Long Burn

14th c. biosphere-climate interaction?

Just ran across an interesting theory. The Black Death of the 14th century is thought to have killed over a third of Europe's population. Trees growing on the abandoned farmland would have removed large amounts of carbon dioxide from the atmosphere. Less greenhouse gas would have lead to cooling of the planet. Indeed, cooling was seen in the little ice age, a 300 year period of below-average temperatures. Could it be true? Perhaps, according to this article. One question I have though is that while the temperature record does support the little ice age, ice core records of gas concentrations do not show a decline in CO2 in the 15th century. There are other theories as to the origin of the little ice age. One links it to changes in ocean circulation. Another links it to the sun, since the timing of the little ice age corresponds to the Maunder Minimum, a period of about 70 years during which there were no sunspots. There is an interesting link between climate and Scandinavian civilization. The heyday of the vikings corresponds to the Medieval Warm Period, with cooler temperatures bringing the end of the viking era (and hard times for viking colonies on e.g. Iceland).

posted by Matt_J @ 4:10 PM