Paul J. Crutzen

In 1956, while on a visit to Switzerland, Crutzen met Terttu Soininen, a Finish student history and literature, working as an au pair in Lucerne. They got married in February 1958. They have two daughters, Ilona and Sylvia

Paul Jozef Crutzen was born on December 3, 1933, in Amsterdam. His father, Jozef Crutzen, originally from Vaal, worked as waiter in Amsterdam. His mother, Anna Gurk, was of mixed Polish and German ancestry; she came to the city from Ruhr region of Germany as a housekeeper. He also has a sister.

Paul entered the elementary school, popularly known as ‘de grote school’, in September 1940; a few months after Netherland was taken over by Germany. Since their school building was confiscated by the Nazis, the classes were taken in different premises.

The situation became even worse during the last months of the Second World War, particularly between the fall of 1944 and the Liberation Day on May 5, 1945. Food, water and heating fuels were scarce and many of his classmates died of hunger and disease during that period.

Classes too were irregular; as a result, most of the children lost a year. However, Paul was able to get outside help and so he was one of the few children, who were promoted to the final class without having to lose a year.

In 1946, he completed his elementary education and entered Hogere Burgerschool (Higher Citizen School). Here, apart from normal curricula, they had to learn English, French and German. Although he did well in them, physics and mathematics was his favorite subject.

In 1954, soon after receiving his degree in civil engineering, Crutzen joined Bridge Construction Bureau of the City of Amsterdam. His service was interrupted in 1956, when he was called to undergo the 21-months compulsory military service.

On being released from military service, he rejoined Bridge Construction Bureau in early 1958; but pined for academic service. So when he saw an advertisement, seeking a computer programmer for the Department of Meteorology of Stockholm Högskola (later Stockholm University), he applied for the job and got it too.

On July 1, 1959, Crutzen joined his new position at Stockholm. Although he did not have any experience in the field of computer programming he quickly got used to the mathematical complexity of early programming and created computer programs suitable for meteorological work.

Concurrently, he also attended lectures on mathematics, mathematical statistics, and meteorology at the University, ultimately receiving his filosofie kandidat (corresponding to MS) degree in 1963. Unfortunately, he could not study physics or chemistry because those subjects required laboratory work, which he could not afford. Thus he became a pure theoretician.

Meanwhile, he kept working in various meteorological projects, helping to build and run some of the first barotropic weather prediction models. Sometime in 1965, he was asked to help a US scientist to develop a numerical model of the oxygen allotrope distribution in different layers of the atmosphere.

Crutzen is the first scientist to establish that human activity could affect the stratospheric ozone layer and endanger life on earth. In 1970, he established that nitrous oxide (N2O), which is produced by soil bacteria and emitted from the Earth’s surface, is the main cause for such depletion.

He demonstrated that since N2O is a stable gas it can reach stratosphere. There, it reacts with the ultraviolet radiation present in the ozone layer and produces nitric acid and oxygen. This causes depletion in the ozone layer. Later, he also noted that increased use of nitrogen rich fertilizers and fossil fuel might have led to such a phenomenon.