Guest Post by Willis Eschenbach
Well, we haven’t had a game of “Spot The Volcano” in a while, so I thought I’d take a look at what is likely the earliest volcanic eruption for which we have actual temperature records. This was the eruption of the Icelandic volcano Laki in June of 1783. It is claimed to have caused a very cold winter in 1783-1784. A study of the effects (see end notes) says:
… the 1783-1784 winter was extremely cold and snowy around the circum-North Atlantic. European temperatures were ~2°C below average for the late 1700s, and it was among the coldest winters in Central England …
Well dang … that sounds pretty scary. However, being a naturally suspicious fellow, I thought I’d take a look and see just what the temperatures actually said. I found eight records in the Berkeley Earth Surface Temperature dataset that went back that far, there may be others, but these cover a wide area of Europe. Here’s your puzzle:
Figure 1. Eight long-term temperature records from Europe. All of them are aligned to start and end on the same date, but the dates have been removed
So … is the year of the “extremely cold and snowy winter” location number 1, 2, 3, or 4?
While you consider that question, let me point out that despite frequent claims of “unusual” or “extremely” or “unprecedented” and the like, I’ve shown in the past even very large volcanic eruptions cause little in the way of temperature changes (see end notes). The Laki volcano is in Iceland, so you’d think that the signal from it would be strong in Europe. And indeed, as the quote above shows, this is the common wisdom.
But as the temperature graphs show, the actual eruption makes little difference to the temperatures. The winter following the eruption of Laki is actually at location number 3, so there is some effect from it visible in all of the records. Looks like it is the one winter that was unusually cold in every one of the eight records.
But even then, it’s not that large and … and … oops … hang on a minute, sorry ’bout that. I got the numbers wrong. Here’s the actual situation regarding the winter of 1783-1784:
Figure 2. As in Figure 1, but including the dates.
As you can see, the winter following the Laki eruption is not the one marked with the red “3”. Actually it’s the one marked by the red “2” … and it is pretty unremarkable. In general it is NOT “~2°C below average for the late 1700s” as the quoted study says, that’s simply untrue. And in several of the datasets, it’s no colder than normal.
We do have one other dataset going back that far, the Central England temperature dataset. Here’s that data:
Figure 3. Central England Temperature (CET), late 1700’s.
Remembering that the study claimed that this was “among the coldest winters in Central England”, which winter looks like the big winner here?
In fact, far from being among the coldest all-time winters, the winter of 1783-1784 was not even in the top three for the quarter century 1775-1800 …
Figure 4. CET including the dates.
My point is simple. We have been told a story all of our lives about how volcanic eruptions have large, widespread, and long-lasting effects on the global weather. It turns out that this was a scientific urban legend. In fact, the effects are small, localized, and short-lived.
UPDATE: For those who like averages, here are the averages of the eight station records.
Regards to everyone,
w.
AS ALWAYS: If you disagree with someone, please QUOTE THE EXACT WORDS YOU DISAGREE WITH, so we can all understand the substance and nature of your objections.
FURTHER READING: I’ve analyzed the effects of a number of large volcanic eruptions. In all cases, their effects have been small. See:
Prediction is hard, especially of the future.
Dronning Maud Meets the Little Ice Age
New Data, Old Claims About Volcanoes
BEST, Volcanoes and Climate Sensitivity
Volcanoes: Active, Inactive, and Retroactive
Stacked Volcanoes Falsify Models
The Eruption Over the IPCC AR5
Eruptions and Ocean Heat Content
DATA: Monthly mean HadCET data
Berkeley Earth Surface Temperature data
Laki Winter study quoted above
Looks to me as though CET had a very warm summer then a cold winter, followed by a cool summer. The big drop from summer to winter would leave the impression that the winter was colder in absolute terms, while only very cold relatively. The subsequent cool summer only cemented the deal.
Having witnessed through the media and via conversations with peeps with a keen interest in weather, would the ‘cold summer’ just be a result of social interaction between people.
My example would be the recent floods in the South West of England. OK, maybe some places got a lot of rain but it was in a place and time that historically spent all winter underwater anyway. The landscape was man-made and then neglected through lack of maintenance, the switching off of drainage pumps and failed forecasts.
But it was what ensued after a Met Office muppet jumped up on TV. He solemnly declared, repeatedly, and then copied onto the main news headlines, that a tin-pot little village, somewhere no-one had ever heard about, cared about nor ever will very much (unless they actually lived there of course) had had TWICE AS MUCH RAIN as it normally got in a year.
Before you knew it, EVERYwhere in England had had twice as much rain. Everyone was talking about it and it was repeatedly reinforced by the lame stream media. Actual weather station data was simply ignored, nobody checked the reality. For a population permanently muddled headed, soporific and chronically depressed by a diet of starch and alcohol, exchanging tales of woe and hardship is second nature – reinforced ever more by the dirge of soap operas that are de-riguer viewing on early evening British TV. The pluvial downpour, well within the bounds of natural variability, that engulfed Lower Middle Nowheresville (Pop. 45) became the national standard.
Did something similar happen after Laki, a small isolated event (a low temperature reading somewhere) get magnified by confirmation bias and social interaction. Possibly the only situation involving real positive feedback in the whole climate system?
Would it be an idea (not really but ykwim) for Lunadonkey and his side kick John Crook to devote some of their energies to analysing this, instead of spending their days (and my money) slagging off skeptics as they do.
The Winter of 1783/84 was exceedingly cold in the American Southeast, both for its long continuance, extremely heavy snowstorms and freeze severity. Feb 1784 and Feb 1899 contain the
only two instances of ice flows passing out of the mouth of the Mississippi River at 29 degrees N
and being meet by ships in the open Gulf of Mexico at 28 degrees N.
Reference David Ludlum-“Early American Winters 1604-1820”.
Pete in Cumbria UK makes an astute observation about perception especially when it comes to weather.
In our area where harsh winters are the norm, the winter of 11/12 was soft and mild and everyone was noting how easy the winter was. I was speaking with a clerk and we were talking about the weather and I said ‘thank heavens the winter is more humane than last year’.
I’ll never forget her response. She looked at me with complete puzzlement and stated that global warming was making all the winters mild. She had completely forgotten the brutal winter we had just endured the previous year.
Reblogged this on gottadobetterthanthis and commented:
–
The only point, volcanoes are not nearly as important as we assume them to be.
The winter after the Laki eruption was colder than the previous 9 winters. Could it be that the other dips in the record indicate volcanic eruptions in other places that the europeans were unaware of?
Thanks Willis. This certainly again throws a wrench in our intuitive sense a volcano’s ash and sulfur must cause cooling.
I actually think it does cause cooling, but the cooling doesn’t manifest in the way our minds look for. Rather it manifests by shifting the jet stream. (I think it was Dr. Tim Ball who started my thinking down these lines, by suggesting a “zonal” jet stream would often become “meridianal” after a major eruption.)
What really messes with our minds is that volcanoes mess with the timing of ordinary shifts in the AMO and PDO which cause ordinary shifts in the jet stream from flat (“zonal”) to loopy (“meridianal.”)
Sometimes I mess with children’s minds to make them laugh, by pretending I don’t know how to push them on a swing. To push them correctly I would, of course, push them from the rear, and time my pushes correctly. Instead I pretend I don’t have a clue, and push from the side, or push at just the wrong time, which stops them dead rather than increasing their swings. The children delight in telling me what a fool I am, and lecturing me about when and where to push.
Some people seem to be inadvertently giving volcanoes similar lectures, by expecting the same result from every volcano, irregardless of the situation created by the AMO, PDO and jet stream as a starting point. Volcanoes don’t heed us, and push whenever they please wherever they please.
What I surmise Tamboro did in 1815 was to push just when the jet stream was in a loopy phase, thus creating a jet stream that was a super duper looper. Where 2007 pushed a lot of ice down through Fram Strait, after 1815 the entire, cotton-pocking icecap got discharged into the North Atlantic. If this occurred again it might please Alarmists, “Look how little ice is at the Pole! It must be warmer” until the North Atlantic being turned into ice-water gave Europe a modern “Year With No Summer.”
What I’m suggesting is that the effect of volcanoes is much more complex than merely the air being cooled.
The real effect of volcanoes on climate is if they inject a lot of debris, including SO2 into the stratosphere, but even that is not lasting long: a few months for the heavy particles and 2-3 years for SOx-water drops for the Pinatubo which was a one-in-a-century VEI 6 event. Most eruptions are a lot less explosive and don’t even reach the stratosphere. The VEI index is a logarithmic scale with a factor 10 of debris ejected for each point on the scale.
Eruptions of the Laki and currently the Bárðarbunga eject a lot of mass, but mostly low in the atmosphere, which has far less climate impact. Besides that, the emissions of SO2 and especially HF (hydrogen fluoride), where the latter is very toxic for sheep and cows, killed about halve of all animals on Iceland and a quarter of the population as result of hunger at the time of the Laki eruption. See the many references at Wiki:
http://en.wikipedia.org/wiki/Laki
They also mention a lot of haze over Iceland and Europe. If that is true, that may not show up in winter temperatures (heat retainment), and reflects sunlight in spring…
For those who haven’t been in Iceland: here a picture from the top of the main Laki volcano (40 km inland from the main circle road, extremely bad road, several rivers to cross!) towards the long fissure: over 100 smaller volcanoes were formed at that time:
http://www.ferdinand-engelbeen.be/familie/island/isl239.jpg
Ferdinand
So basically there may be an effect for a particular type of volcano in a specfic location that projects a great deal of the appropriate material high into the stratosphere, but basically these are very rare and have a short term effect, if at all?
So the LIA is unlikely to have been caused by the 1257 eruption and a couple a few decades later?
tonyb
Hi Tony,
Some -long- time ago we have met…
Indeed, most of the heavy debris of the Pinatubo did drop out in a few months. Only SO2 remained in the stratosphere, was oxidized to SO3 by ozone and attracted water to slowly form drop large enough to reflect/deflect sunlight. As I remember well from some work, the deflection caused more photosynthesis, because more leaves which were part of the day in the shadow of other leaves received more of the scattered sunlight which caused more CO2 uptake. That is visible in the minimum CO2 increase in the year(s) after the eruption.
SO2 emissions in the lower troposphere in general drop out as dry deposit within a few days, with rain even faster, so their climate impact in general is minimal.
I had a few good references some years ago which did show the aerosol impact of explosive volcanoes, but as usual they are gone now…
Correct, as usual.
There is no significant difference between volcanism during the LIA and during the Medieval Warm Period preceding it or the Modern Warm Period following it. Indeed, so far the Modern WP has seen big eruptions at a higher pace than the average across the LIA.
OTOH, the LIA is associated with an unusual number and magnitude of solar minima.
Willis your data is wrong major volcanic eruptions have been shown time and time again to have major climatic impacts. They may be short lived but they are major.
Dr. Spencer agrees with most of us who think volcanic activity does indeed have a cooling effect. I would say over 99% of the scientific community has reached those conclusions.
Dr. Roy Spencer, Ph. D. says:
November 16, 2014 at 8:36 AM
It is a visible reflector, but also an IR absorber. The Earth Radiation Budget Satellite (ERBS) measured a 2%-4% increased reflection by the sulfate aerosols after the 1991 eruption of Pinatubo, but it also measured the decreased IR emission because the aerosol layer in the lower stratosphere was blocking the warmer IR emission from below. The solar reflection effect dominates, which is why volcanoes cool.
The increased IR absorption by the aerosol layer leads to a dramatic warming in the lower stratosphere after a major eruption.
Salvatore, I agree that “volanic activity does indeed have a cooling effect”, as you say … in fact I said in the head post that it does. The question is, how much does it cool, over what area, and for how long? As I said in the head post:
You’ve provided nothing to change my mind, and once again you’ve ignored my request to QUOTE THE WORDS YOU DISAGREE WITH. For example, you say “Willis, your data is wrong” … but you don’t say which data.
Sadly typical of your bluster,
w.
http://icecap.us/images/uploads/HOW_VOLCANISM_AFFECTS_CLIMATE.pdf
In agreement with this and all the other thousands of studies which reach essentially similar conclusions.
http://icecap.us/index.php/go/joes-blog/the_real_climate_drivers_ocean_and_solar_cycles_amplified_by_levels_of_volc/
One last post here, but this one is very enlightening and full of information on solar/volcanic relationships and how they due indeed effect the climate.
The effect of volcanoes has been well studied. Willis would benefit from reading the research. Many such studies have been linked on this blog in the past.
The effect of volcanic eruptions on weather depends on a number of factors besides their magnitude. An important one is where the volcano is located. Tropical eruptions affect global weather differently from higher latitude eruptions. Pinatubo displayed the effect of a large tropical eruption well.
On average, the effects on weather of an eruption big enough to matter is short term cooling followed by longer term warming, but neither persists for sufficient time to affect climate, although a prolonged period of increased volcanism might.
Irish chronicle shows cooling effect of volcanoes:
http://www.iop.org/news/13/jun/page_60307.html
The effects of very large eruptions:
http://rsta.royalsocietypublishing.org/content/364/1845/2073.full
Effect on CCNs and creation of vog:
http://www.hawaii247.com/2014/08/22/volcano-watch-how-do-volcanoes-affect-the-weather-and-climate/
Naturally the USGS had to throw in “climate”, although single volcanic effects rarely last long enough to affect climate.
Thanks Willis, interesting as usual.
Could you clarify the scale of the last (updated) graph. It says ‘anomaly’, but that looks like a large anomaly differential to me (+12 to -12 ºc). But if they are actual temperatures -12ºc looks much too cold for an average European winter.
A quick explanation?
Thanks, R.
An “anomaly” is just the variation of the temperature around a certain arbitrary level. In this case the level is the mean of the data. I’ve subtracted the mean from each dataset so they could be compared.
w.
Willis,
After having a look at the data, like yourself, I found the data unconvincing of an effect.
However, when you look at the prevailing winds, Icelandic volcanic aerosols would be blown mostly southwesterly towards Newfoundland, and somewhat northeasterly towards Norway. Therefore, looking at Prague, Geneva and Milan doesn’t prove much at all either way. Looking at Trondheim seems to be the most relevant… and then maybe CET or Stockholm. But even there, the winter of 1783/1784 doesn’t seem “unprecedented”.
The historic reports of very cold winters might be related to the fact that 1783 seems to have had quite a warm summer. Maybe that had an influence on the amount of snow or humidity? As you will know, there’s a difference between absolute temperature and “perceived” temperature.
Frank
Its possible the CET is not a very good indicator of climate, at least what humans experience. Take for instance 1816 the year without a summer, caused by Tambora:
http://en.wikipedia.org/wiki/Year_Without_a_Summer
Europe
“Cool temperatures and heavy rains resulted in failed harvests in Britain and Ireland. Families in Wales travelled long distances as refugees, begging for food. Famine was prevalent in north and southwest Ireland, following the failure of wheat, oats, and potato harvests. In Germany, the crisis was severe; food prices rose sharply. With the cause of the problems unknown, people demonstrated in front of grain markets and bakeries, and later riots, arson, and looting took place in many European cities. It was the worst famine of 19th-century Europe.[9][15]”
Nothing impressive shows up during 1816 on the CET, even though history clearly documents it as a major disruption of climate and significant hardship for humanity globally.
http://neturania.tumblr.com/post/49592817866/climate-change-part-1-man-made-really
The winter of 1815/16 was cold but not severe in the CET.
This is not surprising, since big tropical eruptions affect various parts of the globe differently. Tropical Asian Tambora’s effect on NW Europe was less than Laki’s, which went off in its own neighborhood. Tambora hammered NE North America worse than NW Europe because its effect on the Gulf Stream was less downstream than upstream, and Central England lies at higher latitude than New England, for instance.
I’ve come across a very interesting and very detailed account of the actual effects of the volcano. The main effect seems to have been an acidic fog. Inter alia they show this graph of the temperatures from 29 stations:
Note that the summer was slightly warmer, but the winter and the annual data was not unusual in any way.
w.
You must have missed this part of the abstract:
“The summer of 1783 was characterized by extreme and unusual weather, including an unusually hot July in western Europe, most likely caused by perseverance of southerly air currents. The following winter was one of
the most severe winters on record in Europe and North America. In these regions, the annual mean surface cooling that followed the Laki eruption was about “1.3!C and lasted for 2–3 years. We propose that the upper troposphere/lower stratosphere aerosols from Laki disrupted the thermal balance of the Arctic regions for two summers and were the main mechanism for the associated climate perturbations.”
I’ve linked to another paper by Self above, on the effect of large eruptions.
In the same comment, a Hawaiian volcano observatory paper discusses vog.
you dont measure the effect by asking whether it was UNUSUAL in any way. wrong headed approach.
this isnt an abduction problem.
The problem is pretty simple.
X is the temperature that WOULD HAVE BEEN but for the volcano
Y is the temperature that was actually recorded.
The effect of volcanos is X-Y. simple.
But we dont have X. we will never have X. we could model X, but that’s not data its an estimate of what would have been.
Or If you do a simple regression you can see that the years with volcanos are, in general, colder than one would expect. the residuals can show that to you. Or you can stack the volcano epoche’s.. or detrend and stack
Which ever method you use ( physical modelling of X or statistically trying to separate out the additional cooling), one thing remains clear. We don’t have X. we will never have X and so any statements we make are going to be heavily caveated.
Since you do not know X for any year when there was a volcano, one can never say “that the years with volcanos are, in general, colder than one would expect.”,
The Laki eruption lasted eight months during which time about 14 cubic km of basaltic lava and some tephra were erupted. Haze from the eruption was reported from Iceland to Syria. In Iceland, the haze lead to the loss of most of the island’s livestock (by eating fluorine contaminated grass), crop failure (by acid rain), and the death of one-quarter of the human residents (by famine). Ben Franklin noted the atmospheric effects of the eruption (Wood, 1992).
It is estimated that 80 Mt of sulfuric acid aerosol was released by the eruption (4 times more than El Chichon and 80 times more than Mount St. Helens).
The climatic effects of the Laki eruption are impressive. In the eastern United States, the winter average temperature was 4.8 degrees C below the 225 year average. The estimate for the temperature decrease of the entire Northern Hemisphere is about 1 degree C. The The top graph shows change in acidity in micro equivalents H+ per kg in the Greenland icecap. The bottom graph represents the winter temperature records in the eastern United States. From Sigurdsson (1982).
Besides devastating Iceland, Laki caused widespread famine in Egypt (1784), Tunisia (1784–85) and probably India (1783–84):
http://www.sciencedaily.com/releases/2006/11/061121232204.htm
You probably won’t like the tree ring data or the modeling to explain the effects of the eruption on Egypt, but there are plenty of other data.
The Tunisian famine killed up to one-fifth of all Tunisians.
India had already suffered a famine in the prior year, probably resulting from El Nino-related drought, but the follow on might well have been worsened by the effects of Laki. Together the two famines killed about 11 million people there:
http://en.wikipedia.org/wiki/Chalisa_famine
These posted above in a reply to Willis (in case overlooked)
Wrong Willis ….. It is/was the coldest winter in the CET (1659 to present)…..
http://en.wikipedia.org/wiki/Central_England_temperature#Data_quality
The DJF mean temp was -1.2C
The next coldest was 1740 at -0.4C
Also from the UKMO for stronger confirmation …..
http://hadobs.metoffice.com/hadcet/ssn_HadCET_mean.txt
Also the study you quote from does not say that the Laki eruption caused the 1683/84 winter … on the contrary (from abstract)…
“Data sources and model simulations support our hypothesis that a combined negative NAO‐ENSO warm phase was the dominant cause of the anomalous winter of 1783–1784, and that these events likely resulted from natural variability unconnected to Laki. “
Late comer here, I have only scanned the comments above and may have overlooked the following topic. Back in the cold war days, the concept of a “nuclear winter” existed. Forecasts based on a program TTAPSS (sp?) predicted severe consequences resulting from nuclear explosions producing great quantities of atmospheric debris. The concept was “tested” when the Iraqi’s blew up the Kuwait oil fields. Memory serves me less well now days, but I seem to recall there was NO detectable effect on global temps. Does anyone have a better memory?
Your memory is basically correct:
http://geo.arc.nasa.gov/sge/jskiles/fliers/all_flier_prose/kuwaitioilfires_pilewskie/kuwaitfires_pilewskie.html
The astronomical Dr. Sagan and his usual suspect cronies Dr. Ehrlich and Dr. Schneider were climastrologists then, as Dr. Ehrlich remains. Dr. Sagan died before being able to jump on the Watermelon climate bandwagon, but Dr. Schneider of course did before his demise.
The point is that to have a large but short (2-3 years) effect on climate, the emissions must reach the stratosphere, which was the case for the Pinatubo and a few other eruptions in the recent past and in part for the Laki, and are certain in the case of nuclear explosions, but not for the Kuwait oil fires. After a few days, the smoke/particulates of the fires rain out are dispose off on land or oceans…
Nuclear winter is as big a crock as man-made climate change, and based upon equally execrable models and false assumptions. Schneider at NCAR did at least have the integrity to lower the doomsday level in his later modeling after consideration of better soot data, to “Nuclear Autumn”.
Besides which nuclear war now would not produce the needed firestorms. First because “countervalue” targeting (bombing cities) by the superpowers is at best highly unlikely, as opposed to attacking military targets. Second because modern cities just don’t burn as easily as did Hamburg and Hiroshima, both of which cases required exceptional meteorological conditions. No firestorm occurred over Nagasaki.
In 1988 Russell Seitz of the Harvard University Center for International Affairs said that the models’ assumptions produced the results that researchers wanted to achieve and were an instance of “worst-case analysis run amok”.
Sound familiar?
Marxist academics happily abuse their positions of trust and will stop at nothing to further their ideological agendas.
Toneb November 19, 2014 at 12:34 pm
Gosh, Tone, you mean this quotation from your citation?
Learn to read before you go all snarky and start accusing me of being wrong, son. That says the coldest winter was 1683, not 1783 … see my graph above, which agrees with Wikipedia about 1683 …
w.
My apologies … i was a century out.
However your article is based on a false premise.
The quoted study was not claiming that Laki was responsible for the winter of 1783/84 … son.
It appears that not only are you so careless that your claims are 100 years wrong, now you’ve proven that either you can’t read or your don’t care about clarity. So let me remind you of my saying the following:
It appears that you think I said that the quoted study claimed that Laki was responsible for the winter of 1783/84 … I quoted exactly what the study said about the temperatures of the winter. I said nothing about whether the study said Laki was responsible or not.
In fact, they said Laki was NOT responsible, which is very unusual among such studies. Most of them claim that Laki was the sole and only cause of the effects on the weather. I assumed that the readers were capable of reading the study and drawing their own conclusions.
Read what I said again, Tone. I never made the claim you think I made.
w.
Willis, can you integrate those graphs. It may be that it was colder by number of degree days, not by absolute or average temps. Thx. As always I am pleased by what you do.
Willis said:
“Remembering that the study claimed that this was “among the coldest winters in Central England”, which winter looks like the big winner here?
In fact, far from being among the coldest all-time winters, the winter of 1783-1784 was not even in the top three for the quarter century 1775-1800 …”
As you saying coldest winters and not coldest months, the usual practice is give the average for December, January and February, you should find that it is the second coldest in that 26yrs.
While there are known astronomical causes for the winter of 1783/84, the effects of aerosols and ash from Laki, being low altitude, had the effect of exacerbating the high temperatures through the summer months when they engulfed the UK.
You are right and Willis dead wrong, for whatever reason. I already pointed this out to Willis, but as per usual, he hasn’t bothered to respond.
For the 50 years 1741 to 1790 (onset of the Dalton Minimum), 1783/84 was the coldest three months. And the following winter tied the next coldest of that half century, 1764/65.
Here again is what I wrote above, typically ignored by Willis:
You are mistaken about the CET record. Only one winter in the period you cite was more severe, and it occurred during the Dalton Minimum.
http://www.theweatheroutlook.com/twoother/twocontent.aspx?type=libgen&id=1488
The second and third coldest CET winters during that quarter century were back to back after Laki:
1783/84 – 3.5c…SEVERE
1784/85 – 4.1c…SEVERE
Only 1794/5 was worse.
1794/95 – 1.4c…SEVERE
Thanks, Ulric. I’ve posted the graph of the winter (DJF) CET upthread.
w.
Again, what counts as “unusual”?
It was the lowest in an ~55 year period, followed by the next lowest winter. The lower winter T of 1704/95, as repeatedly noted, fell during the Dalton Minimum and except for 1739/40, the other two lows were during the Maunder Minimum.
IMO the lowest temperature in a period longer than half a century, followed by another unusually low T winter, is more than “unusual”. Especially when going back another 25 years (1715-39) gets you only one winter colder.
You would benefit from looking at the actual numbers I linked for your benefit, rather than at a graph.
You should also acknowledge that your statement “the winter of 1783 was cold … but according to the CET, it didn’t even make the top three in the quarter century 1775-1800. Hardly impressive” was wrong. As noted over and over again, it was the coldest in that period but one during the Dalton, and it was followed by another which tied for third.
Sadly, Willis is a recidivist, serial ignorer, as of the hundreds of papers showing the influence of solar activity on climatic phenomena. Going “La-la-la, I can’t read you!” is the anti-scientific method.
http://icecap.us/images/uploads/OC19.png
As one can see the volcanic eruption DID have a BIG effect on temperatures, although not long in duration.
Now there’s an instructive graphic.
Thanks!
The chart above and the following below are from Joe D’Aleo of Weatherbell, the best I have ever come across when it comes to climate and why/how it may change..
In North America, the winter of 1784 was the longest and one of the coldest on record. It was the longest period of below-zero temperatures in New England, the largest accumulation of snow in New Jersey, and the longest freezing over of the Chesapeake Bay. There was ice skating in Charleston Harbor, a huge snowstorm hit the south, the Mississippi River froze at New Orleans, and there was ice in the Gulf of Mexico.
The Laki eruption illustrates that low energy, large volume, long duration basaltic eruptions can have climatic impacts greater than large volume explosive silica-rich eruptions. The sulfur contents of basaltic magmas are 10-100 times higher than silica-rich magmas (Palais and Sigurdsson, 1989). The sulfur dioxide is what forms the sulfate aerosols which reflect radiation.
How does sun play a role? I believe the sun drives the oceanic cycles which drive the weather. See the details of how here. Volcanism is the wildcard amplifier. See how the TSI as compiled by Hoyt/Schatten/Willson matches the ocean cycles and temperatures.