When Scientists Dabble in History

Bad things can happen. (Note: the reverse corollary where historians dabble in science also holds great peril.)

Just up over at Boing Boing is an article reporting that scientists at Utrecht University are positing that the Black Death caused the Little Ice Age. (Original link at the BBC.)

I sit back and wait for the medievalists among my readership to recover from their guffaws.

Oh, yeah. Now, part of their observations I can understand — they note a strong increase in cereal pollen through the thirteenth century and up to 1347 after which there was a sharp decline. And the positing of reforestation in some areas could have lead to increased atmospheric carbon dioxide but. . . .

Well, it’s just that most medievalists point to much earlier events than 1347 signalling the start of the Little Ice Age. Glacial advances that were noted in thirteenth century Europe. The two early fourteenth century cold snaps that contributed to the decline of the Greenland colony. The Great Famine of 1315-1317. I could go on and on. . . .

And while the Black Death was briefly effective at reducing Europe’s population, an agricultural and demographic upswing was well underway by the seventeenth and eighteenth centuries. By 1750, England was home to some 3.7 million people (approximately the same population that had inhabited the country circa 1300) intensively working the land, deforesting the countryside and draining the marshlands to increase the total amount of arable land by some 30% over the previous era. Mark Overton at BBC History on the Agricultural Revolution.

Historians generally posit the reverse relationship between the Little Ice Age and the Black Death if they find one at all: they argue that with the world, Europe in particular, weakened by malnutrition and privation caused the worsening climate, the population was particularly vulnerable to the bacillus. And it’s going to take a lot more than some backwards positing based on pollen levels to get us to put the cart before the horse. . . .

What’s interesting, in reading up for this post, I discovered wide dispute over what was meant by the Little Ice Age (pegged, variously, from 1300-1800 or 1550-1850) and the Medieval Warm Period (was it the eighth to tenth century or the eleventh through fourteenth?) and scholars of climate sometimes draw on completely different sources of evidence from the historians. And when the climatologists start making enormous leaps of historical deduction based upon their narrow observations without bothering to examine and analyze the rest of the historical data upon how much of the abandoned land was reforested, how soon and how this affected the climate? It leaves a bad taste in my mouth.

9 Responses to “When Scientists Dabble in History”

  1. New Kid on the Hallway Says:

    Umm… yeah. I’m going to commit a cardinal (or at least venial) sin by commenting without reading the articles you link to, but didn’t anyone consider that cereal pollen would decline post 1347 not because of climate change, but because, you know, all those people who great the cereals DIED? And that because you didn’t have so many people to grow cereals, people switched from cereal production to livestock (less labor intensive)? Are the arguing that demographic decline makes it colder, or do they argue that b/c pollens decrease, climate must have also worsened? (Sorry, I should go read the article, but it sounds pretty ridiculous to me!)

  2. ancarett Says:

    I think their argument is fewer people led to a sudden drop in crops (which I buy) which led to reforestation (mebbeee. . . ) which led to increased carbon dioxide (well, only if there’s significant reforestation!) which led to the Little Ice Age.

    But as we historians know that Europe was feeling much colder circa 1300, that just doesn’t work for me!

    I’m glad I’m not the only one who went “Hey, what?” at the very proposition they put forward!

  3. wolfa Says:

    Oh, come on, I only sat through a single lecture on the little ice age (course shopping) and I even knew the timing was off. This is why it is bad when people don’t have grounding in humanities AND sciences.

  4. New Kid on the Hallway Says:

    Ah. Well, I have to say that I have a hard time thinking that the level of crops vs. forest BEFORE the Black Death was so high that the population loss and crop decrease could really lead to a significant change in climate overall. That is, Europe was a lot less densely populated in general, and more highly forested, in the Middle Ages, and I have a hard time seeing that there was such radical reforestation - crop loss, yes, but reforestation? (all those lost villages in England don’t seem to be buried under new forest!). But you know, I’m not a scientist, so doubtless I’m underestimating the impact we humans have! (And yeah, there’s that whole cold-in-1300 thing!)

  5. Ricki Says:

    Okay… so last night I was shopping online… Oh.. wait… wrong topic… :-)

  6. ancarett Says:

    Ricki! Long time no (virtually) see! Let me know how you’re managing. I hope the weather’s warmer at your end than ours (if not, we’re heading into another “Little Ice Age).

  7. JS Narins Says:

    Seems like the perfect response would be the high school era “achoo” which ends up sounding like “b*llsh*t”

    Science doesn’t have generally agreed upon dates for either.

  8. mgr Says:

    Not having read the article (big sin), but having worked on some climate reconstructions, it would appear that the argument being made is why the Little Ice Age persisted, not when it began. What is appears is that the authors are postulating a positive feedback, that enhanced the cooling initiated by change in insolation that initiated the LIA.


  9. ancarett Says:

    Mike, welcome to the blog and the conversation! Your explanation certainly sounds a more plausible construct than what the newspapers have reported of the research. If the argument for persistence rather than causation is what they’re making, I’ll give their analysis another chance.