As climatologists define it, the Little Ice Age was a long-term cooling of the Northern Hemisphere between 1300 and 1850. They locate maximum cooling in the early seventeenth century, just when European settlers were attempting to establish colonies in North America. To reconstruct past climate, scientists use indicators called climate “proxies,” such as ice cores, tree rings, and lake-bottom sediments that they analyze for indications of past temperatures and precipitation. In addition, zooarchaeologists examine animal bones to see what settlers ate, while bioarchaeologists study human skeletons to probe health and nutrition.
Climate proxies also provide important evidence of volcanic activity. Between the 1580s and 1600 large tropical volcanic eruptions spewed dust and sulfates high into the atmosphere, dimming sunlight, cooling Earth’s surface, and causing oscillations in atmospheric and oceanic circulation. Eruptions in Colima, Mexico, in 1586, in Nevado del Ruiz in present-day Colombia in 1595, and especially the huge Huaynaputina eruption in the Peruvian Andes in 1600 helped produce shockingly cold decades.
Even before colonists departed from Europe, their lack of reliable information about the extremes of weather in the Little Ice Age was compounded by fatal misconceptions linking geographical latitudes with climate. Educated in the work of the classical Greek geographer Ptolemy, for whom climate and latitude were synonymous, Europeans assumed that they would find a relatively mild climate in North America, since Britain lies latitudinally north of the continental United States and Paris north of Quebec, while Spain lines up with New Mexico. The confusion sowed by those misleading notions would doom many of their enterprises.
During those harrowing decades, European countries—England and Spain in particular—also suffered from freezing winters, cold, wet summers, intense rain, flooding, ruined crops, famine, outbreaks of disease, plague, and spikes in mortality. In the mid-1590s, William Shakespeare found poetry in the capricious climate of the age:
And thorough this distemperature we see
The seasons alter: hoary-headed frosts
Fall in the fresh lap of the crimson rose,
…The spring, the summer,
The childing autumn, angry winter, change
Their wonted liveries, and the mazèd world
…now knows not which is which.
Economic and demographic factors, worsened by climate-related disasters, White argues, influenced the colonial ambitions of European nations: “The Little Ice Age came at a particular moment and in a particular way that helped to undermine Spain’s commitment to North American colonization but to reinforce England’s.”