Global Atmosphere Watch was mere scientific interest, but of course, many scientists eventually wondered what effects these trace chemicals could have on the atmosphere, and on life. The GAW's genesis began as far back as the 1950s when the World Meteorological Organization began a programme of monitoring the atmosphere for trace chemicals, and also researching air pollution from a meteorological point of view. They were also responsible for monitoring ozone, establishing the Global Ozone Observing System (GO3OS) in 1957, in the International Geophysical Year. In 1968, the United Nations called for an international conference to address world environmental problems caused by rapid industrialization.
Atmosphere of Earth vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air content and atmospheric pressure vary at different layers, and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth's troposphere and in artificial atmospheres. The atmosphere has a mass of about 5.15 kg, three quarters of which is within about of the surface. The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at , or 1.57% of Earth's radius, is often used as