In the early 1300s, there were three years without summer, in a row. In Europe, the crop failures were devastating. Starvation lead to disease. In a generation, the population was cut in half, and then almost half again. These three years without summer weren't an isolated event, they were the harbinger of what later became known as the Little Ice Age. According to some historians, this little ice age lasted into the early 20th Century. But that's all in the past. Humanity survived. Would you be able to thrive in a year without summer? Two? THree?