Scientists suggest that the Bubonic Plague may have triggered Europe's "Little Ice Age," a a bitter cold period between the 14th and 19th centuries. According to Utrecht University researchers, the Black Death wiped out so many people that millions of trees grew on the abandoned farmland. The huge new population of trees may have absorbed so much carbon dioxide from the atmosphere that the climate cooled. From the BBC News:
Dr Thomas van Hoof and his colleagues studied pollen grains and leaf remains collected from lake-bed sediments in the southeast Netherlands.
Monitoring the ups and downs in abundance of cereal pollen (like buckwheat) and tree pollen (like birch and oak) enabled them to estimate changes in land-use between AD 1000 and 1500.
The team found an increase in cereal pollen from 1200 onwards (reflecting agricultural expansion), followed by a sudden dive around 1347, linked to the agricultural crisis caused by the arrival of the Black Death, most probably a bacterial disease spread by rat fleas…
"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.
