ozone - Anthropogenic ozone depletion Key papers Molina and...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Anthropogenic ozone depletion Key papers: Molina and Rowland (1974) Nature 249:810-812 - Cl could affect O 3 layer Farman et al. (1985) Nature 315:207-210 - O 3 depletion observed over Antarctica • Antarctic ozone observed to decrease every October since 1979 • area of Antarctic ozone hole increased 1980-1992 • anthropogenic ozone depletion is caused by reactive Cl and Br, but not F chlorofluorocarbons (CFCs): C, Cl, F, but no H e.g. CFC-12 CF 2 Cl 2 not destroyed in troposphere, so in the stratosphere. .. UV-C CF 2 Cl 2 ––––––> CF 2 Cl· + Cl· CF 2 Cl· + OH· ––––> CO 2 + HCl + HF + H 2 O HCl + OH· ––––> Cl· + H 2 O rxn = –79.6 kJ mol -1 HF + OH· ––––> F· + H 2 O rxn = +69 kJ mol -1 Br compounds: Halons (C, Br, Cl, F, but no H ), CH 3 Br Good news: • Montreal protocol to phase out worldwide use of CFCs signed in 1987 • CFCs are in decline • Br compounds (Halons, CH 3 Br) have been added to Montreal protocol • Mario Molina, F. Sherwood Rowland, Paul Crutzen awarded 1995
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/25/2011 for the course ENVSCI 202 taught by Professor Staff during the Spring '11 term at Rutgers.

Page1 / 4

ozone - Anthropogenic ozone depletion Key papers Molina and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online