On 6 April 1941, a world war left its mark on Milutin Milanković’s life and climate research for a second time. Nazi bombs destroyed the print works where his new book, summarising 30 years’ work, sat half-complete. As German-led forces occupied Serbia a month later, Milutin still had just one finished copy of his “Canon of Insolation and the Ice-Age Problem”. In it, he brought together his general astronomical theory of climate, which would explain how Earth’s motion in space drives ice sheet advance and retreat over tens of thousands of years.
And when two German officers came to visit the University of Belgrade maths professor, he might have feared no-one else would ever see all his ideas in a single volume. But the officers were geology students, bringing greetings from Wolfgang Soergel at the University of Freiburg, who had previously published studies supporting Milutin’s calculations. Amid the drama unfolding around them, Milutin gave them his only copy to send to Freiburg for safe-keeping. But both Milutin and his work escaped to ultimately make strides forward in understanding what controls Earth’s temperatures.
Milutin fixed his focus on climate after joining the University of Belgrade in 1909, while reading a paper about the Sun’s heat on the Earth’s surface, whose starting equation was wrong. To study how climate could produce dramatic changes like ice ages courted controversy even then because it was unclear the puzzle could ever be solved. So little was known that when Svante Arrhenius correctly identified CO2 in the air as an important factor his findings were ruled out by flawed experiments.
Using heat from the Sun, the incoming solar radiation also known as insolation, Milutin looked at climate both on the Earth and other planets in our solar system. “A connection should be found between planets’ insolation and their atmosphere and surface temperatures,” he wrote. And thanks to the many different complex sciences such an astronomical climate theory combined, Milutin was the only one trying to make that link. Read the rest of this entry »