Between the mid-fourteenth century and the mid-nineteenth century (but these extremes can vary greatly) the average temperatures, especially in some regions of the world such as Europe, saw a substantial decrease, so much so that agricultural harvests were difficult and some rivers such as the Thames froze. or the Tiber – this climatic period in the history of our planet is called Little Ice Age or PEG. It was not a real ice age but a generally cold period with fluctuating average temperatures, the causes of which are not known with certainty and which had a strong impact on society and history.
What is meant by “Little Ice Age”
The Little Ice Age is a time in the making from 1310 to 1850 approximately, in which the climate on Earth was more cold and unpredictable than average. Since 1950, the development of paleoclimatology, or the discipline that studies the climate of the past, has highlighted that the climate on Earth has always changed over time. In particular, the presence of glacial and interglacial cycles: cold periods (glacial) and warmer periods (interglacial) have always alternated on our planet.
During hot periods, however, the climate does not follow a linear path. There are times when it is warmer and others when it is colder, although these variations are not as intense as during real ice ages. These colder periods are called “stage phases” and since the last ice age 8 have occurred, with a periodicity of approximately 1000-1500 years: the Little Ice Age is the last of these. According to NASA, during this period there were three main cold peaks, at the end of the sixteenth century, the end of the seventeenth century and the beginning of the nineteenth century.
What happened during PEG in Europe: an unpredictable climate
Starting from around 1310 and for five and a half centuries, the weather has become more unpredictable and coldin particular between the end of the 17th and the mid-19th century. Over the entire period of the Little Ice Age it was estimated that the global average temperature was 1°C lower compared to what would have been recorded in the twentieth century. This figure, however, can be confusing: one degree less doesn’t seem so cold. In reality, this data represents only an average estimate of that period, giving us a general impression, but does not well describe the climatic complexity of those centuries.
In fact, there has never been a single and constant frost, but rather a climatic swing. There have been arctic winters, hot summers, severe droughts, years of torrential rain, sometimes destroyed and sometimes abundant crops. Cycles of excessive cold and unusual precipitation could last a decade, a few years, or even a single season. The heavy rains and great famines of 1315-16 marked the beginning of centuries of unpredictability across Europe, while advances of glaciers in Greenland had already been recorded since the 13th century. During these centuries the continent suffered theincrease in storms and the most frequent passage from extremely cold conditions to much warmer conditions.
What were the coldest years?
Thanks to climate historians we are able to trace back to the coldest decades of the Little Ice Age. These scholars, reading texts and ancient municipal registers, are able to reconstruct the climate based on direct testimonies and the dates of sowing and harvesting. The coldest conditions occurred between 1570 and 1600, in the 1690s, and in the 1810s. Thanks to the work of these scholars, it is estimated that between 1586 and 1595 Europe was affected by almost uninterrupted cold winters, with temperatures lower by about 2 °C compared to the average of the early 20th century. The same studies indicate 1691-1700 as the coldest decade in Switzerland in the last five centuries. During these centuries also the advance of the glaciers of the poles and the Alps was notablepeaking in 1815.
Causes of the Little Ice Age
The answer to “what caused centuries of cold and climate unpredictability?” it still eludes us. There are many factors at play and in-depth scientific analyzes of the climate only began in 1850. One of the most convincing theories, however, indicates the cause of the Little Ice Age in a less solar activity: between 1645 and 1715, in fact, during a very cold period, the sunspots disappeared, indicating a decrease in the Sun’s activity. However, what we are certain of is that these cold periods are part of the Earth’s natural cycles and they have occurred many times in the past. It would be logical to expect more similar events in the coming millennia, were it not for the fact that humans have been altering the climate equation through the excessive emission of greenhouse gases since the Industrial Revolution.
