Medieval Warm Period, Again

I did mention the Medieval Warm Period in 2012, from the viewpoint of how Greenland must have been warmer than currently. There is, of course, more that can be said.

Also known as the Medieval Climate Anomaly (MCA), research suggests that the warmest decades (about a 50-year span, in fact), occurred at different times in different regions between about 1000 and 1250CE.

Cores taken from sediment in the Sargasso Sea area suggest that the MCA was 1°C warmer. Further sediment cores from the Gulf Coast and Atlantic coastline from New England to Florida show a peak in North Atlantic tropical cyclone activity, consistent with warmer ocean temperatures.

Calling it the "Medieval" Warm Period or Climate Anomaly is, of course, eurocentrism at its finest. Other parts of the world were affected. The climate in Africa was notably drier during this time. Analysis of bones from the Canary Islands shows a drop in temperature of 5°C from the MCA to the later time known as the "Little Ice Age." A study in 2013 found that the water of the Pacific Ocean was 0.9°C warmer in the years in question.

How did it affect daily life and culture is an important question. One belief is that the warmer temperatures benefitted agriculture in Europe, leading to better harvests. This led to healthier individuals and an increase in population. That larger population was more at risk of being culled when disaster struck, such as the Great Famine of 1315-1317.

One other phenomenon the warmer climate might have supported was the Norse colonization of North America, due to less sea ice to deal with, and a convenient stopover at Greenland, but we'll go into that tomorrow. See you then.

Updates

My research (or just day-to-day life) sometimes bring me details that I wish I'd known when I wrote a certain blog post, or that I think are interesting tidbits that tie into posts. Occasionally, I will throw these updates together with links to the originals.

May 19
The Domus Conversorum, the "House of Converts" in London for Jews who converted to Christianity (or else be banished from England). A picture of what is on the modern site is here. (The photographer's caption is a little misleading.)
Also, there was a building called "Domus Conversorum" in Oxford, and for awhile it was thought that Oxford (which had a large Jewish population pre-Expulsion) had its own Converts' Inn. It is accepted now, however, that the property was called thus because the rents from it went to supporting the Domus in London.

July 2, 3, and 5
John Wycliffe was a fascinating character for many reasons, but I may have been remiss in "finishing him off" by not giving you the whole story (one of this blog's followers commented on this on Facebook).
Wycliffe died 31 December, 1384, after suffering a stroke a few days earlier while saying Mass. It wasn't until 4 May 1415 that the Council of Constance declared him a heretic (prior to this, only some of his writings were proscribed). His books were to be gathered and destroyed. The Church—never one to do things by halves when defending the faith was involved—exhumed his body in 1428, burned it, and scattered the ashes in the nearby River Swift near Lutterworth.

July 21
Update on the Greenland/Medieval Warm Period topic
Just this week it was reported that satellites have seen a sudden and massive melting of the ice on Greenland. The specific/immediate cause is unknown. This may make archaeological digs for Erik the Red's settlements easier to examine. The report is here.

(Also, I want to say "hi" to any visitors from reddit.com. Yesterday saw a large influx of visitors from that site to yesterday's post on vocabulary first found in Chaucer's writings. Thanks for visiting anc creating a pleasant spike in my site traffic!)

Medieval Warm Period

The Medieval Warm Period (MWP) existed from 950/1000 to 1200/1250 CE (estimates vary because of the difficulty in collecting accurate data and the desire to allow some leeway for natural change in climate trends). It was followed by cooler temperatures and something called the Little Ice Age (LIA) which lasted from about 1500 until about 1850. (The span is also referred to as the Medieval Climate Anomaly, if you want to Google it.)
Some medieval records indicate weather (drought years, particularly bad storms, et cetera), but they didn't have the organizational longevity (or the interest) to record long-term climate trends. Besides tree rings and ice cores, is there any "anecdotal" evidence from the Middle Ages itself that suggests long-term changes in average temperature?

Erik the Red

Let us look at Erik Thorvaldsson (950-c.1003), aka Erik the Red. Erik's father wasn't the most easygoing guy, and was exiled from Norway, whereupon he took his family to Iceland. Around 982, Erik himself got into trouble for killing some people (poor anger management was apparently a family issue). He sailed from Iceland to Greenland, where legend says he created the first settlement. It is likely that there was already a Norse presence, but Erik can probably claim credit for the first permanent habitation.

If we can believe the sagas and records, then even though life was very harsh, in the 1120s there were sustainable settlements on the eastern shore that held 2000-4000 people. One modern scholar reports "190 small farms, 12 parish churches, a cathedral, an Augustinian monastery, and a Benedictine nunnery." On the western shore were "90 farms and four churches."

Why the Norse settlements ultimately failed is a target for speculation–one theory is that rising amounts of sea ice made navigation, and therefore trade that was necessary to keep their society going, difficult–but here's the thing: excavations of those early settlements have found quite a bit of evidence of their way of life—but they have to dig under "permanently" frozen ground to do so.

It is clear that those settlements existed—could only exist—at a time that was significantly warmer than Greenland's climate is today.