1 / 7

The Ozone Hole

The Ozone Hole. The Ozone Layer. Stratospheric ozone Block 95% harmful UV radiation. http://svs.gsfc.nasa.gov/goto?824. ODC: Ozone Depleting Chemicals. CFC’s: Chlorofluorocarbons Stable, odorless, nonflammable, nontoxic, noncorrosive Coolants, propellants, cleaners, fumigants, insulation

Download Presentation

The Ozone Hole

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Ozone Hole

  2. The Ozone Layer • Stratospheric ozone • Block 95% harmful UV radiation http://svs.gsfc.nasa.gov/goto?824

  3. ODC: Ozone Depleting Chemicals • CFC’s: Chlorofluorocarbons • Stable, odorless, nonflammable, nontoxic, noncorrosive • Coolants, propellants, cleaners, fumigants, insulation • Halons (bromine, fluorine) • Fire extinguishers • Solvents • Fumigants

  4. Rowland and Molina: Groundbreaking Study 1974 • CFC’s remain in troposphere (65 – 385 years) • CFC’s are heavier than air, but are carried to the stratosphere by convection and turbulence • CFC molecules break down with high energy input from UV radiation • Chlorine molecules break apart ozone http://svs.gsfc.nasa.gov/goto?825

  5. The Ozone Hole: Discovered 1984 • Ozone thinning, NOT ozone “hole” • Occurs over Antarctica during spring (Aug – Nov) http://svs.gsfc.nasa.gov/goto?3303

  6. Impacts of Ozone Depletion • Human Health • Skin cancer, sunburns, eye cataracts • Reduced primary productivity in the ocean (kills plankton, algae) • Impacts on food web and CO2 • Potential damage to food crops • Degradation of materials (paints and plastics)

  7. Management: The Montreal Protocol, 1987 • International agreement • Eliminate CFC production (goal) • By 1995 in developed nations • By 2000 in developing nations • Assessment of Effectiveness: • ODC’s will return to pre-1980 levels by 2050 • Ozone “hole” is shrinking!!!

More Related