Medieval climate change

Just as we are discovering now how much climate change can affect us, so medieval people were also affected by climate change.  In both cases, humans seem able to mess things up much more easily than we are able to fix them.

(Any climate change deniers out there, don't bother.  The science is completely clear.  Even the oil companies are now shamefacedly 'fessing up that they've known that burning fossil fuels heats up the planet since the 1970s.)

The early and late Middle Ages were marked by mini ice-ages.  The first one, starting in the sixth century,  seems to have been precipitated by a huge volcano (maybe in Indonesia, reports vary), which threw so much dust into the air that there was a "year without a summer."  Coming as this did at the same time as the outbreak of the Black Death in Europe, the population crashed.  Even once the volcanic dust settled out of the atmosphere, the reforestation of lands that had been cultivated (no one was there to cultivate them anymore) helped keep the European climate cool for another couple of centuries.  Just getting along and staying alive was a challenge.

This mini ice-age started to pass off in the ninth century and was definitely gone in the twelfth.  Things were warming up, and from western Europe's perspective, this was great.  More reliable growing seasons (less fear of early frost), along with better technology led to rapid population growth and an overall improvement in diet and living standard (which of course helped population growth).  Towns began to grow for the first time since the days of the Roman empire.

Then, in the fourteenth century, another mini ice-age showed up.  By the late thirteenth century Europeans had been farming more and more marginal land, as they had already cultivated all the best farm land but had more and more people to feed.  So the population was already stressed when, in the early fourteenth century, a year without a summer and a repeat performance of the Black Death showed up at the same time.

We have much better documentation on what happened in the fourteenth century than the sixth.  But the evidence of economic and population collapse in the later period certainly suggests that the earlier too must have been pretty awful.

This mini ice-age continued through much of the early modern period (that is, post-medieval).  This is why, back in the early 1970s, a number of scientists thought we might be heading toward a new mini ice-age:  the planet seemed to bring them around every six or seven hundred years.  But hah!  We fooled mother nature by starting to burn fossil fuel, which has prevented any such thing.

For the Middle Ages, cold was the problem.  We have replaced it with heat as the chief problem.  Medieval people did not burn fossil fuel, except very occasionally in a few places where pieces of this strange flammable block rock was found lying around, mostly on beaches.

Kind of depressing to realize that humans can improve things on earth much less than we hoped.

© C. Dale Brittain 2019

For more on medieval life, see my new ebook, Positively Medieval: Life and Society in the Middle Ages.