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.