The greatest ice ages – the three most famous from the Precambrian, then the Devonian, as well as the Upper Carboniferous and Permian – were so long ago that their traces are almost invisible today. But did you know that only a few hundred people witnessed a small ice age just a few hundred years ago?
The last ice age, which scientists often point out was not “right”, gripped the Earth in the 13th century – ice began to spread across the Atlantic, and a few decades later summers in northern Europe were no longer warm. The so-called Little Ice Age began imperceptibly and slowly, with only occasional severe winters.
At the beginning of the 16th century, summers became wet, and winters very long. The average annual temperature dropped by about 1.5 degrees Celsius, which caused the disappearance of forests in the higher regions. The ice began to spread in the middle of the 16th century, so it covered some alpine passes, and the surface of the ice sea expanded in the Arctic regions. The Thames was first frozen in 1607, and the last time in 1814.
Due to the great cold, numerous estates in the Alps, Norway and Iceland were abandoned. The farmers changed the time of sowing and harvesting in order to adapt to the always unreliable climatic conditions. Finland has lost a third of its population due to hunger and disease.
Even the northern part of the Adriatic Sea was frozen. The coldest was around 1550 and from 1700 to 1850. Winter 1794/95. it was particularly sharp, so that the French army crossed the frozen rivers in the Netherlands. New York Harbor froze in 1780, so people could walk from Manhattan to Steten Island.
Between 1430 and 1850, due to the appearance of strong north winds, freezing of the sea and rivers, there were changes in the flora and fauna. In the middle of the 19th century, the average annual temperature rose again, so the glaciers retreated again.
The reasons for the appearance of the Little Ice Age could be various and scientists do not have a single position, but some of the possible ones are reduced solar radiation, high volcanic activity, reduction of human population due to the plague that took between 100 and 200 million lives. compared to those earlier great ice ages, they did not leave such profound consequences for the world on Earth.
In the early 20th century, geologists had found a whole body of evidence that the climate changed during the Earth’s geological history, and before this little ice age of which there are records, but there was no correct explanation of what could have been the cause.
The answer was given by our great scientist Milutin Milanković. As an exceptional connoisseur of Newton’s celestial mechanics, Milanković looked for the causes outside the Earth, in space, and concluded that the average temperature of the atmosphere changed because the solar radiation reaching the Earth was not always of equal intensity. This idea existed before, but before Milanković’s accurate calculations, no one managed to prove it and harmonize it with the discovered traces of glaciation.
With patient calculations, Milanković managed to mathematically describe as many as 600,000 years of climate change on Earth. Since many geologists had already accepted his calculations at the end of the 1930s, Milanković decided to unite them all and thus present his theory in a book published on 626 pages by the Serbian Royal Academy in 1941.
“Canon of Sunshine” or, in its full name, “Canon of Sunshine of the Earth and its Application to the Problem of Ice Ages” is still a current work, and one of the few that first came out in Serbia and then laid the foundations of an entire scientific discipline.