The Ozone Layer and the Montreal Protocol

Xavier Timbeau

Anissa Saumtally

Freon kills ozone

1930: Thomas Midgley invents freon
- HCFC&CFC, produced by DuPont de Nemours
- Neutral gaz, no corrosion, not active, not toxic, highly efficient to carry heat (compression/decompression cycles)
- Largely used for refrigeration (fridges, air cooler), solvent, fire extinguisher, spray propelant, plastic foam propulsion

But: interact with O3 and UV, and destroy it in the upper layer of atmosphere
- O3 layer blocks 97-99% of UV radiation
- mostly UV-a and b lethal radiation, Dobson discovered this in the 30-50’s

1985: measure of the ozone layer display a large hole (over Antarctic)
- Farman, Nature ; Rowland&Molina had found the mecanism in 1974 (and a Nobel prize)
- 25y. of O3 hole could have caused 1 to 2 millions skin cancers
- Around 200 000 victims in the US up to 2040, according to NASA

1985: Vienna convention (20 countries)
- 1985-1987: strong action from CFC lobbies
- DuPont, 1987 “we believe that there is no immediate crisis that demands unilateral regulation”
1987: Montreal protocol
- ban use of CFC (immediate) and HCFC (to come) in most of the applications
- 196 states, including USA
- Revised 7 times, last revision being Bejing in 1999
Phasing out of CFC production and consumption by 1996,
- HCFC levels freezed by 2013 (transitory substitution), starting reduction by 2015
- Multilateral fund for the Implementation of the Montreal Protocol
- US$ 2.1 billions for countries with less than 0.3kg/cap/year ODS consumption
- 147/196 are potential receivers from the fund
It worked!
It is expected than ozone hole will disapear in 2045-2050
- wouldn’t it, we’ll be all dead (or nearly)