From BBC News’ “Europe’s chill linked to disease“:
Europe’s “Little Ice Age” may have been triggered by the 14th Century Black Death plague, according to a new study.
Pollen and leaf data support the idea that millions of trees sprang up on abandoned farmland, soaking up carbon dioxide from the atmosphere.
This would have had the effect of cooling the climate, a team from Utrecht University, Netherlands, says.
The Little Ice Age was a period of some 300 years when Europe experienced a dip in average temperatures. …
“Between AD 1200 to 1300, we see a decrease in stomata and a sharp rise in atmospheric carbon dioxide, due to deforestation we think,” says Dr van Hoof, whose findings are published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.
But after AD 1350, the team found the pattern reversed, suggesting that atmospheric carbon dioxide fell, perhaps due to reforestation following the plague.
The researchers think that this drop in carbon dioxide levels could help to explain a cooling in the climate over the following centuries.