Chemistry Crutzen, Paul

A typical example of the interaction between hypothesis and experiment is the story of the work that resulted in worldwide concern over the depletion of the ozone layer in the stratosphere. These studies led to the awarding of the 1995 Nobel Prize for Chemistry to Paul Crutzen, Mario Molina, and F. Sherwood Rowland. Figure FT provides a schematic view of how this prize-winning research advanced. It began in 1971 when experiments revealed that chlorofluorocarbons, or CFCs, had appeared in the Earth s atmosphere. At the time, these CFCs were widely used as refrigerants and as aerosol propellants. Rowland wondered what eventually would happen to these gaseous compounds. He carried out a theoretical analysis, from which he concluded that CFCs are very durable and could persist in the atmosphere for many years. 

Crutzen, Paul. (1933-). From the Netherlands who won the Nobel Prize for chemistry along with Mario Molina and Frank Sherwood Rowland in 1995 for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone. 

Crutzen, Paul Jozef (born 1933) Dutch Nobel prize winning atmospheric chemist worked at the Stockholm University, University of California, Georgia Institute of Technology and 1980-2000 director of the Department of Atmospheric Chemistry (MPI) in Mainz (successor of Christian Junge). 

Crutzen, Paul J. and Veerabhadran Ramanathan, Clouds, Chemistry and Climate, Springer, Berlin, 1996. 

The two scientists who first suggested (in 1974) that CFCs could deplete the ozone layer, F. Sherwood Rowland (1927-) and Mario Molina (1943-), won the 1995 Nobel Prize in chemistry, along with Paul Crutzen (1933—), who first suggested that oxides of nitrogen in the atmosphere could catalyze the decomposition of ozone. 

The ozone hole would almost certainly be much worse if chemists had not studied the reactions of CFCs with atmospheric gases before ozone depletion was discovered. The 1995 Nobel Prize in chemistry was awarded to the three pioneers in this effort. A German chemist, Paul Crutzen, discovered how ozone concentration is regulated in a normal stratosphere, while two Americans, F. Sherwood Rowland and Mario Molina, showed that CFCs can destroy ozone. These studies of molecular reactions allowed quick determination that CFCs are a likely cause of ozone depletion and led to the international restrictions described above. 

Paul Crutzen Germany, b. Netherlands atmospheric chemistry... 

Nitrogen oxides play a key role in ozone chemistry. Paul Crutzen (1933—) received the 1995 Nobel Prize in chemistry for research that helped define the role of nitrogen oxides in ozone depletion. 

R. S. Stolarski, The Antarctic Ozone Hole, Scientific American, January 1988. The 1995 Nobel Prize in Chemistry was shared by Paul Crutzen, Mario Molina, and F. Sherwood Rowland for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone. Their Nobel lectures can be found in P. J. Crutzen, My Life with 03, NO, and Other YZO Compounds, Angew. Chem. lnt. Ed. Engl. 1996,35, 1759 M. J. Molina, Polar Ozone Depletion, ibid., 1779 F. S. Rowland, Stratospheric Ozone Depletion by Chlorofluorocarbons, ibid., 1787. 

Paul Crutzen, Sherwood Rowland, and Mario Molina Chemistry Damage to the stratospheric ozone layer... 

In the mid-1970s F. Sherwood Rowland and M. Molina showed evidence that Freons might drift freely and remain unaffected for up to 100 years, eventually move to the ozone layer, produce free chlorine atoms, and possibly destroy ozone (Molina and Rowland, 1974, pp. 810-812). They thus laid the foundation for a theory of ozone depletion and, together with Paul Crutzen of the Max Planck Institute, received the obel Prize for chemistry in 1995. In 1985 Joseph C. Farman, et al. published an article demonstrating the large volume of diminished ozone over Antarctica (Farman, Gardiner, and Shanklin, 1985, pp. 207-210). 

The importance of this process was not recognized until the mid-1970s when it was realized that Cl could be produced from the photodegradation of chlorofluoro-carbons (CFCs), which had become very widely used as refrigerants and for other applications for which an inert gas was needed. This realization was a big deal, and it eventually earned Mario Molina, F. Sherwood Rowland, and Paul Crutzen the Nobel Prize for chemistry in 1995. 

The speed at which things go in this business means that those of us who are on the fringes of it are always out of date, because by the time you have mastered the chemistry of 1979, you have replaced it widi the chemistry of 1983. So let me ask this question. There has been a great deal of emphasis here on CIO and on the role of chlorine in the ozone depletion but years ago from Paul Crutzen I learned the lesson that it was the nitrous oxide of the stratosphere and not Sherry Rowland s halocarbons that really held die control of the thing. Joking aside, the upfluxing molecules that do the damage — or do the necessary control, — what are they They are water vapor, they are methane, clearly they are synthetic halocarbons, but what is left of the statement that I had learned a few years ago that perhaps the major control is that due to N2O on its way up ... 

The 1995 Nobel Prize in Chemistry was awarded to Mario Molina, Paul Crutzen, and F. Sherwood Rowland for their work in elucidating the interaction of ozone with CFCs. What began as a fundamental research project turned out to have important implications in the practical world. 

While the inertness of CFCs was initially viewed as an asset, their long chemical lifetime enables them to diffuse into the upper atmosphere, where they undergo photochemical reactions when exposed to short-wavelength radiation from the sun. These reactions in turn lead to the destruction of stratospheric ozone and the weakening of the UV protection that ozone provides to Earth. For their work in elucidating these chemical pathways, the 1995 Nobel Prize in Chemistry was awarded to Paul Crutzen, Mario Molina, and Sherwood Rowland. 

In 1995, Paul J. Crutzen, Mario J. Molina, and F. Sherwood Rowland received the Nobel Prize in chemistry for showing that chlorofluorocarbons (CFCs), used as aerosol propellants and air-conditioning coolants, were disrupting this sequence by catalyzing the breakdown reaction. CFCs are unreactive in the lower atmosphere, but slowly rise to the stratosphere, where UV radiation cleaves them ... 

In 1995, the Nobel Prize in chemistry was awarded to Sherwood Rowland, Mario Molina, and Paul Crutzen... 

Paul J. Crutzen (the Netherlands), Mario J. Molina (Mexico / United States), and F. Sherwood Rowland (United States) for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone. Each of these researchers made important contributions toward understanding how atmospheric ozone is depleted through atmospheric reactions. Importantly, each demonstrated ways in which pollution from humans was responsible for depleting the ozone layer, and they did this by learning how atmospheric pollutants caused the breakdown of ozone. This information will hopefully continue to help us protect the ozone layer and the stability of the Earth s climate. 

It has been estimated that one chlorine atom can destroy 10,000 molecules of ozone. Bromine also reacts with ozone, but fluorine does not. In 1995, Molina and Rowland, together with Paul Crutzen, who showed in 1970 that nitrogen oxides also reacted with ozone, received the 1 million Nobel Prize in Chemistry for their discovery of the depletion of the ozone layer, which the Nobel committee termed the Achilles heel of the universe. 

Sherwood Roland, Mario Molina, and Paul Crutzen made the most dramatic contribution to the puzzle of the missing ozone when they proposed that manmade chemicals called chlorofluorocarbons were the key ingredient. They subsequently were awarded the 1995 Nobel Prize in Chemistry for their work. 

FIGURE 10.3 The 1995 Nobel Laureates in Chemistry for their work on the ozone hole. Shown from left to right are Paul J. Crutzen, Mario J. Molina, and F. Sherwood Rowland. The photographs were obtained from the following sources http //commons.wikimedia.org/wiki/ File Paul Crutzen.jpg uselang = de, http //commons.wikimedia.0rg/wiki/File Mario Molina lc389 8387.jpg, and http //commons.wikimedia.0rg/wiki/File F. Sherwood Rowland.jpg. 

Rowland, Molina, and Paul Crutzen (a Dutch chemist at the Max Planck Institute for Chemistry in Germany) were awarded the 1995 Nobel Prize for chemistry. As the Royal Swedish Academy of Sciences noted in awarding the prize, "By explaining the chemical mechanisms that affect the thickness of the ozone layer, these three researchers have contributed to our salvation from a global environmental problem that could have catastrophic consequences."... 

For an account of the discovery and development of the CFC-ozone problem by F. Sherwood Rowland and Mario J. Molina, chemists who initiated ozone depletion research, see Chemical and Engineering News, 1994, 77 (33), 8-13. Rowland, Molina, and Paul Crutzen shared the 1995 Nobel Prize in chemistry for their contributions to atmospheric chemistry. For one overview of the situation, see Chemical and Engineering News, 1997, 75(37), 24. 

In 1995, three chemists, Mario Molina, Sherman Rowland, and Paul Crutzen, warned world leaders of damage being done to the O3 (ozone) layer. This natural layer of O3 molecules, located from 9 to 30 miles up into the atmosphere, protects the Earth from cancer-causing and damaging ultraviolet radiation from the sun. They discovered that human-made compounds of nitrogen oxides and chlorofluorocarbon (CFC) gases, used as refrigerants and propellants in spray cans, reacted with atmospheric ozone and reduced it. For their work, they received the 1995 Nobel Prize for Chemistry. 

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