(1995) Paul Josef Crutzen
Paul Jozef Crutzen born December 3, 1933) is a Dutch, Nobel Prize-winning, atmospheric chemist. Crutzen\\\'s childhood began just a few years before the start of WWII. In September 1940, the same year Germany invaded The Netherlands, Crutzen entered his first year of elementary school. After many delays and school switches all caused by events in the war, Crutzen graduated from elementary school and moved onto ?Hogere Burgerschool? (Higher Citizens School) in 1946, where he became fluent in French, English, and German. Crutzen is best known for his research on ozone depletion. In 1970 he pointed out that emissions of nitrous oxide (N2O), a stable, long-lived gas produced by soil bacteria, from the Earth\\\'s surface could affect the amount of nitric oxide (NO) in the stratosphere. Crutzen showed that nitrous oxide lives long enough to reach the stratosphere, where it is converted into NO. Crutzen then noted that increasing use of fertilizers might have led to an increase in nitrous oxide emissions over the natural background, which would in turn result in an increase in the amount of NO in the stratosphere. Thus human activity could have an impact on the stratospheric ozone layer. In the following year, Crutzen and (independently) Harold Johnston suggested that NO emissions from the fleet of, then proposed, supersonic transport(SST) airliners(a few hundred Boeing 2707s), which would fly in the lower stratosphere, could also deplete the ozone layer; however more recent analysis has disputed this as a large concern.
