The Little Ice Age occurred from the 14th to 19th century, where temperatures dropped around 2-3 degrees Celsius causing disastrous effects. It began after a Medieval Warm Period that led to increased crop yields and prosperity. The Little Ice Age started with 5 years of heavy rain that drowned crop lands, leading to starvation, disease, and overcrowding which allowed the bubonic plague to kill over 25 million people, a third of the population at the time.