The History of the Ozone Layer

"Wonder Gas" CFC's Invented

1928

CFC's were invented, also called "Wonder Gas." Used for commercial applications.

Scientists Discover CFC's Split Up Ozone

1973

"In late 1973, Rowland and Molina, who had recently joined Rowland’s lab, used data from a variety of published sources to calculate that CFC molecules released near the surface of Earth would, over decades, wind up in the stratosphere where UV radiation would split off chlorine atoms. Each chlorine atom would react immediately with an ozone molecule, setting off a chain reaction that would destroy thousands of ozone molecules."

UNEP Gets involved

1977

“In 1977, the United Nations Environment Programme (UNEP)
sets up a co-ordinating committee to study the ozone layer.”

Countries Begin to Ban Some CFC's

1978

“In 1978, the United States of America, Canada,
Sweden and Norway ban the use of CFCs in aerosols.”

UNEP Starts Intergovernmental Negotiations

1981

“In 1981, UNEP starts intergovernmental negotiations to protect the ozone layer.”

Discovering Severe Thinning in the Ozone Over Antartica

1985

“The British Antarctic Team discovers severe thinning in the ozone layer over Antarctica - the ozone hole.”

The Montreal Protocol on Substances that Deplete the Ozone Layer

1987

“In 1987, 46 governments agree to a fifty per cent cut in the
production and consumption of CFCs by the year 2000; a freeze
in production and consumption of halons by 1992; further
controls linked to assessments by experts.”

UNEP Report on Ozone Trends

1988

“In 1988, the UNEP - WMO report on ozone
trends links CFCs to ozone depletion.”