The “Little Ice Age” was an interval of relative cold, beginning about 1450 and lasting until about 1890 (the coldest periods of 1450 and 1700 are often divided into the two Little Ice Ages). It occurred during the current warm, interglacial period, but is not considered a full glacial episode, since the high latitudes of the Northern Hemisphere landmasses remained largely free of permanent ice cover.

Even so, much of the world experienced cooler temperatures during this time of at least 2°F (1°C) lower worldwide average surface temperatures. It was a time of renewed glacial advance in Europe, Asia, and North America, with sea ice causing havoc in the colonies of Greenland and Iceland. In England, the Thames River froze; in France, bishops tried to halt glacial advances with prayer. Several historians also believe the low temperatures caused social conflict and poor food production. Thus, this may have been partially responsible for war and hunger during that time.

Just like the major ice ages, no one really knows what caused the Little Ice Age, though English astronomer Edward Maunder (1851–1928) first hypothesized that it had something to do with solar activity. Other scientists attribute the cooling down to volcanic eruptions, changes in the ocean circulation, changes in the Earth’s orbit, the wobbling of the Earth’s axis, or even our planet’s passage through clouds of interstellar dust.