Paul Josef Crutzen
Crutzen, Paul Josef (1933-) is a Dutch chemist who has been a pioneer in the research of the depletion of the ozone layer. He shared the 1995 Nobel Prize in chemistry with Americans Mario Jose Molina and Frank Sherwood Rowland for their separate discoveries related to the ozone layer in the earth's atmosphere.
Paul Crutzen was born on Dec. 3, 1933, in Amsterdam, the Netherlands. The country was occupied by the Nazi regime of Germany when he started elementary school. He was unable to attain an education until the end of World War II (1939-1945). In 1951, Crutzen went to a technical school in Amsterdam to train as a civil engineer. After completing his training in 1954, he worked in the Bridge Construction Bureau in the city of Amsterdam.
Crutzen served in the military from 1956 to 1958. In 1958, he moved to Gävle, Sweden, and worked in a building construction bureau. A year later, he moved to Stockholm and took a job as a computer programmer in the Department of Meteorology of Stockholm University. He also attended school there. By 1963, he had met the requirements for a master's degree in science, combining mathematics, statistics, and meteorology.
In the 1960's, the focus of Crutzen's research turned to ozone, a bluish, irritating gas that has a very strong odor. It is formed in the atmosphere by a photochemical reaction. The ozone layer begins about 10 miles (16 kilometers) above the earth's surface and serves as a protective layer that absorbs the sun's high-energy ultraviolet radiation.
Crutzen became increasingly interested in the photochemistry of the ozone. In 1968, he received his doctorate in meteorology. In 1970, he discovered that microbes in the soil excrete a gas called nitrous oxide. This gas rises to the stratosphere and is converted by sunlight to nitric oxide and nitrogen dioxide. Crutzen discovered that these two gases were contributing to the depletion of the ozone layer. This discovery revolutionized the study of the ozone and encouraged research on global biogeochemical cycles.
In 1973, Crutzen received his doctor of science degree from the University of Stockholm. A year later, he joined the National Center for Atmospheric Research in Boulder, Colorado. There he studied the effects of smoke on the atmosphere. The study was sparked by farmers in Brazil, who were clearing land at an alarming rate by burning trees and brush. It was believed that the burning caused more carbon monoxide and carbon compounds to enter the atmosphere. Therefore, it was thought that the smoke contributed to the greenhouse effect, the warming of the earth's atmosphere. However, Crutzen's study of the smoke found that the burning was actually decreasing the amount of carbon dioxide in the atmosphere. This led him to study the effects that large amounts of different kinds of smoke can have on the environment. His work eventually paved the way to a study of smoke that would result from a nuclear war.
Crutzen and his colleague John Birks investigated a simulated worldwide nuclear war. They theorized that as much as 99 percent of the sunlight would be absorbed by the black carbon soot caused by the raging fires that would result from nuclear war. The effects of this lack of sunlight, which would be devastating to all forms of life, came to be known as “nuclear winter.”
Because of the work of Crutzen and other scientists, the Montreal Protocol was established in 1987. The goal of this crucial international treaty was to slowly phase out the production of chlorofluorocarbons (CFC's) and other ozone-damaging chemicals.
Crutzen won a share of the 1995 Nobel Prize in chemistry for discovering that nitrogen oxides quicken the breakdown of the ozone layer. He shared the prize with Molina and Rowland, who discovered how CFC's deplete the ozone layer. These explanations of chemical mechanisms on the ozone layer contributed greatly to global awareness of environmental problems.
Crutzen was director of the Air Quality Division of the National Center for Atmospheric Research in Boulder from 1977 to 1980. From 1980 until 2000, he was with the Max Planck Society for the Advancement of Science in Munich, and served as the director of the atmospheric chemistry division at the Max Planck Institute for Chemistry, in Mainz, Germany. In 2000, he became professor emeritus at Utrecht University, Institute for Marine and Atmospheric Sciences, the Netherlands.