When we typically think of an ice age, the first thing that comes to mind is often prehistoric humans hunting woolly mammoths or battling saber-toothed tigers. Technically, an ice age is a prolonged period of colder climates when polar and mountain ice sheets are unusually extensive across the earth's surface and on geological timescales, they happen regularly. During the last ice age, some 16,000 ago, Earth's northern hemisphere was blanketed in ice about two miles thick.
But during the Little Ice Age — a period of regional cooling beginning around 700 years ago, especially in the North Atlantic region — things were a lot less intense. During long stretches of the Little Ice Age, seasonal winters would be unusually cold and the following summers were merely mild instead of hot. And while the recent rash of record-breaking heatwaves might make an ice age sound nice right about now, the period was marked by bitter winters, deadly plagues and brutal famines, including one that killed about 10 percent of Europe's population. Strangely, this little interval in Earth's history is often used to deny the realities of climate change.
