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
HadCRUT4 monthly global surface average air temperature look just like this Historical Total Solar Irradiance Chart.
http://lasp.colorado.edu/lisird/tsi/historical_tsi.html
Picture of chart Hansen did in 1988, Solar Irradiance and N hem temperatures.
https://twitter.com/NJSnowFan/status/380225825263456256/photo/1
Biggest puzzle piece of Global temperature variations I feel.
The SUN
Latitude says:
September 22, 2013 at 7:27 pm
Wheat yield went down, production went down, supply went down, so yes, as you’d expect, prices for the commodity went up. Being a wheat rancher, I was perforce also a commodity trader then.
In 1992, farmers, brokers & traders blamed the ash & SO2 from Pinatubo at least in part for abnormal WX patterns & cool spells in the Midwest & elsewhere in the US, including the famous Father’s Day Freeze. A mild winter & warm, early spring preceded a cool, wet summer & cold, early fall in 1992. Corn was slow to dry that fall & test weights were low, but national average yield set a record, unlike wheat.
Also, California suffered heavy rains during 1991-93.
http://www.nytimes.com/1992/02/13/us/new-california-storm-brings-worst-floods-in-decades.html
http://ks.water.usgs.gov/pubs/reports/wsp.2499.sumca0193.html
There was also the Inauguration Day Windstorm of January 1993 in Washington State. None of this may have anything to do with Pinatubo, of course.
But regardless of the causes, the fact is that Willis was wrong to assert that yields of every single crop went up after Pinatubo. Wheat yield in the US fell, as did global production, by a lot. That’s my point.
Chuck Nolan says:
September 22, 2013 at 6:19 pm
Both of you, go read my post entitled “A Matter Of Some Gravity“. It proves, not asserts but proves, that your mechanism won’t work to heat the surface.
Not only that, it also proves that NO mechanism depending on gravity can heat the surface.
This is why I don’t like what I call “pressureheads” on my threads. I’ve shown you can’t do it, but you keep showing up.
TAKE IT ELSEWHERE! I’m not interested in speculations about impossible mechanisms that depend on pressure/gravity. I’ve shown they can’t work, so please, you’re free to discuss it … anywhere but here.
w.
Willis
A timely article which for the main part details points raised in your earlier articles, but of course, given the impending claim by the IPCC it is relevant to consider volcanos and whether the forcings associated with such and the effect that these claimed forcings have on temperatures.
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.
So for example, consider:
(i) Krakatoa (1883). my eyeballing of Fig2 and 4 suggests that temperatures were trending downwards as from about 1875 and Krakatoa just happened to erupt in the middle of a period when temperatures were already falling. The fall in temperature around the time of Krakatoa, does not appear to be any greater, ie., the eruption does not appear to have added anything over and above natural variation in the midst of an already pre-existing downward trend. According to Wiki: “Average global temperatures fell by as much as 1.2 degrees Celsius in the year following the eruption.” but I cannot see that that claim is sound when one looks at the data you have set out. The claim appears greatly exagerated.
(ii) Novatubo (1912) my eyeballing of Fig2 and 4 suggests that temperatures were trending downwards as from about 1910 and Novatubo just happened to erupt in the middle of a period when temperatures were already falling. The fall in temperature around the time of Novatubo, does not appear to be any greater, ie., the eruption does not appear to have added anything over and above natural variation in the midst of an already pre-existing downward trend.
(iii) Pinatuboa (1992), my eyeballing of Fig2 and 4 suggests that temperatures were trending upwards as from about 1980s and Pinatoa just happened to erupt in the middle of a period when temperatures were already rising. One can see a possible response to Pinatubo in Fig4, but this is very short lived.According to Wiki: “Global temperatures dropped by about 0.5 °C” and that claim could conceivably be reasonable based upon the data that you have set out, but if so, the depression in temperature was very short lived.
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.
Second, the claimed forcings associated with Pinatubo and Krakatoa are remarkably similar, and yet no one in their right mind would consider that Pinatubo was nearly on a par with Krakatoa. I do not know whether the claimed forcing with respect to Karakatoa has been under assessed or whether the claimed forcing with respect to Pinatubo over assessed, but I am highly sceptical of the claim that they are nearly similar to one another. Whilst I do not like Wiki, the comments quoted from their site (of up to 1.2degC cf up to 0.5degC) suggests that the forcings canot be similar.
Third, it is strange that the forcing with respect to the 1912 eruption (Novarupta) is so small given that it was the largest eruption of the 20th century, ie., bigger than Pinatubo. One opines whether the forcing has been assessed to be small simply because the temperature fall (if any, my comment in (ii) above refers) was so small that it would appear ridulous and indeed contradictory for climate scientists to ascribe a large forcing to this eruption.
Fourth, whilst i agree that there is a lag before ocean temperature responds, I do not see why there should be any significant lag to land based temperatures, ie., atmospheric temperature. The atmosphere has little latent heat capacity so responds quickly to change. One can see this on a sunny day when clouds appear; the temperature drops within minutes. Most people have experienced significant temperature changes from one day to the next; it being not uncommon for there to be changes of 10degC from one day to the next and this demonstartes how little latent heat capacity the atmosphere has. Indeed, if the atmosphere possessed significant latent heat capacity, night time temperatures would be far more similar to day time temperatures (as you know over the oceans there is very little diurnal range, about 1 degC because the ocean which has a large heat capacity continuously warms the air above it such that the air temperature reflects very closely the ocean temperature night or day). Additionally, there is in most regions a quick response between summer and autumn, and autumn and winter which once again demonstrates that there is little lag. I would therefore suggest that you might like to give further consideration to lag at least as regards land based temperatures.
In summary, if you go through each and every eruption evaluating the claimed forcing against temperature change, there is no correlation (some small eruptions arguably appear to have large effects on temperatures and some large eruptions appear to have all but no effect on temperatures, and in the main, there is a downward temperure trend pre-existing the eruption in question), and as I have said, numerous times before, this all appears to be a fudge which has been necessitated because of too high a sensitivity being given to CO2 forcings.
I am even more suspicious given the latest claims that druing a period when there has been no notable volcano activity (late 1990s) volcanos are being used as a reson (I would say excuse0 to help explain the lack of warming. Surely, this is a patently bad claim by the IPCC and does not stand up to even cursory scrutiny.
milodonharlani says:
September 22, 2013 at 6:25 pm
Since it also fell at almost exactly the same rate BEFORE Pinatubo, your claim is ignoring the data. Yes, it fell … what I said was that Pinatubo had very little effect. And the data bears that out.
Sorry, but simply pointing to an index that has been falling for seven years, and then claiming that the decrease in the following seven years from a volcanic eruption doesn’t pass the laugh test.
w.
Philip Bradley says:
September 22, 2013 at 7:53 pm
You should. When you make dumb claims like that, it’s you that looks foolish, not me or the rest of the folks. Run the numbers first, and folks won’t be laughing at you.
w.
David Douglass says:
September 22, 2013 at 2:27 pm
So, if you accept the evidence for very vivid, very sharp two-year transmission “brownout” for the most recent two volcanoes volcanoes (shown here from the WUWT solar page )
http://www.esrl.noaa.gov/gmd/webdata/grad/mloapt/mlo_transmission.gif
does the much longer assumption of earlier “brownouts” (because of an assumed greater size for those earlier volcanoes) make sense from a transmission standpoint?
milodonharlani says:
September 22, 2013 at 8:15 pm
Dang. I just went and looked up what I said. Foolish me, I actually believed you when you said I’d made a claim about wheat production … I did no such thing, I spoke only of yield. Nor did I say that “yields of every single crop went up after Pinatubo”. You’re just making things up. Here’s what I actually said:
Note that NOWHERE DID I SAY THAT PRODUCTION OF EVERY SINGLE CROP WENT UP AFTER PINATUBO. That is your fantasy. Heck, I said nothing at all about production, which is what you are either foolishly or deliberately claiming.
I said that we cannot see any sign of Pinatubo in the yield, which is a very, very different claim.
For example, here’s the wheat yield …
If you claim that you can see a drop in wheat yield due to Pinatubo, you’ll have to point it out.
w.
Forcings…never liked the word…a lot of these graphs and figures of Watts/sqm are just Pretended Precision…from Aphelion to Perihelion…sunlight reaching the earth varies by almost 7%….which is a lot….yet the Earth just keeps on truckin….inertia ?…well buffered system ?…whatever it is…we human beans have no say in it.
Thank you, little CO2 molecule, for averting the catastrophe of volcano-induced ice-hockey-stick global freezing.
Thank you, IPCC, for making it clear that it a very good idea to maintain high levels of carbon dioxide in the atmosphere.
Since payday depends on finding and hyping (CO2-driven) instabilities, it’s not surprising that’s what the models are set to project/predict.
Willis Eschenbach says:
September 22, 2013 at 8:44 pm (Edit)
milodonharlani says:
September 22, 2013 at 8:15 pm
No, it didn’t. You’re making things up again.
The 1993 value was the same as 1992. And the drop in 1994, in addition to being well after the eruption, was smaller than the drop 1990-91. In other words, there’s no sign of either a world or a US yield drop due to Pinatubo, that’s just a fantasy.
w.
richardscourtney says:
September 22, 2013 at 10:40 am
/////////////////////////
Richard
I would appreciate your further thoughts/clarification on ocean temperatures..
The paper you refer to suggests that there may be a cap on the temperature of the tropical ocean of about (may be a little less than) 305K (ie.,32degC). You explain (sorry if my para phrasing is not accurate) that at that temperature evapoation is such taht it causes cloud formation which clouds shield the ocean below from receiving as much solar as they would otherwise receive (ie., if the clouds had not formed).
However many oceans have temperatures significantly higher than 32degC, in particular the Red Sea, the Gulf of Mexico, the West coast of Africa (between say Equitorial Guineee and Ivory Coast), some parts of the Indian ocean, some parts of the China sea and seas around Indonesia. Temperatures in these seas frequently reaches 34 degrees, 35 and 36degC is not uncommon and I have seen temnperatures as high as 38degC (incidentally, I have some 30 years experience of reviewing ship’s logs and have reviewed hundreds of thousands of temperature entries so I know that these are not rogue reports).
Now if there is a direct and causal link between temperature and evaporation leading to cloud formation leading to blocking of solar, how come is this not operative over these oceans?
I raised this point when Willis wrote one of his arcticles on ARGO and I provided him with a number of links detailing the then current sea temperature (ie., the temperature on the day of my comment) as recorded by local weather stations covering some of these oceans and these were reporting temperatures in excess of 32 degC (some were reporting 34degC, I think but I can’t recal for certain that one was reporting 35degC or a high of 35degC that year).. I suggested to Willis that whilst evaporation is one factor that seeks to limit temperature, it is not the only operative factor (I suggested some other factors) and Willis only slightly widened his view (iniatially he was suggesting that it was all down to evaporation).
I don’t dispute that evaporation leading to cloud formation is a factor, but in my opinion, it can only be one of a number of different factors, since if it was the sole governor then one would not see significantly higher temperatures in the oceans/seas that I mention.
Your further insight would be appreciated.
PS. ARGO only has sparse coverage. It does not really cover the ocean/sea areas that I am referring to. This is probably due to depth considerations. These oceans/seas are not shallow but neither are they deep oceans. I suspect that ARGO is not deployed in these areas since it would be unable to perform its really deep dives down to 2,000m and this would then lead to bias in that more oceans would be sampled say in the 0-700m range.
Stephen Wilde says:
September 22, 2013 at 3:02 pm
It is the increased rate of evaporation that is the primary effect arising from the addition of extra energy to the ocean surface. Willis does not explain how that increase in evaporation is always sufficient to put a firm lid on maximum sea surface temperature.
——————————————————————————-
Your first sentence is a repeat of what Willis has already said. I thought that he also explained that the once the cloud formation starts that it tends to overcompensate, which is why it always achieves the extra cooling process? Afterwards, an opposite reaction reinstates the normal mode.
Greg Goodman says:
September 22, 2013 at 8:00 pm
/////////////////////////
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? Or, did scientists consider that the temperature drop was probably due to the 2 nuclear bombs dropped on Japan thereby leading them to be fearful of a nuclear winter?
milodonharlani says:
September 22, 2013 at 1:08 pm
Since outside the US, acreage didn’t drop by much (see below), lower production necessarily implied lower yield.
I pointed out in my original comment that wheat yield in the US fell after Pinatubo, from 39.5 bu/A to 34.3. Clearly yield fell globally as well, as your own graph shows. I can see it if you can’t. But I wonder why you posted an imprecise graph instead of the actual data, which show a drop from 2.6 tonnes per hectare to 2.5 post-eruption.
http://www.fas.usda.gov/grain/circular/2010/05-10/grainfull05-10.pdf
Total Wheat and Coarse Grains
Millions of Metric Tons/Hectares
Year Area Harvested Yield Production
1990/91 549.0 2.6 1,417.5
1991/92 546.3 2.5 1,355.5
But the situation is actually worse, because of China, close to the Pinatubo eruption, where yield went down in 1991, then up in 1992, contrary to global average (didn’t check India). Since China, world’s top wheat producer (US is usually third, after India, although Russia beat us in 2009 & 2011), is mainly a spring wheat country, the growth of its crop could have been affected by the June eruption that year. See Table 1 in:
http://repository.cimmyt.org/xmlui/bitstream/handle/10883/1222/64613.pdf
Average wheat yield in China was 3.225 T/ha in 1990, falling to 3.120 in ’91 & rising 3.392 in ’92
(Data Sources: Statistic Books of Chinese Agriculture).
Your whole closing comment was: “That was the point I was trying to make above, that if the weather really had been all that bad in 1992 the crop yield would have reflected it, and it didn’t. Not for any type of produce, not for tubers, not for legumes, not for vegetables, not for fruits, not for grains”. As I noted, this is not true for wheat, as the above figures show.
http://www.agmrc.org/media/cms/ccpwheat_47A4CABBA76E0.pdf
Willis, thank you for using your superb analytical skill to show what a minor impart volcanoes have on climate. I have never accepted volcanoes as being a significant climate force, but I lack your math skill and strong ability to analysis the records.
For a decade I have been convinced that carbon dioxide has only a minor impact on climate. But, I have been greatly concerned that no one has come up with a theory and solid supportive scientific data to explain some other reason behind the shifts in climate. No one has ever explained to my satisfaction how variations in solar activity drive variations in Earth’s climate. Nor has anyone explained how variations in ocean currents and volcanic eruptions have enough impact to drive our climate shifts.
Recently, however, I have been reading the papers from Henrik Svensmark that link cosmic rays with the formation of low clouds on Earth. He explains how the cosmic rays produce cloud droplet nucli particles and how those clouds drive the planets climate swings. I am wondering if he has discovered an important driving force behind climate shifts.
Willis, it would be very helpful, perhaps, if you would do an analysis of Svensmark’s theory. Please consider this as a serious request for you to apply your skills to this concept.
Thank You.
Willis Eschenbach says:
September 22, 2013 at 9:36 pm
It’s you who make things up. I’ve repeatedly posted the actual numbers instead of crayon-drawn graphs. When will you bother to read the data I’ve given, with sources?
US wheat yield (& acreage planted) fell after Pinatubo from 39.5 bushels per acre to 34.3, as above.
Why don’t you bother to check facts before posting such sweeping falsehoods, so easily shown wrong, especially after having been shown the actual data more than once?
Willis Eschenbach: “Also, this is monthly data … how am I “averaging over intervals” that are significant fractions of the time constant? Sure, I’d prefer daily data … but it’s hard to argue with success, and an R^2 of 0.98 is success in my book.”
Well, perhaps 1/6 is not as large a fraction as to be considered “significant,” and it’s true that the formula’s inaccuracies are more apparent at larger fractions. But I would have thought the graph my previous comment’s code drew would give you pause about the formula’s correctness.
I’m not saying that you’re getting wildly inaccurate results. But if you apply your formula to data from a low-time-constant system, I believe your results will overstate the time constant. If the time constant were on the order of only a month, for example, my tests (on synthetic data with no noise) indicate that you’d tend to arrive at 50% too long a time constant. And my guess is that your 6.4-month estimate is likely to be about 25% high.
That’s not a discrepancy of great concern in this context, of course. But I thought you might want to reconsider the formula nonetheless.
(I hasten to add that the formula I use tends for some reason to estimate a little low–but more on the order of 10% in cases where yours gets 50%–and achieves much closer matches on noiseless synthetic data.)
Eric1skeptic says:
September 22, 2013 at 12:05 pm
“I realize that your website concludes that atmospheric composition is not important, but simulations of atmospheric columns differ from that conclusion. See hitran results in table 2:”
When I gave Hitran a fling, I found that one of the first things you do is input a temperature profile. One of the options is the U.S. Standard profile, which is, of course, the lapse rate. So, you input the temperature profile and a CO2 concentration and it calculates downward and upward flux at various levels, including TOA. To get a sensitivity for doubling you double the CO2 concentration and fiddle with the temperature offset at the surface until you recover the original TOA flux. The surface temperature offset is then the sensitivity for a doubling. I checked the output files and yes, the program is simply adding the “offset” to the temperature profile you entered and calculating from there. Now, I had expected the temperature profile to emerge from the calculation and not be a required input. And I speculate that the reason for this is that the mechanism that establishes the lapse rate, convection, is unknown to the program and any attempt to develop a profile from a purely radiative calculation produces a disaster. So, you forge a temperature profile as an input, allowing it to blithely ignore reality.
richard verney. says:
September 22, 2013 at 10:03 pm (replying to)
Please re-consider this question very, very carefully: The two (relatively small!) A-bombs were dropped over a two-day period the first week of August 1945. Immediately after that week, WWII ended, with all firebomb raids over Japan occurring March-July 1945.
The fire bomb and blast raids over Germany ended much earlier in that same year: May, 1945 saw VE Day come and go. (The two A-bomb blasts in August 1945 followed months of fire bomb raids over other Japanese cities, but few other areas of the world outside of ever-smaller areas of Germany and western Poland were attacked after January 1945.)
True, “some” of the limited area blast damage in 1944 over Europe “might” have impacted worldwide dust cover during 1944, but there really were very, very few raids over Japan in 1944 since the aircraft bases had not been built yet to support large raids. And, bombing raids were days-per-month basis, not every-hour-of-every-day.
The IPCC report is meant to fuel doubts about the plateau. It’s the ocean, it’s the volcanoes, it’s whatever as long as a doubt is seeded in the mind of the reader… Not of course a doubt about these alarmists models and catastrophsim, no those are still right despite reality proving otherwise. It’s post modern science and defence of a failed theory.
richard verney. says:
September 22, 2013 at 10:03 pm
The atomic bombs were dropped on Japan in August 1945, not 1944. The conventional fire raids on Japanese cities were also mainly in 1945. European cities were fire-bombed in 1944, but the two biggest fire storms were Hamburg in 1943 & Dresden in 1945.
For the nuclear winter scam to have a hope of working, many cities around the world would have to suffer such storms, lofting soot high into the atmosphere, rather than locally as during the Kuwait oil well fires. It’s rather hard to ignite a firestorm, so “nuclear winter” is improbable even in an all-out nuclear war intentionally targeting cities.
richard verney. says:
September 22, 2013 at 10:03 pm
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.
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The year 1944 was the bottom of the solar minimum. Doesn’t the minimum usually translate to a slightly cooler year?
milodonharlani says:
September 22, 2013 at 11:18 pm
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Whoops. I must be going mad, or may be it was just because I have been up all night with too little sleep, or too much alcohol, or a combination of both..