The Little Ice Age is generally seen as a major event in European history. Analysing a variety of recent weather reconstructions, this column finds that European weather appears constant from the Middle Ages until 1900, and that events like the freezing of the Thames and the disappearance of English vineyards have simpler explanations than changing climate. It appears instead that the European Little Ice Age is a statistical artifact, where the standard climatological practice of smoothing what turn out to be white noise data prior to analysis gives the spurious appearance of irregular oscillation – a Slutsky Effect.
Introduction
The Little Ice Age – dated from the mid-14th century to the early 19th – plays a large role in historical analyses. Anthropologist Brian Fagan suggests that this climate swing demoralised the European peasantry, allowing for the rise of despotic leaders (Fagan 2000). British and Dutch canals and rivers frequently froze, allowing French land forces to invade the Netherlands while the Dutch fleet was ice-locked. But was it really an ice age, or have historians been “fooled by randomness” (Taleb 2005)?
In recent research we attempt to discover how much European weather actually worsened during the Little Ice Age. Our conclusion – using a variety of standard temperature reconstructions – is that there is little evidence that a European Little Ice Age ever occurred (Kelly and Ó Gráda 2014).