Guest Post by Willis Eschenbach
Since I was a kid I’ve been reading stories about “The Year Without A Summer”. This was the summer of 1816, one year after the great eruption of the Tambora volcano in Indonesia. The Tambora eruption, in April of 1815, was so huge it could be heard from 2,600 km away (1,600 miles). The stories were always about how the following summer was outrageously cold. Supposedly, the summer was so cold it was like having no summer at all.
Being a suspicious fellow, I got to thinking about that, and I realized I’d never seen any actual temperature data for the year of 1816. So I went off to find some early temperature data. I started with the ECA dataset, and downloaded the Daily Mean Temperature TG (162Mb). That revealed five stations with daily temperature records with starting dates before 1816—Stockholm, Bologna, Milan, Praha-Klementinum, and Hohenpeissenberg.
So once again, I found myself playing “Spot the Volcanoes”, as in my previous post on this subject. When I wrote that post, I hadn’t been able to spot the smaller eruptions of Pinatubo and other modern volcanoes, but Tambora was the big cheese, the grand gorgonzola of volcanoes. Surely I could find that one … so here’s the record from Stockholm.
Figure 1. Two ten-year periods from the early 1800’s in Stockholm
So the question is, which year is “The Year Without A Summer”? The year indicated by the blue arrow, or the year shown by the green arrow?
Actually, I fear that was a trick question. Here’s the same data, this time with the years indicated.
Figure 2. Two ten-year periods from the early 1800’s in Stockholm, including the dates.
As you can see, the 1816 “Year Without A Summer” actually was warmer than a number of other summers in Stockholm. It’s the third peak from the left in the top panel, and was above 20°C. Just in this tiny sample we see some six summers that were cooler than the summer of 1816 in Stockholm …
So, I looked at the other locations. Here are the other four European cities with records that cover the Tambora eruption—Bologna, Milan, Praha-Klementinum, and Hohenpeissenberg. In these, both the upper and lower panels are from the early 1800s. No more trick questions, in all cases, one or the other of the green and blue arrows actually indicates the “Year Without A Summer”.
Figure 3. Two ten-year periods from the early 1800’s in Bologna.
Figure 4. Two ten-year periods from the early 1800’s in Milan.
Figure 5. Two ten-year periods from the early 1800’s in Praha-Klementinum.
Figure 6. Two ten-year periods from the early 1800’s in Hohenpeissenberg.
That was all the daily temperature records I could find from that far back. There’s a monthly record from Armagh, in Ireland. Here’s that record.
Figure 6. Two ten-year periods from the early 1800’s in Armagh.
I’m sure that you can see the difficulty. If Tambora actually did something to the temperature, you sure couldn’t tell it from these records. Not one of them is readily distinguishable as missing a summer.
In “The Great Tambora Eruption in 1815 and Its Aftermath” (paywalled, Science Magazine, 1984), the author says (emphasis mine):
To Europeans and North Americans, 1816 became known as “the year without a summer” (41). Daily temperatures (especially the daily minimums) were in many cases abnormally low from late spring through early fall; frequent north-west winds brought snow and frost to northern New England and Canada, and heavy rains fell in western Europe. Many crops failed to ripen, and the poor harvests led to famine, disease, and so- cial distress, compounded by the aftermath of the Napoleonic wars.Tambora’s dust veil is often blamed by modern researchers for the cold summer of 1816. The argument given is that the stratospheric dust veil would have absorbed or reflected solar radiation that could otherwise have reached the ground (42). Not all regions,however, experienced abnormally low temperatures, and the preceding winter had generally been mild. Therefore, a few researchers deny that there was any (or at least a strong) connection with the volcano (39,43).
I’m leaning towards the “few researchers” that deny a strong connection with Tambora. What other records do we have? Well, over at KNMI I find the record for Manchester, England:
Figure 6. Two ten-year periods from the early 1800’s in Manchester.
Moving across the Atlantic, here’s the record from New Haven in Connecticut.
Figure 6. Two ten-year periods from the early 1800’s in New Haven, Connecticut.
I’m just not feeling the Tambora love here … where are the records of years without a summer? Or at least of a summer that’s significantly colder than its neighbors?
Don’t get me wrong here. I suspect that generally, the summer of 1816 was a bit colder than most summers. But as the graphs above show, in all of these datasets there are comparable summers within a few decades either side of 1816 that have summers that are as cool, or cooler, than the summer of 1816.
And I would guess that a careful search would reveal some records with cooler summers than the ones I’ve found here. But overall, let me suggest that over the years the Tambora story has gotten greatly exaggerated, just as we do today with our stories of “Cold? You haven’t seen real cold. Why, when I was a young man it was so cold that …”
Conclusions? Well, my main conclusion is what I’ve been saying for some time. The temperature of the earth is not particularly ruled by the changes in how much energy it receives. Tambora cut off a huge amount of sunlight, but the effect was small. Yes, some areas had a summer that was a bit cooler than most summers. And I’m sure there were certain locations where it hit harder than others. But overall? The thermostatic mechanisms of the planet kept Tambora from having a much of a cooling effect.
My best to all. I append all of the figures below, with the dates, so you can see the lack of effect. Note that in many of them, the temperature in 1815 was about the same as 1816 … and that despite the size of the volcano, if there was any effect, it was totally gone by 1817.
w.
If that’s what a really big volcano can do, I’m not impressed. Well, I am impressed, but what’s impressive is the strength of the thermostatic mechanisms that keep the earth’s temperature within a very narrow band. Even a huge volcano can’t put it out of sorts for much more than one summer, and even then not too much.
The place to look for the effect of volcanic eruptions on the climate is in food commodity prices. That is where climate change has its greatest impact on human society. In those records the Tambora eruption is unmissable.
These graphs were daily mean temperatures. Are there daily minimum temperatures that could be plotted over decades?
Your intended trick question isn’t a trick question, since the dates are present in Figure 1.
[REPLY: Grrrr … proofreading 10 different graphs, the title was right but the contents wrong … fixed, in any case, and thanks. -w.]
A small point but Fig 1 and Fig 2 both have dates.
Let’s accept the above as true, “Even a huge volcano can’t put it out of sorts for much more than one summer, and even then not too much.”
Now let’s consider the recent papers that stated that a period of intense volcano activity initiated the last ice age. Hmmm… using a quick Onager estimate, the whole earth must have been erupting, and did so for several centuries, for huge glaciation to have occurred for over 100,000 years.
pretty amazing, really. Really illustrates how susceptible we are to myths and exaggeration about weather and climate. Thanks Willis, impressive as always.
I wondered if the real difference was in precipitation?…. Sometimes people tend to mistake unusually wet for unusually cold and vice versa. For instance, this winter in Spokane was strictly average for temperature but abnormally dry and unsnowy. All the media have been calling it warm and mild.
But no. A quick look at the Klementinum data shows a nice period of strictly average precip around 1816!
http://www.climatestations.com/images/stories/prague/prgprcp.gif
What do the tree-rings say?
The oceans, being a gigantic heat sink, both store and release heat.
Have these data been processed thorugh Mann and Hansen’s disgronificator? We can’t know what the temperatures actually were until we decide what we want them to have been… (that verb tense is what I call the “past superfluous”).
Interesting indeed! Especially interesting in considering arguments that volcanic eruptions can sustain global cooling for long periods of time, including whole glacial periods in the past. Volcanic eruptions are short, punctuated events, not well suited to generating and sustaining long glacial periods. Although this one example is probably typical, similar data on other large eruptions would be nice. What Willis has shown in this example is the kind of real evidence needed to demonstrate whether or not volcanic activity is a viable cause of long-term climate change, as claimed by a number of recent publications.
Based on this “history” — maybe it really was the “low” temperatures on a relatively few key summer days in “sensitive” locations that lead to the stories regarding the year without a summer. I read it snowed in June in Ohio. I also read this:
“In April 1815, Mt. Tambora, .. exploded…
In some parts of the world, the impact was minor but in much of Europe it caused near famine conditions. In New England it helped change history…
Several cold spells in May 1816 delayed the start of the planting season. June began well, but crops were lost in a cold spell between the 5th and 11th. Snow accumulated throughout all but southernmost New Hampshire. A warm spell starting the last third of June provided hope that summer had arrived, but a killing frost on July 9th dashed that hope. The rest of the month was warmer, but didn’t equal the warmest days of June. A warming trend in August abruptly ended with frost on the 21st and a worse one on the 30th. …
After 1816, the weather returned to normal conditions quickly. However, farmers had already started emigrating to the more hospitable weather and soil of Ohio and further west…”
What this demonstrates is just how fragile our agricultural system has been to quite small climate changes.
As the graphs show the difference between a good and bad year can be just a degree or so, hardly perceptable on a graph of several decades and apparently not much different from other years without the influence of a volcanic cooling event.
The place to look for the effect of volcanic eruptions on the climate is in food commodity prices. That is where climate change has its greatest impact on human society. In those records the Tambora eruption is unmissable.
There was a series of large volcanic eruptions starting in 1812, so a comparison with pre-1812 temps would be appropriate. In Europe and China the main effect was heavy rain and lack of sunshine causing crops to fail. Indicating aerosol seeded clouds were the main effect.
The unusual cold in eastern N America might have been a consequence or it might just have been coincidental.
Must be something to do with atmospheric pressure ??
I’m going to reply before I read the full post. I don’t think I’ll be too far afield, if so I’ll do a followup.
I’ve written a web page titled 1816: The Year without a Summer A New Hampshire Perspective. I think New England is where the phrase came from, we ceratinly can take credit for “Eighteen Hundred and Froze to Death.”
First a correction. You say “The Tambora eruption, in April of 1815, was so huge it could be heard from 2,600 km away (1,600 miles). That was the Krakatoa eruption in 1883. There were a lot more Europeans in Indonesia then and the telegraph communications helped get the news about Krakatoa’s explosion to Europe much more quickly than the Tambora eruption. (I wouldn’t be surprised if Krakatoa were louder too. I doubt loudness correlates all that well with material and SO2 released.)
Second, the summer of 1816 wasn’t cold all the time. It was very cold some of the time. I concluded that the major effect was that the norther jet stream didn’t migrate as far north that summer as usual. For example, I note:
The apple crop did quite well due to the lack of insects. That means the blossom managed to miss a freeze, so even in the spring there were stretches of frost-free weather.
Further south, the agricultural impact in Virginia was minor. They would have missed out on the frosts in pretty much any event, but what I recall from my readings was that people’s journals didn’t have much to say about the summer being abnormal.
There were also significant impacts in Europe, but I’m not so conversant about them. One piece of triva – Mary Shelley wrote her novel Frankenstein during her vacation to Switzerland in 1816 when the weather was so inhospitable that she and her friends spent little time outside. http://www.atlantisjournal.org/ARCHIVE/28.2/2006Phillips.pdf is worth reading.
Apparently the climate mechanisms are watching over us, instead of we (humanity) influencing on a global scale the climate. How fortunate we are to live on earth!!
Why so many graphs without any dates??
And the two first wher one is supposed to have no dated, both graphs have dates…
Why not simply show one copy of each graph, with proper dates? It would be easier to follow.
Other than that I remember reading about “The Year Without A Summer” in Scientific American some ~30 years ago… I was fascinated. If it was all wrong, I am fascinated again…
Perhaps you need to look beyond temperature as the sole arbiter of what makes a summer.
Sunshine hours? Crop failures, cold spells that cause them? storms?
As I recall,last year or the year before in the UK was forcast to be a “Barbeque Summer” a dismal non-event.
There may have been a gap between expectations and actualities that wasn’t tied to one factor.
On a clear sky day with the sun beating down on my red neck, it gets quite hot here in Brisbane. But it cools down nicely by evening when I enjoy a nice cold beer on the verandah.
During an overcast day the temperature never reaches the heights of the clear sky day. However the nights can be warm and stifling, difficult to sleep.
How does one determine the above from mean Ts?
As a professional geologist I am greatly impressed by large volcanic eruptions. However, that impressiveness has no relation to climate. As a professional photographer I look forward to the heavy duty red sunrises and sunsets too. That too may be atmospheric but not related to climate. Willis is most correct when he points out, in different terms, that we humans choose
the mythology we believe. That mythology may or may not have any relationship to reality and over time that relationship seems to disappera all together. I grew up in a small town north of Madison, Wisconsin. Yes when I was a boy not only was it coooold but we had way more snow. Thinking about it, my butt was way closer to the ground too.
If one looks at the CET data ( http://mclean.ch/climate/England_Scotland.htm )
it shows a down spike of around -1.6ºC for 1816, which is nothing like the down spike for 1740 of about -2.7ºC or the one of 1880 of -2ºC
http://mclean.ch/climate/Eng_Scot/Fig_02_CET_anomaly.gif
Willis, it is true that 1816 was just a case of “one more cold summer”, and not a really, really cold summer anywhere, but the big difference is that this cold summer happened in all places, while normally, if somewhere in the world is particularly cold, it is because it is hotter in other parts. Tambora made the weather everywhere agree that it was cold, so to say. Not to mention that there may have been places where it was actually extremely cold and we just don’t have the records.
Why don’t you plot the average temperature of all the records that you have for all the years? I mean, something like a “global” temperature of the few records you have. You will probably find Tambora there, shouting out loud. If it doesn’t appear there, then I will have to agree with you.
If you are looking for the effects of a really big volcano, try the Toba event around 74,000 ybp. The Sunda event (around 535 c.e.) was a fun one too. David Keys has an exellent study on the effects of Sunda in his book, Catastrophe. It was also made into an episopde in a series for PBS called “Secrets of the Dead.” That series included a good segment on the demise of Norsemen in Greenland as the LIttle Ice Age set in. But come to think of it, with all the seismic activity in Indonesia lately, I wonder if we’re due for another pyroclyastic event on par with Tambora or Krakatoa.
HADCET: http://www.metoffice.gov.uk/hadobs/hadcet/mly_cet_mean_sort.txt
out of 353/354
1816
Coldest July ever
20th coldest August
26th coldest June
38th coldest May
50th coldest April
34th coldest September
238th coldest October – the outlier
23rd coldest November
11th coldest December
1817
3rd coldest May
15th coldest July
10th coldest August
2nd coldest October.
Just in this tiny sample we see some six summers that were
warmercooler than the summer of 1816 in Stockholm …[REPLY: Thanks, fixed. -w.]