’s not.
Real feedback examples: Engine governors (e.g. steam engines going “balls out”); Op-amps — feeding the output of an amplifier back into the grid.
Back EMF, for example (the phenomena wherein a DC motor acts as a reactive generator as rotational speed increases) is a reactive force and not “feedback”
Here is Willis with his same old wrong reasoning. Willis how do you explain all the abrupt past climatic changes based on your reasoning? How do you reconcile it?
The reason why you do not respond is because you have no answers.
In addition the data shows clearly that many volcanic eruptions have major climatic effects although they are short lived.
Willis conclusion.
Conclusions: The main conclusion that I draw from this is that the central paradigm of modern climate science is wrong—temperature does not slavishly follow the forcings.
Makes sense, I think the fact that Earth exists in this magical state where water is balanced in a strange state where it can exist in 4 molecular configurations, solid, liquid, gas and clouds, creates a very complicated feedback system that is not easily understood. All of the various transfers of energies associated with convection, conduction, evaporation, condensation and precipitation are all made possible because 70% of the surface is covered in liquid water.
The study I have sent below has it spot on and is what most people subscribe to when it comes to volcanic effects versus the climate. It says everything I could possibly say about this subject. Just an excellent study and evaluation of how volcanos interact with the climate.
Look at table 3 of this report. I think they have it about right.
http://climate.envsci.rutgers.edu/pdf/ROG2000.pdf
If I understand the ramifications of Mr. Eschenbach’s “equilibrium response” of climate correctly – then the (few) documented historical instances of large volcanic eruptions causing crop failures is more likely a case of a systemic climate outlier reinforced by the eruption – as opposed to the eruption itself being the primary driver. Kind of like nitrous in a combustion engine vs. the engine’s fuel: the eruption (nitrous) makes the fuel derived engine power greater, but doesn’t offset the fuel type (wood vs. natural gas vs. gasoline).
I had wondered about this because my own personal examination of Pinatubo showed that the actual world climate response seemed so much lower than “expected” – which seemed discordant vs. many documented examples of poor weather due to Tambora.
But then I saw where an article where a historian went back and correlated written documentation of weather related events – primarily agriculture related – and showed a correlation with Tambora, but also with another unknown “super” eruption in 1807 (5 years before Tambora).
Now, the possibility of a completely unknown super eruption on a similar scale to Tambora within just 5 years – with no historical record other than crop failures – is certainly possible. But then again, a simpler explanation might just be that the 1807 to 1814 era was just a particularly cold and bad decade, kind of like the 1970s.
Don’t forget that Tambora took place at the time the Dalton minimum was well underway, after most of the cooling had occurred. Same with the 1811-1812 extreme tectonic event of the new madrid fault. This correlation could suggest a relationship (or not) between those events and solar influences. Possibly the failed crops after Tambora were more the result of the solar influence and the subsequent climate changes of a solar grand minimum.
http://climexp.knmi.nl/data/it2m_land_best_1800:1820_13month_low-pass_loess1a.png
Could it be that Pinatubo erupted during a time of lower cosmic radiation to the atmosphere (due to higher heliospheric density) and less of it’s aerosol emissions were energized to form clouds which cause cooling? Could the lower heliospheric density during the Dalton minimum be part of the difference?
I think it’s only the bigger eruption like Tambora which have much cooling effect.
So anything which has ejecta of over 20 cubic km of rock into stratosphere.
A cubic km of water is 1 billion tonnes, cubic km of rock is over 2 billion tons.
So if had say 5.1 billion tonne of rock put into higher atmosphere and earth has 510 million square
km, on average it’s 10 tons of powdered rock per square km. Or .01 kg per square meter.
Which should begin to effect the clarity of the open oceans. And while it’s in the atmosphere it also has an effect..
I hate the word forciing . Just give me differential equations .
Thanks for dissing this jargon papering over a lack of solid applied math education .
Willis, if you’re still watching this thread, I am curious if this theory also would apply to nuclear explosions or impacts with asteroids, etc.?
Finally Willis is treating all volcanic activity as if each eruption was exactly the same. What could one say. I guess. I throw my hands up when I hear these blanket statements being addressed to the climatic system which is dynamic, chaotic, random ,non linear which means given forcing applied to it is going to give different results, no matter what the source of the forcing, volcanic eruptions included.
This one cause climate effect reasoning with the climate result line is really getting old. I will oppose this because it is plain old wrong.
Not accounting for the location of the eruption, the explosive index of the eruption, the amounts of SO2 from the eruption, how isolated or not the eruption was, the Initial State of the Climate at the time of the eruption for example the Ice Dynamic, all of which make the neat conclusions presented here to be nothing more then some norm with out regard to the specific dynamics of the volcanic eruption itself and the Initial State Of The Climate which are not going to give the same outcomes he wrongly keeps suggesting.
While I am at it your line of reasoning just does not reconcile with what the historical climatic record shows, as produced for Ice Cores. This thermoregulation theory you try to present is proven wrong time and time again by the historical climatic record.
It is time to think again.
http://wattsupwiththat.com/2013/06/02/multiple-intense-abrupt-late-pleisitocene-warming-and-cooling-implications-for-understanding-the-cause-of-global-climate-change/
Douglass and Knox published on this a little over ten years ago (http://onlinelibrary.wiley.com/doi/10.1029/2004GL022119/full). They used a linear systems feedback model and concluded. Their conclusion: “results are contrary to a paradigm that involves long response times and positive feedback”.
Thanks, Thomas. I had a distant memory of that but I haven’t read it. I’ll have to get a copy and get back to you. I do note that there were two comments, here and here, that claimed that D&K were wrong. These analyses are interesting in themselves. Santer et al. argue that D&K ignored the deep ocean … I’m not sure how much difference that would make. Robock argues that the Santer conclusions are correct, and that there is no negative feedback shown.
Without reading the paper, I’d have to agree with the D&K conclusion that there is what they call “negative feedback” … with reservations. The effect of the complex thermoregulatory system is to maintain the temperature in a fairly narrow range (e.g. ± 0.3°C over the 20th century). As such, whether the disturbance is too much forcing or too little forcing, the system acts in a proportional “Le Chatelier” manner to move the system back towards the status quo ante.
If you wish to analyze that as a simple feedback with a single feedback factor tau, you’ve only done half a job. Oh, you’ll get an answer, but it needs to be placed in the Le Chatelier context to make any sense.
The answer you get from a Le Chatelier analysis is the strength of the restoring force. Note that the strength of this restoring force has nothing to do with the current forcing of the system. Let me give you an example.
On a cool day, the cumulus cloud field in the tropics develops later in the day, letting in more sunshine. And if the next day is warmer, the clouds respond to the increased warmth and moisture by forming earlier and cutting out some of the sunshine. This simple system has kept the tropical temperatures relatively stable for billions of years.
Now, the variations in the ground-level tropical sunshine is what I’ve called the “restoring force” above. It acts to keep the temperature within some narrow range. Note that on a cool day this cloud system turns up the heat, and on a warm day it turns down the heat … but the incoming top-of-atmosphere (TOA) solar forcing is the same in both cases. So clearly, the temperature control system acts independently of the total incoming TOA forcing. The clouds form based on temperature, not basedn on the strength of the sun, not based on the volcanic aerosols, not based on the CO2 levels. The clouds form later when the temperature is cooler, and they form earlier when it is warmer, and they pay no attention to the forcing levels.
This shows that temperature is NOT a function of the TOA forcings such as solar or volcanic forcings, neither a simple feedback formula nor otherwise. Instead, a powerful active system, with tropical cumulus as only one component, acts constantly to keep the global surface temperatures from varying more than the above-mentioned ± 0.3°C per century.
And that is the ultimate reason why it is wrong to conceive of what is going on as being a simple feedback of the input forcings of the type used by Douglass and Knox in their analysis … because ultimately, global surface temperature is NOT a function of TOA forcing, and the “feedback” concept implicitly and incorrectly assumes that temperature IS a function of TOA forcing, just one with feedback.
Best regards,
w.
Willis,
Interesting, but I do not find this convincing. My problem is that you do not seem to have investigated the question of whether the data are sufficient to see the effect you look for. The available solar energy data are clearly quite noisy. They are also likely to be affected by El Nino (I think there was one in 91-92) and La Nina events. So your failure to detect an appropriate signal due to the eruption could be, as you suppose, that the signal is not there or it could just be that the signal is lost in the noise. Without addressing the latter, your case for the former is unconvincing.
Thanks, Mike. That’s why I did the hemispheric analysis. If “the signal is lost in the noise” then we would not see a larger, quicker effect in the northern hemisphere observations than in the southern. But we do see that, in both the absorption and the albedo data, and exactly as theory suggests. This greatly increases the odds that it is a real signal.
w.
Willis,
“This greatly increases the odds that it is a real signal.”
Maybe by a factor of two. Seems to me like there is a 50-50 chance of having the noise respond in one hemisphere ahead of the other.
It is oh so easy to see what you want when you have autocorrelated noise. I tend to be skeptical whether it is what I want to see, or not.
More likely the eruptions cause El Nino.
I can’t wait for Willis to start including data from NASA’s OCO-2 satellite in his analysis.
Access to that data appears to be forbidden to all except the ‘science elite’.
http://wattsupwiththat.com/2009/04/06/mt-redoubt-eruptions-%e2%80%93-what-effect-if-any-on-the-summer-winter/
Joe D’ Aleo also has it spot on.
Excellent post Willis! How does the response from El Chichon, or other major eruptions, look when analysed using the same method?
NVM, I had skipped over your “data” note.
I am less titillated by smaller volcanic events (that I think the global weather pattern system recovers from within a season or two) than I am larger catastrophic events and their interactions with ENSO timing and memory mechanisms. It is now generally accepted that under normal conditions ENSO processes have memories related to the normal delayed oscillating La Nina to neutral processes that are somewhat randomly interrupted by El Nino events, especially if La Nina conditions hang around too long. The results of this overall process and its many different short and long term pattern variations are then echoed significantly throughout the globe through its many oceanic/atmospheric teleconnections. It is also generally accepted that they do NOT cancel out over long term time scales but instead of short, long, and very long patterns of variation. For further information the following webpage is a good place to gather educational understandings of ENSO processes http://faculty.washington.edu/kessler/.
Now add a catastrophic blow that pumps out copious amounts of sulfuric acid into the stratosphere along with near continuous pulses after the initial event. And place this catastrophic blow directly in the path of ENSO processes that depend on clear sky solar insolation to replenish copious amounts of energy lost during El Nino events. For me, that is where the money is in terms of discussing sudden and severe global cold periods that result in multiple years of flora and fauna death. And because ENSO processes are interacting with this disruptive catastrophic event, the resultant ENSO disruption echoes across the global weather pattern oceanic/atmospheric systems in a variety of ways and timing. These effects, once set in motion in terms of a less than normally recharged ocean, continue in spite of the eventual clearing of stratospheric veiling and may take decades to fully recover from.
Unfortunately, the last catastrophic event (1257) does not have the fine scale of sensor data to inform us as to the accuracy of its echoed effects on global climate processes. So at this point, it remains a conjecture, but one that is spurring a debate that is heating up http://www.pnas.org/content/111/28/10077.full.
Pam your line of reasoning is correct
Typo: “It is also generally accepted that they do NOT cancel out over long term time scales but instead [have] short, long, and very long patterns of variation.”
How does it feel to be in bed with Michael Mann of the Inappropriate Tree Rings?
The Warmunista phony paper you cite is is pure, unadulterated garbage.
In fact, the period 1250 to 1300 was one of the peaks of warmth during the MWP, as you’ve repeatedly been shown.
Volcanoes have no climatic effect, only on weather for much less than ten years. Even tropical VEI7 eruptions.
PS
The coldest 40 years of the LIA were during the Maunder Minimum, not the Dalton, even with the boost downward of Tambora.
Sturgis, you fail to understand the significant difference in calibration between Mann’s malpractice attempt at temperature reconstructions and the significant work done by the authors of the paper I linked to. You also fail to understand Earth’s teleconnected system and it’s lagged temperature response to catastrophic atmospheric disruptions. Under normal conditions, the world’s temperature producing systems do not turn on a dime when it comes to its cycles (the Arctic and Antarctic cycle being a good example) and tend towards having a fading memory with various responses on a regional basis of its regimes. Evidence is mounting that catastrophic atmospheric events can indeed cause a regime shift that stays around awhile.
Pamela,
I’m pretty sure I understand the climate system better than your presumed expertise, not that anyone knows much about it.
But, if I may take their names in vain, Willis, Dr. Brown, Bob Tisdale, Bill Illis, Tony and other regular commenters here can explain to you at least as well as I why a volcano in 1257 wasn’t responsible for the LIA, as you and Mann presume. In fact I’m closer to your position than any of those esteemed commenters, since I allow for WX effects for years, just not for climatic effects for centuries, as you so unjustifiably imagine.
But then you could be much smarter and better informed than all of us. It’s possible.
Tree rings are not thermometers, period. Unless you have an ax to grind, like Mann and yourself.
PS
It’s not just the tree ring circus, but the fact that in order to get rid of the Medieval Warm Period, Mann et al also sink to citing volcanoes to explain the LIA.
Nothing could be further from the truth. Both the LIA and MWP are natural fluctuations, just like those which preceded them in the Holocene and in all previous interglacials. And glacials for that matter, but deeper.
“randomly interrupted by El Nino events”
Not random but an amplified negative feedback to weak solar wind conditions, and volcanic aerosol cooling.
It is just as likely that the stratospheric conversion of SO2 to H2SO4 from El-Chichon and Pinatubo had a long term warming effect that we are still experiencing because the conversion process altered the water vapor content and or ozone levels within the Stratosphere in a cascaded manner which would alter the radiative properties in the stratosphere in a stepped function that is seen in the RSS and UAH datasets.
LT July 30, 2015 at 9:19 pm
Thanks, LT. If you gave us some data to support your hypothesis of long-term warming having a stratospheric origin we could discuss its likelihood … but as it stands, it’s just another of the thousands of hypotheses about climate without factual support.
As such, I fear we cannot tell whether it is “just as likely” as anything else we might hypothesize, or not.
w.
Oh Willis your such a charmer,
http://www.noaanews.noaa.gov/stories2010/20100128_watervapor.html
LT July 30, 2015 at 9:19 pm says:
“…It is just as likely that the stratospheric conversion of SO2 to H2SO4 from El-Chichon and Pinatubo had a long term warming effect that we are still experiencing because the conversion process altered the water vapor content and or ozone levels within the Stratosphere in a cascaded manner which would alter the radiative properties in the stratosphere in a stepped function that is seen in the RSS and UAH datasets.”
Nonsense. It has nothing to do with conversion of SO2 to H2SO4. There is no such thing as a stepped function in the satellite data. What is there is a an ENSO wave train that you obviously cannot recognize in your poor quality graph. It precedes the super El Nino and comprises five El Nino peaks with La Nina valleys in between. Look at figure 15 in my book and follow up the explanation.
Arno, there is most certainly a stepped function that occurred in the stratospheric temperature record in which the stratosphere cooled in a steeped function after the effects of El-Chichon and Pinatubo that altered the radiative properties of the stratosphere.
http://wattsupwiththat.com/2015/07/29/why-volcanoes-dont-matter-much/#comment-1996836
Unless your book can explain why the stratosphere dropped from a minimum of 212.5K to 212K after El-Chichon and remained at or above that temperature until after the effects of Pinatubo in which it dropped to 211.5 K and has remained at roughly that temperature since 1995.
Interesting Willis. There are other areas where this hypothesis might be explored such as the supposed climate disruption caused by impact events. I’ve personally thought that so far the effect has been exaggerated on mostly an almost anecdotal basis…”everybody knows” the great dinosaur extinction was “caused” by the climate changes associated with an asteroid impact.
This student has studied the entire Article by Willis and all the comments that followed. I conclude that volcanoes do have a significant impact in the hemisphere in which they are located but only for around a year. Then the pattern and trend of temperatures continues where it left off. I have long felt that forcing is a misnomer.
But that would not make sense in an oceanic/teleconnected system that when disrupted in any one of the major connections, would tend to echo that disruption, and if a major disruption, would put the system out of balance for quite some time and like ripples in a pond, continue to echo the memory of that event. It is also possible that the disrupted system could lead to a rebound greater than its initial state.
Dr. Spencer’s Conclusions. Again correct. We have the data.
The eruption of Mt. Pinatubo in the Philippines on June 15, 1991 provided a natural test of the climate system to radiative forcing by producing substantial cooling of global average temperatures over a period of 1 to 2 years