Volcanoes Erupt Again

Guest Post by Willis Eschenbach

I see that Susan Solomon and her climate police have rounded up the usual suspects, which in this case are volcanic eruptions, in their desperation to explain the so-called “pause” in global warming that’s stretching towards two decades now. Their problem is that for a long while the climate alarmists have been shouting about about TWO DEGREES! PREPARE FOR TWO DEGREES OF DOOM BY 2100!! But to warm two degrees by 2100, you have to warm at 0.2°C per decade, or around 0.4°C during “the pause” … so they are now left trying to explain a missing warming that’s two-thirds of the 20th century warming of 0.6°C. One hates to confess to schadenfreude, but I’m sworn to honesty in these pages … 

In any case, I got to thinking about their explanation that it wuz the volcanoes what done it, guv’nor, honest it wuz, and I did something I’d never thought to do. I calculated how much actual loss of solar energy occurs when there is a volcanic eruption. I did this by using the Mauna Loa atmospheric transmission data. These observations record what percentage of the solar energy is being absorbed by the atmosphere above the observatory. I multiplied this absorption percentage by the 24/7 average amount of solar energy (after albedo) which strikes Mauna Loa, which turns out to be 287 W/m2. (As you’d expect from their tropical location, this is larger than the global average of 240 W/m2 of sunlight after albedo). Figure 1 shows that result, which was a surprise to me:

clear air solar energy absorption

Figure 1. Amount of solar energy absorbed by the atmosphere above Mauna Loa, Hawaii. Data Source

Now, before I discuss the surprising aspects of this graph, let me note that the Mauna Loa data very sensitively measures the effect of volcanic eruptions. Even small volcanoes show up in the record, and the big volcanoes are clearly visible. Given that … is there anyone out there foolish enough to buy the Susan Solomon explanation that the cause of the pause can be found in the volcanoes? I guess there must be people like that, the claim has been uncritically accepted in far too many circles, but really … who ya gonna trust? Susan Solomon, or your own lying eyes?

I’ll return to the question of the pause, but first let me talk of surprises. The thing that was surprising to me in this was the size of the loss of solar energy. The El Chichón and Pinatubo eruptions reduced the downwelling solar energy by maxima of forty and thirty watts per square metre at Mauna Loa. This is a huge reduction, much more than I would have guessed.

One measure of how much energy is lost is the total loss until such time as the absorption returns to its pre-eruption value. It turns out that in the case of both El Chichon and Pinatubo, the net loss of solar energy was about 450 watt-months per square metre. The loss was spread more widely (5 years) in the case of El Chichon than in the case of Pinatubo (3 years) before it returned to normal.

This means that for the period 1982-1987, Mauna Loa was running at 450 W-months/m2 divided by 60 months equals an average deficit of no less than 7.5 W/m2 of incoming energy over the five-year period … and it’s worse for Pinatubo, since that involved the same total energy but only lasted for three years. So for the three years from 1991-1994, Mauna Loa was running at a whacking great average solar energy deficit of 14 W/m2 …

Now, how much difference did this surprisingly large lack of incoming energy make? According to the IPCC, climate sensitivity is 3° per doubling of CO2, and a doubling of CO2 is a forcing increase of 3.7 W/m2 … and Mauna Loa was running at 14W/m2 shy of normal, that’s almost four doublings of CO2. So according to the IPCC, that kind of a decrease in forcing should have lead to a temperature drop of 11°C … so what actually happened?

Well, we’re in fantastic luck, because the temperature records at Mauna Loa are very good. Here’s what they say (study here):

temperatures mauna loa 1977 2006Figure 2. Mauna Loa temperatures. Vertical red lines show the dates of the El Chichon (March 1982) and Pinatubo (June 1991) Graph from B. D. Malamud et al.: Temperature trends at the Mauna Loa observatory, Hawaii.

As you can see, despite the large decrease in incoming sunshine, there is absolutely no visible change in either the noon or the midnight temperatures … go figure. What happened from the volcano is nothing at all. No effect.

Now, y’all may recall that I have argued over and over against the concept of climate sensitivity. This is the widely-accepted hypothesis that the changes in temperature are determined by the changes in forcing. I’m a climate heretic—I don’t think climate works that way at all.

In particular, despite widespread skepticism, I have persisted in saying that volcanoes basically don’t do jack in the way of affecting the global temperature. I can finally demonstrate that unequivocally because I’ve stumbled across a very well-documented and precisely measured natural experiment.

At Mauna Loa we have a clear example of a measured decrease of 7 W/m2 in the average incoming solar energy for five years (1982-1987), and a decrease of 14 W/m2 for 3 years (1991-1994) … and there is absolutely no sign of either forcing decrease in the temperature record of the very place where the solar decrease was measured.

As I’ve said over and over, the emergent phenomena of the climate system respond instantly (hours or days, not months or years) to any change in the temperature. If it cools, we rapidly get a drop in albedo, which allows in more sun, and the balance is restored. If it warms, very soon thereafter albedo increases, we get less sun, and again the balance is restored. So while I was surprised by the size of the drop in downwelling solar energy, I was not surprised that we can’t find the signal of the solar drop in the temperature records.

Setting that question aside, let me return to the “pause”. Solomon et al. used the Vernier aerosol optical depth (AOD) dataset, which is available here. It is a calculated global dataset based on various observations. The explanation of the calculations is here. If anything, there is less recent variation in that dataset than in the Mauna Loa dataset. Figure 3 compares the two over the period of the satellite temperature observations.

mauna loa transmissivity vs vernier optical depthFigure 3. Compares the negative of the aerosol optical depth with the Mauna Loa transmissivity data. Mauna Loa data rescaled to match AOD data for comparison purposes only. 

So it doesn’t much matter which one we use to compare to the temperature data. Let me use the Mauna Loa transmissivity data, since the native units are in the same range as the temperature anomaly. Figure 4 shows the comparison of the Mauna Loa transmission data with the UAH MSU satellite-based lower troposphere temperature data:

uah msu satellite t2lt temps mauna loa solarFigure 4. Satellite lower tropospheric temperatures (blue) and Mauna Loa solar transmission (black line). Note that while Pinatubo happened at the start of a temperature drop, El Chichon happened at the start of a temperature rise. In addition, in neither case are the rise or the drop notable—the drop 1988-1989 or 2007-2009 is indistinguishable from the post-Pinatubo drop.

Finally, lest some folks claim that because Mauna Loa is in the northern hemisphere we can’t compare it to the global temperature changes, Figure 5 shows the comparison of the Mauna Loa with the northern hemisphere temperatures:

uah msu satellite temps plus mlo solarLike I said … I know there must be folks out there that can be convinced that the changes in the black line, the known effects of the volcanoes, are the reason that there is a “pause” in the global temperatures … I’m not one of them.


• I may never find better evidence of the lack of connection between changes in forcing and changes in temperature than the measured large drop in solar forcing and the total lack of corresponding temperature change at Mauna Loa. It is a superb natural experiment, and has been very precisely measured for over half a century. It provides strong evidence in favor of my hypothesis that the temperature is controlled by emergent phenomena, and has very little to do with forcing.

• The change in forcing from the 21st century volcanoes is trivially small in both the Vernier AOD dataset and the Mauna Loa dataset. It is far too small to have the effect that they are claiming. I don’t care what the climate models told Solomon et al., the post-2000 changes in volcanic forcing are meaningless.

• My oft-repeated claims about the lack of effect of volcanoes on the global temperature are completely borne out by these results.

My regards to all,


AS ALWAYS: If you disagree with me or anyone, please quote the words you disagree with. That way we can all know exactly what it is you have a problem with. Vague handwaving claims go nowhere.


The “apparent” transmission, or transmission ratio (Ellis & Pueschel, Science, 1971), is derived from broadband (0.3 to 2.8um) direct solar irradiance observations at the Mauna Loa Observatory (19.533 ° N, 155.578 ° W, elev. 3.4 km) in Hawaii. Data are for clear-sky mornings between solar elevations of 11.3 and 30 degrees.


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Is it possible that volcanoes cause more outgoing energy to be absorbed so temperatures go up?
Ore more incoming UV to be absorbed. Or more incoming IR?
It appears to me that more volcanic eruptions cause warming.

I’m not arguing with what you say here, but maybe with something unsaid. The light which was not transmitted, accounted for as a transmission drop, has one of two other paths to take: (1) It can be reflected back to space; or (2) it can be absorbed. The first should result in less net heating. The second will have little direct effect upon heating. (Indirectly, the aerosols might participate in a so-called greenhouse effect, but I don’t know their spectral characteristics.)
Can your results be taken to support the absorption path?


As has often been the case with your work, this needs to be in a major science journal for all the world’s scientists to see. Of course I understand your reasons for not wanting the hassle of dealing with the gatekeepers, but it would be nice to remove the blinders from the science herd animals.


Hi from Oz. Really nice work Willis – now get back to that framing job! 😉

george e. smith

Well like I have said; “It’s the water !”
Less sun, get’s cold, more rain, less clouds, more sun, gets warm; and verse vicea. It’s called negative feedback.
How many times has Dr Svalgaard told us, it ISN’T the TSI. (or the volcanoes.)


Are these people not speaking to each other:
Travesty Trenberth: The missing heat’s hiding in the deep oceans, ooooh errrr hold on a sec – it comes out and causes heatwaves occasionally, but only when they’re in the news.
Tamino: There is no pause in anthropogenic global warming. Just look at my statistical treatment, not to mention my mom and sister’s praise in the comments section telling the world what an ace scientist I am.
Solomon the Wise: It were the volcanoes wot did it. Honest.
LA Times Editor: Waaaaaaaah, I’m taking my ball home you horrid d*niers.
Jones: Fk off, leave me alone, can’t you see I’m in hiding.
Mann: Sue them, that’ll shut them up.
Cook: OK, I admit, I’m just a f-kin idiot.
Oreskes: Put them in jail on RICO charges, that’ll shut them up.
6-year old girl: Mommy, the Emperor has no clothes.
Nobody: The hard scientific evidence that atmospheric carbon dioxide going from 280 ppm to 400 ppm has any measurable effect on any climate parameter is as follows:
Bullet point 1 ……

Pamela Gray

The animation shows the emission and transport of key tropospheric aerosols from August 17, 2006 to April 10, 2007. It shows the aerosol optical thickness of black and organic carbon (in green), dust (in red/orange), sulfates (in white), and sea salt (in blue) from a 10 km resolution GEOS-5 “nature run” using the GOCART model.

Now add to that the now and then event of a volcano. It just can’t match the huge continuous dust storm out of Africa. What happens when the Trade Winds pick up and the air is dryer? More dust! A lot more dust! Hmmmmmmmm
By the way, this dust fertilizes the Atlantic equatorial ocean. And it probably has an oscillation to it.

Nancy C

obligatory request for watt months/m^2 to be converted into the more familiar hiroshima units, please.


They sure have erupted.
Mann goes after Andrew Bolt!
Steyn smiles. He knows a lawyer to recommend.

If there is significant number of active, new active volcanoes during this solar minimum, we may lose the fight for true science of climate in our lifetime.
But we know to stack the wood high and long during a solar minimum.
Goood bye to the Alarmists either way. It’s all about Ice Ages.

Thanks Willis for this observational debunking of the radiative forcing concept.
There is a simple explanation for all of this & why the Earth surface temperature has little to do with radiative forcing, and is primarily determined by thermodynamics [convection, phase change, pressure, etc], not radiation.
1. The surface temperature, as well as the entire atmospheric temperature profile, is entirely explained by solar insolation plus the behavior of adiabatic gases in a gravity field, which establishes the wet and dry adiabatic lapse rates.
2. The dry adiabatic lapse rate equation: dT/h = -g/Cp [g is gravity, Cp is heat capacity of the atmosphere] does not have a term for radiative forcing and is independent of radiative forcing.
3. Addition of GHGs increase the heat capacity Cp, which causes a decrease in the lapse rate, as is observed: the dry lapse rate is much steeper than the wet. A decrease in the lapse rate causes a cooler surface.
4. The entire 33K “greenhouse effect” is entirely explainable by the average adiabatic lapse rate i.e. the observed average lapse rate = 6.5K/km * 5 km = 33K. The 255K equilibrium temperature with the Sun at the TOA + 33K due to the lapse rate sets the surface temperature at 288K or 15C
5, Thus, a large volcanic eruption or large change in RF doesn’t change surface temperature, because there is no effect on the average lapse rate, and no change of the equilibrium temperature with the Sun at the TOA.


Does this negate the nuclear winter theory?

Louis Hissink

Let me get this straight. The pause is due to additional volcanic activity which increased the aerosols which caused the cooling, while at the same pumping additional CO2 into the same atmosphere from the same volcanos.
And they accuse us of being delusional?


Another elegant contribution, Willis. You have a knack for going right to the observational data, whereas the “modeling clowns” twiddle another partial differential or jigger another parameterization exercise.
Volcanoes never maintain eruption cycles long enough to change “climate” (that 30-year so-called standard). And clearly ash and sulfates and whatever get cleansed out of the atmosphere in a couple of years anyway.
Solomon is in a “double ethical bind” (to borrow a famous Stephen Schneider line). She has claimed that CO2 persists for hundreds of years in the atmosphere (the “heat in the pipeline” boogeyman) , and yet here we are with 17+ years of rising CO2 and not a whit of temperature rise to show for it. That’s what Kevin calls “a travesty”. Rational minds call it evidence of a failed hypothesis.
Susan also blew the fluorocarbon-ozone thingy years ago. I think it’s pretty clear now that ozone over the poles is just a seasonal oscillation.
Like Ehrlich, Solomon will be lionized by environmentalists despite a persistent track record of error and failure, because they claimed human cause for perceived calamities. Rachel Carson, on the other hand, was not only wrong about DDT – – her ideas led to millions of unnecessary deaths of tropical children.
That might be labeled an “emergent phenomenon” of a most perverse variety.


Very interesting! To further test the theory, I’d suggest looking at inland stations where there’s no ocean thermostat. I guess the global/NH temperature chart already suggests you’ll find nothing (El Chichon did not cause a drop), but still worth a look I think.


I don’t understand your arithmetics, when you are trying to find .6 degrees missing when it really should be only .4. There is a reality, come to Paris and I will show you olive trees blooming there, that would never have occurred fifty years ago. What is your explanation? urban heat island effect? We are just like the Brits, we stopped using coal to warm up our houses years ago, we are not more wasteful of energy than any other capital-city inhabitant. Paris is warmer than it was before. So are the surrounding areas, up to a thousand km away from there (ours is not such a huge country, but there is a bit of room around…).

“The “apparent” transmission, or transmission ratio (Ellis & Pueschel, Science, 1971), is derived from broadband (0.3 to 2.8um) direct solar irradiance observations at the Mauna Loa Observatory (19.533 ° N, 155.578 ° W, elev. 3.4 km) in Hawaii. Data are for clear-sky mornings between solar elevations of 11.3 and 30 degrees.”
two clues here.


Curious to see if there were any changes in humidity and/or rainfall at that location for the volcano affected time periods. Greatly despise thinking of everything in terms of ‘temperature’ as that does not equate to energy, at least not entirely. Quick search brought up a west Hawaii stations 12 month moving mean here:http://hi.water.usgs.gov/recent/westhawaii/rainfall.html. The naked eye doesn’t see anything I can attach to the Pinatubo eruption, and the graph doesn’t go back far enough for El Chichon. There appears to be a step from one mode of operation to another in ’92, though I wonder how much of that is actual data and how much of that is % based moving mean. Have to pull the raws down.
Also am considering that the feedback effects from cloud/albedo affects described break down in extra tropical areas, particularly NH landmass. Too late to poke into it atm, but the thinking goes that tropical areas already exist in a negative feedback scenario. As such, less sunlight would be reflected in a change to the feedback mechanism but not greatly affecting the ground level temperature. However, the lower energy areas such as the North/South Atlantic and Indian oceans, or especially the continents, would not react the same way to lower sunlight input because they largely operate below that threshold already, right? If so you would expect to see a positive feedback emergent phenomenon, where applicable.
Concern is that the negative feedback is powerful and persistent thanks to tropical cloud cover, as described, but an extra tropical positive feedback phenomenon may not be. Or I could simply be lacking sleep.

Thank you.


Even if you accept, at least for the sake of argument, that the major volcanic eruptions, and the resultant reduction in insolation at the surface, did cause cooling, we have not seen any of these during the “pause”.
Until now, the climate establishment claimed that the more minor volcanic eruptions did not have long lasting effects, because their plumes did not get high enough to avoid being quickly rained out. Only the really major eruptions sent their plumes into the stratosphere, where the effects are long lasting. I’ve been trying to figure out how this wisdom has changed recently…


one of the funniest things i’ve ever read on our “academics” website in Australia!
24 Feb: The Conversation: University of Utah: Human well-being leaves large carbon footprint
Improving life conditions for humans has been linked to increased carbon emissions.
Professor Andrew Jorgenson’s research measured the carbon intensity of human well-being (CIWB) by using the ratio between per capita carbon dioxide emissions and average life expectancy at birth — for 106 countries over the period 1970–2009.
The largest CIWB was found to be in North America, Europe and Oceania, but generally increased across the board.
Jorgenson says that as long as societies rely on fossil fuels, achieving better life conditions will drive up carbon emissions worldwide.
Read more at the University of Utah…
Gerard Dean:
Amazing! Who would have thought that raising human living standards through the use of fossil fuels to create electricity, gasoline, diesel and gas would increase our carbon footprint.
Our ancestors learnt how to light a fire for warmth, then to cook and to light their nights. Noticing a funny rock that melted lead to smelting of metals and it took off from there.Then we found coal, then oil and finally uranium.
It is blindingly obvious that humans improve their living conditions by burning more stuff dragged out of old mother earth.
Can I have my PhD now?
Professor Andrew Jorgenson
Dear Gerald Dean,
Perhaps before making such flippant remarks you should first read the research article as well as the supplemental materials. I’d be happy to send you both.
Andrew Jorgenson

Mario Lento

Thank you Willis!

Willis Eschenbach

Steven Mosher says:
February 24, 2014 at 10:16 pm

“The “apparent” transmission, or transmission ratio (Ellis & Pueschel, Science, 1971), is derived from broadband (0.3 to 2.8um) direct solar irradiance observations at the Mauna Loa Observatory (19.533 ° N, 155.578 ° W, elev. 3.4 km) in Hawaii. Data are for clear-sky mornings between solar elevations of 11.3 and 30 degrees.”

two clues here.

Steven, it’s usually good to hear from you … you are a smart fellow.
However, when you get into your cryptic one-liner mood, you’re worse than useless. Let me kindly request that you say what’s on your mind, and leave off the cutesy sound bites. They’re not working.
What are the two clues, what do you conclude from the clues, and what does it have to do with my post?
Even if I could figure it out for myself (obviously I can’t), I’d still be missing your thoughts, insights, and illumination. So if you’ve got something to say … how about you give us the benefits of your understanding?


So, how many times do these people call “wolf” before the everyone ignores them?

Peter Hessellund Sørensen

I agree with your conclusions here but I think it is fair to mention that there is not necesarily a linear relation between size of volcanic eruption and changes in temperature. Som of the large prehistoric volcanic eruptions might have had large effects on temperature simply because they were so large that they reached a treshold size. Another thing is that volcanoes are very different. The Pinatubo for example was a short explosive eruption throwing large amounts of dust into the atmosphere whereas the Laki eruption on icland lasted a year or so but was primarily lava flows and emissions af gasses like sulfuric fumes. Historic records show a large climate effect in Northern Europe during the Laki eruption and the harvest is reported to have failed for several years. This eruption was so big that the smell of sulfur reached Denmark a distance of almost 2000 km.


François – you’re right that Paris was cooler 50 years ago. But what about 80 years ago? My guess: It probably was almost the same as today. I found some temperatures here: http://www.tutiempo.net/en/Climate/Paris_Le_Bourget/71500.htm and plotted them: http://espen.vestre.net/tmp/paris-le-bourget-all.png
You can recognize the European climate shift around 1988 (apparent in most Central Europe temperature series), but since then it has been cooling (or at least not warming, I forgot to check the significance of that trend and don’t have my spreadsheet here right now) for 25 years! See this chart: http://espen.vestre.net/tmp/paris-le-bourget.png


Thanks Willis. This seems so simple and cogent an argument that one wonders what Santer et. al. (12 authors ? really ?) really were after ? We can only wonder…
BTW, only $32 to see the article – what a deal.


• I many never’
I may never?
[Thanks, fixed. Perfect is good enough. -w.]

Questing Vole

If it took 3 and 5 years respectively for absorption rates to recover from the major eruptions of Pinatubo and El Chichon, why did it take so long after the relatively minor Mt Agung event?


Hi Willis,
one thing was not mentioned. How can volcanoes be “the cause”, when (according to your figures) there has been no major eruption after Pinatubo ?


Well I take Solomon claims as a sign there is a god, for who else to arrange it so that volcanic eruptions could have so much influence to actually balance out the effect of AGW but only for the period when ‘the pause ‘ during other periods it could only have been ‘climate doom ‘ and volcanic eruptions play no role , along with the sun and lots of other elements which we often poorly understand.

Larry Brasfield says:
February 24, 2014 at 9:18 pm
I’m not arguing with what you say here, but maybe with something unsaid. The light which was not transmitted, accounted for as a transmission drop, has one of two other paths to take: (1) It can be reflected back to space; or (2) it can be absorbed.
A lot of volcanic debris is gray/black lava injected in the stratosphere, but only with huge eruptions like the Pinatubo. Most plumes don’t reach the stratosphere and are rained out within days/weeks. Most of the debris is heavy and drops out into the troposphere and surface within months.
Of interest is the SO2 which follows the plume. That remains in the stratosphere and is turned into SO3 (by ozone) which attracts a lot of water. That takes time, as there is very little water in the stratosphere, which also makes that it takes years before the drops are heavy enough to drop out of the stratosphere. It is these water drops which scatter sunlight in all directions, including partly back to space.
The main effect is not on temperature, but on CO2 uptake bij plants: the scattering makes that more leaves which are in the shadow of other leaves during part of the day then receive more scattered sunlight, which makes that the CO2 increase after the Pinatubo eruption was minimal, including any CO2 from the eruption itself…


François says:
February 24, 2014 at 10:14 pm
I don’t understand your arithmetics, when you are trying to find .6 degrees missing when it really should be only .4. There is a reality, come to Paris and I will show you olive trees blooming there, that would never have occurred fifty years ago. What is your explanation? urban heat island effect?
Here is a link about UHI in Paris during heat waves. The increases in temperature a enormous
Steve McIntyre has more data. 10 degrees for big cities and 5 degrees for smaller cities etc…
In Tokyo air conditioning alone increases temperatures by 2 degrees.

Christopher Hanley

Steyn smiles. He knows a lawyer to recommend …
Lordy, it won’t be long before suing Mann becomes a class action.


re Bolt
2 replies by Mann
One he apologises for use of the term “lie”
the other says that Bolt promoted falsehoods, but they were not necessarily “lies”.

Richard Keen

Manfred says:
…How can volcanoes be “the cause”, when (according to your figures) there has been no major eruption after Pinatubo ?…
Great question!
Six years ago I made the case that the series of big volcanoes from 1963 to 1991 (Agung, el Chichon, and Pinatubo) threw enough stuff into the stratosphere to cool the earth by a few tenths of a degree, and that since 1995 the stratosphere has been clear. The punch line was that half of the warming over the past 40 years can be attributed to the this clearing – that volcanoes cooled the climate early on, and after Pinatubo was over and gone, the earth warmed back up. It was a good enough story that the New Scientist wrote it up:
I presented an update last year that showed the lack of volcanoes for the past 17 years actually contributed more to the overall warming than did CO2 and other greenhouse gases:
Of course, the New Scientist went for a second opinion, from none other than Susan Solomon. Solomon stated that volcanoes were adequately accounted for in the IPCC models and that volcanoes had no detectable (in the models) effect on the warming.
So now the same Susan Solomon claims the teeny volcanoes since 2000, all of which are less than a tenth the magnitude of the likes of Agung, el Chichon, and Pinatubo, can now outweigh the greenhouse effect. Meanwhile, those big guys way back then had no effect.
Curiously, the New Scientist has yet to call me for a second opinion on Solomon’s excuses for the “pause”.

M Courtney

This seems like a good basis for a retraction of the paper by Susan Solomon.
Which could become a little rolling snowball.


This is a very interesting analysis. Very interesting indeed. A few questions:
– Playing devils advocate, I can imagine a (consensus/orthodox) response regarding the the Mauna Loa connection between reduced insolation after the eruptions and local temperatures along the lines of; the vulcanism has a global impact on temperature and not a regional one. The individual location is going to be affected by local conditions and may not necessarily respond to a localised reduction in sunshine in the way the overall climate system might. How might you counter that?
– Secondly, and related to the first, what is the location of the temperature station wrt the measurements for solar irradiance? Are they the same station? Obviously it’s Mauna Loa, but are the locations identical or is the temperature taken at a lower altitude? If so how would that effect the connection between temp and irradiance?
– I agree, no response at all in the temp record from what appears to be a really big reduction of insolation is really surprising. Are you saying there is virtually no lag in the response of the system to correct for it? If there is a lag, how long do you think? A few hours, days, months?
FWIW (probably not very much) I agree broadly with your “emergent phenomena” hypothesis. With a little bit left over for known unknowns, and unknown unknowns.


The more reasons they find to explain the not happening CAGW, the more they admit their theory is wrong without saying so, meanwhile losing the scientific battle.
Never interrupt your enemy when he is making a mistake. Just watch and smile.


Manfred says: February 24, 2014 at 11:44 pm
One thing was not mentioned. How can volcanoes be “the cause”, when (according to your figures) there has been no major eruption after Pinatubo ?
How can they “it was the volcanos” and keep a straight face, when there have been no significant volcanos??
Surely, this must be some kind of criminal offence. (Misuse of public funds in the US, I believe…)

Something is fishy here Did Solomon have no idea of the Mauna Loa apparent transmission data? Then she would have know that it weren’t the volcanoes.
But what does it mean that this reference is the first listed on the NOAA site:
Solomon, S., J. S. Daniel, R. R. Neely III, J. P. Vernier, E. G. Dutton, and L. W. Thomason, 2011: The Persistently Variable “Background” Stratospheric Aerosol Layer and Global Climate Change. Science, Published online 21 July, Science Express, 2011,DOI:10.1126/science.1206027]
So what does that mean?
– Is it another Solomon or she has a very short memory?
– Willis is wrong somehow?
– Somebody does a lot of wishful thinking?
– honest mistake?
– noble cause corruption?

Michael Larkin

Willis, you say (in reference to fig 1):
“The El Chichón and Pinatubo eruptions reduced the downwelling solar energy by maxima of forty and thirty watts per square metre at Mauna Loa.”
I keep looking at fig.1, and I make it around 60 and 50 watts per square metre respectively. I may well be misinterpreting the graph, or maybe what you’re talking about doesn’t directly relate to the graph: I can’t claim to be a whizz kid when it comes to physics. Whatever, I’m puzzled about where your 40 and 30 figures come from. Could you please clarify?

Dr. Strangelove

The 14 W/m^2 you measure at Mauna Loa is not comparable to the 3.7 W/m^2/K climate sensitivity. The units are different. The latter is per degrees kelvin change in surface temperature, and the forcing is at TOA (about 10,000 m altitude). Mauna Loa Observatory is at 3,400 m elevation.
The effect of Mt. Pinatubo eruption is global, not local in Hawaii, since the aerosols circulate in the stratosphere. And in fact global temperature did drop circa 1991.


There is another experiment you can do. It’s to do with the lags in the atmosphere. How quickly do atmospheric temperatures change when the forcings are changed.
To do the experiment, you need to change the forcings. Now plenty of people say you can’t experiment with the climate, but its not the case.
Go out, measure the temperature at midday. Then we turn the forcing off, and see how quickly the temperature drops. You don’t have long to wait. About 12 hours will do it. The sun gets ‘turned off’ once a day, and you can see the change.
It turns out the change is very rapid. Diurnal temperature variations are large, highest for deserts, lowest for oceans, but rapid in all cases.
Hard to justify any long term lags to changes in forcings.

David L

You’re forgetting about all the volcanoes in the deep oceans that are erupting all the time without or knowledge. /sarc

Stephen Richards

This is why I get really annoyed with people like Roy Spencer who insist on saying that co² causes an increase in forcings (ooooh I hate those words) and therefore a rise in global temps.
Global temp as a parametre stinks and forcings as a concept in nonsense. BUT on question remains in my empty head all the time: How does an ice age form ? Milankovic possible but there are many if and buts around the predicted incoming energy change. So what else is there.?


This is why I get really annoyed with people like Roy Spencer who insist on saying that co² causes an increase in forcings
My pet hate is that El Nino is an input into the system and not an output of the system


Willis, as always, very interesting. Thank you. Many/most of us appreciate your work. However, some fear it.


David L says:
February 25, 2014 at 1:29 am
You’re forgetting about all the volcanoes in the deep oceans that are erupting all the time without or knowledge. /sarc
We do know about them. They’re the ones making the bottom of the sea warmer.
That’s where the heat is hiding, but that naughty heat can’t fool us…

Kelvin Vaughan

Only yesterday Willis, I compared the CET with the big drops in transmissivity and found nothing obvious. I am strongly being converted to the argument that temperature is governed by pressure. How else can you explain that massive instantaneous swings in the amount of infrared coming down from the sky (clouds v clear sky) has very little effect on ground and air temperature.