Guest Post by Willis Eschenbach
In the leaked version of the upcoming United Nations Intergovernmental Panel on Climate Change (UN IPCC) Fifth Assessment Report (AR5) Chapter 1, we find the following claims regarding volcanoes.
The forcing from stratospheric volcanic aerosols can have a large impact on the climate for some years after volcanic eruptions. Several small eruptions have caused an RF for the years 2008−2011 of −0.10 [–0.13 to –0.07] W m–2, approximately double the 1999−2002 volcanic aerosol RF.
and
The observed reduction in warming trend over the period 1998–2012 as compared to the period 1951–2012, is due in roughly equal measure to a cooling contribution from internal variability and a reduced 2 trend in radiative forcing (medium confidence). The reduced trend in radiative forcing is primarily due 3 to volcanic eruptions and the downward phase of the current solar cycle.
Now, before I discuss these claims about volcanoes, let me remind folks that regarding the climate, I’m neither a skeptic nor am I a warmist.
I am a climate heretic. I say that the current climate paradigm, that forcing determines temperature, is incorrect. I hold that changes in forcing only marginally and briefly affect the temperature. Instead, I say that a host of emergent thermostatic phenomena act
quickly to cool the planet when it is too warm, and to warm it when it is too cool.
One of the corollaries of this position is that the effects of volcanic eruptions on global climate will be very, very small. Although I’ve demonstrated this before, Anthony recently pointed me to an updated volcanic forcing database, by Sato et al. Figure 1 shows the amount of forcing from the historical volcanoes.
Figure 1. Monthly changes in radiative forcing (downwelling radiation) resulting from historical volcanic eruptions. The two large recent spikes are from El Chichon (1983) and Pinatubo (1992) eruptions. You can see the average forcing of -0.1 W/m2 from 2008-2011 mentioned by the IPCC above. These are the equilibrium forcings Fe, and not the instantaneous forcing Fi.
Note that the forcings are negative, because the eruptions inject reflective aerosols into the stratosphere. These aerosols reflect the sunlight, and the forcing is reduced. So the question is … do these fairly large known volcanic forcings actually have any effect on the global surface air temperature, and if so how much?
To answer the question, we can use linear regression to calculate the actual effect of the changes in forcing on the temperature. Figure 2 shows the HadCRUT4 monthly global surface average air temperature.
Figure 2. Monthly surface air temperatures anomalies, from the HadCRUT4 dataset. The purple line shows a centered Gaussian average with a full width at half maximum (FWHM) of 8 years.
One problem with doing this particular linear regression is that the volcanic forcing is approximately trendless, while the temperature has risen overall. We are interested in the short-term (within four years or so) changes in temperature due to the volcanoes. So what we can do to get rid of the long-term trend is to only consider the temperature variations around the average for that historical time. To do that, we subtract the Gaussian average from the actual data, leaving what are called the “residuals”:
Figure 3. Residual anomalies, after subtracting out the centered 8-year FWHM gaussian average.
As you can see, these residuals still contain all of the short-term variations, including whatever the volcanoes might or might not have done to the temperature. And as you can also see, there is little sign of the claimed cooling from the eruptions. There is certainly no obvious sign of even the largest eruptions. To verify that, here is the same temperature data overlaid on the volcanic forcing. Note the different scales on the two sides.
Figure 4. Volcanic forcing (red), with the HadCRUT4 temperature residual overlaid.
While some volcanoes line up with temperature changes, some show increases after the eruptions. In addition, the largest eruptions don’t seem correlated with proportionately large drops in temperatures.
So now we can start looking at how much the volcanic forcing is actually affecting the temperature. The raw linear regression yields the following results.
R^2 = 0.01 (a measure from zero to one of how much effect the volcanoes have on temperature) "p" value of R^2 = 0.03 (a measure from zero to one how likely it is that the results occurred by chance) (adjusted for autocorrelation). Trend = 0.04°C per W/m2, OR 0.13°C per doubling of CO2 (how much the temperature varies with the volcanic forcing) "p" value of the TREND = 0.02 (a measure from zero to one how likely it is that the results occurred by chance) (adjusted for autocorrelation).
So … what does that mean? Well, it’s a most interesting and unusual result. It strongly confirms a very tiny effect. I don’t encounter that very often in climate science. It simultaneously says that yes, volcanoes do affect the temperature … and yet, the effect is vanishingly small—only about a tenth of a degree per doubling of CO2.
Can we improve on that result? Yes, although not a whole lot. As our estimate improves, we’d expect a better R^2 and a larger trend. To do this, we note that we wouldn’t expect to find an instantaneous effect from the eruptions. It takes time for the land and ocean to heat and cool. So we’d expect a lagged effect. To investigate that, we can calculate the R^2 for a variety of time lags. I usually include negative lags as well to make sure I’m looking at a real phenomenon. Here’s the result:
Figure 5. Analysis of the effects of lagging the results of the volcanic forcing.
That’s a lovely result, sharply peaked. It shows that as expected, after a volcano, it takes about seven-eight months for the maximum effects to be felt.
Including the lag, of course, gives us new results for the linear regress, viz:
R^2 = 0.03 [previously 0.01] "p" value of R^2 = 0.02 (adjusted for autocorrelation) [previously 0.03] Trend = 0.05°C per W/m2, OR 0.18 ± 0.02°C per doubling of CO2 [previously 0.13°C/doubling] "p" value of the Trend = 0.001 (adjusted for autocorrelation). [previously 0.02]
As expected, both the R^2 and the trend have increased. In addition the p-values have improved, particularly for the trend. At the end of the day, what we have is a calculated climate sensitivity (change in temperature with forcing) which is only about two-tenths of a degree per doubling of CO2.
Here are the conclusions that I can draw from this analysis.
1) The effect of volcanic eruptions is far smaller than generally assumed. Even the largest volcanoes make only a small difference in the temperature. This agrees with my eight previous analyses (see list in the Notes). For those who have questions about this current analysis, let me suggest that you read through all of my previous analyses, as this is far from my only evidence that volcanoes have very little effect on temperature.
2) As Figure 5 shows, the delay in the effects of the temperature is on the order of seven or eight months from the eruption. This is verified by a complete lagged analysis (see the Notes below). That analysis also gives the same value for the climate sensitivity, about two tenths of a degree per doubling.
3) However, this is not the whole story. The reason that the temperature change after an eruption is so small is that the effect is quickly neutralized by the homeostatic nature of the climate.
Finally, to return to the question of the IPCC Fifth Assessment Report, it says:
There is very high confidence that models reproduce the more rapid warming in the second half of the 20th century, and the cooling immediately following large volcanic eruptions.
Since there is almost no cooling that follows large volcanic eruptions … whatever the models are doing, they’re doing it wrong. You can clearly see the volcanic eruptions in the model results … but you can’t see them at all in the actual data.
The amazing thing to me is that this urban legend about volcanoes having some big effect on the global average temperature is so hard to kill. I’ve analyzed it from a host of directions, and I can’t find any substance there at all … but it is widely believed.
I ascribe this to an oddity of the climate control system … it’s invisible. For example, I’ve shown that the time of onset of tropical clouds has a huge effect on incoming solar radiation, with a change of about ten minutes in onset time being enough to counteract a doubling of CO2. But no one would ever notice such a small change.
So we can see the cooling effect of the volcanoes where it is occurring … but what we can’t see is the response of the rest of the climate system to that cooling. And so, the myth of the volcanic fingerprints stays alive, despite lots of evidence that while they have large local effects, their global effect is trivially small.
Best to all,
w.
PS—The IPCC claims that the explanation for the “pause” in warming is half due to “natural variations”, a quarter is solar, and a quarter is from volcanoes. Here’s the truly bizarre part. In the last couple decades, using round numbers, the IPCC predicted about 0.4°C of warming … which hasn’t happened. So if a quarter of that (0.1°C) is volcanoes, and the recent volcanic forcing is (by their own numbers) about 0.1 W/m2, they’re saying that the climate sensitivity is 3.7° per doubling of CO2.
Of course, if that were the case we’d have seen a drop of about 3°C from Pinatubo … and I fear that I don’t see that in the records.
They just throw out these claims … but they don’t run the numbers, and they don’t think them through to the end.
Notes and Data
For the value of the forcing, I have not used the instantaneous value of the volcanic forcing, which is called “Fi“. Instead, I’ve used the effective forcing “Fe“, which is the value of the forcing after the system has completely adjusted to the changes. As you might expect, Fi is larger than Fe. See the spreadsheet containing the data for the details.
As a result, what I have calculated here is NOT the transient climate response (TCR). It is the equilibrium climate sensitivity (ECS).
For confirmation, the same result is obtained by first using the instantaneous forcing Fi to calculate the TCR, and then using the TCR to calculate the ECS.
Further confirmation comes from doing a full interative lagged analysis (not shown), using the formula for a lagged linear relationship, viz:
T2 = T1 + lambda (F2 – F1) (1 – exp(-1/tau)) + exp(-1/tau) (T1 – T0)
where T is temperature, F is forcing, lambda is the proportionality coefficient, and tau is the time constant.
That analysis gives the same result for the trend, 0.18°C/doubling of CO2. The time constant tau was also quite similar, with the best fit at 6.4 months lag between forcing and response.
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In this case it’s the Sato paper, which provides a dataset of optical thicknesses “tau”, and says:
The relation between the optical thickness and the forcings are roughly (See “Efficacy …” below):
instantaneous forcing Fi (W/m2) = -27 τ
adjusted forcing Fa (W/m2) = -25 τ
SST-fixed forcing Fs (W/m2) = -26 τ
effective forcing Fe (W/m2) = -23 τ
And “Efficacy” refers to
Hansen, J., M. Sato, R. Ruedy, L. Nazarenko, A. Lacis, G.A. Schmidt, G. Russell, et al. 2005. Efficacy of climate forcings. J. Geophys. Res., 110, D18104, doi:10.1029/2005/JD005776.
Forcing Data
For details on the volcanic forcings used, see the Sato paper, which provides a dataset of optical thicknesses “tau”, and says:
The relation between the optical thickness and the forcings are roughly (See “Efficacy …” below):
instantaneous forcing Fi (W/m2) = -27 τ
adjusted forcing Fa (W/m2) = -25 τ
SST-fixed forcing Fs (W/m2) = -26 τ
effective forcing Fe (W/m2) = -23 τ
And “Efficacy” refers to
Hansen, J., M. Sato, R. Ruedy, L. Nazarenko, A. Lacis, G.A. Schmidt, G. Russell, et al. 2005. Efficacy of climate forcings. J. Geophys. Res., 110, D18104, doi:10.1029/2005/JD005776.
(Again, remember I’m using their methods, but I’m not claiming that their methods are correct.)
Future Analyses
My next scheme is that I want to gin up some kind of prototype governing system that mimics what it seems the climate system is doing. The issue is that to keep a lagged system on course, you need to have “overshoot”. This means that when the temperature goes below average, it then goes above average, and then finally returns to the prior value. Will I ever do the analysis? Depends on whether something shinier shows up before I get to it … I would love to have about a dozen bright enthusiastic graduate students to hand out this kind of analysis to.
I also want to repeat my analysis using “stacking” of the volcanoes, but using this new data, along with some mathematical method to choose the starting points for the stacking … which turns out to be a bit more difficult than I expected.
Previous posts on the effects of the volcano.
Prediction is hard, especially of the future.
Pinatubo and the Albedo Thermostat
Dronning Maud Meets the Little Ice Age
New Data, Old Claims about Volcanoes
Volcanoes: Active, Inactive and Interactive
Stacked Volcanoes Falsify Models
jai mitchell says:… If the energy going into that sphere containing the whole earth and all of it’s functions is more than the energy leaving that sphere then the planet is warming.
To add to what Willis said, rain does indeed help transport heat out of the earth. Sunlight primarily heats the oceans, since they account for 3/4 of its surface. One of the primary ways for that heat to get back into outer space is through evaporation, which transports heat as water vapor into the upper atmosphere, where it forms clouds. When that water vapor turns to rain, that heat is released into the atmosphere, where it can be radiated away into space. So even for the entire earth system, rain is part of the cooling mechanism whereby incoming heat is gotten rid of. The fact that it also cools the surface is simply an additional benefit. Without it, more heat would remain trapped in both the oceans and the atmosphere for longer periods of time. So rain does indeed cool the system.
richard verney. says:
September 22, 2013 at 9:42 pm
Thanks for that additional input regarding maximum sea surface temperatures.
I wasn’t aware of the extent to which 305K can be exceeded locally.
Having considered the matter further overnight I still don’t see how emergent cloudiness can provide any sort of cap on achievable temperatures because a cap has to be exceeded before the clouds form (at least the types of clouds proposed).
It is true that once the clouds form they do provide a negative feedback but they don’t form at all unless the cap is exceeded.
It has to be surface pressure because the weight of the atmosphere pressing down sets the amount of energy required to break the bonds between water molecules.
If that breaking of bonds didn’t occur first the clouds would not form.
richard verney. says:
According to Hadcrut4, there was a drop of some 0.3degC (or even more) between the start of 1944 and the end of that year. Was this due to the 2 nuclear bombs dropped on Japan?
HadCRUT=hadSST+CRUtem
There was a 0.5 deg C “adjustment” made to the SST record in 1945 which I refer to as Folland’s folly in honour of its founder.
Since you obviously are not aware of it I suggest you read my article of last year:
judithcurry.com/2012/03/15/on-the-adjustments-to-the-hadsst3-data-set-2
As for the bombs it’s a reasonable question to ask but is quickly dismissed. I have specifically tried to find some evidence of an effect , more likely from the much larger aerial explosion tests or the french test at Bikini Island that unintentionally reached the ocean surface , and found none.
Dear Willis,
Yo will recognise that I have been a critic of your signal processing methods. having gained a PhD in a world class DSP lab and used it for 30 years (on and off). If you want some help I am happy to advise you.
Richard Saumarez
Having looked at Willis’s original Thermostat Hypothesis again I see that he includes vapour pressure as a relevant variable but not absolute pressure.
I think that is a significant omission because absolute atmospheric pressure for an entire atmosphere sets the average strength of the bond between water molecules on any given planet and thus the basic minimum amount of energy required to break those bonds (latent heat of vaporisation).
Absolute surface pressure over a dry surface also sets the average amount of energy required to lift a molecule of any particular weight off the surface to form an atmosphere.
This is relevant to Willis’s hypothesis and to this thread because it sets the basic energy requirement from which the thermostatic process starts and the baseline to which it inevitably returns.
The thermostat deals not only with water in vapour form but also any molecules that are caused to lift off the surface in the first place. Hence the relevance to the gaseous and particulate products of volcanic eruptions.
Without something to set that basic energy requirement there is no baseline to which any thermostatic mechanism can return.
It is indeed all about absolute pressure and that is a function of atmospheric mass and not composition.
That is an elephant in this particular room.
substracting the gaussian average is far from neutral, and the demonstration would be much more effective showing harcut data,the several things appear clear to me, you can “see something” in recent time, but you can’t see much in the oldest period but to me it means that uncertainties of temperature may be very underestimated for this time.
Hard to apply the same method t and he same filters on such an “object”.
Willis.
A couple of thoughts on the diurnal tropical temperature charts you showed, many moons ago, whilst explaining your tropical cumulus governor theory. The graphs showed a cooling in the afternoon, and then a slight uptick in temperature before sunset, which was unexplained. A couple of possibilities for you:
The afternoon has decreasing convective activity, and so less cooler air from the upper troposphere is being brought to the surface. Thus the lower atmosphere is able to recover some warmth from the warm land surface, without any tropospheric cooling.
The afternoon heralds the end of the daytime sea breeze. If these temperatures were from coastal recording stations, they would change in the afternoon from the cooler sea breeze, to the warmer land breeze. Again, you might get a late afternoon recovery in temperature.
Just a thought.
richard verney. says:
September 22, 2013 at 8:20 pm
“First, it should be noted that often temperature trends pre date the vocano eruption, by which I mean there is often a short term downward temperature trend occurring shortly before a volcano eruption and this masks the effect, if any, of the eruption since it is not known whether that short term trend would or would not have continued but for the eruption. ”
===
I made the same point just a few posts above yours, 20m earlier.
I also a whole series of graphs and comments I did on this that no one seems to read or comment on.
http://climategrog.wordpress.com/?attachment_id=278
http://climategrog.wordpress.com/?attachment_id=310
http://climategrog.wordpress.com/?attachment_id=312
http://climategrog.wordpress.com/?attachment_id=285
These specifically show a marked difference in the response of the tropics and extra tropical regions.
The method is not statistically rigorous but is prima facea evidence of the kind of non-linear feedback response Willis is suggesting. It also shows that degree.day integral is maintained in the tropics but not outside, where the temperature does recover but there is loss of degree days.
I suggested Willis repeat the analysis he presented here on extra-tropical data. Oddly he has not even commented on the suggestion.
There clearly is a detectable response in ex-tropics, looking for it directly may allow a better evaluation of its magnitude and significance.
My impression was that is was land based rather than sea based, hence more marked in NH. Some zonal mixing due to ocean gyres probably allows the very stable tropics to diminish the impact on extra-tropical zones.
Stephen Wilde:
Thankyou for your post addressed to me at September 22, 2013 at 3:02 pm.
http://wattsupwiththat.com/2013/09/22/the-eruption-over-the-ipcc-ar5/#comment-1423915
Firstly, to ensure that everyone is clear about this, we are discussing the Ramanathan&Collins (R&C) effect and not my work.
You ask me
OK. My first answer is that I don’t know. I merely reported the findings of R&C. So, I will mention the reaction in the literature and then state some suggestions I make as to why the effect is not observed everywhere.
The R&C paper initially received much opposition in the literature. The main question was whether the maximum tropical sea surface temperature actually existed. R&C ‘stood their ground’ and others reported the same result so opposition to the R&C Effect withdrew.
But the R&C effect is observed in the tropical ocean and not everywhere. So you ask the very reasonable question (which was raised in the literature decades ago) as to WHY doesn’t it happen everywhere.
I suggest – and please note this is merely opinion – the difference is probably a combination of geography and atmospheric circulation patterns. I explain this suggestion as follows.
The R&C Effect results in increased evapouration from sea surface and this has two direct effects; viz.
(a) the ocean surface is cooled by extraction of heat of evapouration
and
(b) the air above the cooled ocean surface gains humidity (I,e. water).
But. both theoretical calculation and – as you say – observations elsewhere indicate the direct cooling of the sea surface is not sufficient to keep the surface temperature below 305K. This is why R&C required an additional effect to explain the maximum temperature limit.
The R&C Effect overcomes the difficulty posed by the inability of evapouration alone to establish the maximum sea surface temperature observed in the tropics. Other observations indicate that in other regions the R&C Effect either does not exist or is not sufficient to keep sea surface temperature below 305K.
The high temperatures in the Red Sea and the Gulf of Mexico may be because the sea is surrounded by land, and cirrus shielding of the land will not cool the water. Cirrus forms at altitude (typically higher than 20,000 feet) and winds may carry the moist air over land before it rises to an altitude where it can form cirrus.
In other places the R&C Effect may be reduced by winds, too. When the cooling by cirrus shielding occurs adjacent to the region of highest temperature then the shielded adjacent region will cool. But the maximum sea surface temperature may rise above the limit of 305K because it is not shielded from solar radiation by the cirrus which forms nearby. In this case, total heating of sea surface is reduced by the cirrus formation, but the limit to maximum sea surface temperature is not imposed in the hottest region.
Nearly a quarter of a century has passed since the R&C Effect was discovered. In that time US$billions have been spent on climate modelling. Nothing has been spent on field work to investigate the R&C Effect.
Richard
I couldn’t find any direct evidence of time of year of a volcanic eruption influencing the lag to minimum temperature, only the indirect evidence that major volcanic eruptions reduce monsoon intensity and in particular reduce rainfall in Central and other parts of Asia.
http://onlinelibrary.wiley.com/doi/10.1029/2010GL044843/abstract
https://www.geo.umass.edu/climate/papers2/Fan_etalJClimate09.pdf
As water vapour (latent heat) in the monsoon is a major mode of heat transport poleward, cooling the climate, the reduced monsoon is a season specific negative feedback to volcanic aerosol cooling. Although its hard to say how this will pan out for surface temperatures, as reduced monsoonal flow will increase the length of the pre-monsoon season. Always the hottest time of year in monsoonal zones. A negative feedback to a negative feedback.
Willis: There is a flaw in your post: You are looking for a correlation between radiative forcing (W/m2 or POWER per unit AREA) and temperature, which is proportional to mean kinetic ENERGY. The larger the object, the more kinetic energy it contains; so temperature is really ENERGY per unit VOLUME. Dimensional analysis immediately tells you that any relationship between radiative forcing and temperature needs to take into account additional factors.
To convert power into energy, one multiplies by time. A radiative forcing by itself can’t cause any temperature change, but a radiation forcing applied for several months or years can change temperature. You need to INTEGRATE the radiative forcing over time in order to have any hope of understanding how much the temperature will change. Looking for a lagged relationship between radiative forcing and temperature isn’t a very good substitute for integrating the forcing over time (as your poor R2 shows).
You also need to take into account the volume of material whose temperature is being changed by a forcing. We know that every summer and winter, seasonal temperature change in the ocean can be detected down to about 100 m, so several months of seasonal radiative forcing is able to warm an average of roughly the top 50 m of the ocean – the mixed layer. So the radiative forcing from volcanos passing through every m^2 of the ocean’s surface also effects the temperature of about 50 m^3 of ocean.
With the correct factors for converting area to volume and power to energy, you might have some chance of performing a useful calculation. This complicated subject has been discussed for Pinatubo at the Blackboard by Paul_K and in references he cites. He arrives at a climate sensitivity of about 1.4 degC for doubling CO2. It appears as if he might be trying to publish this result. http://rankexploits.com/musings/2012/pinatubo-climate-sensitivity-and-two-dogs-that-didnt-bark-in-the-night/
To get started, how long will it take a radiative forcing of 1 W/m^2 to warm the 50 m^3 of mixed layer underneath by 1 degC? The heat capacity of water is 4.17 J/cm^3/degC or 4.18*10^6 J/m^3/degC. With 50 m^3 of mixed layer below every m^2 of ocean surface, 2.09*10^8 J of energy needs to enter every m^2 of ocean surface to warm 1 degC. It therefore takes a radiative forcing of 1 W/m^2 or 1 J/s for every m^2 of surface 6.6 years for the ocean to warm 1 degC!
The real situation is far more complicated than this: Ocean covers only 70% of the surface, but the air and land have some heat capacity too. And a little energy escapes into the deeper ocean over a period of a few years. Even worse, as the ocean warms, it will emit more energy through radiative cooling. The Planck feedback (the increase in “blackbody” radiative cooling with temperature) is -3.2 W/m^2/degC. So we can actually can warm the ocean only about 0.3 degC before the increase in radiative cooling completely negates a 1 W/m^2 of radiative forcing! And half of the forcing has been negated once the temperature has risen 0.15 degC during the first year. So the correct answer is that a forcing of 1 W/m^2 can never raise the temperature 1 degC!
These calculations suggest that it is absurd to expect a radiative forcing of a few W/m^2 – which is mostly gone in two years – to produce more than a fraction of a degC of cooling. And Planck feedback begins to counteract this cooling as soon as begins. With Figure 3 showing noisy spikes in global temperature of about 0.3 degC, it is going to be hard to convincingly see the cooling from every big volcanic eruption. BEST averaged the results from about 9 large eruptions to reduce noise by a factor of three and the cooling from volcanos became obvious. Paul_K reduced noise by analyzing the change in temperature over 18+ individual months.
So it makes complete sense that you can’t find unambiguous evidence for cooling by inspecting the record by eye, but others can find evidence by performing more sophisticated analyses. ALARMISTS have increased your expectations for volcanic cooling far past what is expected from my “back of the envelop” calculation. For example, those who attribute the “year without a summer” in 1816 in New England to the 1815 eruption of Mt. Tambora are confusing unusually cold WEATHER in New England with transient global cooling of perhaps 1 degC. New England is not normally within 1 degC from getting snow in August, so Tambora didn’t cause the year without a summer, it simply enhanced it a little.
In my view, there is a simpler way to show the absurdity of AR5 speculation.
According to Wikipedia, there were 18 major volcanic eruptions in the 21st century, none over VEI 4.
In the period 1991-2000 there were two eruptions of VEI 5 or more, Mt. Hudson VEI 5+ and Pinatubo VEI 6, both in 1991. (plus a number of lesser eruptions).
Now remember that if the Volcanic Explosively Index increases by 1, the volume of erupted material is increased by a factor of 10. Which means that Pinatubo alone ejected over 20-times the material of *all* the eruptions in the 21st century.
If the 18 21st century eruptions caused the “hiatus” in global warming – why was the climate warming in the 1990s, despite more then 20-times larger volume of volcanic emissions?
richard verney. says: “To properly evaluate these claims, I consider that better resolution is required and it would be useful to set out the temperatures on a monthly basis for the 7 years before and after each eruption so one can see what is going on and whether the eruption adds anything significant to what ever short lived trends were already occurring in and around the time of the eruption.”
Almost exactly what I did. Try looking at the links.
Frank: ” You need to INTEGRATE the radiative forcing over time in order to have any hope of understanding how much the temperature will change.”
A valid point.
What Willis writes in Notes and Data appendix includes an iterative formula which is in fact a exponentially weighted integral. I would have thought that doing a similar integral on the forcing would be the correct way to do the simple regression. I suspect this is what the difference between his Fi and Fe data is , though this is not stated explicitly.
milodonharlani (September 22, 2013 at 10:14 pm) “US wheat yield (& acreage planted) fell after Pinatubo from 39.5 bushels per acre to 34.3, as above.”
Please post a link that shows wheat yield in the US falling from 39.5 bu/acre to 34.3 bu/acre.
The only document you have posted with yield data is http://www.fas.usda.gov/grain/circular/2010/05-10/grainfull05-10.pdf which shows yield fluctuating between 2.5 and 2.6 for the years in question. The particular drop from 2.6 to 2.5 has no significance since many years show similar fluctuations (or larger).http://www.fas.usda.gov/grain/circular/2010/05-10/grainfull05-10.pdf
Richard: Nearly a quarter of a century has passed since the R&C Effect was discovered. In that time US$billions have been spent on climate modelling. Nothing has been spent on field work to investigate the R&C Effect.
Yes, it seems that before 1990 there was a much broader range of ‘normal’ scientific investigation. Since about that point the zealots took over, trying to ‘save the planet’ by distorting science. Defunding, gatekeeping and nobel 😉 cause corruption seem to have replaced objectivity.
That process is starting to reverse but it’s going to take years.
“I say that the current climate paradigm, that forcing determines temperature, is incorrect. I hold that changes in forcing only marginally and briefly affect the temperature. Instead, I say that a host of emergent thermostatic phenomena act
quickly to cool the planet when it is too warm, and to warm it when it is too cool.”
Willis why use such convoluted and hard to understand language – Why not just say “I believe there is strong negative feedback in the climate system” because that’s what your comment boils down to.
Frank: “These calculations suggest that it is absurd to expect a radiative forcing of a few W/m^2 – which is mostly gone in two years – to produce more than a fraction of a degC of cooling.”
My estimation shows 0.2 degree.years in extra-tropical SH , that mostly happened between 6 and 18mths. ( similar in hadSST3 and hadCRUT4)
http://climategrog.wordpress.com/?attachment_id=285
NH hadSST3 shows about 0.4 degree.years withi similar form.
http://climategrog.wordpress.com/?attachment_id=310
That means as an average it was 0.2 (0.4) K cooler for a year, or 0.1 (0.2) K cooler for two years. then back to previous conditions. The tropics show no such loss.
michael hammer says:
Willis why use such convoluted and hard to understand language – Why not just say “I believe there is strong negative feedback in the climate system” because that’s what your comment boils down to.
===
Willis is trying to refute the idea that tropical storms and cloud cover can be treated as a simple linear negative feedback globally. This is how climate models deal with it as well as being based on guestimated “parameters” not a modelled response based in science.
Thus he dislikes use of the word feedback at all.
Emergent phenomena are _positive feedbacks_ at work. They are ultimately constrained by more powerful negative feedbacks that prevent the system from being unstable. Since the overall effect is a negative feedback on temperature, the internal +ve f/b makes the storms into a NON-LINEAR negative feedback.
It is the key word non-linear that makes the overshoot required to preserve the degree.day integral. A linear neg. f/b will not do this.
This broader understanding of feedbacks seems to be outside Willis’ way of looking at things so he tends to reject any description using the word feedback, which he associates with the IPCC linear feedback which is inadequate and denies the possible role of tropical storms he is proposing.
The self-sustaining nature of tropical storms is due to internal +ve feebacks. I think it would be useful if Willis saw that feedback based descriptions are the proof of what he is saying , not the opposite.
RC Saumarez says: “…If you want some help I am happy to advise you.”
Willis has been specific enough here for you to be able to critique his method. If you have actual suggestions then I’m sure he’d like to hear them but I’ve now seen a couple of posts of yours implying criticism of his method in a general sense without actually being specific about anything.
michael hammer:
Your entire post at September 23, 2013 at 2:33 am says
No! Your misunderstanding has induced you to misrepresent Willis, so I write to answer in hope of reducing the ear-bashing which your misrepresentation deserves.
There is no definition of emergent effects such as the Eschenbach Effect, the R&C Effect, and any similar effects which may exist. So, for convenience, I will call them ‘Reversal Effects’.
A negative feedback reduces the magnitude of an effect.
A governor limits the magnitude of an effect.
A Reversal Effect arises in response to a direct effect, and it combines with the direct effect such that the combination has opposite sign to the direct effect (i.e. when the direct effect is +ve the combination is –ve).
Richard
I think your “reversal effect” is so vague as to be unhelpful. “Governor” in the sense you define necessarily uses a negative feedback.
A “governor” will not maintain the degree.day integral as appears to happen in the tropics and so is also inadequate.
Someone in another of Willis’ threads suggested this was closer to an industrial PID controller. I think that description is more suitable.
In any case there is a need for precise well defined terms here which is why I favour feedback descriptions. There is a whole branch of engineering that knows how these work and describe things in precise mathematical terms.
proportional-integral-derivative controller
http://en.wikipedia.org/wiki/PID_controller
milodonharlani, never mind. I found your numbers here http://usda01.library.cornell.edu/usda/ers/WHS//1990s/1994/WHS-11-15-1994.pdf
In appendix table 1 it shows yield decreasing from 39.5 in 1990/91 to 34.3 in 1991/92. But it also shows an increase from 32.7 in 1989/90 to 39.5 in 1990/91. If the drop was caused by the volcano, what caused the rise, an anti-volcano?
Clearly you have cherry-picked that fluctuation. A primary cause of the fluctuations is weather, specifically drought or too much rain. It is obvious from the data that those factors vary without volcanoes. The variation you attribute to the volcano is well within the range of variation for previous and subsequent years.
richardscourtney says:
September 23, 2013 at 1:47 am
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Richard
Thank you for your reply which was a response to a request raised by me, not Stephen. i was aware that the point that I raised related to the R&C paper, not to your own research, but you are one of the commentators whose comments I always seek to read and consider (because of your informed research led views) and hence the reason why I addressed my point to you.
I accept the points that you raise. I would add to those points ocean overturning and ocean currents to the mix. These oceanic currents effectively take away from the tropical ocean much heat that is/would be generated by the solar irradiance received by the tropical oceans as the heat is being created and effectively distributing this ‘excess’ ‘energy’/’heat’ to other regions of the globe, particularly polewards. I suspect that but for these currents, one would see higher temperatures in many parts of the tropical oceans.
Personally, I consider that we have a slightly biased view of ocean temperatures due to the sampling by ARGO buoys (and I am sceptical as to whether the free floating nature adds to the bias since these buoys float with currents/density profiles which in themselves are heat dependent/correlated) . If I recall Willis’ post correctly (appologies to Willis if I have got this wrong through being too lazy to check it out), he was arguing that for practical purposes the tropical ocean temperature is capped at 30degC. I recall pointing out to him that the process he described did not cap ocean temperature at that figure and that was clear from his own data which showed some ARGO buoys reporting 32degC. My recollection was that Willis took the view that the number of ARGO buoys reporting 32degC was very small (which is so) and even took a similar approach with the buoys reporting 31degC.
I accept that relatively few ARGO buoys report temperatures of 32degC, and whilst Willis and I may disagree as to what consitutes a ‘few’ for the purposes of considering the number that report 31degC, the small numbers are a consequence of the chosen distribution of ARGO, and the fact that this chosen distribution excludes ARGO from sampling some of the warmest oceans on the planet..
By way of aside, in my view, the most important element of understanding the climate and how it is driven is the full and proper understanding of the oceans, their temperature profiles, oceanic currents, the interaction of the oceans with the atmosphere immediately above the oceans, the manner in which ocean heat content is distributed around the globe including how this influences the jet streams etc. In this I would include the detailed interaction of DWLWIR in the immediate atmosphere above the oceans (which is not only high in water vapour content, but also contains water droplets/a fine mist of windswept spray and spume) and not simply its absorption in the first millimetre (bearing in mind that about 60% of all LWIR is fully absorbed in just a few microns and probably less than 10% makes it way to past 10 microns – given that DWLWIR is omni-directional even the absorbtion could be even greater in the first few microns). i guess that one should not overlook the fact that it is only oceanic temperature measurements which inform upon the energy budget given that land based temperature data sets are not measuring energy and therefore can inform little as to whether there is any ongoing change to the energy budget of planet Earth. Planet Earth is a water world, and understanding the significance of that is, in my opinion, the key to understanding the planet’s climate and how it is driven. personally,I do not consider that enough emphasis has been placed on this, but this may change given the ‘warmists’ mantra that energy is being sequested and hiding in the deep oceans. This claim will inevitably lead to greater investigation and scrutiny of the oceans and the role they play in influencing climate.