Crutzen, Paul (1933- )

Dutch meteorologist who shared the Nobel Prize for Chemistry in 1995 with Mexican chemist Mario Molina and US chemist F Sherwood Rowland for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone. They explained the chemical reactions which are destroying the ozone layer.

Crutzen, while working at Stockholm University in 1970, discovered that the nitrogen oxides NO and NO2 speed up the breakdown of atmospheric ozone into molecular oxygen. These gases are produced in the atmosphere from nitrous oxide N2O which is released by micro-organisms in the soil. He showed that this process is the main natural method of ozone breakdown. Crutzen also discovered that ozone-depleting chemical reactions occur on the surface of cloud particles in the stratosphere.

Crutzen was born in Amsterdam. He received his doctor's degree in meteorology from Stockholm University in 1973. He is currently at the Max Planck Institute for Chemistry in Mainz, Germany.