Medieval climate change shown by osteological analysis

17 August 2007

In September, Human Osteologist Don Walker and former MoLAS colleague Amy Gray Jones will be presenting a poster at the annual BABAO conference on the catastrophic effects of climate change on the population of medieval London.

Evidence from ice cores suggests that the largest volcanic eruption of the last millennium occurred in 1258 somewhere in the tropics. Palaeoclimate models demonstrate that the stratospheric spread of a blanket of volcanic particles would have led to a significant summer cooling.

Contemporary writings from England note a long cool period from February to June 1258 and a very cold winter in 1260-1261. Severe summer and autumn rains caused crop failures throughout north-west Europe and in England this led to famine. A great pestilence struck the weakened London population in the spring of 1259.

Almost half (2323/5387: 43.1%) of the individuals studied as part of the Spitalfields project were buried within mass pits shown by  a combination of stratigraphic analysis and radiocarbon dating to originate in the mid 13th century. Whilst famine and disease were no strangers to urban populations throughout the medieval period, it is highly probable that the suffering in the late 1250s was part of a global scenario brought about by volcanic activity.