Siccitas magna ultra modum: Examining the occurrence and societal impact of droughts in Prehistoric Ireland

When considering past human-environment relationships in Ireland, we rarely contemplate the potentially detrimental effects of drought on populations. The summer of 2018 drew attention, however, to some of the ways in which reduced precipitation can impact on societies, even in an oceanic setting such as Ireland. Here, we examine ways in which we can identify the past occurrence of droughts through palaeoenvironmental records. We focus on three time intervals (c. 6200 BC, 3200 BC and 900 BC) for which there is evidence for centennial-scale droughts—drought phases—and consider the available archaeological and palynological records to evaluate whether the droughts may have triggered economic responses or population collapses. We find little evidence to confirm that any of these events undermined the subsistence base to the extent of triggering population collapse. We briefly explore alternative mechanisms by which the drought phases might have impacted upon human perception of their environment.