ENVIRONMENT

The Little Ice Age

~1250 CE

History · Middle Ages · Holocene · Meghalayan

From about 1250 to the mid-nineteenth century, Europe and much of the northern hemisphere ran cold: Alpine glaciers advanced over farms, the Thames froze hard enough to hold fairs, and cold winters piled up in the chronicles. The causes are now ranked: clusters of volcanic eruptions first, weaker sunlight a distant second, with sea ice and ocean feedbacks holding the chill in place. Its final act was a volley of nineteenth-century eruptions, Tambora among them, and the recovery from them merged into the first human-caused warming.

Why it matters

The Little Ice Age is the climate backdrop of half of modern history, from the end of Norse Greenland to the famines and frost fairs of early modern Europe, and proof that a degree or less, held long enough, rearranges harvests and societies. It also complicates today's baseline: the 'pre-industrial' climate we measure warming against was itself climbing out of volcanic winters. Climate history has no flat reference line, only chapters.

Dating & uncertainty

European reconstructions run the Little Ice Age from about 1250 to 1860, likely the coldest stretch of the past 8,000 years there, though a hemispheric definition of 1440 to 1920 is also defended, and not all of it was cold. The drivers were clusters of volcanic eruptions above all, with grand solar minima a smaller contribution, amplified by sea ice and ocean feedbacks; the Maunder Minimum alone, analysis shows, does not explain it.

Sources

1. Wanner et al. (2022), Quaternary Science Reviews · The variable European Little Ice Agedoi:10.1016/j.quascirev.2022.107531
2. Owens et al. (2017), Journal of Space Weather and Space Climate · The Maunder minimum and the Little Ice Age: an update from recent reconstructions and climate simulationsdoi:10.1051/swsc/2017034
3. Brönnimann et al. (2019), Nature Geoscience · Last phase of the Little Ice Age forced by volcanic eruptionsdoi:10.1038/s41561-019-0402-y

Our species’ history as one day

23:56:273 min 33 s before midnight

if the 315,000 years of Homo sapiens were compressed into a single day