The Little Ice Age occurred roughly between the sixteenth to the nineteenth centuries. It was a period of cooling that occurred after the Medieval Warm Period" href="https://en.wikipedia.org/wiki/Medieval_Warm_Period">Medieval Warm Period (Medieval Climate Optimum), which had occurred between 400-900 AD, whose more abundant crops had led to a period of prosperity and cultural achievement in Europe.
The Medieval Warm Period had, itself followed the “Dark Ages”, a far cooler period, which followed the fall of the Roman Empire. So, just between 536 AD to the mid-1800s, we can see an oscillation that has created 4 distinct climactic periods (including our own), which had huge impacts on the populations – and which belie our general perception today that the weather is a constant.
Several causes have been proposed for The Little Ice Age: cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, an inherent variability in global climate, or decreases in the human population.
If it were to happen now, it would cause serious disruptions to our lives and there are several climate scientists who believe that the Earth is headed toward a period of increased glaciation.
Contrary to what’s presented in this film, climatologists generally agree that technically (glaciologically), an ice age implies the presence of extensive ice sheets in the northern and southern hemispheres. By this definition, we are actually in an interglacial period, similar to the Medieval Warm Period – within the Holocene Era – of the Ice Age that began 2.6 million years ago, at the start of the Pleistocene epoch.