1995 Nobel Prize in Chemistry Summary

Feb 26, 2025

Nobel Prize in Chemistry 1995

Award Recipients

  • Paul J. Crutzen
    • Institution: Max-Planck-Institute for Chemistry, Mainz, Germany
    • Contribution: Nitrogen oxides' role in ozone depletion
  • Mario J. Molina
    • Institution: Department of Earth, Atmospheric and Planetary Sciences, MIT, Cambridge, MA, USA
    • Contribution: CFCs' impact on ozone layer
  • F. Sherwood Rowland
    • Institution: Department of Chemistry, University of California, Irvine, CA, USA
    • Contribution: CFCs and ozone layer research

Focus of Award

  • Atmospheric Chemistry
    • Formation and decomposition of ozone
    • Sensitivity of the ozone layer to human emissions

Importance of Ozone Layer

  • Absorbs majority of the sun’s UV radiation
  • Essential for life on Earth

Scientific Contributions

Historical Context

  • Sidney Chapman (1930)
    • Initial theory on ozone formation/decomposition
    • Discrepancies in calculated vs. observed ozone levels
  • Marcel Nicolet
    • Role of hydrogen radicals in ozone decomposition

Paul Crutzen's Advances (1970)

  • Nitrogen oxides (NO and NO2) catalytically decompose ozone
  • Connection to microbiological transformations producing N2O

Threats to Ozone Layer

  • Harold Johnston (1971)
    • Supersonic aircraft's nitrogen oxides as a potential threat

Molina and Rowland's Breakthrough (1974)

  • CFCs and their global spread
  • Chlorine atoms in the atmosphere decompose ozone
  • Predicted significant ozone depletion by CFCs

Antarctic Ozone Hole (1985)

  • Discovered by Joseph Farman et al.
  • Greater depletion than expected

New Insights

  • Crutzen and Colleagues
    • Role of polar stratospheric clouds in ozone depletion
    • Introduction of heterogeneous chemical reactions

Ozone and Climate Interaction

  • Ozone as a greenhouse gas
  • Impact of increased ozone in lower atmosphere

Future Outlook

  • Montreal Protocol (1987)
    • International agreement to protect the ozone layer
    • Expected gradual recovery of the ozone layer post-turn of the century

Further Reading

  • Books and articles on ozone research and environmental impact

Notable Laureates’ Backgrounds

  • Paul Crutzen
    • Born 1933, Amsterdam, Netherlands
    • PhD in meteorology
  • Mario Molina
    • Born 1943, Mexico City, Mexico
    • PhD in physical chemistry
  • F. Sherwood Rowland
    • Born 1927, Delaware, Ohio, USA
    • PhD in chemistry

Additional Information

  • Nobel Prize Outreach activities
  • Prize awarding institutions and history

This summary captures the essence of the Nobel Prize in Chemistry 1995, focusing on the laureates, their research contributions, and the implications for environmental science and policy.