These then react with the ozone molecules, resulting in their removal. CFCs have a lifetime in the atmosphere of about 20 to 100 years, and consequently one free chlorine atom from a CFC molecule can do a lot of damage, destroying ozone molecules for a long time.
exists and is an alternate of . In the northern hemisphere of Earth, Fall begins on the Autumnal equinox (22-23 September) (in Persian calender it will begin at the first day of Mehr) and ends on the Winter solstice (21-22 December). In the southern hemisphere of Earth, Fall begins on the Autumnal equinox (20-21 March) and ends on the Winter solstice (20-21 June).
When does autumn really start? With the autumn equinox fast approaching, signifying the official start of the season for astronomers, the age old debate of the true beginning of the autumn continues. Different disciplines of science use different events or dates to mark the changing of the seasons Photo: Christopher Pledger.